Add pretty printers for the NPTL lock types

This patch adds pretty printers for the following NPTL types:

- pthread_mutex_t
- pthread_mutexattr_t
- pthread_cond_t
- pthread_condattr_t
- pthread_rwlock_t
- pthread_rwlockattr_t

To load the pretty printers into your gdb session, do the following:

python
import sys
sys.path.insert(0, '/path/to/glibc/build/nptl/pretty-printers')
end

source /path/to/glibc/source/pretty-printers/nptl-printers.py

You can check which printers are registered and enabled by issuing the
'info pretty-printer' gdb command. Printers should trigger automatically when
trying to print a variable of one of the types mentioned above.

The printers are architecture-independent, and were tested on an AMD64 running
Ubuntu 14.04 and an x86 VM running Fedora 24.

In order to work, the printers need to know the values of various flags that
are scattered throughout pthread.h and pthreadP.h as enums and #defines. Since
replicating these constants in the printers file itself would create a
maintenance burden, I wrote a script called gen-py-const.awk that Makerules uses
to extract the constants. This script is pretty much the same as gen-as-const.awk,
except it doesn't cast the constant values to 'long' and is thorougly documented.
The constants need only to be enumerated in a .pysym file, which is then referenced
by a Make variable called gen-py-const-headers.

As for the install directory, I discussed this with Mike Frysinger and Siddhesh
Poyarekar, and we agreed that it can be handled in a separate patch, and shouldn't
block merging of this one.

In addition, I've written a series of test cases for the pretty printers.
Each lock type (mutex, condvar and rwlock) has two test programs, one for itself
and other for its related 'attributes' object. Each test program in turn has a
PExpect-based Python script that drives gdb and compares its output to the
expected printer's. The tests run on the glibc host, which is assumed to have
both gdb and PExpect; if either is absent the tests will fail with code 77
(UNSUPPORTED). For cross-testing you should use cross-test-ssh.sh as test-wrapper.
I've tested the printers on both native builds and a cross build using a Beaglebone
Black running Debian, with the build system's filesystem shared with the board
through NFS.

Finally, I've written a README that explains all this and more.

	* INSTALL: Regenerated.
	* Makeconfig: Add comments and whitespace to make the control flow
	clearer.
	(+link-printers-tests, +link-pie-printers-tests, CFLAGS-printers-tests,
	installed-rtld-LDFLAGS, built-rtld-LDFLAGS, link-libc-rpath,
	link-libc-tests-after-rpath-link, link-libc-printers-tests): New.
	(rtld-LDFLAGS, rtld-tests-LDFLAGS, link-libc-tests-rpath-link,
	link-libc-tests): Use the new variables as required.
	* Makerules ($(py-const)): New rule.
	generated: Add $(py-const).
	* README.pretty-printers: New file.
	* Rules (tests-printers-programs, tests-printers-out, py-env): New.
	(others): Depend on $(py-const).
	(tests): Depend on $(tests-printers-programs) or $(tests-printers-out),
	as required.  Pass $(tests-printers) to merge-test-results.sh.
	* manual/install.texi: Add requirements for testing the pretty printers.
	* nptl/Makefile (gen-py-const-headers, pretty-printers, tests-printers,
	CFLAGS-test-mutexattr-printers.c CFLAGS-test-mutex-printers.c,
	CFLAGS-test-condattr-printers.c, CFLAGS-test-cond-printers.c,
	CFLAGS-test-rwlockattr-printers.c CFLAGS-test-rwlock-printers.c,
	tests-printers-libs): Define.
	* nptl/nptl-printers.py: New file.
	* nptl/nptl_lock_constants.pysym: Likewise.
	* nptl/test-cond-printers.c: Likewise.
	* nptl/test-cond-printers.py: Likewise.
	* nptl/test-condattr-printers.c: Likewise.
	* nptl/test-condattr-printers.py: Likewise.
	* nptl/test-mutex-printers.c: Likewise.
	* nptl/test-mutex-printers.py: Likewise.
	* nptl/test-mutexattr-printers.c: Likewise.
	* nptl/test-mutexattr-printers.py: Likewise.
	* nptl/test-rwlock-printers.c: Likewise.
	* nptl/test-rwlock-printers.py: Likewise.
	* nptl/test-rwlockattr-printers.c: Likewise.
	* nptl/test-rwlockattr-printers.py: Likewise.
	* scripts/gen-py-const.awk: Likewise.
	* scripts/test_printers_common.py: Likewise.
	* scripts/test_printers_exceptions.py: Likewise.

26 files changed, 2769 insertions, 20 deletions

diff --git a/ChangeLog b/ChangeLog
index 57ce74d446..d5ef99ce8d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,48 @@
+2016-12-08  Martin Galvan  <martin.galvan@tallertechnologies.com>
+
+	* INSTALL: Regenerated.
+	* Makeconfig: Add comments and whitespace to make the control flow
+	clearer.
+	(+link-printers-tests, +link-pie-printers-tests,
+	CFLAGS-printers-tests, installed-rtld-LDFLAGS,
+	built-rtld-LDFLAGS, link-libc-rpath,
+	link-libc-tests-after-rpath-link,
+	link-libc-printers-tests): New.
+	(rtld-LDFLAGS, rtld-tests-LDFLAGS, link-libc-tests-rpath-link,
+	link-libc-tests): Use the new variables as required.
+	* Makerules ($(py-const)): New rule.
+	generated: Add $(py-const).
+	* README.pretty-printers: New file.
+	* Rules (tests-printers-programs, tests-printers-out, py-env): New.
+	(others): Depend on $(py-const).
+	(tests): Depend on $(tests-printers-programs) or
+	$(tests-printers-out),
+	as required.  Pass $(tests-printers) to merge-test-results.sh.
+	* manual/install.texi: Add requirements for testing the pretty
+	printers.
+	* nptl/Makefile (gen-py-const-headers, pretty-printers,
+	tests-printers, CFLAGS-test-mutexattr-printers.c
+	CFLAGS-test-mutex-printers.c, CFLAGS-test-condattr-printers.c,
+	CFLAGS-test-cond-printers.c, CFLAGS-test-rwlockattr-printers.c
+	CFLAGS-test-rwlock-printers.c, tests-printers-libs): Define.
+	* nptl/nptl-printers.py: New file.
+	* nptl/nptl_lock_constants.pysym: Likewise.
+	* nptl/test-cond-printers.c: Likewise.
+	* nptl/test-cond-printers.py: Likewise.
+	* nptl/test-condattr-printers.c: Likewise.
+	* nptl/test-condattr-printers.py: Likewise.
+	* nptl/test-mutex-printers.c: Likewise.
+	* nptl/test-mutex-printers.py: Likewise.
+	* nptl/test-mutexattr-printers.c: Likewise.
+	* nptl/test-mutexattr-printers.py: Likewise.
+	* nptl/test-rwlock-printers.c: Likewise.
+	* nptl/test-rwlock-printers.py: Likewise.
+	* nptl/test-rwlockattr-printers.c: Likewise.
+	* nptl/test-rwlockattr-printers.py: Likewise.
+	* scripts/gen-py-const.awk: Likewise.
+	* scripts/test_printers_common.py: Likewise.
+	* scripts/test_printers_exceptions.py: Likewise.
+
 2016-12-07  Joseph Myers  <joseph@codesourcery.com>
 
 	* scripts/build-many-glibcs.py (Context.__init__): Take strip
diff --git a/INSTALL b/INSTALL
index b5acedcc96..acb622a102 100644
--- a/INSTALL
+++ b/INSTALL
@@ -224,6 +224,33 @@ You can specify 'stop-on-test-failure=y' when running 'make check' to
 make the test run stop and exit with an error status immediately when a
 failure occurs.
 
+   The GNU C Library pretty printers come with their own set of scripts
+for testing, which run together with the rest of the testsuite through
+'make check'.  These scripts require the following tools to run
+successfully:
+
+   * Python 2.7.6/3.4.3 or later
+
+     Python is required for running the printers' test scripts.
+
+   * PExpect 4.0
+
+     The printer tests drive GDB through test programs and compare its
+     output to the printers'.  PExpect is used to capture the output of
+     GDB, and should be compatible with the Python version in your
+     system.
+
+   * GDB 7.8 or later with support for Python 2.7.6/3.4.3 or later
+
+     GDB itself needs to be configured with Python support in order to
+     use the pretty printers.  Notice that your system having Python
+     available doesn't imply that GDB supports it, nor that your
+     system's Python and GDB's have the same version.
+
+If these tools are absent, the printer tests will report themselves as
+'UNSUPPORTED'.  Notice that some of the printer tests require the GNU C
+Library to be compiled with debugging symbols.
+
    To format the 'GNU C Library Reference Manual' for printing, type
 'make dvi'.  You need a working TeX installation to do this.  The
 distribution builds the on-line formatted version of the manual, as Info
diff --git a/Makeconfig b/Makeconfig
index a7858607b0..e9d8da9d60 100644
--- a/Makeconfig
+++ b/Makeconfig
@@ -416,6 +416,11 @@ $(+link-pie-before-libc) $(rtld-tests-LDFLAGS) $(link-libc-tests) \
 			 $(+link-pie-after-libc)
 $(call after-link,$@)
 endef
+define +link-pie-printers-tests
+$(+link-pie-before-libc) $(built-rtld-LDFLAGS) $(link-libc-printers-tests) \
+			 $(+link-pie-after-libc)
+$(call after-link,$@)
+endef
 endif
 # Command for statically linking programs with the C library.
 ifndef +link-static
@@ -445,7 +450,8 @@ ifeq (yes,$(build-pie-default))
 no-pie-ldflag = -no-pie
 +link = $(+link-pie)
 +link-tests = $(+link-pie-tests)
-else
++link-printers-tests = $(+link-pie-printers-tests)
+else  # not build-pie-default
 +link-before-libc = $(CC) -nostdlib -nostartfiles -o $@ \
 	      $(sysdep-LDFLAGS) $(LDFLAGS) $(LDFLAGS-$(@F)) \
 	      $(combreloc-LDFLAGS) $(relro-LDFLAGS) $(hashstyle-LDFLAGS) \
@@ -466,51 +472,87 @@ $(+link-before-libc) $(rtld-tests-LDFLAGS) $(link-libc-tests) \
 		     $(+link-after-libc)
 $(call after-link,$@)
 endef
-endif
-else
+define +link-printers-tests
+$(+link-before-libc) $(built-rtld-LDFLAGS) $(link-libc-printers-tests) \
+		     $(+link-after-libc)
+$(call after-link,$@)
+endef
+endif  # build-pie-default
+else  # build-static
 +link = $(+link-static)
 +link-tests = $(+link-static-tests)
-endif
-endif
++link-printers-tests = $(+link-static-tests)
+endif  # build-shared
+endif  # +link
+
+# The pretty printer test programs need to be compiled without optimizations
+# so they won't confuse gdb.  We could use either the 'GCC optimize' pragma
+# or the 'optimize' function attribute to achieve this; however, at least on
+# ARM, gcc always produces different debugging symbols when invoked with
+# a -O greater than 0 than when invoked with -O0, regardless of anything else
+# we're using to suppress optimizations.  Therefore, we need to explicitly pass
+# -O0 to it through CFLAGS.
+# Additionally, the build system will try to -include $(common-objpfx)/config.h
+# when compiling the tests, which will throw an error if some special macros
+# (such as __OPTIMIZE__ and IS_IN_build) aren't defined.  To avoid this, we
+# tell gcc to define IS_IN_build.
+CFLAGS-printers-tests := -O0 -ggdb3 -DIS_IN_build
+
 ifeq (yes,$(build-shared))
+# These indicate whether to link using the built ld.so or the installed one.
+installed-rtld-LDFLAGS = -Wl,-dynamic-linker=$(rtlddir)/$(rtld-installed-name)
+built-rtld-LDFLAGS = -Wl,-dynamic-linker=$(elf-objpfx)ld.so
+
 ifndef rtld-LDFLAGS
-rtld-LDFLAGS = -Wl,-dynamic-linker=$(rtlddir)/$(rtld-installed-name)
+rtld-LDFLAGS = $(installed-rtld-LDFLAGS)
 endif
+
 ifndef rtld-tests-LDFLAGS
 ifeq (yes,$(build-hardcoded-path-in-tests))
-rtld-tests-LDFLAGS = -Wl,-dynamic-linker=$(elf-objpfx)ld.so
+rtld-tests-LDFLAGS = $(built-rtld-LDFLAGS)
 else
-rtld-tests-LDFLAGS = $(rtld-LDFLAGS)
-endif
-endif
-endif
+rtld-tests-LDFLAGS = $(installed-rtld-LDFLAGS)
+endif  # build-hardcoded-path-in-tests
+endif  # rtld-tests-LDFLAGS
+
+endif  # build-shared
+
 ifndef link-libc
 ifeq (yes,$(build-shared))
 # We need the versioned name of libc.so in the deps of $(others) et al
 # so that the symlink to libc.so is created before anything tries to
 # run the linked programs.
+link-libc-rpath = -Wl,-rpath=$(rpath-link)
 link-libc-rpath-link = -Wl,-rpath-link=$(rpath-link)
+
 ifeq (yes,$(build-hardcoded-path-in-tests))
-link-libc-tests-rpath-link = -Wl,-rpath=$(rpath-link)
+link-libc-tests-rpath-link = $(link-libc-rpath)
 else
 link-libc-tests-rpath-link = $(link-libc-rpath-link)
-endif
+endif  # build-hardcoded-path-in-tests
+
 link-libc-before-gnulib = $(common-objpfx)libc.so$(libc.so-version) \
 			  $(common-objpfx)$(patsubst %,$(libtype.oS),c) \
 			  $(as-needed) $(elf-objpfx)ld.so \
 			  $(no-as-needed)
 link-libc = $(link-libc-rpath-link) $(link-libc-before-gnulib) $(gnulib)
+
+link-libc-tests-after-rpath-link = $(link-libc-before-gnulib) $(gnulib-tests)
 link-libc-tests = $(link-libc-tests-rpath-link) \
-		  $(link-libc-before-gnulib) $(gnulib-tests)
+		  $(link-libc-tests-after-rpath-link)
+# Pretty printer test programs always require rpath instead of rpath-link.
+link-libc-printers-tests = $(link-libc-rpath) \
+			   $(link-libc-tests-after-rpath-link)
+
 # This is how to find at build-time things that will be installed there.
 rpath-dirs = math elf dlfcn nss nis rt resolv crypt mathvec
 rpath-link = \
 $(common-objdir):$(subst $(empty) ,:,$(patsubst ../$(subdir),.,$(rpath-dirs:%=$(common-objpfx)%)))
-else
+else  # build-static
 link-libc = $(common-objpfx)libc.a $(otherlibs) $(gnulib) $(common-objpfx)libc.a $(gnulib)
 link-libc-tests = $(common-objpfx)libc.a $(otherlibs) $(gnulib-tests) $(common-objpfx)libc.a $(gnulib-tests)
-endif
-endif
+endif  # build-shared
+endif  # link-libc
 
