aboutsummaryrefslogtreecommitdiff
path: root/csu
diff options
context:
space:
mode:
Diffstat (limited to 'csu')
-rw-r--r--csu/Makefile25
-rw-r--r--csu/gmon-start.c47
2 files changed, 64 insertions, 8 deletions
diff --git a/csu/Makefile b/csu/Makefile
index 8f97624240..4fddba2f3a 100644
--- a/csu/Makefile
+++ b/csu/Makefile
@@ -20,18 +20,21 @@
# This directory contains the C startup code (that which calls main). This
# consists of the startfile, built from start.c and installed as crt0.o
-# (traditionally) or crt1.o (for ELF); and some initialization code which
-# is in the C library itself. In ELF we also install crti.o and crtn.o,
-# special "initializer" and "finalizer" files in used in the link to make
-# the .init and .fini sections work right; both these files are built (in
-# an arcane manner) from initfini.c.
+# (traditionally) or crt1.o (for ELF). In ELF we also install crti.o and
+# crtn.o, special "initializer" and "finalizer" files in used in the link
+# to make the .init and .fini sections work right; both these files are
+# built (in an arcane manner) from initfini.c.
subdir := csu
csu-dummies = $(filter-out $(start-installed-name),crt1.o Mcrt1.o)
-extra-objs = start.o $(start-installed-name) $(csu-dummies)
-omit-deps = $(patsubst %.o,%,$(start-installed-name) $(csu-dummies))
-install-lib = $(start-installed-name) $(csu-dummies)
+extra-objs = start.o gmon-start.o \
+ $(start-installed-name) g$(start-installed-name) \
+ $(csu-dummies)
+omit-deps = $(patsubst %.o,%,$(start-installed-name) g$(start-installed-name) \
+ $(csu-dummies))
+install-lib = $(start-installed-name) g$(start-installed-name) \
+ $(csu-dummies)
distribute = initfini.c
all: # Make this the default target; it will be defined in Rules.
@@ -95,6 +98,12 @@ $(objpfx)$(start-installed-name): $(objpfx)start.o
ln $< $@
endif
+# The profiling startfile is made by linking together the normal
+# startfile with gmon-start.o, which defines a constructor function
+# to turn on profiling code at startup.
+$(objpfx)g$(start-installed-name): $(objpfx)start.o $(objpfx)gmon-start.o
+ $(CC) -nostdlib -nostartfiles -r -o $@ $^
+
# These extra files are sometimes expected by system standard linking
# procedures, but we have nothing for them to do. So compile empty files.
$(addprefix $(objpfx),$(filter-out $(start-installed-name),$(csu-dummies))):
diff --git a/csu/gmon-start.c b/csu/gmon-start.c
new file mode 100644
index 0000000000..c9d51b113b
--- /dev/null
+++ b/csu/gmon-start.c
@@ -0,0 +1,47 @@
+/* Code to enable profiling at program startup.
+Copyright (C) 1995 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 Library General Public License as
+published by the Free Software Foundation; either version 2 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
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB. If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA. */
+
+#include <sys/types.h>
+#include <sys/gmon.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+/* Beginning and end of our code segment. */
+extern void _start (), etext ();
+
+/* These functions are defined in gmon/gmon.c;
+ they do all the work of setting up and cleaning up profiling. */
+extern void monstartup (u_long, u_long);
+extern void _mcleanup (void);
+
+/* This function gets called at startup by the normal constructor
+ mechanism. We link this file together with start.o to produce gcrt1.o,
+ so this constructor will be first in the list. */
+static void gmon_start (void) __attribute__ ((constructor));
+static void
+gmon_start (void)
+{
+ /* Start keeping profiling records. */
+ monstartup ((u_long) &_start, (u_long) &etext);
+
+ /* Call _mcleanup before exitting; it will write out gmon.out from the
+ collected data. */
+ atexit (&_mcleanup);
+}
+