cmake: update nanosecond selection

For consistency, specify the nanosecond option in the same way as other options, and identify it as such. Split the detection of platform support (`FindStatNsec`) and its selection (`SelectNsec`).
2026-01-25 02:56:17 +00:00 · 2024-12-31 11:29:41 +00:00
parent 8bbd2f406e
commit 890d70856c
15 changed files with 97 additions and 63 deletions
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -27,9 +27,8 @@ option(BUILD_FUZZERS           "Build the fuzz targets"

 # Suggested functionality that may not be available on a per-platform basis
 option(USE_THREADS             "Use threads for parallel processing when possible"      ON)
-option(USE_NSEC                "Support nanosecond precision file mtimes and ctimes"    ON)

-# Backend selection
+# Feature enablement and backend selection
   set(USE_SSH                 "" CACHE STRING "Enables SSH support and optionally selects provider. One of ON, OFF, or a specific provider: libssh2 or exec. (Defaults to OFF.)")
   set(USE_HTTPS               "" CACHE STRING "Enable HTTPS support and optionally selects the provider. One of ON, OFF, or a specific provider: OpenSSL, OpenSSL-FIPS, OpenSSL-Dynamic, mbedTLS, SecureTransport, Schannel, or WinHTTP. (Defaults to ON.)")
   set(USE_SHA1                "" CACHE STRING "Selects SHA1 provider. One of builtin, HTTPS, or a specific provider. (Defaults to builtin.)")
@@ -40,6 +39,7 @@ option(USE_NSEC                "Support nanosecond precision file mtimes and cti
 #  set(USE_XDIFF               "" CACHE STRING "Specifies the xdiff implementation; either system or builtin.")
   set(USE_REGEX               "" CACHE STRING "Selects regex provider. One of regcomp_l, pcre2, pcre, regcomp, or builtin.")
   set(USE_COMPRESSION         "" CACHE STRING "Selects compression backend. Either builtin or zlib.")
+   set(USE_NSEC                "" CACHE STRING "Enable nanosecond precision timestamps. One of ON, OFF, or a specific provider: mtimespec, mtim, mtime, or win32. (Defaults to ON).")

 if(APPLE)
 	# Currently only available on macOS for `precomposeUnicode` support
--- a/cmake/FindStatNsec.cmake
+++ b/cmake/FindStatNsec.cmake
@@ -1,20 +1,6 @@
-include(FeatureSummary)
-
 check_struct_has_member("struct stat" st_mtim "sys/types.h;sys/stat.h"
 	HAVE_STRUCT_STAT_ST_MTIM LANGUAGE C)
 check_struct_has_member("struct stat" st_mtimespec "sys/types.h;sys/stat.h"
 	HAVE_STRUCT_STAT_ST_MTIMESPEC LANGUAGE C)
 check_struct_has_member("struct stat" st_mtime_nsec sys/stat.h
 	HAVE_STRUCT_STAT_MTIME_NSEC LANGUAGE C)
-
-if(HAVE_STRUCT_STAT_ST_MTIM)
-	check_struct_has_member("struct stat" st_mtim.tv_nsec sys/stat.h
-		HAVE_STRUCT_STAT_NSEC LANGUAGE C)
-elseif(HAVE_STRUCT_STAT_ST_MTIMESPEC)
-	check_struct_has_member("struct stat" st_mtimespec.tv_nsec sys/stat.h
-		HAVE_STRUCT_STAT_NSEC LANGUAGE C)
-else()
-	set(HAVE_STRUCT_STAT_NSEC ON )
-endif()
-
-add_feature_info(nanoseconds USE_NSEC "support nanosecond precision file mtimes and ctimes")
--- a/cmake/SelectNsec.cmake
+++ b/cmake/SelectNsec.cmake
@@ -0,0 +1,58 @@
+include(SanitizeBool)
+include(FeatureSummary)
+
+sanitizebool(USE_NSEC)
+
+if((USE_NSEC STREQUAL ON OR USE_NSEC STREQUAL "") AND HAVE_STRUCT_STAT_ST_MTIM)
+	set(USE_NSEC "mtim")
+elseif((USE_NSEC STREQUAL ON OR USE_NSEC STREQUAL "") AND HAVE_STRUCT_STAT_ST_MTIMESPEC)
+	set(USE_NSEC "mtimespec")
+elseif((USE_NSEC STREQUAL ON OR USE_NSEC STREQUAL "") AND HAVE_STRUCT_STAT_MTIME_NSEC)
+	set(USE_NSEC "mtime_nsec")
+elseif((USE_NSEC STREQUAL ON OR USE_NSEC STREQUAL "") AND WIN32)
+	set(USE_NSEC "win32")
+elseif(USE_NSEC STREQUAL "")
+	message(WARNING "nanosecond timestamp precision was not detected")
+	set(USE_NSEC OFF)
+elseif(USE_NSEC STREQUAL ON)
+        message(FATAL_ERROR "nanosecond support was requested but no platform support is available")
+endif()
+
+if(USE_NSEC STREQUAL "mtim")
+        if(NOT HAVE_STRUCT_STAT_ST_MTIM)
+                message(FATAL_ERROR "stat mtim could not be found")
+        endif()
+
+        set(GIT_NSEC 1)
+        set(GIT_NSEC_MTIM 1)
+        add_feature_info("Nanosecond support" ON "using mtim")
+elseif(USE_NSEC STREQUAL "mtimespec")
+        if(NOT HAVE_STRUCT_STAT_ST_MTIMESPEC)
+                message(FATAL_ERROR "mtimespec could not be found")
+        endif()
+
+        set(GIT_NSEC 1)
+        set(GIT_NSEC_MTIMESPEC 1)
+        add_feature_info("Nanosecond support" ON "using mtimespec")
+elseif(USE_NSEC STREQUAL "mtime_nsec")
+        if(NOT HAVE_STRUCT_STAT_MTIME_NSEC)
+                message(FATAL_ERROR "mtime_nsec could not be found")
+        endif()
+
+        set(GIT_NSEC 1)
+        set(GIT_NSEC_MTIME_NSEC 1)
+        add_feature_info("Nanosecond support" ON "using mtime_nsec")
+elseif(USE_NSEC STREQUAL "win32")
+        if(NOT WIN32)
+                message(FATAL_ERROR "Win32 API support is not available on this platform")
+        endif()
+
+        set(GIT_NSEC 1)
+        set(GIT_NSEC_WIN32 1)
+        add_feature_info("Nanosecond support" ON "using Win32 APIs")
+elseif(USE_NSEC STREQUAL OFF)
+        set(GIT_NSEC 0)
+        add_feature_info("Nanosecond support" OFF "Nanosecond timestamp resolution is disabled")
+else()
+        message(FATAL_ERROR "unknown nanosecond option: ${USE_NSEC}")
+endif()
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -36,6 +36,7 @@ add_feature_info(debugopen GIT_DEBUG_STRICT_OPEN "path validation in open")
 # Optional feature enablement
 #

