Re: [PATCH] libbacktrace: Avoid GNU ld --compress-debug-sections=zlib-gabi

[Ian Lance Taylor <iant@golang.org>]

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On Tue, Apr 23, 2024 at 7:24 AM Jakub Jelinek <jakub@redhat.com> wrote:
>
> What we could do is drop the HAVE_COMPRESSED_DEBUG stuff altogether, and
> instead similarly how we have HAVE_COMPRESSED_DEBUG_ZSTD have
> HAVE_COMPRESSED_DEBUG_{ZLIB,ZLIB_GABI,ZLIB_GNU} and for each of those
> if linker supports them test with that corresponding flag.

I think that's right.  Committed this patch after testing on
x86_64-pc-linux-gnu.  While I was at it I added an _alloc version of
ctestzstd.

Ian

* configure.ac: Test --compress-debug-sections=zlib-gnu and
--compress-debug-sections=zlib-gabi separately, setting new
automake conditionals.
* Makefile.am (ctestg, ctestg_alloc): Only build if
HAVE_COMPRESSED_DEBUG_ZLIB_GNU.
(ctesta, ctesta_alloc): Only build if
HAVE_COMPRESSED_DEBUG_ZLIB_GABI.
(ctestzstd_alloc): New test if HAVE_COMPRESSED_DEBUG_ZSTD.
* configure, Makefile.in: Regenerate.

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3943de6986271466652cb619dbc60881060b180c
diff --git a/libbacktrace/Makefile.am b/libbacktrace/Makefile.am
index 5677ecd8865..bed42c29329 100644
--- a/libbacktrace/Makefile.am
+++ b/libbacktrace/Makefile.am
@@ -493,19 +493,37 @@ endif HAVE_OBJCOPY_DEBUGLINK
 	  $<
 	$(OBJCOPY) --strip-all $< $@
 
-if HAVE_COMPRESSED_DEBUG
+if HAVE_COMPRESSED_DEBUG_ZLIB_GNU
 
 ctestg_SOURCES = btest.c testlib.c
 ctestg_CFLAGS = $(libbacktrace_TEST_CFLAGS)
 ctestg_LDFLAGS = -Wl,--compress-debug-sections=zlib-gnu $(libbacktrace_testing_ldflags)
 ctestg_LDADD = libbacktrace.la
 
+ctestg_alloc_SOURCES = $(ctestg_SOURCES)
+ctestg_alloc_CFLAGS = $(ctestg_CFLAGS)
+ctestg_alloc_LDFLAGS = $(ctestg_LDFLAGS) $(libbacktrace_testing_ldflags)
+ctestg_alloc_LDADD = libbacktrace_alloc.la
+
+BUILDTESTS += ctestg ctestg_alloc
+
+endif
+
+if HAVE_COMPRESSED_DEBUG_ZLIB_GABI
+
 ctesta_SOURCES = btest.c testlib.c
 ctesta_CFLAGS = $(libbacktrace_TEST_CFLAGS)
 ctesta_LDFLAGS = -Wl,--compress-debug-sections=zlib-gabi $(libbacktrace_testing_ldflags)
 ctesta_LDADD = libbacktrace.la
 
-BUILDTESTS += ctestg ctesta
+ctesta_alloc_SOURCES = $(ctesta_SOURCES)
+ctesta_alloc_CFLAGS = $(ctesta_CFLAGS)
+ctesta_alloc_LDFLAGS = $(ctesta_LDFLAGS) $(libbacktrace_testing_ldflags)
+ctesta_alloc_LDADD = libbacktrace_alloc.la
+
+BUILDTESTS += ctesta ctesta_alloc
+
+endif
 
 if HAVE_COMPRESSED_DEBUG_ZSTD
 
@@ -514,21 +532,12 @@ ctestzstd_CFLAGS = $(libbacktrace_TEST_CFLAGS)
 ctestzstd_LDFLAGS = -Wl,--compress-debug-sections=zstd $(libbacktrace_testing_ldflags)
 ctestzstd_LDADD = libbacktrace.la
 
