aboutsummaryrefslogtreecommitdiffstats
path: root/scripts/Makefile.lib
diff options
context:
space:
mode:
authorPeter Oberparleiter <oberpar@linux.vnet.ibm.com>2009-06-17 23:28:08 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2009-06-18 20:03:57 (GMT)
commit2521f2c228ad750701ba4702484e31d876dbc386 (patch)
tree2221de3e3de9512979b8244c6304366e3be5be63 /scripts/Makefile.lib
parent0b923606e75f1ab672e25b14ac039a1cdcfa382f (diff)
gcov: add gcov profiling infrastructure
Enable the use of GCC's coverage testing tool gcov [1] with the Linux kernel. gcov may be useful for: * debugging (has this code been reached at all?) * test improvement (how do I change my test to cover these lines?) * minimizing kernel configurations (do I need this option if the associated code is never run?) The profiling patch incorporates the following changes: * change kbuild to include profiling flags * provide functions needed by profiling code * present profiling data as files in debugfs Note that on some architectures, enabling gcc's profiling option "-fprofile-arcs" for the entire kernel may trigger compile/link/ run-time problems, some of which are caused by toolchain bugs and others which require adjustment of architecture code. For this reason profiling the entire kernel is initially restricted to those architectures for which it is known to work without changes. This restriction can be lifted once an architecture has been tested and found compatible with gcc's profiling. Profiling of single files or directories is still available on all platforms (see config help text). [1] http://gcc.gnu.org/onlinedocs/gcc/Gcov.html Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Huang Ying <ying.huang@intel.com> Cc: Li Wei <W.Li@Sun.COM> Cc: Michael Ellerman <michaele@au1.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com> Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: WANG Cong <xiyou.wangcong@gmail.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'scripts/Makefile.lib')
-rw-r--r--scripts/Makefile.lib11
1 files changed, 11 insertions, 0 deletions
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 2b70661..7a77787 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -116,6 +116,17 @@ _a_flags = $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(KBUILD_SUBDIR_ASFLAGS) \
$(asflags-y) $(AFLAGS_$(basetarget).o)
_cpp_flags = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(@F))
+#
+# Enable gcov profiling flags for a file, directory or for all files depending
+# on variables GCOV_PROFILE_obj.o, GCOV_PROFILE and CONFIG_GCOV_PROFILE_ALL
+# (in this order)
+#
+ifeq ($(CONFIG_GCOV_KERNEL),y)
+_c_flags += $(if $(patsubst n%,, \
+ $(GCOV_PROFILE_$(basetarget).o)$(GCOV_PROFILE)$(CONFIG_GCOV_PROFILE_ALL)), \
+ $(CFLAGS_GCOV))
+endif
+
# If building the kernel in a separate objtree expand all occurrences
# of -Idir to -I$(srctree)/dir except for absolute paths (starting with '/').

Privacy Policy