+include(SelectNsec)
 include(SelectHTTPSBackend)
 include(SelectHashes)
 include(SelectHTTPParser)
@@ -110,22 +111,6 @@ else()
 	message(FATAL_ERROR "Unsupported architecture (CMAKE_SIZEOF_VOID_P is unset)")
 endif()

-# nanosecond mtime/ctime support
-
-if(USE_NSEC)
-	set(GIT_USE_NSEC 1)
-endif()
-
-# high-resolution stat support
-
-if(HAVE_STRUCT_STAT_ST_MTIM)
-	set(GIT_USE_STAT_MTIM 1)
-elseif(HAVE_STRUCT_STAT_ST_MTIMESPEC)
-	set(GIT_USE_STAT_MTIMESPEC 1)
-elseif(HAVE_STRUCT_STAT_ST_MTIME_NSEC)
-	set(GIT_USE_STAT_MTIME_NSEC 1)
-endif()
-
 # realtime support

 check_library_exists(rt clock_gettime "time.h" NEED_LIBRT)
--- a/src/libgit2/index.c
+++ b/src/libgit2/index.c
@@ -902,7 +902,7 @@ void git_index_entry__init_from_stat(
 {
 	entry->ctime.seconds = (int32_t)st->st_ctime;
 	entry->mtime.seconds = (int32_t)st->st_mtime;
-#if defined(GIT_USE_NSEC)
+#if defined(GIT_NSEC)
 	entry->mtime.nanoseconds = st->st_mtime_nsec;
 	entry->ctime.nanoseconds = st->st_ctime_nsec;
 #endif
--- a/src/libgit2/index.h
+++ b/src/libgit2/index.h
@@ -85,7 +85,7 @@ GIT_INLINE(bool) git_index_time_eq(const git_index_time *one, const git_index_ti
 	if (one->seconds != two->seconds)
 		return false;

-#ifdef GIT_USE_NSEC
+#ifdef GIT_NSEC
 	if (one->nanoseconds != two->nanoseconds)
 		return false;
 #endif
@@ -106,7 +106,7 @@ GIT_INLINE(bool) git_index_entry_newer_than_index(
 		return false;