 # Differences in the linkers on the various platforms.
 LDFLAGS-rpath-ORIGIN = -Wl,-rpath,'$$ORIGIN'
diff --git a/Makerules b/Makerules
index e865782b43..7214b2b43c 100644
--- a/Makerules
+++ b/Makerules
@@ -210,6 +210,52 @@ sed-remove-dotdot := -e 's@  *\([^ 	\/$$][^ 	\]*\)@ $$(..)\1@g' \
 		     -e 's@^\([^ 	\/$$][^ 	\]*\)@$$(..)\1@g'
 endif
 
+ifdef gen-py-const-headers
+# We'll use a static pattern rule to match .pysym files with their
+# corresponding generated .py files.
+# The generated .py files go in the submodule's dir in the glibc build dir.
+py-const-files := $(patsubst %.pysym,%.py,$(gen-py-const-headers))
+py-const-dir := $(objpfx)
+py-const := $(addprefix $(py-const-dir),$(py-const-files))
+py-const-script := $(..)scripts/gen-py-const.awk
+
+# This is a hack we use to generate .py files with constants for Python
+# pretty printers.  It works the same way as gen-as-const.
+# See scripts/gen-py-const.awk for details on how the awk | gcc mechanism
+# works.
+#
+# $@.tmp and $@.tmp2 are temporary files we use to store the partial contents
+# of the target file.  We do this instead of just writing on $@ because, if the
+# build process terminates prematurely, re-running Make wouldn't run this rule
+# since Make would see that the target file already exists (despite it being
+# incomplete).
+#
+# The sed line replaces "@name@SOME_NAME@value@SOME_VALUE@" strings from the
+# output of 'gcc -S' with "SOME_NAME = SOME_VALUE" strings.
+# The '-n' option, combined with the '/p' command, makes sed output only the
+# modified lines instead of the whole input file.  The output is redirected
+# to a .py file; we'll import it in the pretty printers file to read
+# the constants generated by gen-py-const.awk.
+# The regex has two capturing groups, for SOME_NAME and SOME_VALUE
+# respectively.  Notice SOME_VALUE may be prepended by a special character,
+# depending on the assembly syntax (e.g. immediates are prefixed by a '$'
+# in AT&T x86, and by a '#' in ARM).  We discard it using a complemented set
+# before the second capturing group.
+$(py-const): $(py-const-dir)%.py: %.pysym $(py-const-script) \
+	     $(common-before-compile)
+	$(make-target-directory)
+	$(AWK) -f $(py-const-script) $< \
+	       | $(CC) -S -o $@.tmp $(CFLAGS) $(CPPFLAGS) -x c -
+	echo '# GENERATED FILE\n' > $@.tmp2
+	echo '# Constant definitions for pretty printers.' >> $@.tmp2
+	echo '# See gen-py-const.awk for details.\n' >> $@.tmp2
+	sed -n -r 's/^.*@name@([^@]+)@value@[^[:xdigit:]Xx-]*([[:xdigit:]Xx-]+)@.*/\1 = \2/p' \
+	    $@.tmp >> $@.tmp2
+	mv -f $@.tmp2 $@
+	rm -f $@.tmp
+
+generated += $(py-const)
+endif  # gen-py-const-headers
 
 ifdef gen-as-const-headers
 # Generating headers for assembly constants.
diff --git a/NEWS b/NEWS
index c2e973d183..922a5004ff 100644
--- a/NEWS
+++ b/NEWS
@@ -141,6 +141,11 @@ Version 2.25
   variable for a particular architecture in the GCC source file
   'gcc/config.gcc'.
 
+* GDB pretty printers have been added for mutex and condition variable
+  structures in POSIX Threads. When installed and loaded in gdb these pretty
+  printers show various pthread variables in human-readable form when read
+  using the 'print' or 'display' commands in gdb.
+
 Security related changes:
 
   On ARM EABI (32-bit), generating a backtrace for execution contexts which
diff --git a/README.pretty-printers b/README.pretty-printers
new file mode 100644
index 0000000000..86629001e6
--- /dev/null
+++ b/README.pretty-printers
@@ -0,0 +1,169 @@
+README for the glibc Python pretty printers
+===========================================
+
+Pretty printers are gdb extensions that allow it to print useful, human-readable
+information about a program's variables.  For example, for a pthread_mutex_t
+gdb would usually output something like this:
+
+(gdb) print mutex
+$1 = {
+  __data = {
+    __lock = 22020096,
+    __count = 0,
+    __owner = 0,
+    __nusers = 0,
+    __kind = 576,
+    __spins = 0,
+    __elision = 0,
+    __list = {
+      __prev = 0x0,
+      __next = 0x0
+    }
+  },
+  __size = "\000\000P\001", '\000' <repeats 12 times>, "@\002", '\000' <repeats 21 times>,
+  __align = 22020096
+}
+
+However, with a pretty printer gdb will output something like this:
+
+(gdb) print mutex
+$1 = pthread_mutex_t = {
+  Type = Normal,
+  Status = Unlocked,
+  Robust = No,
+  Shared = No,
+  Protocol = Priority protect,
+  Priority ceiling = 42
+}
+
+Before printing a value, gdb will first check if there's a pretty printer
+registered for it.  If there is, it'll use it, otherwise it'll print the value
+as usual.  Pretty printers can be registered in various ways; for our purposes
+we register them for the current objfile by calling
+gdb.printing.register_pretty_printer().
+
+Currently our printers are based on gdb.RegexpCollectionPrettyPrinter, which
+means they'll be triggered if the type of the variable we're printing matches
+a given regular expression.  For example, MutexPrinter will be triggered if
+our variable's type matches the regexp '^pthread_mutex_t$'.
+
+Besides the printers themselves, each module may have a constants file which the
+printers will import.  These constants are generated from C headers during the
+build process, and need to be in the Python search path when loading the
+printers.
+
+
+Installing and loading
+----------------------
+
+The pretty printers and their constant files may be installed in different paths
+for each distro, though gdb should be able to automatically load them by itself.
+When in doubt, you can use the 'info pretty-printer' gdb command to list the
+loaded pretty printers.
+
+If the printers aren't automatically loaded for some reason, you should add the
+following to your .gdbinit:
+
+python
+import sys
+sys.path.insert(0, '/path/to/constants/file/directory')
+end
+
+source /path/to/printers.py
+
+If you're building glibc manually, '/path/to/constants/file/directory' should be
+'/path/to/glibc-build/submodule', where 'submodule' is e.g. nptl.
+
+
+Testing
+-------
+
+The pretty printers come with a small test suite based on PExpect, which is a
+Python module with Expect-like features for spawning and controlling interactive
+programs.  Each printer has a corresponding C program and a Python script
+that uses PExpect to drive gdb through the program and compare its output to
+the expected printer's.
+
+The tests run on the glibc host, which is assumed to have both gdb and PExpect;
+if any of those is absent the tests will fail with code 77 (UNSUPPORTED).
+Native builds can be tested simply by doing 'make check'; cross builds must use
+cross-test-ssh.sh as test-wrapper, like this:
+
+make test-wrapper='/path/to/scripts/cross-test-ssh.sh user@host' check
+
+(Remember to share the build system's filesystem with the glibc host's through
+NFS or something similar).
+
+Running 'make check' on a cross build will only compile the test programs,
+without running the scripts.
+
+
+Adding new pretty printers
+--------------------------
+
+Adding new pretty printers to glibc requires following these steps:
+
+1. Identify which constants must be generated from C headers, and write the
+corresponding .pysym file.  See scripts/gen-py-const.awk for more information
+on how this works.  The name of the .pysym file must be added to the
+'gen-py-const-headers' variable in your submodule's Makefile (without the .pysym
+extension).
+
+2. Write the pretty printer code itself.  For this you can follow the gdb
+Python API documentation, and use the existing printers as examples.  The printer
+code must import the generated constants file (which will have the same name
+as your .pysym file).  The names of the pretty printer files must be added
+to the 'pretty-printers' variable in your submodule's Makefile (without the .py
+extension).
+
+3. Write the unit tests for your pretty printers.  The build system calls each
+test script passing it the paths to the test program source, the test program
+binary, and the printer files you added to 'pretty-printers' in the previous
+step.  The test scripts, in turn, must import scripts/test_printers_common
+and call the init_test function passing it, among other things, the name of the
+set of pretty printers to enable (as seen by running 'info pretty-printer').
+You can use the existing unit tests as examples.
+
+4. Add the names of the pretty printer tests to the 'tests-printers' variable
+in your submodule's Makefile (without extensions).  In addition, for each test
+program you must define a corresponding CFLAGS-* variable and set it to
+$(CFLAGS-printers-tests) to ensure they're compiled correctly.  For example,
+test-foo-printer.c requires the following:
+
+CFLAGS-test-foo-printer.c := $(CFLAGS-printers-tests)
+
+Finally, if your programs need to be linked with a specific library, you can add
+its name to the 'tests-printers-libs' variable in your submodule's Makefile.
+
+
+Known issues
+------------
+
+* Pretty printers are inherently coupled to the code they're targetting, thus
+any changes to the target code must also update the corresponding printers.
+On the plus side, the printer code itself may serve as a kind of documentation
+for the target code.
+
+* Older versions of the gdb Python API have a bug where
+gdb.RegexpCollectionPrettyPrinter would not be able to get a value's real type
+if it was typedef'd.  This would cause gdb to ignore the pretty printers for
+types like pthread_mutex_t, which is defined as:
+
+typedef union
+{
+  ...
+} pthread_mutex_t;
+
+This was fixed in commit 1b588015839caafc608a6944a78aea170f5fb2f6, and released
+as part of gdb 7.8.  However, typedef'ing an already typedef'd type may cause
+a similar issue, e.g.:
+
+typedef pthread_mutex_t mutex;
+mutex a_mutex;
+
+Here, trying to print a_mutex won't trigger the pthread_mutex_t printer.
+
+* The test programs must be compiled without optimizations.  This is necessary
+because the test scripts rely on the C code structure being preserved when
+stepping through the programs.  Things like aggressive instruction reordering
+or optimizing variables out may make this kind of testing impossible.
diff --git a/Rules b/Rules
index 466db076f0..714e917de4 100644
--- a/Rules
+++ b/Rules
@@ -108,17 +108,28 @@ endif
 
 .PHONY: others tests bench bench-build
 
+# Test programs for the pretty printers.
+tests-printers-programs := $(addprefix $(objpfx),$(tests-printers))
+
+# .out files with the output of running the pretty printer tests.
+tests-printers-out := $(patsubst %,$(objpfx)%.out,$(tests-printers))
+
 ifeq ($(build-programs),yes)
 others: $(addprefix $(objpfx),$(others) $(sysdep-others) $(extra-objs))
 else
 others: $(addprefix $(objpfx),$(extra-objs))
 endif
+
+# Generate constant files for Python pretty printers if required.
+others: $(py-const)
+
 ifeq ($(run-built-tests),no)
 tests: $(addprefix $(objpfx),$(filter-out $(tests-unsupported),$(tests)) \
-			     $(test-srcs)) $(tests-special)
+			     $(test-srcs)) $(tests-special) \
+       $(tests-printers-programs)
 xtests: tests $(xtests-special)
 else
-tests: $(tests:%=$(objpfx)%.out) $(tests-special)
+tests: $(tests:%=$(objpfx)%.out) $(tests-special) $(tests-printers-out)
 xtests: tests $(xtests:%=$(objpfx)%.out) $(xtests-special)
 endif
 
@@ -131,7 +142,8 @@ tests-expected = $(tests)
 endif
 tests:
 	$(..)scripts/merge-test-results.sh -s $(objpfx) $(subdir) \
-	  $(sort $(tests-expected) $(tests-special-notdir:.out=)) \
+	  $(sort $(tests-expected) $(tests-special-notdir:.out=) \
+	  $(tests-printers)) \
 	  > $(objpfx)subdir-tests.sum
 xtests:
 	$(..)scripts/merge-test-results.sh -s $(objpfx) $(subdir) \
@@ -241,6 +253,32 @@ endif
 
 endif	# tests
 
+ifneq "$(strip $(tests-printers))" ""
+# We're defining this here for now; later it'll be defined at configure time
+# inside Makeconfig.
+PYTHON := python
+
+# Static pattern rule for building the test programs for the pretty printers.
+$(tests-printers-programs): %: %.o $(tests-printers-libs) \
+  $(sort $(filter $(common-objpfx)lib%,$(link-libc-static-tests))) \
+  $(addprefix $(csu-objpfx),start.o) $(+preinit) $(+postinit)
+	$(+link-printers-tests)
+
+# Add the paths to the generated constants file and test_common_printers.py
+# to PYTHONPATH so the test scripts can find them.
+py-env := PYTHONPATH=$(py-const-dir):$(..)scripts:$${PYTHONPATH}
+
+# Static pattern rule that matches the test-* targets to their .c and .py
+# prerequisites.  It'll run the corresponding test script for each test program
+# we compiled and place its output in the corresponding .out file.
+# The pretty printer files and test_common_printers.py must be present for all.
+$(tests-printers-out): $(objpfx)%.out: $(objpfx)% %.py %.c $(pretty-printers) \
+		       $(..)scripts/test_printers_common.py
+	$(test-wrapper-env) $(py-env) \
+	    $(PYTHON) $*.py $*.c $(objpfx)$* $(pretty-printers) > $@; \
+	$(evaluate-test)
+endif
+
 
 .PHONY: distclean realclean subdir_distclean subdir_realclean \
 	subdir_clean subdir_mostlyclean subdir_testclean
diff --git a/manual/install.texi b/manual/install.texi
index de1c2030d3..35e02ada58 100644
--- a/manual/install.texi
+++ b/manual/install.texi
@@ -256,6 +256,36 @@ occurred.  You can specify @samp{stop-on-test-failure=y} when running
 @code{make check} to make the test run stop and exit with an error
 status immediately when a failure occurs.
 
