Fix failing pretty printer tests when CPPFLAGS has optimizations.

The value of CPPFLAGS provided by the environment may have optimizations
that interfere with the pretty printer test requirements. To override
such optimizations the pretty printer tests must also specify CPPFLAGS.
The existing pretty printer tests are fixed and the
README.pretty-printers is updated with the new requirement.

1 files changed, 4 insertions, 3 deletions

diff --git a/README.pretty-printers b/README.pretty-printers
index 86629001e6..a2536cad80 100644
--- a/README.pretty-printers
+++ b/README.pretty-printers
@@ -126,11 +126,12 @@ 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:
+program you must define a corresponding CFLAGS-* and CPPFLAGS-* 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)
+CPPFLAGS-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.