libbacktrace: read symbol table of debuginfo file

These become another symbol table to search.  This is needed if people
use --strip-all rather than --strip-debug when adding a debuglink
section.

Patch is from GitHub user pickard1.

Fixes #113

	* elf.c (elf_add): Add the symbol table from a debuginfo file.
	* Makefile.am (MAKETESTS): Add buildidfull and gnudebuglinkfull
	variants of buildid and gnudebuglink tests.
	(%_gnudebuglinkfull, %_buildidfull): New patterns.
	* Makefile.in: Regenerate.

Makefile.am

@@ -258,7 +258,7 @@ b2test_LDFLAGS = -Wl,--build-id
 b2test_LDADD = libbacktrace_elf_for_test.la
 
 check_PROGRAMS += b2test
-MAKETESTS += b2test_buildid
+MAKETESTS += b2test_buildid b2test_buildidfull
 
 if HAVE_DWZ
 
@@ -268,7 +268,7 @@ b3test_LDFLAGS = -Wl,--build-id
 b3test_LDADD = libbacktrace_elf_for_test.la
 
 check_PROGRAMS += b3test
-MAKETESTS += b3test_dwz_buildid
+MAKETESTS += b3test_dwz_buildid b3test_dwz_buildidfull
 
 endif HAVE_DWZ
 
@@ -444,12 +444,16 @@ endif HAVE_PTHREAD
 
 if HAVE_OBJCOPY_DEBUGLINK
 
-MAKETESTS += btest_gnudebuglink
+MAKETESTS += btest_gnudebuglink btest_gnudebuglinkfull
 
 %_gnudebuglink: %
 	$(OBJCOPY) --only-keep-debug $< $@.debug
 	$(OBJCOPY) --strip-debug --add-gnu-debuglink=$@.debug $< $@
 
+%_gnudebuglinkfull: %
+	$(OBJCOPY) --only-keep-debug $< $@.debug
+	$(OBJCOPY) --strip-all --add-gnu-debuglink=$@.debug $< $@
+
 endif HAVE_OBJCOPY_DEBUGLINK
 
 %_buildid: %
@@ -458,6 +462,12 @@ endif HAVE_OBJCOPY_DEBUGLINK
 	  $<
 	$(OBJCOPY) --strip-debug $< $@
 
+%_buildidfull: %
+	./install-debuginfo-for-buildid.sh \
+	  "$(TEST_BUILD_ID_DIR)" \
+	  $<
+	$(OBJCOPY) --strip-all $< $@
+
 if HAVE_COMPRESSED_DEBUG
 