 	/* If the timestamp is the same or newer than the index, it's racy */
-#if defined(GIT_USE_NSEC)
+#if defined(GIT_NSEC)
 	if ((int32_t)index->stamp.mtime.tv_sec < entry->mtime.seconds)
 		return true;
 	else if ((int32_t)index->stamp.mtime.tv_sec > entry->mtime.seconds)
--- a/src/libgit2/iterator.c
+++ b/src/libgit2/iterator.c
@@ -1520,7 +1520,7 @@ static void filesystem_iterator_set_current(
 	iter->entry.ctime.seconds = (int32_t)entry->st.st_ctime;
 	iter->entry.mtime.seconds = (int32_t)entry->st.st_mtime;

-#if defined(GIT_USE_NSEC)
+#if defined(GIT_NSEC)
 	iter->entry.ctime.nanoseconds = entry->st.st_ctime_nsec;
 	iter->entry.mtime.nanoseconds = entry->st.st_mtime_nsec;
 #else
--- a/src/libgit2/libgit2.c
+++ b/src/libgit2/libgit2.c
@@ -90,7 +90,7 @@ int git_libgit2_features(void)
 #ifdef GIT_SSH
 		| GIT_FEATURE_SSH
 #endif
-#ifdef GIT_USE_NSEC
+#ifdef GIT_NSEC
 		| GIT_FEATURE_NSEC
 #endif
 		| GIT_FEATURE_HTTP_PARSER
@@ -152,15 +152,15 @@ const char *git_libgit2_feature_backend(git_feature_t feature)
 		break;

 	case GIT_FEATURE_NSEC:
-#if defined(GIT_USE_NSEC) && defined(GIT_USE_STAT_MTIMESPEC)
+#if defined(GIT_NSEC_MTIMESPEC)
 		return "mtimespec";
-#elif defined(GIT_USE_NSEC) && defined(GIT_USE_STAT_MTIM)
+#elif defined(GIT_NSEC_MTIM)
 		return "mtim";
-#elif defined(GIT_USE_NSEC) && defined(GIT_USE_STAT_MTIME_NSEC)
-		return "mtime";
-#elif defined(GIT_USE_NSEC) && defined(GIT_WIN32)
+#elif defined(GIT_NSEC_MTIME_NSEC)
+		return "mtime_nsec";
+#elif defined(GIT_NSEC_WIN32)
 		return "win32";
-#elif defined(GIT_USE_NSEC)
+#elif defined(GIT_NSEC)
 		GIT_ASSERT_WITH_RETVAL(!"Unknown high-resolution time backend", NULL);
 #endif
 		break;
--- a/src/util/futils.c
+++ b/src/util/futils.c
@@ -1158,7 +1158,7 @@ int git_futils_filestamp_check(
 		return GIT_ENOTFOUND;

 	if (stamp->mtime.tv_sec == st.st_mtime &&
-#if defined(GIT_USE_NSEC)
+#if defined(GIT_NSEC)
 		stamp->mtime.tv_nsec == st.st_mtime_nsec &&
 #endif
 		stamp->size  == (uint64_t)st.st_size   &&
@@ -1166,7 +1166,7 @@ int git_futils_filestamp_check(
 		return 0;

 	stamp->mtime.tv_sec = st.st_mtime;
-#if defined(GIT_USE_NSEC)
+#if defined(GIT_NSEC)
 	stamp->mtime.tv_nsec = st.st_mtime_nsec;
 #endif
 	stamp->size  = (uint64_t)st.st_size;
@@ -1190,7 +1190,7 @@ void git_futils_filestamp_set_from_stat(
 {
 	if (st) {
 		stamp->mtime.tv_sec = st->st_mtime;
-#if defined(GIT_USE_NSEC)
+#if defined(GIT_NSEC)
 		stamp->mtime.tv_nsec = st->st_mtime_nsec;
 #else
 		stamp->mtime.tv_nsec = 0;
--- a/src/util/git2_features.h.in
+++ b/src/util/git2_features.h.in
@@ -14,10 +14,12 @@
 #cmakedefine GIT_I18N 1
 #cmakedefine GIT_I18N_ICONV 1

-#cmakedefine GIT_USE_NSEC 1
-#cmakedefine GIT_USE_STAT_MTIM 1
-#cmakedefine GIT_USE_STAT_MTIMESPEC 1
-#cmakedefine GIT_USE_STAT_MTIME_NSEC 1
+#cmakedefine GIT_NSEC 1
+#cmakedefine GIT_NSEC_MTIM 1
+#cmakedefine GIT_NSEC_MTIMESPEC 1
+#cmakedefine GIT_NSEC_MTIME_NSEC 1
+#cmakedefine GIT_NSEC_WIN32 1
+
 #cmakedefine GIT_USE_FUTIMENS 1

 #cmakedefine GIT_REGEX_REGCOMP_L 1
--- a/src/util/unix/posix.h
+++ b/src/util/unix/posix.h
@@ -23,16 +23,16 @@ typedef int GIT_SOCKET;
 #define p_lstat(p,b) lstat(p,b)
 #define p_stat(p,b) stat(p, b)