+The @glibcadj{} pretty printers come with their own set of scripts for testing,
+which run together with the rest of the testsuite through @code{make check}.
+These scripts require the following tools to run successfully:
+
+@itemize @bullet
+@item
+Python 2.7.6/3.4.3 or later
+
+Python is required for running the printers' test scripts.
+
+@item PExpect 4.0
+
+The printer tests drive GDB through test programs and compare its output
+to the printers'.  PExpect is used to capture the output of GDB, and should be
+compatible with the Python version in your system.
+
+@item
+GDB 7.8 or later with support for Python 2.7.6/3.4.3 or later
+
+GDB itself needs to be configured with Python support in order to use the
+pretty printers.  Notice that your system having Python available doesn't imply
+that GDB supports it, nor that your system's Python and GDB's have the same
+version.
+@end itemize
+
+@noindent
+If these tools are absent, the printer tests will report themselves as
+@code{UNSUPPORTED}.  Notice that some of the printer tests require @theglibc{}
+to be compiled with debugging symbols.
+
 To format the @cite{GNU C Library Reference Manual} for printing, type
 @w{@code{make dvi}}.  You need a working @TeX{} installation to do
 this.  The distribution builds the on-line formatted version of the
diff --git a/nptl/Makefile b/nptl/Makefile
index 11588fe996..7ac9196975 100644
--- a/nptl/Makefile
+++ b/nptl/Makefile
@@ -312,6 +312,24 @@ gen-as-const-headers = pthread-errnos.sym \
 		       unwindbuf.sym \
 		       lowlevelrobustlock.sym pthread-pi-defines.sym
 
+gen-py-const-headers := nptl_lock_constants.pysym
+pretty-printers := nptl-printers.py
+tests-printers := test-mutexattr-printers test-mutex-printers \
+		  test-condattr-printers test-cond-printers \
+		  test-rwlockattr-printers test-rwlock-printers
+
+CFLAGS-test-mutexattr-printers.c := $(CFLAGS-printers-tests)
+CFLAGS-test-mutex-printers.c := $(CFLAGS-printers-tests)
+CFLAGS-test-condattr-printers.c := $(CFLAGS-printers-tests)
+CFLAGS-test-cond-printers.c := $(CFLAGS-printers-tests)
+CFLAGS-test-rwlockattr-printers.c := $(CFLAGS-printers-tests)
+CFLAGS-test-rwlock-printers.c := $(CFLAGS-printers-tests)
+
+ifeq ($(build-shared),yes)
+tests-printers-libs := $(shared-thread-library)
+else
+tests-printers-libs := $(static-thread-library)
+endif
 
