[ was: Re: [libbacktrace] Fix and simplify xcoff_%.c pattern rule ] On 28-01-19 10:25, Tom de Vries wrote: > [ was: Re: [backtrace] Avoid segfault ] > On 27-01-19 22:53, Ian Lance Taylor wrote: >> On Sun, Jan 27, 2019 at 1:16 PM Tom de Vries <tdevr...@suse.de> wrote: >>> >>> On 25-01-19 18:15, Nathan Sidwell wrote: >>>> On 1/25/19 5:28 AM, Tom de Vries wrote: >>>>> >>>>> This patch fixes it by passing "" instead of NULL, in the call to >>>>> elf_add at line 3083 (for .gnu_debugaltlink), not the call to elf_add at >>>>> line 3044 (for .gnu_debuglink) mentioned above. >>>>> >>>>> Nathan, does this fix the problem for you? If not, can you provide a >>>>> reproducer, or give a hint on how one could be constructed? >>>> >>>> I still hit the problem, and am installing this as sufficiently obvious. >>>> I'm on a fedora system debugging pr88995. The debuglink_name is >>>> "../../.dwz/isl-0.16.1-7.fc29.x86_64" >>>> >>> >>> I've managed to reproduce this segfault instance by adding a test-case >>> that uses both build-id and dwz. >>> >>> OK for trunk? >> >>> +elf_for_test.c: elf.c >>> + PWD=$$(pwd -P); \ >>> + BUILD_ID_DIR="usr/lib/debug/.build-id/"; \ >>> + SEARCH='#define SYSTEM_BUILD_ID_DIR'; \ >>> + REPLACE="#define SYSTEM_BUILD_ID_DIR \"$$PWD/$$BUILD_ID_DIR\""; \ >>> + $(SED) "s%^$$SEARCH.*\$$%$$REPLACE%" \ >>> + $< \ >>> + > $@ >> >> You need to use a temporary file, such as $@.tmp, for the final sed >> command, followed by a mv to $@. Otherwise a failure in the sed will >> leave what appears to be an up to date file. > > I noticed the same problem in the xcoff_%.c pattern rule. >
And looking over the rule again, I wondered if it would be more readable if split off into a separate script file. Is this follow-up patch OK for trunk? Thanks, - Tom
[Libbacktrace] Add gen-xcoff-n.sh Factor out xcoff_%.c generation into gen-xcoff-n.c, getting rid of the escaping of shell variables. 2019-01-28 Tom de Vries <tdevr...@suse.de> * Makefile.am: Factor out xcoff_%.c generation ... * gen-xcoff-n.sh: ... here. New file. * Makefile.in: Regenerate. --- libbacktrace/Makefile.am | 8 +------- libbacktrace/Makefile.in | 8 +------- libbacktrace/gen-xcoff-n.sh | 20 ++++++++++++++++++++ 3 files changed, 22 insertions(+), 14 deletions(-) diff --git a/libbacktrace/Makefile.am b/libbacktrace/Makefile.am index 0d5b3193e25..43d0c9ffd73 100644 --- a/libbacktrace/Makefile.am +++ b/libbacktrace/Makefile.am @@ -104,13 +104,7 @@ libbacktrace_noformat_la_LIBADD = $(BACKTRACE_FILE) $(VIEW_FILE) $(ALLOC_FILE) libbacktrace_noformat_la_DEPENDENCIES = $(libbacktrace_noformat_la_LIBADD) xcoff_%.c: xcoff.c - SEARCH='#error "Unknown BACKTRACE_XCOFF_SIZE"'; \ - REPLACE='#undef BACKTRACE_XCOFF_SIZE\ - #define BACKTRACE_XCOFF_SIZE'; \ - $(SED) "s/^$$SEARCH\$$/$$REPLACE $*/" \ - $< \ - > $@.tmp - mv $@.tmp $@ + $(srcdir)/gen-xcoff-n.sh $(SED) $< $* $@ test_elf_SOURCES = test_format.c testlib.c test_elf_LDADD = libbacktrace_noformat.la elf.lo diff --git a/libbacktrace/Makefile.in b/libbacktrace/Makefile.in index b25ac92aeda..650392c2988 100644 --- a/libbacktrace/Makefile.in +++ b/libbacktrace/Makefile.in @@ -1750,13 +1750,7 @@ uninstall-am: @NATIVE_TRUE@xcoff_%.c: xcoff.c -@NATIVE_TRUE@ SEARCH='#error "Unknown BACKTRACE_XCOFF_SIZE"'; \ -@NATIVE_TRUE@ REPLACE='#undef BACKTRACE_XCOFF_SIZE\ -@NATIVE_TRUE@ #define BACKTRACE_XCOFF_SIZE'; \ -@NATIVE_TRUE@ $(SED) "s/^$$SEARCH\$$/$$REPLACE $*/" \ -@NATIVE_TRUE@ $< \ -@NATIVE_TRUE@ > $@.tmp -@NATIVE_TRUE@ mv $@.tmp $@ +@NATIVE_TRUE@ $(srcdir)/gen-xcoff-n.sh $(SED) $< $* $@ @NATIVE_TRUE@instrumented_alloc.lo: alloc.c diff --git a/libbacktrace/gen-xcoff-n.sh b/libbacktrace/gen-xcoff-n.sh new file mode 100755 index 00000000000..c8825a9deba --- /dev/null +++ b/libbacktrace/gen-xcoff-n.sh @@ -0,0 +1,20 @@ +#!/bin/sh + +sed="$1" +src="$2" +n="$3" +dst="$4" + +tmp=$dst.tmp + +search='^#error "Unknown BACKTRACE_XCOFF_SIZE"$' + +replace='#undef BACKTRACE_XCOFF_SIZE\ + #define BACKTRACE_XCOFF_SIZE '"$n" + +$sed \ + "s/$search/$replace/" \ + $src \ + > $tmp + +mv $tmp $dst
