From 64e6c1e12372840e7caf8e25325a9e9c5fd370e6 Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Mon, 1 Dec 2008 14:21:01 -0800 Subject: genksyms: track symbol checksum changes Sometimes it is preferable to avoid changes of exported symbol checksums (to avoid breaking externally provided modules). When a checksum change occurs, it can be hard to figure out what caused this change: underlying types may have changed, or additional type information may simply have become available at the point where a symbol is exported. Add a new --reference option to genksyms which allows it to report why checksums change, based on the type information dumps it creates with the --dump-types flag. Genksyms will read in such a dump from a previous run, and report which symbols have changed (and why). The behavior can be controlled for an entire build as follows: If KBUILD_SYMTYPES is set, genksyms uses --dump-types to produce *.symtypes dump files. If any *.symref files exist, those will be used as the reference to check against. If KBUILD_PRESERVE is set, checksum changes will fail the build. Signed-off-by: Andreas Gruenbacher Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Sam Ravnborg --- scripts/Makefile.build | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) (limited to 'scripts/Makefile.build') diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 468fbc9016c7..d21f0eac2e52 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -153,12 +153,18 @@ $(obj)/%.i: $(src)/%.c FORCE quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@ cmd_cc_symtypes_c = \ + set -e; \ $(CPP) -D__GENKSYMS__ $(c_flags) $< \ - | $(GENKSYMS) -T $@ >/dev/null; \ + | $(GENKSYMS) -T $@ \ + -r $(firstword $(wildcard \ + $(@:.symtypes=.symref) /dev/null)) \ + $(if $(KBUILD_PRESERVE),-p) \ + -a $(ARCH) \ + >/dev/null; \ test -s $@ || rm -f $@ $(obj)/%.symtypes : $(src)/%.c FORCE - $(call if_changed_dep,cc_symtypes_c) + $(call cmd,cc_symtypes_c) # C (.c) files # The C file is compiled and updated dependency information is generated. @@ -187,7 +193,11 @@ cmd_modversions = \ if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \ $(CPP) -D__GENKSYMS__ $(c_flags) $< \ | $(GENKSYMS) $(if $(KBUILD_SYMTYPES), \ - -T $(@D)/$(@F:.o=.symtypes)) -a $(ARCH) \ + -T $(@:.o=.symtypes)) \ + -r $(firstword $(wildcard \ + $(@:.o=.symref) /dev/null)) \ + $(if $(KBUILD_PRESERVE),-p) \ + -a $(ARCH) \ > $(@D)/.tmp_$(@F:.o=.ver); \ \ $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \ -- cgit v1.2.3