 LDFLAGS-pthread.so = -Wl,--enable-new-dtags,-z,nodelete,-z,initfirst
 
diff --git a/nptl/nptl-printers.py b/nptl/nptl-printers.py
new file mode 100644
index 0000000000..e402f232c7
--- /dev/null
+++ b/nptl/nptl-printers.py
@@ -0,0 +1,633 @@
+# Pretty printers for the NPTL lock types.
+#
+# Copyright (C) 2016 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+#
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# The GNU C Library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <http://www.gnu.org/licenses/>.
+
+"""This file contains the gdb pretty printers for the following types:
+
+    * pthread_mutex_t
+    * pthread_mutexattr_t
+    * pthread_cond_t
+    * pthread_condattr_t
+    * pthread_rwlock_t
+    * pthread_rwlockattr_t
+
+You can check which printers are registered and enabled by issuing the
+'info pretty-printer' gdb command.  Printers should trigger automatically when
+trying to print a variable of one of the types mentioned above.
+"""
+
+from __future__ import print_function
+
+import gdb
+import gdb.printing
+from nptl_lock_constants import *
+
+MUTEX_TYPES = {
+    PTHREAD_MUTEX_NORMAL: ('Type', 'Normal'),
+    PTHREAD_MUTEX_RECURSIVE: ('Type', 'Recursive'),
+    PTHREAD_MUTEX_ERRORCHECK: ('Type', 'Error check'),
+    PTHREAD_MUTEX_ADAPTIVE_NP: ('Type', 'Adaptive')
+}
+
+class MutexPrinter(object):
+    """Pretty printer for pthread_mutex_t."""
+
+    def __init__(self, mutex):
+        """Initialize the printer's internal data structures.
+
+        Args:
+            mutex: A gdb.value representing a pthread_mutex_t.
+        """
+
+        data = mutex['__data']
+        self.lock = data['__lock']
+        self.count = data['__count']
+        self.owner = data['__owner']
+        self.kind = data['__kind']
+        self.values = []
+        self.read_values()
+
+    def to_string(self):
+        """gdb API function.
+
+        This is called from gdb when we try to print a pthread_mutex_t.
+        """
+
+        return 'pthread_mutex_t'
+
+    def children(self):
+        """gdb API function.
+
+        This is called from gdb when we try to print a pthread_mutex_t.
+        """
+
+        return self.values
+
+    def read_values(self):
+        """Read the mutex's info and store it in self.values.
+
+        The data contained in self.values will be returned by the Iterator
+        created in self.children.
+        """
+
+        self.read_type()
+        self.read_status()
+        self.read_attributes()
+        self.read_misc_info()
+
+    def read_type(self):
+        """Read the mutex's type."""
+
+        mutex_type = self.kind & PTHREAD_MUTEX_KIND_MASK
+
+        # mutex_type must be casted to int because it's a gdb.Value
+        self.values.append(MUTEX_TYPES[int(mutex_type)])
+
+    def read_status(self):
+        """Read the mutex's status.
+
+        For architectures which support lock elision, this method reads
+        whether the mutex appears as locked in memory (i.e. it may show it as
+        unlocked even after calling pthread_mutex_lock).
+        """
+
+        if self.kind == PTHREAD_MUTEX_DESTROYED:
+            self.values.append(('Status', 'Destroyed'))
+        elif self.kind & PTHREAD_MUTEX_ROBUST_NORMAL_NP:
+            self.read_status_robust()
+        else:
+            self.read_status_no_robust()
+
+    def read_status_robust(self):
+        """Read the status of a robust mutex.
+
+        In glibc robust mutexes are implemented in a very different way than
+        non-robust ones.  This method reads their locking status,
+        whether it may have waiters, their registered owner (if any),
+        whether the owner is alive or not, and the status of the state
+        they're protecting.
+        """
+
+        if self.lock == PTHREAD_MUTEX_UNLOCKED:
+            self.values.append(('Status', 'Unlocked'))
+        else:
+            if self.lock & FUTEX_WAITERS:
+                self.values.append(('Status', 'Locked, possibly with waiters'))
+            else:
+                self.values.append(('Status',
+                                    'Locked, possibly with no waiters'))
+
+            if self.lock & FUTEX_OWNER_DIED:
+                self.values.append(('Owner ID', '%d (dead)' % self.owner))
+            else:
+                self.values.append(('Owner ID', self.lock & FUTEX_TID_MASK))
+
+        if self.owner == PTHREAD_MUTEX_INCONSISTENT:
+            self.values.append(('State protected by this mutex',
+                                'Inconsistent'))
+        elif self.owner == PTHREAD_MUTEX_NOTRECOVERABLE:
+            self.values.append(('State protected by this mutex',
+                                'Not recoverable'))
+
+    def read_status_no_robust(self):
+        """Read the status of a non-robust mutex.
+
+        Read info on whether the mutex is locked, if it may have waiters
+        and its owner (if any).
+        """
+
+        lock_value = self.lock
+
+        if self.kind & PTHREAD_MUTEX_PRIO_PROTECT_NP:
+            lock_value &= ~(PTHREAD_MUTEX_PRIO_CEILING_MASK)
+
+        if lock_value == PTHREAD_MUTEX_UNLOCKED:
+            self.values.append(('Status', 'Unlocked'))
+        else:
+            if self.kind & PTHREAD_MUTEX_PRIO_INHERIT_NP:
+                waiters = self.lock & FUTEX_WAITERS
+                owner = self.lock & FUTEX_TID_MASK
+            else:
+                # Mutex protocol is PP or none
+                waiters = (self.lock != PTHREAD_MUTEX_LOCKED_NO_WAITERS)
+                owner = self.owner
+
+            if waiters:
+                self.values.append(('Status', 'Locked, possibly with waiters'))
+            else:
+                self.values.append(('Status',
+                                    'Locked, possibly with no waiters'))
+
+            self.values.append(('Owner ID', owner))
+
+    def read_attributes(self):
+        """Read the mutex's attributes."""
+
+        if self.kind != PTHREAD_MUTEX_DESTROYED:
+            if self.kind & PTHREAD_MUTEX_ROBUST_NORMAL_NP:
+                self.values.append(('Robust', 'Yes'))
+            else:
+                self.values.append(('Robust', 'No'))
+
+            # In glibc, robust mutexes always have their pshared flag set to
+            # 'shared' regardless of what the pshared flag of their
+            # mutexattr was.  Therefore a robust mutex will act as shared
+            # even if it was initialized with a 'private' mutexattr.
+            if self.kind & PTHREAD_MUTEX_PSHARED_BIT:
+                self.values.append(('Shared', 'Yes'))
+            else:
+                self.values.append(('Shared', 'No'))
+
+            if self.kind & PTHREAD_MUTEX_PRIO_INHERIT_NP:
+                self.values.append(('Protocol', 'Priority inherit'))
+            elif self.kind & PTHREAD_MUTEX_PRIO_PROTECT_NP:
+                prio_ceiling = ((self.lock & PTHREAD_MUTEX_PRIO_CEILING_MASK)
+                                >> PTHREAD_MUTEX_PRIO_CEILING_SHIFT)
+
+                self.values.append(('Protocol', 'Priority protect'))
+                self.values.append(('Priority ceiling', prio_ceiling))
+            else:
+                # PTHREAD_PRIO_NONE
+                self.values.append(('Protocol', 'None'))
+
+    def read_misc_info(self):
+        """Read miscellaneous info on the mutex.
+
+        For now this reads the number of times a recursive mutex was locked
+        by the same thread.
+        """
+
+        mutex_type = self.kind & PTHREAD_MUTEX_KIND_MASK
+
+        if mutex_type == PTHREAD_MUTEX_RECURSIVE and self.count > 1:
+            self.values.append(('Times locked recursively', self.count))
+
+class MutexAttributesPrinter(object):
+    """Pretty printer for pthread_mutexattr_t.
+
+    In the NPTL this is a type that's always casted to struct pthread_mutexattr
+    which has a single 'mutexkind' field containing the actual attributes.
+    """
+
+    def __init__(self, mutexattr):
+        """Initialize the printer's internal data structures.
+
+        Args:
+            mutexattr: A gdb.value representing a pthread_mutexattr_t.
+        """
+
+        self.values = []
+
+        try:
+            mutexattr_struct = gdb.lookup_type('struct pthread_mutexattr')
+            self.mutexattr = mutexattr.cast(mutexattr_struct)['mutexkind']
+            self.read_values()
+        except gdb.error:
+            # libpthread doesn't have debug symbols, thus we can't find the
+            # real struct type.  Just print the union members.
+            self.values.append(('__size', mutexattr['__size']))
+            self.values.append(('__align', mutexattr['__align']))
+
+    def to_string(self):
+        """gdb API function.
+
+        This is called from gdb when we try to print a pthread_mutexattr_t.
+        """
+
+        return 'pthread_mutexattr_t'
+
+    def children(self):
+        """gdb API function.
+
+        This is called from gdb when we try to print a pthread_mutexattr_t.
+        """
+
+        return self.values
+
+    def read_values(self):
+        """Read the mutexattr's info and store it in self.values.
+
+        The data contained in self.values will be returned by the Iterator
+        created in self.children.
+        """
+
+        mutexattr_type = (self.mutexattr
+                          & ~PTHREAD_MUTEXATTR_FLAG_BITS
+                          & ~PTHREAD_MUTEX_NO_ELISION_NP)
+
+        # mutexattr_type must be casted to int because it's a gdb.Value
+        self.values.append(MUTEX_TYPES[int(mutexattr_type)])
+
+        if self.mutexattr & PTHREAD_MUTEXATTR_FLAG_ROBUST:
+            self.values.append(('Robust', 'Yes'))
+        else:
+            self.values.append(('Robust', 'No'))
+
+        if self.mutexattr & PTHREAD_MUTEXATTR_FLAG_PSHARED:
+            self.values.append(('Shared', 'Yes'))
+        else:
+            self.values.append(('Shared', 'No'))
+
+        protocol = ((self.mutexattr & PTHREAD_MUTEXATTR_PROTOCOL_MASK) >>
+                    PTHREAD_MUTEXATTR_PROTOCOL_SHIFT)
+
+        if protocol == PTHREAD_PRIO_NONE:
+            self.values.append(('Protocol', 'None'))
+        elif protocol == PTHREAD_PRIO_INHERIT:
+            self.values.append(('Protocol', 'Priority inherit'))
+        elif protocol == PTHREAD_PRIO_PROTECT:
+            self.values.append(('Protocol', 'Priority protect'))
+
+CLOCK_IDS = {
+    CLOCK_REALTIME: 'CLOCK_REALTIME',
+    CLOCK_MONOTONIC: 'CLOCK_MONOTONIC',
+    CLOCK_PROCESS_CPUTIME_ID: 'CLOCK_PROCESS_CPUTIME_ID',
+    CLOCK_THREAD_CPUTIME_ID: 'CLOCK_THREAD_CPUTIME_ID',
+    CLOCK_MONOTONIC_RAW: 'CLOCK_MONOTONIC_RAW',
+    CLOCK_REALTIME_COARSE: 'CLOCK_REALTIME_COARSE',
+    CLOCK_MONOTONIC_COARSE: 'CLOCK_MONOTONIC_COARSE'
+}
+
+class ConditionVariablePrinter(object):
+    """Pretty printer for pthread_cond_t."""
+
+    def __init__(self, cond):
+        """Initialize the printer's internal data structures.
+
+        Args:
+            cond: A gdb.value representing a pthread_cond_t.
+        """
+
+        # Since PTHREAD_COND_SHARED is an integer, we need to cast it to void *
+        # to be able to compare it to the condvar's __data.__mutex member.
+        #
+        # While it looks like self.shared_value should be a class variable,
+        # that would result in it having an incorrect size if we're loading
+        # these printers through .gdbinit for a 64-bit objfile in AMD64.
+        # This is because gdb initially assumes the pointer size to be 4 bytes,
+        # and only sets it to 8 after loading the 64-bit objfiles.  Since
+        # .gdbinit runs before any objfiles are loaded, this would effectively
+        # make self.shared_value have a size of 4, thus breaking later
+        # comparisons with pointers whose types are looked up at runtime.
+        void_ptr_type = gdb.lookup_type('void').pointer()
+        self.shared_value = gdb.Value(PTHREAD_COND_SHARED).cast(void_ptr_type)
+
+        data = cond['__data']
+        self.total_seq = data['__total_seq']
+        self.mutex = data['__mutex']
+        self.nwaiters = data['__nwaiters']
+        self.values = []
+
+        self.read_values()
+
+    def to_string(self):
+        """gdb API function.
+
+        This is called from gdb when we try to print a pthread_cond_t.
+        """
+
+        return 'pthread_cond_t'
+
+    def children(self):
+        """gdb API function.
+
+        This is called from gdb when we try to print a pthread_cond_t.
+        """
+
+        return self.values
+
+    def read_values(self):
+        """Read the condvar's info and store it in self.values.
+
+        The data contained in self.values will be returned by the Iterator
+        created in self.children.
+        """
+
+        self.read_status()
+        self.read_attributes()
+        self.read_mutex_info()
+
+    def read_status(self):
+        """Read the status of the condvar.
+
+        This method reads whether the condvar is destroyed and how many threads
+        are waiting for it.
+        """
+
+        if self.total_seq == PTHREAD_COND_DESTROYED:
+            self.values.append(('Status', 'Destroyed'))
+
+        self.values.append(('Threads waiting for this condvar',
+                            self.nwaiters >> COND_NWAITERS_SHIFT))
+
+    def read_attributes(self):
+        """Read the condvar's attributes."""
+
+        clock_id = self.nwaiters & ((1 << COND_NWAITERS_SHIFT) - 1)
+
+        # clock_id must be casted to int because it's a gdb.Value
+        self.values.append(('Clock ID', CLOCK_IDS[int(clock_id)]))
+
+        shared = (self.mutex == self.shared_value)
+
+        if shared:
+            self.values.append(('Shared', 'Yes'))
+        else:
+            self.values.append(('Shared', 'No'))
+
+    def read_mutex_info(self):
+        """Read the data of the mutex this condvar is bound to.
+
+        A pthread_cond_t's __data.__mutex member is a void * which
+        must be casted to pthread_mutex_t *.  For shared condvars, this
+        member isn't recorded and has a special value instead.
+        """
+
+        if self.mutex and self.mutex != self.shared_value:
+            mutex_type = gdb.lookup_type('pthread_mutex_t')
+            mutex = self.mutex.cast(mutex_type.pointer()).dereference()
+