-BUILDTESTS += ctestzstd
-
-endif
-
-ctestg_alloc_SOURCES = $(ctestg_SOURCES)
-ctestg_alloc_CFLAGS = $(ctestg_CFLAGS)
-ctestg_alloc_LDFLAGS = $(ctestg_LDFLAGS) $(libbacktrace_testing_ldflags)
-ctestg_alloc_LDADD = libbacktrace_alloc.la
-
-ctesta_alloc_SOURCES = $(ctesta_SOURCES)
-ctesta_alloc_CFLAGS = $(ctesta_CFLAGS)
-ctesta_alloc_LDFLAGS = $(ctesta_LDFLAGS) $(libbacktrace_testing_ldflags)
-ctesta_alloc_LDADD = libbacktrace_alloc.la
+ctestzstd_alloc_SOURCES = $(ctestzstd_SOURCES)
+ctestzstd_alloc_CFLAGS = $(ctestzstd_CFLAGS)
+ctestzstd_alloc_LDFLAGS = $(ctestzstd_LDFLAGS) $(libbacktrace_testing_ldflags)
+ctestzstd_alloc_LDADD = libbacktrace_alloc.la
 
-BUILDTESTS += ctestg_alloc ctesta_alloc
+BUILDTESTS += ctestzstd ctestzstd_alloc
 
 endif
 
diff --git a/libbacktrace/configure.ac b/libbacktrace/configure.ac
index 0f61f2b28ab..3e0075a2b79 100644
--- a/libbacktrace/configure.ac
+++ b/libbacktrace/configure.ac
@@ -502,16 +502,27 @@ AC_LINK_IFELSE([AC_LANG_PROGRAM(,)],
 LDFLAGS=$LDFLAGS_hold])
 AM_CONDITIONAL(HAVE_BUILDID, test "$libbacktrace_cv_ld_buildid" = yes)
 
-dnl Test whether the linker supports the --compress-debug-sections option.
-AC_CACHE_CHECK([whether --compress-debug-sections is supported],
-[libgo_cv_ld_compress],
+dnl Test whether the linker supports the --compress-debug-sections=zlib-gnu
+dnl option.
+AC_CACHE_CHECK([whether --compress-debug-sections=zlib-gnu is supported],
+[libgo_cv_ld_compress_zlib_gnu],
 [LDFLAGS_hold=$LDFLAGS
 LDFLAGS="$LDFLAGS -Wl,--compress-debug-sections=zlib-gnu"
 AC_LINK_IFELSE([AC_LANG_PROGRAM(,)],
-[libgo_cv_ld_compress=yes],
-[libgo_cv_ld_compress=no])
+[libgo_cv_ld_compress_zlib_gnu=yes],
+[libgo_cv_ld_compress_zlib_gnu=no])
 LDFLAGS=$LDFLAGS_hold])
-AM_CONDITIONAL(HAVE_COMPRESSED_DEBUG, test "$libgo_cv_ld_compress" = yes)
+AM_CONDITIONAL(HAVE_COMPRESSED_DEBUG_ZLIB_GNU, test "$libgo_cv_ld_compress_zlib_gnu" = yes)
+
+AC_CACHE_CHECK([whether --compress-debug-sections=zlib-gabi is supported],
+[libgo_cv_ld_compress_zlib_gabi],
+[LDFLAGS_hold=$LDFLAGS
+LDFLAGS="$LDFLAGS -Wl,--compress-debug-sections=zlib-gabi"
+AC_LINK_IFELSE([AC_LANG_PROGRAM(,)],
+[libgo_cv_ld_compress_zlib_gabi=yes],
+[libgo_cv_ld_compress_zlib_gabi=no])
+LDFLAGS=$LDFLAGS_hold])
+AM_CONDITIONAL(HAVE_COMPRESSED_DEBUG_ZLIB_GABI, test "$libgo_cv_ld_compress_zlib_gabi" = yes)
 
 AC_CHECK_LIB([zstd], [ZSTD_compress],
     [AC_DEFINE(HAVE_ZSTD, 1, [Define if -lzstd is available.])])