Makefile: add USE_WILDMATCH to use wildmatch as fnmatch

This is similar to NO_FNMATCH but it uses wildmatch instead of
compat/fnmatch. This is an intermediate step to let wildmatch be used
as fnmatch replacement for wider audience before it replaces fnmatch
completely and compat/fnmatch is removed.

fnmatch in test-wildmatch is not impacted by this and is the only
place that NO_FNMATCH or NO_FNMATCH_CASEFOLD remain active when
USE_WILDMATCH is set.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -99,6 +99,9 @@ all::
 # Define NO_FNMATCH_CASEFOLD if your fnmatch function doesn't have the
 # FNM_CASEFOLD GNU extension.
 #
+# Define USE_WILDMATCH if you want to use Git's wildmatch
+# implementation as fnmatch
+#
 # Define NO_GECOS_IN_PWENT if you don't have pw_gecos in struct passwd
 # in the C library.
 #
@@ -1625,6 +1628,9 @@ ifdef NO_FNMATCH_CASEFOLD
 	COMPAT_OBJS += compat/fnmatch/fnmatch.o
 endif
 endif
+ifdef USE_WILDMATCH
+	COMPAT_CFLAGS += -DUSE_WILDMATCH
+endif
 ifdef NO_SETENV
 	COMPAT_CFLAGS += -DNO_SETENV
 	COMPAT_OBJS += compat/setenv.o

git-compat-util.h

@@ -106,7 +106,9 @@
 #include <sys/time.h>
 #include <time.h>
 #include <signal.h>
+#ifndef USE_WILDMATCH
 #include <fnmatch.h>
+#endif
 #include <assert.h>
 #include <regex.h>
 #include <utime.h>
@@ -238,6 +240,17 @@ extern char *gitbasename(char *);
 
 #include "compat/bswap.h"
 
+#ifdef USE_WILDMATCH
+#include "wildmatch.h"
+#define FNM_PATHNAME WM_PATHNAME
+#define FNM_CASEFOLD WM_CASEFOLD
+#define FNM_NOMATCH  WM_NOMATCH
+static inline int fnmatch(const char *pattern, const char *string, int flags)
+{
+	return wildmatch(pattern, string, flags, NULL);
+}
+#endif
+
 /* General helper functions */
 extern void vreportf(const char *prefix, const char *err, va_list params);
 extern void vwritef(int fd, const char *prefix, const char *err, va_list params);

test-wildmatch.c

@@ -1,3 +1,6 @@
+#ifdef USE_WILDMATCH
+#undef USE_WILDMATCH  /* We need real fnmatch implementation here */
+#endif
 #include "cache.h"
 #include "wildmatch.h"