ci: address Copilot round 3 review

Five real findings:

1. scripts/gen-version-h.sh: shebang said #!/usr/bin/env bash but the
   script is pure POSIX sh.  Switched to /usr/bin/env sh so it runs
   in environments without bash.  Updated the header comment to
   describe the actual call sites (Makefile parse-time $(shell),
   Android.mk, c89-lint, install-hooks pre-commit, msvc-check).
2. scripts/c89-lint.sh: now invokes the generator via \`sh\`, not
   \`bash\` -- so the C89 lint hook works on POSIX-only environments.
3. jni/Android.mk: ndk-build doesn't go through the project Makefile,
   so the parse-time version.h gen there didn't fire for local
   Android builds (only c-cpp.yml's CI step had it).  Added the
   \`$(shell sh ... gen-version-h.sh ...)\` invocation to Android.mk.
   Also dropped the now-redundant -DGIT_VERSION wiring (handled by
   the generated header).
4. scripts/install-hooks.sh header comment: corrected dist/info/.info
   path reference to "anything under dist/info/ or Makefile".
5. Makefile \`make benchmark\` target: -ldl is Linux-specific and was
   hard-coded.  macOS clang accepts it as a no-op but other linkers
   may not.  Now conditional via \`$(if $(filter Linux,$(uname)),-ldl)\`.

Local sanity: sh scripts/gen-version-h.sh runs clean, c89-lint passes,
make benchmark on Apple Silicon produces expected ~240 FPS without
spurious -ldl warnings.

Co-Authored-By: Claude Opus 4.7 <[email protected]>

Author: JoeMatt

Makefile

@@ -872,8 +872,12 @@ BENCH_BLITTER ?= fast
 benchmark: $(TARGET)
 	@# Build the harness inline so this works whether or not TEST_EXPORTS=1
 	@# was used for $(TARGET); the harness only uses retro_* exports.
+	@# -ldl is Linux-specific; macOS/BSD provide dl* in libSystem/libc
+	@# (and Apple's clang silently accepts -ldl as a no-op, but other
+	@# linkers may not).
 	$(CC) -O2 -Wall -std=c99 $(INCFLAGS) \
-		-o test/tools/test_benchmark test/tools/test_benchmark.c -ldl
+		-o test/tools/test_benchmark test/tools/test_benchmark.c \
+		$(if $(filter Linux,$(shell uname -s)),-ldl)
 	./test/tools/test_benchmark ./$(TARGET) $(BENCH_ROM) $(BENCH_FRAMES) \
 		--warmup $(BENCH_WARMUP) --blitter $(BENCH_BLITTER)
 

jni/Android.mk

@@ -6,10 +6,10 @@ include $(CORE_DIR)/Makefile.common
 
 COREFLAGS := -DINLINE="inline" -D__LIBRETRO__ $(INCFLAGS)
 
-GIT_VERSION := " $(shell git rev-parse --short HEAD || echo unknown)"
-ifneq ($(GIT_VERSION)," unknown")
-  COREFLAGS += -DGIT_VERSION=\"$(GIT_VERSION)\"
-endif
+# libretro.c includes the generated src/core/version.h.  Generate it
+# at parse time -- ndk-build doesn't go through the project Makefile,
+# so the parse-time $(shell ...) there doesn't fire for us.
+_VERSION_GEN := $(shell sh $(CORE_DIR)/scripts/gen-version-h.sh && echo ok)
 
 include $(CLEAR_VARS)
 LOCAL_MODULE    := retro

scripts/c89-lint.sh

@@ -12,7 +12,7 @@ set -e
 # exists before we run -fsyntax-only -- this script is invoked from CI
 # and pre-commit hooks where `make` may not have run yet.
 ROOT=$(cd "$(dirname "$0")/.." && pwd)
-[ -f "$ROOT/src/core/version.h" ] || bash "$ROOT/scripts/gen-version-h.sh"
+[ -f "$ROOT/src/core/version.h" ] || sh "$ROOT/scripts/gen-version-h.sh"
 
 CC="${CC:-gcc}"
 CFLAGS="-fsyntax-only -std=gnu89 -Werror=declaration-after-statement"

scripts/gen-version-h.sh

@@ -1,12 +1,17 @@
-#!/usr/bin/env bash
+#!/usr/bin/env sh
 # Generates src/core/version.h from CORE_BASE_VERSION pinned in
-# Makefile + the current short git rev.  Called by the Makefile on
-# every build (FORCE rule) and by the c-cpp.yml msvc-check step which
-# invokes cl.exe directly without going through make.
+# Makefile + the current short git rev.  Called by:
+#   - The project Makefile at parse time via $(shell ...) (gated to
+#     skip read-only goals like clean / print-* / lint).
+#   - jni/Android.mk via $(shell ...) so ndk-build picks it up.
+#   - scripts/c89-lint.sh, scripts/install-hooks.sh's pre-commit, and
+#     the c-cpp.yml msvc-check step (which invokes cl.exe directly).
 #
 # Output is gitignored.  Re-runs are content-aware: if the new
 # contents match the existing file, the mtime is left alone so
 # incremental builds don't needlessly rebuild libretro.o.
+#
+# POSIX sh compatible -- no bashisms.
 
 set -e
 

scripts/install-hooks.sh

@@ -3,7 +3,8 @@
 #
 # Currently installs a pre-commit that runs:
 #   - scripts/c89-lint.sh on staged .c files (catches MSVC C89 violations)
-#   - scripts/check-info-version.sh if dist/info/.info or Makefile is staged
+#   - scripts/check-info-version.sh if anything under dist/info/ or
+#     Makefile is staged (verifies display_version stays in sync)
 #
 # Skip with `git commit --no-verify` if you really need to (e.g., a WIP
 # squash); CI will catch it later anyway.