[binutils-gdb] objcopy: Don't add zstd to the debug compression options if not available

[Alan Modra]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=4cfcc5412cc2dd1ebe31ca467f2afe4752d45952

commit 4cfcc5412cc2dd1ebe31ca467f2afe4752d45952
Author: Pietro Monteiro <pietro@sociotechnical.xyz>
Date:   Sun Oct 19 20:14:51 2025 -0400

    objcopy: Don't add zstd to the debug compression options if not available
    
    If zstd is not available or was intentionally disabled by the user
    don't add it to the list of the available options to compress debug
    sections when showing usage.
    
    binutils/
            * objcopy.c (copy_usage): Only output
            --compress-debug-sections=zstd if HAVE_ZSTD.

Diff:
---
 binutils/objcopy.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/binutils/objcopy.c b/binutils/objcopy.c
index 3c1bcf622ff..9373b75d6ed 100644
--- a/binutils/objcopy.c
+++ b/binutils/objcopy.c
@@ -570,6 +570,12 @@ static bool write_debugging_info (bfd *, void *, long *, asymbol ***);
 static const char *lookup_sym_redefinition (const char *);
 static const char *find_section_rename (const char *, flagword *);
 

+#ifdef HAVE_ZSTD
+#define ZSTD_OPT "|zstd"
+#else
+#define ZSTD_OPT ""
+#endif
+
 ATTRIBUTE_NORETURN static void
 copy_usage (FILE *stream, int exit_status)
 {
@@ -692,8 +698,8 @@ copy_usage (FILE *stream, int exit_status)
                                    <commit>\n\
      --subsystem <name>[:<version>]\n\
                                    Set PE subsystem to <name> [& <version>]\n\
-     --compress-debug-sections[={none|zlib|zlib-gnu|zlib-gabi|zstd}]\n\
-				   Compress DWARF debug sections\n\
+     --compress-debug-sections[={none|zlib|zlib-gnu|zlib-gabi" ZSTD_OPT "}]\n\
+                                   Compress DWARF debug sections\n\
      --decompress-debug-sections   Decompress DWARF debug sections using zlib\n\
      --elf-stt-common=[yes|no]     Generate ELF common symbols with STT_COMMON\n\
                                      type\n\