[PATCH v3] config.mak.uname: avoid macOS dup-library warning

["Harald Nordgren via GitGitGadget" <gitgitgadget@gmail.com>]

From: Harald Nordgren <haraldnordgren@gmail.com>

Building on macOS with Xcode 15 or newer emits:

    ld: warning: ignoring duplicate libraries: 'libgit.a',
    'target/release/libgitcore.a'

Some link recipes list the same archive twice, which is harmless.
Quiet the warning instead.

Pass -Wl,-no_warn_duplicate_libraries on Xcode 15 and newer, whose
linkers added both the warning and the suppression flag (ld64-907
and dyld-1009). Earlier linkers reject the flag, so gate on the
linker version. Broaden the existing -fno-common version probe to
also match the "ld64-NNN" and "dyld-NNN" forms Xcode 15 reports.

Signed-off-by: Harald Nordgren <haraldnordgren@gmail.com>
---
    Makefile: drop duplicate %.a from test-helper link rule
    
    Fix warning of duplicate libraries on macOS.
    
    Changes in v3:
    
     * Suppress the warning at the linker rather than dedup the archive list
     * Pass -Wl,-no_warn_duplicate_libraries in config.mak.uname, gated on
       the linker version (reuses the probe added for -fno-common), and
       broaden the regex to match all three PROJECT:{ld64,dyld,ld}-NNN forms
     * Floor of 907 and the version forms (ld64-907, dyld-1009.5) per meson:
       https://github.com/mesonbuild/meson/blob/master/mesonbuild/linkers/linkers.py

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-2314%2FHaraldNordgren%2Fmakefile-test-helper-dedup-libs-v3
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-2314/HaraldNordgren/makefile-test-helper-dedup-libs-v3
Pull-Request: https://github.com/git/git/pull/2314

Range-diff vs v2:

 1:  0ef442ea05 < -:  ---------- Makefile: dedup archives in $(LIBS) so link recipes don't repeat them
 -:  ---------- > 1:  5bf560c5ad config.mak.uname: avoid macOS dup-library warning


 config.mak.uname | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/config.mak.uname b/config.mak.uname
index 8719e09f66..9ebd240378 100644
--- a/config.mak.uname
+++ b/config.mak.uname
@@ -173,8 +173,15 @@ ifeq ($(uname_S),Darwin)
 		NEEDS_GOOD_LIBICONV = UnfortunatelyYes
         endif
 
-	# Silence Xcode 16.3+ linker warning about __DATA,__common alignment.
-	LD_MAJOR_VERSION = $(shell ld -v 2>&1 | sed -n 's/.*PROJECT:ld-\([0-9]*\).*/\1/p')
+	# ld reports "PROJECT:{ld,ld64,dyld}-NNN", match any of the three.
+	LD_MAJOR_VERSION = $(shell ld -v 2>&1 | sed -n 's/.*PROJECT:[^ ]*-\([0-9][0-9]*\).*/\1/p')
+
+	# Silence the Xcode 15+ warning about archives listed more than once.
+        ifeq ($(shell test -n "$(LD_MAJOR_VERSION)" && test "$(LD_MAJOR_VERSION)" -ge 907 && echo 1),1)
+		BASIC_LDFLAGS += -Wl,-no_warn_duplicate_libraries
+        endif
+
+	# Silence the Xcode 16.3+ warning about __DATA,__common alignment.
         ifeq ($(shell test -n "$(LD_MAJOR_VERSION)" && test "$(LD_MAJOR_VERSION)" -ge 1167 && echo 1),1)
 		BASIC_CFLAGS += -fno-common
         endif

base-commit: 95e20213faefeb95df29277c58ac1980ab68f701
-- 
gitgitgadget