+            self.values.append(('Mutex', mutex))
+
+class ConditionVariableAttributesPrinter(object):
+    """Pretty printer for pthread_condattr_t.
+
+    In the NPTL this is a type that's always casted to struct pthread_condattr,
+    which has a single 'value' field containing the actual attributes.
+    """
+
+    def __init__(self, condattr):
+        """Initialize the printer's internal data structures.
+
+        Args:
+            condattr: A gdb.value representing a pthread_condattr_t.
+        """
+
+        self.values = []
+
+        try:
+            condattr_struct = gdb.lookup_type('struct pthread_condattr')
+            self.condattr = condattr.cast(condattr_struct)['value']
+            self.read_values()
+        except gdb.error:
+            # libpthread doesn't have debug symbols, thus we can't find the
+            # real struct type.  Just print the union members.
+            self.values.append(('__size', condattr['__size']))
+            self.values.append(('__align', condattr['__align']))
+
+    def to_string(self):
+        """gdb API function.
+
+        This is called from gdb when we try to print a pthread_condattr_t.
+        """
+
+        return 'pthread_condattr_t'
+
+    def children(self):
+        """gdb API function.
+
+        This is called from gdb when we try to print a pthread_condattr_t.
+        """
+
+        return self.values
+
+    def read_values(self):
+        """Read the condattr's info and store it in self.values.
+
+        The data contained in self.values will be returned by the Iterator
+        created in self.children.
+        """
+
+        clock_id = self.condattr & ((1 << COND_NWAITERS_SHIFT) - 1)
+
+        # clock_id must be casted to int because it's a gdb.Value
+        self.values.append(('Clock ID', CLOCK_IDS[int(clock_id)]))
+
+        if self.condattr & 1:
+            self.values.append(('Shared', 'Yes'))
+        else:
+            self.values.append(('Shared', 'No'))
+
+class RWLockPrinter(object):
+    """Pretty printer for pthread_rwlock_t."""
+
+    def __init__(self, rwlock):
+        """Initialize the printer's internal data structures.
+
+        Args:
+            rwlock: A gdb.value representing a pthread_rwlock_t.
+        """
+
+        data = rwlock['__data']
+        self.readers = data['__nr_readers']
+        self.queued_readers = data['__nr_readers_queued']
+        self.queued_writers = data['__nr_writers_queued']
+        self.writer_id = data['__writer']
+        self.shared = data['__shared']
+        self.prefers_writers = data['__flags']
+        self.values = []
+        self.read_values()
+
+    def to_string(self):
+        """gdb API function.
+
+        This is called from gdb when we try to print a pthread_rwlock_t.
+        """
+
+        return 'pthread_rwlock_t'
+
+    def children(self):
+        """gdb API function.
+
+        This is called from gdb when we try to print a pthread_rwlock_t.
+        """
+
+        return self.values
+
+    def read_values(self):
+        """Read the rwlock's info and store it in self.values.
+
+        The data contained in self.values will be returned by the Iterator
+        created in self.children.
+        """
+
+        self.read_status()
+        self.read_attributes()
+
+    def read_status(self):
+        """Read the status of the rwlock."""
+
+        # Right now pthread_rwlock_destroy doesn't do anything, so there's no
+        # way to check if an rwlock is destroyed.
+
+        if self.writer_id:
+            self.values.append(('Status', 'Locked (Write)'))
+            self.values.append(('Writer ID', self.writer_id))
+        elif self.readers:
+            self.values.append(('Status', 'Locked (Read)'))
+            self.values.append(('Readers', self.readers))
+        else:
+            self.values.append(('Status', 'Unlocked'))
+
+        self.values.append(('Queued readers', self.queued_readers))
+        self.values.append(('Queued writers', self.queued_writers))
+
+    def read_attributes(self):
+        """Read the attributes of the rwlock."""
+
+        if self.shared:
+            self.values.append(('Shared', 'Yes'))
+        else:
+            self.values.append(('Shared', 'No'))
+
+        if self.prefers_writers:
+            self.values.append(('Prefers', 'Writers'))
+        else:
+            self.values.append(('Prefers', 'Readers'))
+
+class RWLockAttributesPrinter(object):
+    """Pretty printer for pthread_rwlockattr_t.
+
+    In the NPTL this is a type that's always casted to
+    struct pthread_rwlockattr, which has two fields ('lockkind' and 'pshared')
+    containing the actual attributes.
+    """
+
+    def __init__(self, rwlockattr):
+        """Initialize the printer's internal data structures.
+
+        Args:
+            rwlockattr: A gdb.value representing a pthread_rwlockattr_t.
+        """
+
+        self.values = []
+
+        try:
+            rwlockattr_struct = gdb.lookup_type('struct pthread_rwlockattr')
+            self.rwlockattr = rwlockattr.cast(rwlockattr_struct)
+            self.read_values()
+        except gdb.error:
+            # libpthread doesn't have debug symbols, thus we can't find the
+            # real struct type.  Just print the union members.
+            self.values.append(('__size', rwlockattr['__size']))
+            self.values.append(('__align', rwlockattr['__align']))
+
+    def to_string(self):
+        """gdb API function.
+
+        This is called from gdb when we try to print a pthread_rwlockattr_t.
+        """
+
+        return 'pthread_rwlockattr_t'
+
+    def children(self):
+        """gdb API function.
+
+        This is called from gdb when we try to print a pthread_rwlockattr_t.
+        """
+
+        return self.values
+
+    def read_values(self):
+        """Read the rwlockattr's info and store it in self.values.
+
+        The data contained in self.values will be returned by the Iterator
+        created in self.children.
+        """
+
+        rwlock_type = self.rwlockattr['lockkind']
+        shared = self.rwlockattr['pshared']
+
+        if shared == PTHREAD_PROCESS_SHARED:
+            self.values.append(('Shared', 'Yes'))
+        else:
+            # PTHREAD_PROCESS_PRIVATE
+            self.values.append(('Shared', 'No'))
+
+        if (rwlock_type == PTHREAD_RWLOCK_PREFER_READER_NP or
+            rwlock_type == PTHREAD_RWLOCK_PREFER_WRITER_NP):
+            # This is a known bug.  Using PTHREAD_RWLOCK_PREFER_WRITER_NP will
+            # still make the rwlock prefer readers.
+            self.values.append(('Prefers', 'Readers'))
+        elif rwlock_type == PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP:
+            self.values.append(('Prefers', 'Writers'))
+
+def register(objfile):
+    """Register the pretty printers within the given objfile."""
+
+    printer = gdb.printing.RegexpCollectionPrettyPrinter('glibc-pthread-locks')
+
+    printer.add_printer('pthread_mutex_t', r'^pthread_mutex_t$',
+                        MutexPrinter)
+    printer.add_printer('pthread_mutexattr_t', r'^pthread_mutexattr_t$',
+                        MutexAttributesPrinter)
+    printer.add_printer('pthread_cond_t', r'^pthread_cond_t$',
+                        ConditionVariablePrinter)
+    printer.add_printer('pthread_condattr_t', r'^pthread_condattr_t$',
+                        ConditionVariableAttributesPrinter)
+    printer.add_printer('pthread_rwlock_t', r'^pthread_rwlock_t$',
+                        RWLockPrinter)
+    printer.add_printer('pthread_rwlockattr_t', r'^pthread_rwlockattr_t$',
+                        RWLockAttributesPrinter)
+
+    if objfile == None:
+        objfile = gdb
+
+    gdb.printing.register_pretty_printer(objfile, printer)
+
+register(gdb.current_objfile())
diff --git a/nptl/nptl_lock_constants.pysym b/nptl/nptl_lock_constants.pysym
new file mode 100644
index 0000000000..303ec61213
--- /dev/null
+++ b/nptl/nptl_lock_constants.pysym
@@ -0,0 +1,75 @@
+#include <pthreadP.h>
+
+-- Mutex types
+PTHREAD_MUTEX_KIND_MASK          PTHREAD_MUTEX_KIND_MASK_NP
+PTHREAD_MUTEX_NORMAL
+PTHREAD_MUTEX_RECURSIVE          PTHREAD_MUTEX_RECURSIVE_NP
+PTHREAD_MUTEX_ERRORCHECK         PTHREAD_MUTEX_ERRORCHECK_NP
+PTHREAD_MUTEX_ADAPTIVE_NP
+
+-- Mutex status
+-- These are hardcoded all over the code; there are no enums/macros for them.
+PTHREAD_MUTEX_DESTROYED         -1
+PTHREAD_MUTEX_UNLOCKED           0
+PTHREAD_MUTEX_LOCKED_NO_WAITERS  1
+
+-- For robust mutexes
+PTHREAD_MUTEX_INCONSISTENT
+PTHREAD_MUTEX_NOTRECOVERABLE
+FUTEX_OWNER_DIED
+
+-- For robust and PI mutexes
+FUTEX_WAITERS
+FUTEX_TID_MASK
+
+-- Mutex attributes
+PTHREAD_MUTEX_ROBUST_NORMAL_NP
+PTHREAD_MUTEX_PRIO_INHERIT_NP
+PTHREAD_MUTEX_PRIO_PROTECT_NP
+PTHREAD_MUTEX_PSHARED_BIT
+PTHREAD_MUTEX_PRIO_CEILING_SHIFT
+PTHREAD_MUTEX_PRIO_CEILING_MASK
+
+-- Mutex attribute flags
+PTHREAD_MUTEXATTR_PROTOCOL_SHIFT
+PTHREAD_MUTEXATTR_PROTOCOL_MASK
+PTHREAD_MUTEXATTR_PRIO_CEILING_MASK
+PTHREAD_MUTEXATTR_FLAG_ROBUST
+PTHREAD_MUTEXATTR_FLAG_PSHARED
+PTHREAD_MUTEXATTR_FLAG_BITS
+PTHREAD_MUTEX_NO_ELISION_NP
+
+-- Priority protocols
+PTHREAD_PRIO_NONE
+PTHREAD_PRIO_INHERIT
+PTHREAD_PRIO_PROTECT
+
+-- These values are hardcoded as well:
+-- Value of __mutex for shared condvars.
+PTHREAD_COND_SHARED             (void *)~0l
+
+-- Value of __total_seq for destroyed condvars.
+PTHREAD_COND_DESTROYED          -1ull
+
+-- __nwaiters encodes the number of threads waiting on a condvar
+-- and the clock ID.
+-- __nwaiters >> COND_NWAITERS_SHIFT gives us the number of waiters.
+COND_NWAITERS_SHIFT
+
+-- Condvar clock IDs
+CLOCK_REALTIME
+CLOCK_MONOTONIC
+CLOCK_PROCESS_CPUTIME_ID
+CLOCK_THREAD_CPUTIME_ID
+CLOCK_MONOTONIC_RAW
+CLOCK_REALTIME_COARSE
+CLOCK_MONOTONIC_COARSE
+
+-- Rwlock attributes
+PTHREAD_RWLOCK_PREFER_READER_NP
+PTHREAD_RWLOCK_PREFER_WRITER_NP
+PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP
+
+-- 'Shared' attribute values
+PTHREAD_PROCESS_PRIVATE
+PTHREAD_PROCESS_SHARED
diff --git a/nptl/test-cond-printers.c b/nptl/test-cond-printers.c
new file mode 100644
index 0000000000..0f2a5f4827
--- /dev/null
+++ b/nptl/test-cond-printers.c
@@ -0,0 +1,57 @@
+/* Helper program for testing the pthread_cond_t pretty printer.
+
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* Keep the calls to the pthread_* functions on separate lines to make it easy
+   to advance through the program using the gdb 'next' command.  */
+
+#include <time.h>
+#include <pthread.h>
+
+#define PASS 0
+#define FAIL 1
+
+static int test_status_destroyed (pthread_cond_t *condvar);
+
+int
+main (void)
+{
+  pthread_cond_t condvar;
+  pthread_condattr_t attr;
+  int result = FAIL;
+
+  if (pthread_condattr_init (&attr) == 0
+      && test_status_destroyed (&condvar) == PASS)
+    result = PASS;
+  /* Else, one of the pthread_cond* functions failed.  */
+
+  return result;
+}
+
+/* Initializes CONDVAR, then destroys it.  */
+static int
+test_status_destroyed (pthread_cond_t *condvar)
+{
+  int result = FAIL;
+
+  if (pthread_cond_init (condvar, NULL) == 0
+      && pthread_cond_destroy (condvar) == 0)
+    result = PASS; /* Test status (destroyed).  */
+
+  return result;
+}
diff --git a/nptl/test-cond-printers.py b/nptl/test-cond-printers.py
new file mode 100644
index 0000000000..af0e12eb97
--- /dev/null
+++ b/nptl/test-cond-printers.py
@@ -0,0 +1,50 @@
+# Common tests for the ConditionVariablePrinter class.
+#
+# Copyright (C) 2016 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+#
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# The GNU C Library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <http://www.gnu.org/licenses/>.
+
+import sys
+
+from test_printers_common import *
+
+test_source = sys.argv[1]
+test_bin = sys.argv[2]
+printer_files = sys.argv[3:]
+printer_names = ['global glibc-pthread-locks']
+
+try:
+    init_test(test_bin, printer_files, printer_names)
+    go_to_main()
+
+    var = 'condvar'
+    to_string = 'pthread_cond_t'
+
+    break_at(test_source, 'Test status (destroyed)')
+    continue_cmd() # Go to test_status_destroyed
+    test_printer(var, to_string, {'Status': 'Destroyed'})
+
+    continue_cmd() # Exit
+
+except (NoLineError, pexpect.TIMEOUT) as exception:
+    print('Error: {0}'.format(exception))
+    result = FAIL
+
+else:
+    print('Test succeeded.')
+    result = PASS
+
+exit(result)
diff --git a/nptl/test-condattr-printers.c b/nptl/test-condattr-printers.c
new file mode 100644
index 0000000000..4db4098827
--- /dev/null
+++ b/nptl/test-condattr-printers.c
@@ -0,0 +1,94 @@
+/* Helper program for testing the pthread_cond_t and pthread_condattr_t
+   pretty printers.
+
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* Keep the calls to the pthread_* functions on separate lines to make it easy
+   to advance through the program using the gdb 'next' command.  */
+
+#include <time.h>
+#include <pthread.h>
+
+#define PASS 0
+#define FAIL 1
+
+static int condvar_reinit (pthread_cond_t *condvar,
+			   const pthread_condattr_t *attr);
+static int test_setclock (pthread_cond_t *condvar, pthread_condattr_t *attr);
+static int test_setpshared (pthread_cond_t *condvar, pthread_condattr_t *attr);
+
+/* Need these so we don't have lines longer than 79 chars.  */
+#define SET_SHARED(attr, shared) pthread_condattr_setpshared (attr, shared)
+
+int
+main (void)
+{
+  pthread_cond_t condvar;
+  pthread_condattr_t attr;
+  int result = FAIL;
+
+  if (pthread_condattr_init (&attr) == 0
+      && pthread_cond_init (&condvar, NULL) == 0
+      && test_setclock (&condvar, &attr) == PASS
+      && test_setpshared (&condvar, &attr) == PASS)
+    result = PASS;
+  /* Else, one of the pthread_cond* functions failed.  */
+
+  return result;
+}
+
+/* Destroys CONDVAR and re-initializes it using ATTR.  */
+static int
+condvar_reinit (pthread_cond_t *condvar, const pthread_condattr_t *attr)
+{
+  int result = FAIL;
+
+  if (pthread_cond_destroy (condvar) == 0
+      && pthread_cond_init (condvar, attr) == 0)
+    result = PASS;
+
+  return result;
+}
+
+/* Tests setting the clock ID attribute.  */
+static int
+test_setclock (pthread_cond_t *condvar, pthread_condattr_t *attr)
+{
+  int result = FAIL;
+
+  if (pthread_condattr_setclock (attr, CLOCK_REALTIME) == 0 /* Set clock.  */