-#if defined(GIT_USE_STAT_MTIMESPEC)
+#if defined(GIT_NSEC_MTIMESPEC)
 # define st_atime_nsec st_atimespec.tv_nsec
 # define st_mtime_nsec st_mtimespec.tv_nsec
 # define st_ctime_nsec st_ctimespec.tv_nsec
-#elif defined(GIT_USE_STAT_MTIM)
+#elif defined(GIT_NSEC_MTIM)
 # define st_atime_nsec st_atim.tv_nsec
 # define st_mtime_nsec st_mtim.tv_nsec
 # define st_ctime_nsec st_ctim.tv_nsec
-#elif !defined(GIT_USE_STAT_MTIME_NSEC) && defined(GIT_USE_NSEC)
-# error GIT_USE_NSEC defined but unknown struct stat nanosecond type
+#elif !defined(GIT_NSEC_MTIME_NSEC) && defined(GIT_NSEC)
+# error GIT_NSEC defined but unknown struct stat nanosecond type
 #endif

 #define p_utimes(f, t) utimes(f, t)
--- a/src/util/win32/w32_util.h
+++ b/src/util/win32/w32_util.h
@@ -77,8 +77,10 @@ GIT_INLINE(void) git_win32__filetime_to_timespec(
 	int64_t winTime = ((int64_t)ft->dwHighDateTime << 32) + ft->dwLowDateTime;
 	winTime -= INT64_C(116444736000000000); /* Windows to Unix Epoch conversion */
 	ts->tv_sec = (time_t)(winTime / 10000000);
-#ifdef GIT_USE_NSEC
+#ifdef GIT_NSEC_WIN32
 	ts->tv_nsec = (winTime % 10000000) * 100;
+#elif GIT_NSEC
+# error GIT_NSEC defined but GIT_NSEC_WIN32 not defined
 #else
 	ts->tv_nsec = 0;
 #endif
--- a/tests/libgit2/checkout/checkout_helpers.h
+++ b/tests/libgit2/checkout/checkout_helpers.h
@@ -1,5 +1,6 @@
 #include "git2/object.h"
 #include "git2/repository.h"
+#include "git2_features.h"

 extern void assert_on_branch(git_repository *repo, const char *branch);
 extern void reset_index_to_treeish(git_object *treeish);
--- a/tests/libgit2/core/features.c
+++ b/tests/libgit2/core/features.c
@@ -20,7 +20,7 @@ void test_core_features__basic(void)
 	cl_assert((caps & GIT_FEATURE_SSH) == 0);
 #endif

-#if defined(GIT_USE_NSEC)
+#if defined(GIT_NSEC)
 	cl_assert((caps & GIT_FEATURE_NSEC) != 0);
 #else
 	cl_assert((caps & GIT_FEATURE_NSEC) == 0);
@@ -118,15 +118,15 @@ void test_core_features__backends(void)
 	cl_assert(ssh == NULL);
 #endif

-#if defined(GIT_USE_NSEC) && defined(GIT_USE_STAT_MTIMESPEC)
+#if defined(GIT_NSEC_MTIMESPEC)
 	cl_assert_equal_s("mtimespec", nsec);
-#elif defined(GIT_USE_NSEC) && defined(GIT_USE_STAT_MTIM)
+#elif defined(GIT_NSEC_MTIM)
 	cl_assert_equal_s("mtim", nsec);
-#elif defined(GIT_USE_NSEC) && defined(GIT_USE_STAT_MTIME_NSEC)
-	cl_assert_equal_s("mtime", nsec);
-#elif defined(GIT_USE_NSEC) && defined(GIT_WIN32)
+#elif defined(GIT_NSEC_MTIME_NSEC)
+	cl_assert_equal_s("mtime_nsec", nsec);
+#elif defined(GIT_NSEC_WIN32)
 	cl_assert_equal_s("win32", nsec);
-#elif defined(GIT_USE_NSEC)
+#elif defined(GIT_NSEC)
 	cl_assert(0);
 #else
 	cl_assert(nsec == NULL);
--- a/tests/libgit2/merge/workdir/dirty.c
+++ b/tests/libgit2/merge/workdir/dirty.c
@@ -162,7 +162,7 @@ static void hack_index(char *files[])

 		entry->ctime.seconds = (int32_t)statbuf.st_ctime;
 		entry->mtime.seconds = (int32_t)statbuf.st_mtime;
-#if defined(GIT_USE_NSEC)
+#if defined(GIT_NSEC)
 		entry->ctime.nanoseconds = statbuf.st_ctime_nsec;
 		entry->mtime.nanoseconds = statbuf.st_mtime_nsec;
 #else