Merge pull request DeusData#829 from SyntaxSawdust/codex/issue-801-libgit2-floor

fix(build): gate libgit2 allocator support

Author: DeusData

.github/workflows/_test.yml

@@ -33,7 +33,7 @@ jobs:
           BROAD: ${{ inputs.broad_platforms }}
         run: |
           CORE_UNIX='[
-            {"os":"ubuntu-latest","cc":"gcc","cxx":"g++"},
+            {"os":"ubuntu-latest","cc":"gcc","cxx":"g++","libgit2":true},
             {"os":"ubuntu-24.04-arm","cc":"gcc","cxx":"g++"},
             {"os":"macos-14","cc":"cc","cxx":"c++"},
             {"os":"macos-15-intel","cc":"cc","cxx":"c++"}
@@ -79,10 +79,15 @@ jobs:
 
       - name: Install deps (Ubuntu)
         if: startsWith(matrix.os, 'ubuntu')
-        run: sudo apt-get update && sudo apt-get install -y zlib1g-dev
+        run: sudo apt-get update && sudo apt-get install -y zlib1g-dev ${{ matrix.libgit2 == true && 'libgit2-dev pkg-config' || '' }}
 
       - name: Test
-        run: scripts/test.sh CC=${{ matrix.cc }} CXX=${{ matrix.cxx }}
+        run: |
+          if [ "${{ matrix.libgit2 == true }}" = "true" ]; then
+            echo "REQUIRE_LIBGIT2=1"
+            pkg-config --modversion libgit2
+          fi
+          scripts/test.sh CC=${{ matrix.cc }} CXX=${{ matrix.cxx }} ${{ matrix.libgit2 == true && 'REQUIRE_LIBGIT2=1' || '' }}
         env:
           CBM_SKIP_PERF: ${{ inputs.skip_perf && '1' || '' }}
 

Makefile.cbm

@@ -35,12 +35,25 @@ TS_INCLUDE = $(CBM_DIR)/vendored/ts_runtime/include
 TS_SRC = $(CBM_DIR)/vendored/ts_runtime/src
 
 # ── Optional libgit2 (faster git history parsing) ────────────────
-# Auto-detected via pkg-config. Falls back to popen("git log ...") if absent.
-LIBGIT2_CFLAGS := $(shell pkg-config --cflags libgit2 2>/dev/null)
-LIBGIT2_LIBS := $(shell pkg-config --libs libgit2 2>/dev/null)
-ifneq ($(LIBGIT2_LIBS),)
+# Auto-detected via pkg-config. Falls back to popen("git log ...") if absent
+# or too old for the git_allocator ABI used by the production allocator bind.
+PKG_CONFIG ?= pkg-config
+LIBGIT2_MIN_VERSION := 1.7.0
+LIBGIT2_AVAILABLE := $(shell $(PKG_CONFIG) --atleast-version=$(LIBGIT2_MIN_VERSION) libgit2 >/dev/null 2>&1 && echo yes || echo no)
+
+ifeq ($(REQUIRE_LIBGIT2),1)
+ifneq ($(LIBGIT2_AVAILABLE),yes)
+LIBGIT2_VERSION := $(shell $(PKG_CONFIG) --modversion libgit2 2>/dev/null)
+$(error libgit2 >= $(LIBGIT2_MIN_VERSION) is required when REQUIRE_LIBGIT2=1; pkg-config found $(if $(LIBGIT2_VERSION),$(LIBGIT2_VERSION),none))
+endif
+endif
+
+ifeq ($(LIBGIT2_AVAILABLE),yes)
+LIBGIT2_CFLAGS := $(shell $(PKG_CONFIG) --cflags libgit2 2>/dev/null)
+LIBGIT2_LIBS := $(shell $(PKG_CONFIG) --libs libgit2 2>/dev/null)
 LIBGIT2_FLAGS = -DHAVE_LIBGIT2 $(LIBGIT2_CFLAGS)
 else
+LIBGIT2_CFLAGS =
 LIBGIT2_FLAGS =
 LIBGIT2_LIBS =
 endif

internal/cbm/cbm.c

@@ -22,6 +22,19 @@
 #if defined(CBM_BIND_TS_ALLOCATOR) && CBM_BIND_TS_ALLOCATOR
 #include "sqlite3.h" // sqlite3_mem_methods, sqlite3_config, SQLITE_CONFIG_MALLOC — bind sqlite to mimalloc
 #if defined(HAVE_LIBGIT2)
+#include <git2/version.h>
+#if defined(LIBGIT2_VERSION_CHECK)
+#if !LIBGIT2_VERSION_CHECK(1, 7, 0)
+#error "HAVE_LIBGIT2 requires libgit2 >= 1.7.0 for git_allocator"
+#endif
+#elif defined(LIBGIT2_VER_MAJOR) && defined(LIBGIT2_VER_MINOR) && defined(LIBGIT2_VER_REVISION)
+#if ((LIBGIT2_VER_MAJOR * 1000000) + (LIBGIT2_VER_MINOR * 10000) + (LIBGIT2_VER_REVISION * 100)) < \
+    1070000
+#error "HAVE_LIBGIT2 requires libgit2 >= 1.7.0 for git_allocator"
+#endif
+#else
+#error "HAVE_LIBGIT2 requires known libgit2 version macros for the >= 1.7.0 git_allocator guard"
+#endif
 #include <git2.h>           // git_libgit2_opts, GIT_OPT_SET_ALLOCATOR — bind libgit2 to mimalloc
 #include <git2/sys/alloc.h> // git_allocator — not pulled in by <git2.h> (it's a sys/ header)
 #endif
@@ -289,8 +302,8 @@ static void cbm_sqlite_memshutdown(void *appdata) {
 }
 
 #if defined(HAVE_LIBGIT2)
-/* libgit2 git_allocator backed by mimalloc. The struct (current libgit2) has
- * exactly three members: gmalloc(size_t,file,line), grealloc(ptr,size,file,line),
+/* libgit2 >= 1.7 git_allocator backed by mimalloc. The struct has exactly
+ * three members: gmalloc(size_t,file,line), grealloc(ptr,size,file,line),
  * gfree(ptr). The file/line args are ignored. */
 static void *cbm_git_malloc(size_t n, const char *file, int line) {
     (void)file;