add --enable-default-compressed-debug-sections-algorithm configure option

ChangeLog:

	* configure.ac: Add --enable-default-compressed-debug-sections-algorithm.
	* configure: Regenerate.

gas/ChangeLog:

	* NEWS: Document the new option.
	* as.c (flag_compress_debug): Set default algorithm based
	on the configure option.
	* configure.ac: Add --enable-default-compressed-debug-sections-algorithm.
	* configure: Regenerate.
	* config.in: Likewise.

ld/ChangeLog:

	* NEWS: Document the new option.
	* configure.ac: Add --enable-default-compressed-debug-sections-algorithm.
	* configure: Regenerate.
	* config.in: Likewise.
	* ldmain.c: Set default algorithm based
	on the configure option.

5 files changed, 40 insertions, 3 deletions

diff --git a/ld/NEWS b/ld/NEWS
index dfe2690..d7ceb0c 100644
--- a/ld/NEWS
+++ b/ld/NEWS
@@ -2,6 +2,9 @@
 
 * ld now supports zstd compressed debug sections.  The new option
   --compress-debug-sections=zstd compresses debug sections with zstd.
+* Add --enable-default-compressed-debug-sections-algorithm={zlib,zstd}
+  that selects the default compression algorithm
+  for --enable-compressed-debug-sections.
 
 Changes in 2.39:
 
diff --git a/ld/config.in b/ld/config.in
index 3916740..ad0dc6a 100644
--- a/ld/config.in
+++ b/ld/config.in
@@ -7,6 +7,9 @@
 #endif
 #define __CONFIG_H__ 1
 
+/* Default compression algorithm for --enable-compressed-debug-sections. */
+#undef DEFAULT_COMPRESSED_DEBUG_ALGORITHM
+
 /* Define to 1 if you want to emit gnu hash in the ELF linker by default. */
 #undef DEFAULT_EMIT_GNU_HASH
 
diff --git a/ld/configure b/ld/configure
index 9dd3ed5..7906f52 100755
--- a/ld/configure
+++ b/ld/configure
@@ -841,6 +841,7 @@ with_sysroot
 enable_gold
 enable_got
 enable_compressed_debug_sections
+enable_default_compressed_debug_sections_algorithm
 enable_new_dtags
 enable_relro
 enable_textrel_check
@@ -1524,6 +1525,9 @@ Optional Features:
                           multigot)
   --enable-compressed-debug-sections={all,ld,none}
                           compress debug sections by default]
+  --enable-default-compressed-debug-sections-algorithm={zlib,zstd}
+                          Default compression algorithm for
+                          --enable-compressed-debug-sections.
   --enable-new-dtags      set DT_RUNPATH instead of DT_RPATH by default]
   --enable-relro          enable -z relro in ELF linker by default
   --enable-textrel-check=[yes|no|warning|error]
@@ -11620,7 +11624,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11623 "configure"
+#line 11627 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -11726,7 +11730,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11729 "configure"
+#line 11733 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -15544,6 +15548,15 @@ if test "${enable_compressed_debug_sections+set}" = set; then :
 esac
 fi
 
+# Select default compression algorithm.
+ac_default_compressed_debug_sections_algorithm=COMPRESS_DEBUG_GABI_ZLIB
+# Check whether --enable-default_compressed_debug_sections_algorithm was given.
+if test "${enable_default_compressed_debug_sections_algorithm+set}" = set; then :
+  enableval=$enable_default_compressed_debug_sections_algorithm; case "${enableval}" in
+   zstd) ac_default_compressed_debug_sections_algorithm=COMPRESS_DEBUG_ZSTD ;;
+esac
+fi
+
 # Decide setting DT_RUNPATH instead of DT_RPATH by default
 ac_default_new_dtags=unset
 # Provide a configure time option to override our default.
@@ -17340,6 +17353,12 @@ $as_echo "#define DEFAULT_FLAG_COMPRESS_DEBUG 1" >>confdefs.h
 
 fi
 
+
+cat >>confdefs.h <<_ACEOF
+#define DEFAULT_COMPRESSED_DEBUG_ALGORITHM $ac_default_compressed_debug_sections_algorithm
+_ACEOF
+
+
 if test "${ac_default_new_dtags}" = unset; then
   ac_default_new_dtags=0
 fi
diff --git a/ld/configure.ac b/ld/configure.ac
index f1b2f98..6123ea7 100644
--- a/ld/configure.ac
+++ b/ld/configure.ac
@@ -163,6 +163,15 @@ AC_ARG_ENABLE(compressed_debug_sections,
   ,no, | ,none,)  ac_default_compressed_debug_sections=no ;;
 esac])dnl
 
+# Select default compression algorithm.
+ac_default_compressed_debug_sections_algorithm=COMPRESS_DEBUG_GABI_ZLIB
+AC_ARG_ENABLE(default_compressed_debug_sections_algorithm,
+	      AS_HELP_STRING([--enable-default-compressed-debug-sections-algorithm={zlib,zstd}],
+	      [Default compression algorithm for --enable-compressed-debug-sections.]),
+[case "${enableval}" in
+   zstd) ac_default_compressed_debug_sections_algorithm=COMPRESS_DEBUG_ZSTD ;;
+esac])dnl
+
 # Decide setting DT_RUNPATH instead of DT_RPATH by default
 ac_default_new_dtags=unset
 # Provide a configure time option to override our default.
@@ -510,6 +519,9 @@ if test x$ac_default_compressed_debug_sections = xyes ; then
   AC_DEFINE(DEFAULT_FLAG_COMPRESS_DEBUG, 1, [Define if you want compressed debug sections by default.])
 fi
 
+AC_DEFINE_UNQUOTED(DEFAULT_COMPRESSED_DEBUG_ALGORITHM, $ac_default_compressed_debug_sections_algorithm,
+		   [Default compression algorithm for --enable-compressed-debug-sections.])
+
 if test "${ac_default_new_dtags}" = unset; then
   ac_default_new_dtags=0
 fi
diff --git a/ld/ldmain.c b/ld/ldmain.c
index d63002c..10f7a05 100644
--- a/ld/ldmain.c
+++ b/ld/ldmain.c
@@ -352,7 +352,7 @@ main (int argc, char **argv)
   link_info.spare_dynamic_tags = 5;
   link_info.path_separator = ':';
 #ifdef DEFAULT_FLAG_COMPRESS_DEBUG
-  link_info.compress_debug = COMPRESS_DEBUG_GABI_ZLIB;
+  link_info.compress_debug = DEFAULT_COMPRESSED_DEBUG_ALGORITHM;
 #endif
 #ifdef DEFAULT_NEW_DTAGS
   link_info.new_dtags = DEFAULT_NEW_DTAGS;