[PATCH 3/7] kbuild: delay object file renaming during module versioning
From: Peter Oberparleiter
Date: Mon May 19 2008 - 04:44:20 EST
From: Peter Oberparleiter <peter.oberparleiter@xxxxxxxxxx>
Change module versioning to alter object file names only after
compiling.
Required by the gcov profiling infrastructure: when compiling with
option -fprofile-arcs, gcc stores file names inside object files.
A name change before compilation would prevent the gcov tool from
finding the corresponding source files.
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@xxxxxxxxxx>
---
scripts/Makefile.build | 25 ++++++++++---------------
1 file changed, 10 insertions(+), 15 deletions(-)
Index: linux-2.6.26-rc3/scripts/Makefile.build
===================================================================
--- linux-2.6.26-rc3.orig/scripts/Makefile.build
+++ linux-2.6.26-rc3/scripts/Makefile.build
@@ -165,26 +165,23 @@ $(obj)/%.symtypes : $(src)/%.c FORCE
# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
-
-ifndef CONFIG_MODVERSIONS
cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
-else
-# When module versioning is enabled the following steps are executed:
-# o compile a .tmp_<file>.o from <file>.c
-# o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
-# not export symbols, we just rename .tmp_<file>.o to <file>.o and
-# are done.
-# o otherwise, we calculate symbol versions using the good old
-# genksyms on the preprocessed source and postprocess them in a way
-# that they are usable as a linker script
+ifdef CONFIG_MODVERSIONS
+# When module versioning is enabled the following steps are executed
+# in addition to compiling:
+# o if <file>.o doesn't contain a __ksymtab version, i.e. does
+# not export symbols, we are done
+# o otherwise, we rename <file>.o into .tmp_<file.o> and calculate symbol
+# versions using the good old genksyms on the preprocessed source and
+# postprocess them in a way that they are usable as a linker script
# o generate <file>.o from .tmp_<file>.o using the linker to
# replace the unresolved symbols __crc_exported_symbol with
# the actual value of the checksum generated by genksyms
-cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
cmd_modversions = \
- if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
+ if $(OBJDUMP) -h $@ | grep -q __ksymtab; then \
+ mv -f $@ $(@D)/.tmp_$(@F); \
$(CPP) -D__GENKSYMS__ $(c_flags) $< \
| $(GENKSYMS) $(if $(KBUILD_SYMTYPES), \
-T $(@D)/$(@F:.o=.symtypes)) -a $(ARCH) \
@@ -193,8 +190,6 @@ cmd_modversions = \
$(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
-T $(@D)/.tmp_$(@F:.o=.ver); \
rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
- else \
- mv -f $(@D)/.tmp_$(@F) $@; \
fi;
endif
--
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