 ctestg_SOURCES = btest.c testlib.c

Makefile.in

@@ -135,9 +135,9 @@ TESTS = $(am__append_4) $(MAKETESTS) $(am__EXEEXT_16)
 @NATIVE_TRUE@@USE_DSYMUTIL_TRUE@	stest.dSYM stest_alloc.dSYM \
 @NATIVE_TRUE@@USE_DSYMUTIL_TRUE@	edtest.dSYM edtest_alloc.dSYM
 @HAVE_BUILDID_TRUE@@HAVE_ELF_TRUE@@HAVE_OBJCOPY_DEBUGLINK_TRUE@@NATIVE_TRUE@am__append_6 = b2test
-@HAVE_BUILDID_TRUE@@HAVE_ELF_TRUE@@HAVE_OBJCOPY_DEBUGLINK_TRUE@@NATIVE_TRUE@am__append_7 = b2test_buildid
+@HAVE_BUILDID_TRUE@@HAVE_ELF_TRUE@@HAVE_OBJCOPY_DEBUGLINK_TRUE@@NATIVE_TRUE@am__append_7 = b2test_buildid b2test_buildidfull
 @HAVE_BUILDID_TRUE@@HAVE_DWZ_TRUE@@HAVE_ELF_TRUE@@HAVE_OBJCOPY_DEBUGLINK_TRUE@@NATIVE_TRUE@am__append_8 = b3test
-@HAVE_BUILDID_TRUE@@HAVE_DWZ_TRUE@@HAVE_ELF_TRUE@@HAVE_OBJCOPY_DEBUGLINK_TRUE@@NATIVE_TRUE@am__append_9 = b3test_dwz_buildid
+@HAVE_BUILDID_TRUE@@HAVE_DWZ_TRUE@@HAVE_ELF_TRUE@@HAVE_OBJCOPY_DEBUGLINK_TRUE@@NATIVE_TRUE@am__append_9 = b3test_dwz_buildid b3test_dwz_buildidfull
 @HAVE_ELF_TRUE@@NATIVE_TRUE@am__append_10 = btest_lto
 @NATIVE_TRUE@am__append_11 = btest_alloc stest stest_alloc
 @HAVE_DWZ_TRUE@@NATIVE_TRUE@am__append_12 = btest_dwz
@@ -153,7 +153,7 @@ TESTS = $(am__append_4) $(MAKETESTS) $(am__EXEEXT_16)
 @HAVE_PTHREAD_TRUE@@NATIVE_TRUE@@USE_DSYMUTIL_TRUE@am__append_21 =  \
 @HAVE_PTHREAD_TRUE@@NATIVE_TRUE@@USE_DSYMUTIL_TRUE@	ttest.dSYM \
 @HAVE_PTHREAD_TRUE@@NATIVE_TRUE@@USE_DSYMUTIL_TRUE@	ttest_alloc.dSYM
-@HAVE_OBJCOPY_DEBUGLINK_TRUE@@NATIVE_TRUE@am__append_22 = btest_gnudebuglink
+@HAVE_OBJCOPY_DEBUGLINK_TRUE@@NATIVE_TRUE@am__append_22 = btest_gnudebuglink btest_gnudebuglinkfull
 @HAVE_COMPRESSED_DEBUG_TRUE@@NATIVE_TRUE@am__append_23 = ctestg ctesta
 @HAVE_COMPRESSED_DEBUG_TRUE@@HAVE_COMPRESSED_DEBUG_ZSTD_TRUE@@NATIVE_TRUE@am__append_24 = ctestzstd
 @HAVE_COMPRESSED_DEBUG_TRUE@@NATIVE_TRUE@am__append_25 = ctestg_alloc ctesta_alloc
@@ -2137,6 +2137,13 @@ b2test_buildid.log: b2test_buildid
 	--log-file $$b.log --trs-file $$b.trs \
 	$(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS) -- $(LOG_COMPILE) \
 	"$$tst" $(AM_TESTS_FD_REDIRECT)
+b2test_buildidfull.log: b2test_buildidfull
+	@p='b2test_buildidfull'; \
+	b='b2test_buildidfull'; \
+	$(am__check_pre) $(LOG_DRIVER) --test-name "$$f" \
+	--log-file $$b.log --trs-file $$b.trs \
+	$(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS) -- $(LOG_COMPILE) \
+	"$$tst" $(AM_TESTS_FD_REDIRECT)
 b3test_dwz_buildid.log: b3test_dwz_buildid
 	@p='b3test_dwz_buildid'; \
 	b='b3test_dwz_buildid'; \
@@ -2144,6 +2151,13 @@ b3test_dwz_buildid.log: b3test_dwz_buildid
 	--log-file $$b.log --trs-file $$b.trs \
 	$(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS) -- $(LOG_COMPILE) \
 	"$$tst" $(AM_TESTS_FD_REDIRECT)
+b3test_dwz_buildidfull.log: b3test_dwz_buildidfull
+	@p='b3test_dwz_buildidfull'; \
+	b='b3test_dwz_buildidfull'; \
+	$(am__check_pre) $(LOG_DRIVER) --test-name "$$f" \
+	--log-file $$b.log --trs-file $$b.trs \
+	$(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS) -- $(LOG_COMPILE) \
+	"$$tst" $(AM_TESTS_FD_REDIRECT)
 btest_dwz.log: btest_dwz
 	@p='btest_dwz'; \
 	b='btest_dwz'; \
@@ -2165,6 +2179,13 @@ btest_gnudebuglink.log: btest_gnudebuglink
 	--log-file $$b.log --trs-file $$b.trs \
 	$(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS) -- $(LOG_COMPILE) \
 	"$$tst" $(AM_TESTS_FD_REDIRECT)
+btest_gnudebuglinkfull.log: btest_gnudebuglinkfull
+	@p='btest_gnudebuglinkfull'; \
+	b='btest_gnudebuglinkfull'; \
+	$(am__check_pre) $(LOG_DRIVER) --test-name "$$f" \
+	--log-file $$b.log --trs-file $$b.trs \
+	$(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS) -- $(LOG_COMPILE) \
+	"$$tst" $(AM_TESTS_FD_REDIRECT)
 mtest_minidebug.log: mtest_minidebug
 	@p='mtest_minidebug'; \
 	b='mtest_minidebug'; \
@@ -2604,12 +2625,22 @@ uninstall-am: uninstall-includeHEADERS uninstall-libLTLIBRARIES
 @HAVE_OBJCOPY_DEBUGLINK_TRUE@@NATIVE_TRUE@	$(OBJCOPY) --only-keep-debug $< $@.debug
 @HAVE_OBJCOPY_DEBUGLINK_TRUE@@NATIVE_TRUE@	$(OBJCOPY) --strip-debug --add-gnu-debuglink=$@.debug $< $@
 