+      && condvar_reinit (condvar, attr) == PASS)
+    result = PASS;
+
+  return result;
+}
+
+/* Tests setting whether the condvar can be shared between processes.  */
+static int
+test_setpshared (pthread_cond_t *condvar, pthread_condattr_t *attr)
+{
+  int result = FAIL;
+
+  if (SET_SHARED (attr, PTHREAD_PROCESS_SHARED) == 0 /* Set shared.  */
+      && condvar_reinit (condvar, attr) == PASS
+      && SET_SHARED (attr, PTHREAD_PROCESS_PRIVATE) == 0
+      && condvar_reinit (condvar, attr) == PASS)
+    result = PASS;
+
+  return result;
+}
diff --git a/nptl/test-condattr-printers.py b/nptl/test-condattr-printers.py
new file mode 100644
index 0000000000..7ea01db158
--- /dev/null
+++ b/nptl/test-condattr-printers.py
@@ -0,0 +1,71 @@
+# Common tests for the ConditionVariablePrinter and
+# ConditionVariableAttributesPrinter classes.
+#
+# Copyright (C) 2016 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+#
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# The GNU C Library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <http://www.gnu.org/licenses/>.
+
+import sys
+
+from test_printers_common import *
+
+test_source = sys.argv[1]
+test_bin = sys.argv[2]
+printer_files = sys.argv[3:]
+printer_names = ['global glibc-pthread-locks']
+
+try:
+    init_test(test_bin, printer_files, printer_names)
+    go_to_main()
+
+    check_debug_symbol('struct pthread_condattr')
+
+    condvar_var = 'condvar'
+    condvar_to_string = 'pthread_cond_t'
+
+    attr_var = 'attr'
+    attr_to_string = 'pthread_condattr_t'
+
+    break_at(test_source, 'Set clock')
+    continue_cmd() # Go to test_setclock
+    next_cmd(2)
+    test_printer(condvar_var, condvar_to_string, {'Clock ID': 'CLOCK_REALTIME'})
+    test_printer(attr_var, attr_to_string, {'Clock ID': 'CLOCK_REALTIME'})
+
+    break_at(test_source, 'Set shared')
+    continue_cmd() # Go to test_setpshared
+    next_cmd(2)
+    test_printer(condvar_var, condvar_to_string, {'Shared': 'Yes'})
+    test_printer(attr_var, attr_to_string, {'Shared': 'Yes'})
+    next_cmd(2)
+    test_printer(condvar_var, condvar_to_string, {'Shared': 'No'})
+    test_printer(attr_var, attr_to_string, {'Shared': 'No'})
+
+    continue_cmd() # Exit
+
+except (NoLineError, pexpect.TIMEOUT) as exception:
+    print('Error: {0}'.format(exception))
+    result = FAIL
+
+except DebugError as exception:
+    print(exception)
+    result = UNSUPPORTED
+
+else:
+    print('Test succeeded.')
+    result = PASS
+
+exit(result)
diff --git a/nptl/test-mutex-printers.c b/nptl/test-mutex-printers.c
new file mode 100644
index 0000000000..b973e82840
--- /dev/null
+++ b/nptl/test-mutex-printers.c
@@ -0,0 +1,151 @@
+/* Helper program for testing the pthread_mutex_t pretty printer.
+
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* Keep the calls to the pthread_* functions on separate lines to make it easy
+   to advance through the program using the gdb 'next' command.  */
+
+#include <stdlib.h>
+#include <errno.h>
+#include <pthread.h>
+
+#define PASS 0
+#define FAIL 1
+
+static int test_status_destroyed (pthread_mutex_t *mutex);
+static int test_status_no_robust (pthread_mutex_t *mutex,
+				  pthread_mutexattr_t *attr);
+static int test_status_robust (pthread_mutex_t *mutex,
+			       pthread_mutexattr_t *attr);
+static int test_locking_state_robust (pthread_mutex_t *mutex);
+static void *thread_func (void *arg);
+static int test_recursive_locks (pthread_mutex_t *mutex,
+				 pthread_mutexattr_t *attr);
+
+int
+main (void)
+{
+  pthread_mutex_t mutex;
+  pthread_mutexattr_t attr;
+  int result = FAIL;
+
+  if (pthread_mutexattr_init (&attr) == 0
+      && test_status_destroyed (&mutex) == PASS
+      && test_status_no_robust (&mutex, &attr) == PASS
+      && test_status_robust (&mutex, &attr) == PASS
+      && test_recursive_locks (&mutex, &attr) == PASS)
+    result = PASS;
+  /* Else, one of the pthread_mutex* functions failed.  */
+
+  return result;
+}
+
+/* Initializes MUTEX, then destroys it.  */
+static int
+test_status_destroyed (pthread_mutex_t *mutex)
+{
+  int result = FAIL;
+
+  if (pthread_mutex_init (mutex, NULL) == 0
+      && pthread_mutex_destroy (mutex) == 0)
+    result = PASS; /* Test status (destroyed).  */
+
+  return result;
+}
+
+/* Tests locking of non-robust mutexes.  */
+static int
+test_status_no_robust (pthread_mutex_t *mutex, pthread_mutexattr_t *attr)
+{
+  int result = FAIL;
+
+  if (pthread_mutexattr_setrobust (attr, PTHREAD_MUTEX_STALLED) == 0
+      && pthread_mutex_init (mutex, attr) == 0
+      && pthread_mutex_lock (mutex) == 0 /* Test status (non-robust).  */
+      && pthread_mutex_unlock (mutex) == 0
+      && pthread_mutex_destroy (mutex) == 0)
+    result = PASS;
+
+  return result;
+}
+
+/* Tests locking of robust mutexes.  */
+static int
+test_status_robust (pthread_mutex_t *mutex, pthread_mutexattr_t *attr)
+{
+  int result = FAIL;
+
+  if (pthread_mutexattr_setrobust (attr, PTHREAD_MUTEX_ROBUST) == 0
+      && pthread_mutex_init (mutex, attr) == 0
+      && test_locking_state_robust (mutex) == PASS /* Test status (robust).  */
+      && pthread_mutex_destroy (mutex) == 0)
+    result = PASS;
+
+  return result;
+}
+
+/* Tests locking and state corruption of robust mutexes.  We'll mark it as
+   inconsistent, then not recoverable.  */
+static int
+test_locking_state_robust (pthread_mutex_t *mutex)
+{
+  int result = FAIL;
+  pthread_t thread;
+
+  if (pthread_create (&thread, NULL, thread_func, mutex) == 0 /* Create.  */
+      && pthread_join (thread, NULL) == 0
+      && pthread_mutex_lock (mutex) == EOWNERDEAD /* Test locking (robust).  */
+      && pthread_mutex_unlock (mutex) == 0)
+    result = PASS;
+
+  return result;
+}
+
+/* Function to be called by the child thread when testing robust mutexes.  */
+static void *
+thread_func (void *arg)
+{
+  pthread_mutex_t *mutex = (pthread_mutex_t *)arg;
+
+  if (pthread_mutex_lock (mutex) != 0) /* Thread function.  */
+    exit (FAIL);
+
+  /* Thread terminates without unlocking the mutex, thus marking it as
+     inconsistent.  */
+  return NULL;
+}
+
+/* Tests locking the mutex multiple times in a row.  */
+static int
+test_recursive_locks (pthread_mutex_t *mutex, pthread_mutexattr_t *attr)
+{
+  int result = FAIL;
+
+  if (pthread_mutexattr_settype (attr, PTHREAD_MUTEX_RECURSIVE) == 0
+      && pthread_mutex_init (mutex, attr) == 0
+      && pthread_mutex_lock (mutex) == 0
+      && pthread_mutex_lock (mutex) == 0
+      && pthread_mutex_lock (mutex) == 0 /* Test recursive locks.  */
+      && pthread_mutex_unlock (mutex) == 0
+      && pthread_mutex_unlock (mutex) == 0
+      && pthread_mutex_unlock (mutex) == 0
+      && pthread_mutex_destroy (mutex) == 0)
+    result = PASS;
+
+  return result;
+}
diff --git a/nptl/test-mutex-printers.py b/nptl/test-mutex-printers.py
new file mode 100644
index 0000000000..7f542adcd7
--- /dev/null
+++ b/nptl/test-mutex-printers.py
@@ -0,0 +1,97 @@
+# Tests for the MutexPrinter class.
+#
+# Copyright (C) 2016 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+#
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# The GNU C Library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <http://www.gnu.org/licenses/>.
+
+import sys
+
+from test_printers_common import *
+
+test_source = sys.argv[1]
+test_bin = sys.argv[2]
+printer_files = sys.argv[3:]
+printer_names = ['global glibc-pthread-locks']
+
+try:
+    init_test(test_bin, printer_files, printer_names)
+    go_to_main()
+
+    var = 'mutex'
+    to_string = 'pthread_mutex_t'
+
+    break_at(test_source, 'Test status (destroyed)')
+    continue_cmd() # Go to test_status_destroyed
+    test_printer(var, to_string, {'Status': 'Destroyed'})
+
+    break_at(test_source, 'Test status (non-robust)')
+    continue_cmd() # Go to test_status_no_robust
+    test_printer(var, to_string, {'Status': 'Unlocked'})
+    next_cmd()
+    thread_id = get_current_thread_lwpid()
+    test_printer(var, to_string, {'Status': 'Locked, possibly with no waiters',
+                                  'Owner ID': thread_id})
+
+    break_at(test_source, 'Test status (robust)')
+    continue_cmd() # Go to test_status_robust
+    test_printer(var, to_string, {'Status': 'Unlocked'})
+
+    # We'll now test the robust mutex locking states.  We'll create a new
+    # thread that will lock a robust mutex and exit without unlocking it.
+    break_at(test_source, 'Create')
+    continue_cmd() # Go to test_locking_state_robust
+    # Set a breakpoint for the new thread to hit.
+    break_at(test_source, 'Thread function')
+    continue_cmd()
+    # By now the new thread is created and has hit its breakpoint.
+    set_scheduler_locking(True)
+    parent = 1
+    child = 2
+    select_thread(child)
+    child_id = get_current_thread_lwpid()
+    # We've got the new thread's ID.
+    select_thread(parent)
+    # Make the new thread finish its function while we wait.
+    continue_cmd(thread=child)
+    # The new thread should be dead by now.
+    break_at(test_source, 'Test locking (robust)')
+    continue_cmd()
+    test_printer(var, to_string, {'Owner ID': r'{0} \(dead\)'.format(child_id)})
+    # Try to lock and unlock the mutex.
+    next_cmd()
+    test_printer(var, to_string, {'Owner ID': thread_id,
+                           'State protected by this mutex': 'Inconsistent'})
+    next_cmd()
+    test_printer(var, to_string, {'Status': 'Unlocked',
+                        'State protected by this mutex': 'Not recoverable'})
+    set_scheduler_locking(False)
+
+    break_at(test_source, 'Test recursive locks')
+    continue_cmd() # Go to test_recursive_locks
+    test_printer(var, to_string, {'Times locked recursively': '2'})
+    next_cmd()
+    test_printer(var, to_string, {'Times locked recursively': '3'})
+    continue_cmd() # Exit
+
+except (NoLineError, pexpect.TIMEOUT) as exception:
+    print('Error: {0}'.format(exception))
+    result = FAIL
+
+else:
+    print('Test succeeded.')
+    result = PASS
+
+exit(result)
diff --git a/nptl/test-mutexattr-printers.c b/nptl/test-mutexattr-printers.c
new file mode 100644
index 0000000000..9ecfff76c3
--- /dev/null
+++ b/nptl/test-mutexattr-printers.c
@@ -0,0 +1,144 @@
+/* Helper program for testing the pthread_mutex_t and pthread_mutexattr_t
+   pretty printers.
+
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* Keep the calls to the pthread_* functions on separate lines to make it easy
+   to advance through the program using the gdb 'next' command.  */
+
+#include <pthread.h>
+
+#define PASS 0
+#define FAIL 1
+#define PRIOCEILING 42
+
+/* Need these so we don't have lines longer than 79 chars.  */
+#define SET_TYPE(attr, type) pthread_mutexattr_settype (attr, type)
+#define SET_ROBUST(attr, robust) pthread_mutexattr_setrobust (attr, robust)
+#define SET_SHARED(attr, shared) pthread_mutexattr_setpshared (attr, shared)
+#define SET_PROTOCOL(attr, protocol) \
+	pthread_mutexattr_setprotocol (attr, protocol)
+#define SET_PRIOCEILING(mutex, prioceiling, old_ceiling) \
+	pthread_mutex_setprioceiling (mutex, prioceiling, old_ceiling)
+
+static int mutex_reinit (pthread_mutex_t *mutex,
+			 const pthread_mutexattr_t *attr);
+static int test_settype (pthread_mutex_t *mutex, pthread_mutexattr_t *attr);
+static int test_setrobust (pthread_mutex_t *mutex, pthread_mutexattr_t *attr);
+static int test_setpshared (pthread_mutex_t *mutex, pthread_mutexattr_t *attr);
+static int test_setprotocol (pthread_mutex_t *mutex,
+			     pthread_mutexattr_t *attr);
+
+int
+main (void)
+{
+  pthread_mutex_t mutex;
+  pthread_mutexattr_t attr;
+  int result = FAIL;
+
+  if (pthread_mutexattr_init (&attr) == 0
+      && pthread_mutex_init (&mutex, NULL) == 0
+      && test_settype (&mutex, &attr) == PASS
+      && test_setrobust (&mutex, &attr) == PASS
+      && test_setpshared (&mutex, &attr) == PASS
+      && test_setprotocol (&mutex, &attr) == PASS)
+    result = PASS;
+  /* Else, one of the pthread_mutex* functions failed.  */
+
+  return result;
+}
+
+/* Destroys MUTEX and re-initializes it using ATTR.  */
+static int
+mutex_reinit (pthread_mutex_t *mutex, const pthread_mutexattr_t *attr)
+{
+  int result = FAIL;
+
+  if (pthread_mutex_destroy (mutex) == 0
+      && pthread_mutex_init (mutex, attr) == 0)
+    result = PASS;
+
+  return result;
+}
+
+/* Tests setting the mutex type.  */
+static int
+test_settype (pthread_mutex_t *mutex, pthread_mutexattr_t *attr)
+{
+  int result = FAIL;
+
+  if (SET_TYPE (attr, PTHREAD_MUTEX_ERRORCHECK) == 0 /* Set type.  */
+      && mutex_reinit (mutex, attr) == 0
+      && SET_TYPE (attr, PTHREAD_MUTEX_RECURSIVE) == 0
+      && mutex_reinit (mutex, attr) == 0
+      && SET_TYPE (attr, PTHREAD_MUTEX_NORMAL) == 0
+      && mutex_reinit (mutex, attr) == 0)
+    result = PASS;
+
+  return result;
+}
+
+/* Tests setting whether the mutex is robust.  */
+static int
+test_setrobust (pthread_mutex_t *mutex, pthread_mutexattr_t *attr)
+{
+  int result = FAIL;
+
+  if (SET_ROBUST (attr, PTHREAD_MUTEX_ROBUST) == 0 /* Set robust.  */
+      && mutex_reinit (mutex, attr) == 0
+      && SET_ROBUST (attr, PTHREAD_MUTEX_STALLED) == 0
+      && mutex_reinit (mutex, attr) == 0)
+    result = PASS;
+
+  return result;
+}
+
+/* Tests setting whether the mutex can be shared between processes.  */
+static int
+test_setpshared (pthread_mutex_t *mutex, pthread_mutexattr_t *attr)
+{
+  int result = FAIL;
+
+  if (SET_SHARED (attr, PTHREAD_PROCESS_SHARED) == 0 /* Set shared.  */
+      && mutex_reinit (mutex, attr) == 0
+      && SET_SHARED (attr, PTHREAD_PROCESS_PRIVATE) == 0
+      && mutex_reinit (mutex, attr) == 0)
+    result = PASS;
+
+  return result;
+}
+
+/* Tests setting the mutex protocol and, for Priority Protect, the Priority
+   Ceiling.  */
+static int
+test_setprotocol (pthread_mutex_t *mutex, pthread_mutexattr_t *attr)
+{
+  int result = FAIL;
+  int old_prioceiling;
+
+  if (SET_PROTOCOL (attr, PTHREAD_PRIO_INHERIT) == 0 /* Set protocol.  */
+      && mutex_reinit (mutex, attr) == 0
+      && SET_PROTOCOL (attr, PTHREAD_PRIO_PROTECT) == 0
+      && mutex_reinit (mutex, attr) == 0
+      && SET_PRIOCEILING(mutex, PRIOCEILING, &old_prioceiling) == 0
+      && SET_PROTOCOL (attr, PTHREAD_PRIO_NONE) == 0
+      && mutex_reinit (mutex, attr) == 0)
+    result = PASS;
+
+  return result;
+}
diff --git a/nptl/test-mutexattr-printers.py b/nptl/test-mutexattr-printers.py
new file mode 100644
index 0000000000..4464723fbe
--- /dev/null
+++ b/nptl/test-mutexattr-printers.py
@@ -0,0 +1,101 @@
+# Common tests for the MutexPrinter and MutexAttributesPrinter classes.
+#
+# Copyright (C) 2016 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+#
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# The GNU C Library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <http://www.gnu.org/licenses/>.
+
+import sys
+
+from test_printers_common import *
+
+test_source = sys.argv[1]
+test_bin = sys.argv[2]
+printer_files = sys.argv[3:]
+printer_names = ['global glibc-pthread-locks']
+PRIOCEILING = 42
+
+try:
+    init_test(test_bin, printer_files, printer_names)
+    go_to_main()
+
+    check_debug_symbol('struct pthread_mutexattr')
+
+    mutex_var = 'mutex'
+    mutex_to_string = 'pthread_mutex_t'
+
+    attr_var = 'attr'
+    attr_to_string = 'pthread_mutexattr_t'
+
+    break_at(test_source, 'Set type')
+    continue_cmd() # Go to test_settype
+    next_cmd(2)
+    test_printer(attr_var, attr_to_string, {'Type': 'Error check'})
+    test_printer(mutex_var, mutex_to_string, {'Type': 'Error check'})
+    next_cmd(2)
+    test_printer(attr_var, attr_to_string, {'Type': 'Recursive'})
+    test_printer(mutex_var, mutex_to_string, {'Type': 'Recursive'})
+    next_cmd(2)
+    test_printer(attr_var, attr_to_string, {'Type': 'Normal'})
+    test_printer(mutex_var, mutex_to_string, {'Type': 'Normal'})
+
+    break_at(test_source, 'Set robust')
+    continue_cmd() # Go to test_setrobust
+    next_cmd(2)
+    test_printer(attr_var, attr_to_string, {'Robust': 'Yes'})
+    test_printer(mutex_var, mutex_to_string, {'Robust': 'Yes'})
+    next_cmd(2)
+    test_printer(attr_var, attr_to_string, {'Robust': 'No'})
+    test_printer(mutex_var, mutex_to_string, {'Robust': 'No'})
+
+    break_at(test_source, 'Set shared')
+    continue_cmd() # Go to test_setpshared
+    next_cmd(2)
+    test_printer(attr_var, attr_to_string, {'Shared': 'Yes'})
+    test_printer(mutex_var, mutex_to_string, {'Shared': 'Yes'})
+    next_cmd(2)
+    test_printer(attr_var, attr_to_string, {'Shared': 'No'})
+    test_printer(mutex_var, mutex_to_string, {'Shared': 'No'})
+
+    break_at(test_source, 'Set protocol')
+    continue_cmd() # Go to test_setprotocol
+    next_cmd(2)
+    test_printer(attr_var, attr_to_string, {'Protocol': 'Priority inherit'})
+    test_printer(mutex_var, mutex_to_string, {'Protocol': 'Priority inherit'})
+    next_cmd(2)
+    test_printer(attr_var, attr_to_string, {'Protocol': 'Priority protect'})
+    test_printer(mutex_var, mutex_to_string, {'Protocol': 'Priority protect'})
+    next_cmd(2)
+    test_printer(mutex_var, mutex_to_string, {'Priority ceiling':
+                                              str(PRIOCEILING)})
+    next_cmd()
+    test_printer(attr_var, attr_to_string, {'Protocol': 'None'})
+    test_printer(mutex_var, mutex_to_string, {'Protocol': 'None'})
+
+    continue_cmd() # Exit
+
+except (NoLineError, pexpect.TIMEOUT) as exception:
+    print('Error: {0}'.format(exception))
+    result = FAIL
+
+except DebugError as exception:
+    print(exception)
+    result = UNSUPPORTED
+
+else:
+    print('Test succeeded.')
+    result = PASS
+
+exit(result)
diff --git a/nptl/test-rwlock-printers.c b/nptl/test-rwlock-printers.c
new file mode 100644
index 0000000000..dbbe9b80d6
--- /dev/null
+++ b/nptl/test-rwlock-printers.c
@@ -0,0 +1,78 @@
+/* Helper program for testing the pthread_rwlock_t pretty printer.
+
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* Keep the calls to the pthread_* functions on separate lines to make it easy
+   to advance through the program using the gdb 'next' command.  */
+
+#include <pthread.h>
+
+#define PASS 0
+#define FAIL 1
+
+static int test_locking_reader (pthread_rwlock_t *rwlock);
+static int test_locking_writer (pthread_rwlock_t *rwlock);
+
+int
+main (void)
+{
+  pthread_rwlock_t rwlock;
+
+  int result = FAIL;
+
+  if (test_locking_reader (&rwlock) == PASS
+      && test_locking_writer (&rwlock) == PASS)
+    result = PASS;
+  /* Else, one of the pthread_rwlock* functions failed.  */
+
+  return result;
+}
+
+/* Tests locking the rwlock multiple times as a reader.  */
+static int
+test_locking_reader (pthread_rwlock_t *rwlock)
+{
+  int result = FAIL;
+
+  if (pthread_rwlock_init (rwlock, NULL) == 0
+      && pthread_rwlock_rdlock (rwlock) == 0 /* Test locking (reader).  */
+      && pthread_rwlock_rdlock (rwlock) == 0
+      && pthread_rwlock_rdlock (rwlock) == 0
+      && pthread_rwlock_unlock (rwlock) == 0
+      && pthread_rwlock_unlock (rwlock) == 0
+      && pthread_rwlock_unlock (rwlock) == 0
+      && pthread_rwlock_destroy (rwlock) == 0)
+    result = PASS;
+
+  return result;
+}
+
+/* Tests locking the rwlock as a writer.  */
+static int
+test_locking_writer (pthread_rwlock_t *rwlock)
+{
+  int result = FAIL;
+
+  if (pthread_rwlock_init (rwlock, NULL) == 0
+      && pthread_rwlock_wrlock (rwlock) == 0 /* Test locking (writer).  */
+      && pthread_rwlock_unlock (rwlock) == 0
+      && pthread_rwlock_destroy (rwlock) == 0)
+    result = PASS;
+
+  return result;
+}
diff --git a/nptl/test-rwlock-printers.py b/nptl/test-rwlock-printers.py
new file mode 100644
index 0000000000..b972fa60d0
--- /dev/null
+++ b/nptl/test-rwlock-printers.py
@@ -0,0 +1,64 @@
+# Common tests for the RWLockPrinter class.
+#
+# Copyright (C) 2016 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+#
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# The GNU C Library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <http://www.gnu.org/licenses/>.
+
+import sys
+
+from test_printers_common import *
+
+test_source = sys.argv[1]
+test_bin = sys.argv[2]
+printer_files = sys.argv[3:]
+printer_names = ['global glibc-pthread-locks']
+
+try:
+    init_test(test_bin, printer_files, printer_names)
+    go_to_main()
+
+    var = 'rwlock'
+    to_string = 'pthread_rwlock_t'
+
+    break_at(test_source, 'Test locking (reader)')
+    continue_cmd() # Go to test_locking_reader
+    test_printer(var, to_string, {'Status': 'Unlocked'})
+    next_cmd()
+    test_printer(var, to_string, {'Status': r'Locked \(Read\)', 'Readers': '1'})
+    next_cmd()
+    test_printer(var, to_string, {'Readers': '2'})
+    next_cmd()
+    test_printer(var, to_string, {'Readers': '3'})
+
+    break_at(test_source, 'Test locking (writer)')
+    continue_cmd() # Go to test_locking_writer
+    test_printer(var, to_string, {'Status': 'Unlocked'})
+    next_cmd()
+    thread_id = get_current_thread_lwpid()
+    test_printer(var, to_string, {'Status': r'Locked \(Write\)',
+                                  'Writer ID': thread_id})
+
+    continue_cmd() # Exit
+
+except (NoLineError, pexpect.TIMEOUT) as exception:
+    print('Error: {0}'.format(exception))
+    result = FAIL
+
+else:
+    print('Test succeeded.')
+    result = PASS
+
+exit(result)
diff --git a/nptl/test-rwlockattr-printers.c b/nptl/test-rwlockattr-printers.c
new file mode 100644
index 0000000000..d12facf41c
--- /dev/null
+++ b/nptl/test-rwlockattr-printers.c
@@ -0,0 +1,98 @@
+/* Helper program for testing the pthread_rwlock_t and pthread_rwlockattr_t
+   pretty printers.
+
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* Keep the calls to the pthread_* functions on separate lines to make it easy
+   to advance through the program using the gdb 'next' command.  */
+
+#include <pthread.h>
+
+#define PASS 0
+#define FAIL 1
+
+/* Need these so we don't have lines longer than 79 chars.  */
+#define SET_KIND(attr, kind) pthread_rwlockattr_setkind_np (attr, kind)
+#define SET_SHARED(attr, shared) pthread_rwlockattr_setpshared (attr, shared)
+
+static int rwlock_reinit (pthread_rwlock_t *rwlock,
+			  const pthread_rwlockattr_t *attr);
+static int test_setkind_np (pthread_rwlock_t *rwlock,
+			    pthread_rwlockattr_t *attr);
+static int test_setpshared (pthread_rwlock_t *rwlock,
+			    pthread_rwlockattr_t *attr);
+
+int
+main (void)
+{
+  pthread_rwlock_t rwlock;
+  pthread_rwlockattr_t attr;
+  int result = FAIL;
+
+  if (pthread_rwlockattr_init (&attr) == 0
+      && pthread_rwlock_init (&rwlock, NULL) == 0
+      && test_setkind_np (&rwlock, &attr) == PASS
+      && test_setpshared (&rwlock, &attr) == PASS)
+    result = PASS;
+  /* Else, one of the pthread_rwlock* functions failed.  */
+
+  return result;
+}
+
+/* Destroys RWLOCK and re-initializes it using ATTR.  */
+static int
+rwlock_reinit (pthread_rwlock_t *rwlock, const pthread_rwlockattr_t *attr)
+{
+  int result = FAIL;
+
+  if (pthread_rwlock_destroy (rwlock) == 0
+      && pthread_rwlock_init (rwlock, attr) == 0)
+    result = PASS;
+
+  return result;
+}
+
+/* Tests setting whether the rwlock prefers readers or writers.  */
+static int
+test_setkind_np (pthread_rwlock_t *rwlock, pthread_rwlockattr_t *attr)
+{
+  int result = FAIL;
+
+  if (SET_KIND (attr, PTHREAD_RWLOCK_PREFER_READER_NP) == 0 /* Set kind.  */
+      && rwlock_reinit (rwlock, attr) == PASS
+      && SET_KIND (attr, PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP) == 0
+      && rwlock_reinit (rwlock, attr) == PASS)
+    result = PASS;
+
+  return result;
+}
+
+/* Tests setting whether the rwlock can be shared between processes.  */
+static int
+test_setpshared (pthread_rwlock_t *rwlock, pthread_rwlockattr_t *attr)
+{
+  int result = FAIL;
+
+  if (SET_SHARED (attr, PTHREAD_PROCESS_SHARED) == 0 /* Set shared.  */
+      && rwlock_reinit (rwlock, attr) == PASS
+      && SET_SHARED (attr, PTHREAD_PROCESS_PRIVATE) == 0
+      && rwlock_reinit (rwlock, attr) == PASS)
+    result = PASS;
+
+  return result;
+}
diff --git a/nptl/test-rwlockattr-printers.py b/nptl/test-rwlockattr-printers.py
new file mode 100644
index 0000000000..1ca2dc6c33
--- /dev/null
+++ b/nptl/test-rwlockattr-printers.py
@@ -0,0 +1,73 @@
+# Common tests for the RWLockPrinter and RWLockAttributesPrinter classes.
+#
+# Copyright (C) 2016 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+#
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# The GNU C Library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <http://www.gnu.org/licenses/>.
+
+import sys
+
+from test_printers_common import *
+
+test_source = sys.argv[1]
+test_bin = sys.argv[2]
+printer_files = sys.argv[3:]
+printer_names = ['global glibc-pthread-locks']
+
+try:
+    init_test(test_bin, printer_files, printer_names)
+    go_to_main()
+
+    check_debug_symbol('struct pthread_rwlockattr')
+
+    rwlock_var = 'rwlock'
+    rwlock_to_string = 'pthread_rwlock_t'
+
+    attr_var = 'attr'
+    attr_to_string = 'pthread_rwlockattr_t'
+
+    break_at(test_source, 'Set kind')
+    continue_cmd() # Go to test_setkind_np
+    next_cmd(2)
+    test_printer(rwlock_var, rwlock_to_string, {'Prefers': 'Readers'})
+    test_printer(attr_var, attr_to_string, {'Prefers': 'Readers'})
+    next_cmd(2)
+    test_printer(rwlock_var, rwlock_to_string, {'Prefers': 'Writers'})
+    test_printer(attr_var, attr_to_string, {'Prefers': 'Writers'})
+
+    break_at(test_source, 'Set shared')
+    continue_cmd() # Go to test_setpshared
+    next_cmd(2)
+    test_printer(rwlock_var, rwlock_to_string, {'Shared': 'Yes'})
+    test_printer(attr_var, attr_to_string, {'Shared': 'Yes'})
+    next_cmd(2)
+    test_printer(rwlock_var, rwlock_to_string, {'Shared': 'No'})
+    test_printer(attr_var, attr_to_string, {'Shared': 'No'})
+
+    continue_cmd() # Exit
+
+except (NoLineError, pexpect.TIMEOUT) as exception:
+    print('Error: {0}'.format(exception))
+    result = FAIL
+
+except DebugError as exception:
+    print(exception)
+    result = UNSUPPORTED
+
+else:
+    print('Test succeeded.')
+    result = PASS
+
+exit(result)
diff --git a/scripts/gen-py-const.awk b/scripts/gen-py-const.awk
new file mode 100644
index 0000000000..4586f59d89
--- /dev/null
+++ b/scripts/gen-py-const.awk
@@ -0,0 +1,118 @@
+# Script to generate constants for Python pretty printers.
+#
+# Copyright (C) 2016 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+#
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# The GNU C Library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <http://www.gnu.org/licenses/>.
+
+# This script is a smaller version of the clever gen-asm-const.awk hack used to
+# generate ASM constants from .sym files.  We'll use this to generate constants
+# for Python pretty printers.
+#
+# The input to this script are .pysym files that look like:
+# #C_Preprocessor_Directive...
+# NAME1
+# NAME2 expression...
+#
+# A line giving just a name implies an expression consisting of just that name.
+# Comments start with '--'.
+#
+# The output of this script is a 'dummy' function containing 'asm' declarations
+# for each non-preprocessor line in the .pysym file.  The expression values
+# will appear as input operands to the 'asm' declaration.  For example, if we
+# have:
+#
+# /* header.h */
+# #define MACRO 42
+#
+# struct S {
+#     char c1;
+#     char c2;
+#     char c3;
+# };
+#
+# enum E {
+#     ZERO,
+#     ONE
+# };
+#
+# /* symbols.pysym */
+# #include <stddef.h>
+# #include "header.h"
+# -- This is a comment
+# MACRO
+# C3_OFFSET offsetof(struct S, c3)
+# E_ONE ONE
+#
+# the output will be:
+#
+# #include <stddef.h>
+# #include "header.h"
+# void dummy(void)
+# {
+#   asm ("@name@MACRO@value@%0@" : : "i" (MACRO));
+#   asm ("@name@C3_OFFSET@value@%0@" : : "i" (offsetof(struct S, c3)));
+#   asm ("@name@E_ONE@value@%0@" : : "i" (ONE));
+# }
+#
+# We'll later feed this output to gcc -S.  Since '-S' tells gcc to compile but
+# not assemble, gcc will output something like:
+#
+# dummy:
+# 	...
+# 	@name@MACRO@value@$42@
+# 	@name@C3_OFFSET@value@$2@
+# 	@name@E_ONE@value@$1@
+#
+# Finally, we can process that output to extract the constant values.
+# Notice gcc may prepend a special character such as '$' to each value.
+
+# found_symbol indicates whether we found a non-comment, non-preprocessor line.
+BEGIN { found_symbol = 0 }
+
+# C preprocessor directives go straight through.
+/^#/ { print; next; }
+
+# Skip comments.
+/--/ { next; }
+
+# Trim leading whitespace.
+{ sub(/^[[:blank:]]*/, ""); }
+
+# If we found a non-comment, non-preprocessor line, print the 'dummy' function