+@HAVE_OBJCOPY_DEBUGLINK_TRUE@@NATIVE_TRUE@%_gnudebuglinkfull: %
+@HAVE_OBJCOPY_DEBUGLINK_TRUE@@NATIVE_TRUE@	$(OBJCOPY) --only-keep-debug $< $@.debug
+@HAVE_OBJCOPY_DEBUGLINK_TRUE@@NATIVE_TRUE@	$(OBJCOPY) --strip-all --add-gnu-debuglink=$@.debug $< $@
+
 @NATIVE_TRUE@%_buildid: %
 @NATIVE_TRUE@	./install-debuginfo-for-buildid.sh \
 @NATIVE_TRUE@	  "$(TEST_BUILD_ID_DIR)" \
 @NATIVE_TRUE@	  $<
 @NATIVE_TRUE@	$(OBJCOPY) --strip-debug $< $@
 
+@NATIVE_TRUE@%_buildidfull: %
+@NATIVE_TRUE@	./install-debuginfo-for-buildid.sh \
+@NATIVE_TRUE@	  "$(TEST_BUILD_ID_DIR)" \
+@NATIVE_TRUE@	  $<
+@NATIVE_TRUE@	$(OBJCOPY) --strip-all $< $@
+
 @HAVE_MINIDEBUG_TRUE@@NATIVE_TRUE@%_minidebug: %
 @HAVE_MINIDEBUG_TRUE@@NATIVE_TRUE@	$(NM) -D $< -P --defined-only | $(AWK) '{ print $$1 }' | sort > $<.dsyms
 @HAVE_MINIDEBUG_TRUE@@NATIVE_TRUE@	$(NM) $< -P --defined-only | $(AWK) '{ if ($$2 == "T" || $$2 == "t" || $$2 == "D") print $$1 }' | sort > $<.fsyms

elf.c

@@ -6872,7 +6872,7 @@ elf_add (struct backtrace_state *state, const char *filename, int descriptor,
 
   if (symtab_shndx == 0)
     symtab_shndx = dynsym_shndx;
-  if (symtab_shndx != 0 && !debuginfo)
+  if (symtab_shndx != 0)
     {
       const b_elf_shdr *symtab_shdr;
       unsigned int strtab_shndx;