+# header.
+NF > 0 && !found_symbol {
+    print "void dummy(void)\n{";
+    found_symbol = 1;
+}
+
+# If the line contains just a name, duplicate it so we can use that name
+# as the value of the expression.
+NF == 1 { sub(/^.*$/, "& &"); }
+
+# If a line contains a name and an expression...
+NF > 1 {
+    name = $1;
+
+    # Remove any characters before the second field.
+    sub(/^[^[:blank:]]+[[:blank:]]+/, "");
+
+    # '$0' ends up being everything that appeared after the first field
+    # separator.
+    printf "  asm (\"@name@%s@value@%0@\" : : \"i\" (%s));\n", name, $0;
+}
+
+# Close the 'dummy' function.
+END { if (found_symbol) print "}"; }
diff --git a/scripts/test_printers_common.py b/scripts/test_printers_common.py
new file mode 100644
index 0000000000..c79d7e3be2
--- /dev/null
+++ b/scripts/test_printers_common.py
@@ -0,0 +1,364 @@
+# Common functions and variables for testing the Python pretty printers.
+#
+# Copyright (C) 2016 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+#
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# The GNU C Library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <http://www.gnu.org/licenses/>.
+
+"""These tests require PExpect 4.0 or newer.
+
+Exported constants:
+    PASS, FAIL, UNSUPPORTED (int): Test exit codes, as per evaluate-test.sh.
+"""
+
+import os
+import re
+from test_printers_exceptions import *
+
+PASS = 0
+FAIL = 1
+UNSUPPORTED = 77
+
+gdb_bin = 'gdb'
+gdb_options = '-q -nx'
+gdb_invocation = '{0} {1}'.format(gdb_bin, gdb_options)
+pexpect_min_version = 4
+gdb_min_version = (7, 8)
+encoding = 'utf-8'
+
+try:
+    import pexpect
+except ImportError:
+    print('PExpect 4.0 or newer must be installed to test the pretty printers.')
+    exit(UNSUPPORTED)
+
+pexpect_version = pexpect.__version__.split('.')[0]
+
+if int(pexpect_version) < pexpect_min_version:
+    print('PExpect 4.0 or newer must be installed to test the pretty printers.')
+    exit(UNSUPPORTED)
+
+if not pexpect.which(gdb_bin):
+    print('gdb 7.8 or newer must be installed to test the pretty printers.')
+    exit(UNSUPPORTED)
+
+timeout = 5
+TIMEOUTFACTOR = os.environ.get('TIMEOUTFACTOR')
+
+if TIMEOUTFACTOR:
+    timeout = int(TIMEOUTFACTOR)
+
+try:
+    # Check the gdb version.
+    version_cmd = '{0} --version'.format(gdb_invocation, timeout=timeout)
+    gdb_version_out = pexpect.run(version_cmd, encoding=encoding)
+
+    # The gdb version string is "GNU gdb <PKGVERSION><version>", where
+    # PKGVERSION can be any text.  We assume that there'll always be a space
+    # between PKGVERSION and the version number for the sake of the regexp.
+    version_match = re.search(r'GNU gdb .* ([1-9]+)\.([0-9]+)', gdb_version_out)
+
+    if not version_match:
+        print('The gdb version string (gdb -v) is incorrectly formatted.')
+        exit(UNSUPPORTED)
+
+    gdb_version = (int(version_match.group(1)), int(version_match.group(2)))
+
+    if gdb_version < gdb_min_version:
+        print('gdb 7.8 or newer must be installed to test the pretty printers.')
+        exit(UNSUPPORTED)
+
+    # Check if gdb supports Python.
+    gdb_python_cmd = '{0} -ex "python import os" -batch'.format(gdb_invocation,
+                                                                timeout=timeout)
+    gdb_python_error = pexpect.run(gdb_python_cmd, encoding=encoding)
+
+    if gdb_python_error:
+        print('gdb must have python support to test the pretty printers.')
+        exit(UNSUPPORTED)
+
+    # If everything's ok, spawn the gdb process we'll use for testing.
+    gdb = pexpect.spawn(gdb_invocation, echo=False, timeout=timeout,
+                        encoding=encoding)
+    gdb_prompt = u'\(gdb\)'
+    gdb.expect(gdb_prompt)
+
+except pexpect.ExceptionPexpect as exception:
+    print('Error: {0}'.format(exception))
+    exit(FAIL)
+
+def test(command, pattern=None):
+    """Sends 'command' to gdb and expects the given 'pattern'.
+
+    If 'pattern' is None, simply consumes everything up to and including
+    the gdb prompt.
+
+    Args:
+        command (string): The command we'll send to gdb.
+        pattern (raw string): A pattern the gdb output should match.
+
+    Returns:
+        string: The string that matched 'pattern', or an empty string if
+            'pattern' was None.
+    """
+
+    match = ''
+
+    gdb.sendline(command)
+
+    if pattern:
+        # PExpect does a non-greedy match for '+' and '*'.  Since it can't look
+        # ahead on the gdb output stream, if 'pattern' ends with a '+' or a '*'
+        # we may end up matching only part of the required output.
+        # To avoid this, we'll consume 'pattern' and anything that follows it
+        # up to and including the gdb prompt, then extract 'pattern' later.
+        index = gdb.expect([u'{0}.+{1}'.format(pattern, gdb_prompt),
+                            pexpect.TIMEOUT])
+
+        if index == 0:
+            # gdb.after now contains the whole match.  Extract the text that
+            # matches 'pattern'.
+            match = re.match(pattern, gdb.after, re.DOTALL).group()
+        elif index == 1:
+            # We got a timeout exception.  Print information on what caused it
+            # and bail out.
+            error = ('Response does not match the expected pattern.\n'
+                     'Command: {0}\n'
+                     'Expected pattern: {1}\n'
+                     'Response: {2}'.format(command, pattern, gdb.before))
+
+            raise pexpect.TIMEOUT(error)
+    else:
+        # Consume just the the gdb prompt.
+        gdb.expect(gdb_prompt)
+
+    return match
+
+def init_test(test_bin, printer_files, printer_names):
+    """Loads the test binary file and the required pretty printers to gdb.
+
+    Args:
+        test_bin (string): The name of the test binary file.
+        pretty_printers (list of strings): A list with the names of the pretty
+            printer files.
+    """
+
+    # Load all the pretty printer files.  We're assuming these are safe.
+    for printer_file in printer_files:
+        test('source {0}'.format(printer_file))
+
+    # Disable all the pretty printers.
+    test('disable pretty-printer', r'0 of [0-9]+ printers enabled')
+
+    # Enable only the required printers.
+    for printer in printer_names:
+        test('enable pretty-printer {0}'.format(printer),
+             r'[1-9][0-9]* of [1-9]+ printers enabled')
+
+    # Finally, load the test binary.
+    test('file {0}'.format(test_bin))
+
+def go_to_main():
+    """Executes a gdb 'start' command, which takes us to main."""
+
+    test('start', r'main')
+
+def get_line_number(file_name, string):
+    """Returns the number of the line in which 'string' appears within a file.
+
+    Args:
+        file_name (string): The name of the file we'll search through.
+        string (string): The string we'll look for.
+
+    Returns:
+        int: The number of the line in which 'string' appears, starting from 1.
+    """
+    number = -1
+
+    with open(file_name) as src_file:
+        for i, line in enumerate(src_file):
+            if string in line:
+                number = i + 1
+                break
+
+    if number == -1:
+        raise NoLineError(file_name, string)
+
+    return number
+
+def break_at(file_name, string, temporary=True, thread=None):
+    """Places a breakpoint on the first line in 'file_name' containing 'string'.
+
+    'string' is usually a comment like "Stop here".  Notice this may fail unless
+    the comment is placed inline next to actual code, e.g.:
+
+        ...
+        /* Stop here */
+        ...
+
+    may fail, while:
+
+        ...
+        some_func(); /* Stop here */
+        ...
+
+    will succeed.
+
+    If 'thread' isn't None, the breakpoint will be set for all the threads.
+    Otherwise, it'll be set only for 'thread'.
+
+    Args:
+        file_name (string): The name of the file we'll place the breakpoint in.
+        string (string): A string we'll look for inside the file.
+            We'll place a breakpoint on the line which contains it.
+        temporary (bool): Whether the breakpoint should be automatically deleted
+            after we reach it.
+        thread (int): The number of the thread we'll place the breakpoint for,
+            as seen by gdb.  If specified, it should be greater than zero.
+    """
+
+    if not thread:
+        thread_str = ''
+    else:
+        thread_str = 'thread {0}'.format(thread)
+
+    if temporary:
+        command = 'tbreak'
+        break_type = 'Temporary breakpoint'
+    else:
+        command = 'break'
+        break_type = 'Breakpoint'
+
+    line_number = str(get_line_number(file_name, string))
+
+    test('{0} {1}:{2} {3}'.format(command, file_name, line_number, thread_str),
+         r'{0} [0-9]+ at 0x[a-f0-9]+: file {1}, line {2}\.'.format(break_type,
+                                                                   file_name,
+                                                                   line_number))
+
+def continue_cmd(thread=None):
+    """Executes a gdb 'continue' command.
+
+    If 'thread' isn't None, the command will be applied to all the threads.
+    Otherwise, it'll be applied only to 'thread'.
+
+    Args:
+        thread (int): The number of the thread we'll apply the command to,
+            as seen by gdb.  If specified, it should be greater than zero.
+    """
+
+    if not thread:
+        command = 'continue'
+    else:
+        command = 'thread apply {0} continue'.format(thread)
+
+    test(command)
+
+def next_cmd(count=1, thread=None):
+    """Executes a gdb 'next' command.
+
+    If 'thread' isn't None, the command will be applied to all the threads.
+    Otherwise, it'll be applied only to 'thread'.
+
+    Args:
+        count (int): The 'count' argument of the 'next' command.
+        thread (int): The number of the thread we'll apply the command to,
+            as seen by gdb.  If specified, it should be greater than zero.
+    """
+
+    if not thread:
+        command = 'next'
+    else:
+        command = 'thread apply {0} next'
+
+    test('{0} {1}'.format(command, count))
+
+def select_thread(thread):
+    """Selects the thread indicated by 'thread'.
+
+    Args:
+        thread (int): The number of the thread we'll switch to, as seen by gdb.
+            This should be greater than zero.
+    """
+
+    if thread > 0:
+        test('thread {0}'.format(thread))
+
+def get_current_thread_lwpid():
+    """Gets the current thread's Lightweight Process ID.
+
+    Returns:
+        string: The current thread's LWP ID.
+    """
+
+    # It's easier to get the LWP ID through the Python API than the gdb CLI.
+    command = 'python print(gdb.selected_thread().ptid[1])'
+
+    return test(command, r'[0-9]+')
+
+def set_scheduler_locking(mode):
+    """Executes the gdb 'set scheduler-locking' command.
+
+    Args:
+        mode (bool): Whether the scheduler locking mode should be 'on'.
+    """
+    modes = {
+        True: 'on',
+        False: 'off'
+    }
+
+    test('set scheduler-locking {0}'.format(modes[mode]))
+
+def test_printer(var, to_string, children=None, is_ptr=True):
+    """ Tests the output of a pretty printer.
+
+    For a variable called 'var', this tests whether its associated printer
+    outputs the expected 'to_string' and children (if any).
+
+    Args:
+        var (string): The name of the variable we'll print.
+        to_string (raw string): The expected output of the printer's 'to_string'
+            method.
+        children (map {raw string->raw string}): A map with the expected output
+            of the printer's children' method.
+        is_ptr (bool): Whether 'var' is a pointer, and thus should be
+            dereferenced.
+    """
+
+    if is_ptr:
+        var = '*{0}'.format(var)
+
+    test('print {0}'.format(var), to_string)
+
+    if children:
+        for name, value in children.items():
+            # Children are shown as 'name = value'.
+            test('print {0}'.format(var), r'{0} = {1}'.format(name, value))
+
+def check_debug_symbol(symbol):
+    """ Tests whether a given debugging symbol exists.
+
+    If the symbol doesn't exist, raises a DebugError.
+
+    Args:
+        symbol (string): The symbol we're going to check for.
+    """
+
+    try:
+        test('ptype {0}'.format(symbol), r'type = {0}'.format(symbol))
+
+    except pexpect.TIMEOUT:
+        # The symbol doesn't exist.
+        raise DebugError(symbol)
diff --git a/scripts/test_printers_exceptions.py b/scripts/test_printers_exceptions.py
new file mode 100644
index 0000000000..17034b544e
--- /dev/null
+++ b/scripts/test_printers_exceptions.py
@@ -0,0 +1,61 @@
+# Exception classes used when testing the Python pretty printers.
+#
+# Copyright (C) 2016 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+#
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# The GNU C Library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <http://www.gnu.org/licenses/>.
+
+class NoLineError(Exception):
+    """Custom exception to indicate that a test file doesn't contain
+    the requested string.
+    """
+
+    def __init__(self, file_name, string):
+        """Constructor.
+
+        Args:
+            file_name (string): The name of the test file.
+            string (string): The string that was requested.
+        """
+
+        super(NoLineError, self).__init__()
+        self.file_name = file_name
+        self.string = string
+
+    def __str__(self):
+        """Shows a readable representation of the exception."""
+
+        return ('File {0} has no line containing the following string: {1}'
+                .format(self.file_name, self.string))
+
+class DebugError(Exception):
+    """Custom exception to indicate that a required debugging symbol is missing.
+    """
+
+    def __init__(self, symbol):
+        """Constructor.
+
+        Args:
+            symbol (string): The name of the entity whose debug info is missing.
+        """
+
+        super(DebugError, self).__init__()
+        self.symbol = symbol
+
+    def __str__(self):
+        """Shows a readable representation of the exception."""
+
+        return ('The required debugging information for {0} is missing.'
+                .format(self.symbol))