macos: more adjustments for OSX systems

* instead of /usr/include use the current SDK path as system
  include directory (/usr/include is empty with current tools)
  (this also removes the need to add these paths in individual
  Makefiles)
* define _DARWIN_C_SOURCE in tcc.h to get the full set of decls
  from system headers (e.g. vsnprintf), similar to _GNU_SOURCE
  (and don't define _ANSI_SOURCE in the main Makefile anymore)
* tests/tests2/Makefile: remove the -w flag, it's added when necessary
  in the rules generating the .expect files

Makefile

@@ -58,9 +58,6 @@ TCCFLAGS-unx = -B$(TOP) -I$(TOPSRC)/include -I$(TOPSRC) -I$(TOP)
 TCCFLAGS-win = -B$(TOPSRC)/win32 -I$(TOPSRC)/include -I$(TOPSRC) -I$(TOP) -L$(TOP)
 TCCFLAGS = $(TCCFLAGS$(CFGWIN))
 TCC = $(TOP)/tcc$(EXESUF) $(TCCFLAGS)
-ifdef CONFIG_OSX
- TCCFLAGS += -D_ANSI_SOURCE
-endif
 
 # cross compiler targets to build
 TCC_X = i386 x86_64 i386-win32 x86_64-win32 x86_64-osx arm arm64 arm-wince c67

configure

@@ -35,6 +35,7 @@ mingw32="no"
 LIBSUF=".a"
 EXESUF=""
 DLLSUF=".so"
+tcc_usrinclude=""
 tcc_sysincludepaths=""
 tcc_libpaths=""
 tcc_crtprefix=""
@@ -53,6 +54,7 @@ targetos=`uname`
 case $targetos in
   Darwin)
     confvars="$confvars OSX"
+    tcc_usrinclude="`xcrun --show-sdk-path`/usr/include"
     DLLSUF=".dylib"
     ;;
   Windows_NT|MINGW*|MSYS*|CYGWIN*)
@@ -401,6 +403,7 @@ fcho "Manual directory    " "$mandir"
 fcho "Info directory      " "$infodir"
 fcho "Doc directory       " "$docdir"
 fcho "Target root prefix  " "$sysroot"
+fcho "/usr/include dir    " "$tcc_usrinclude"
 echo "Source path         $source_path"
 echo "C compiler          $cc ($gcc_major.$gcc_minor)"
 echo "Target OS           $targetos"
@@ -455,6 +458,7 @@ echo "/* Automatically generated by configure - do not modify */" > $TMPH
 
 print_inc CONFIG_SYSROOT "$sysroot"
 print_inc CONFIG_TCCDIR "$tccdir"
+print_mak CONFIG_USR_INCLUDE "$tcc_usrinclude"
 print_mak CONFIG_TCC_SYSINCLUDEPATHS "$tcc_sysincludepaths"
 print_mak CONFIG_TCC_LIBPATHS "$tcc_libpaths"
 print_mak CONFIG_TCC_CRTPREFIX "$tcc_crtprefix"

lib/Makefile

@@ -17,10 +17,6 @@ XFLAGS = $(XFLAGS$(XCFG)) -I$(TOP)
 XCFG = $(or $(findstring -win,$T),-unx)
 S = $(if $(findstring yes,$(SILENT)),@$(info * $@))
 
-ifdef CONFIG_OSX
-  XFLAGS += -I`xcrun --show-sdk-path`/usr/include
-endif
-
 # in order to use gcc, type: make <target>-libtcc1-usegcc=yes
 arm-libtcc1-usegcc ?= no
 

tcc.h

@@ -22,6 +22,7 @@
 #define _TCC_H
 
 #define _GNU_SOURCE
+#define _DARWIN_C_SOURCE
 #include "config.h"
 
 #include <stdarg.h>
@@ -217,6 +218,10 @@ extern long double strtold (const char *__nptr, char **__endptr);
 # define CONFIG_TCC_CRTPREFIX USE_TRIPLET(CONFIG_SYSROOT "/usr/" CONFIG_LDDIR)
 #endif
 
+#ifndef CONFIG_USR_INCLUDE
+# define CONFIG_USR_INCLUDE "/usr/include"
+#endif
+
 /* Below: {B} is substituted by CONFIG_TCCDIR (rsp. -B option) */
 
 /* system include paths */
@@ -227,7 +232,7 @@ extern long double strtold (const char *__nptr, char **__endptr);
 #  define CONFIG_TCC_SYSINCLUDEPATHS \
         "{B}/include" \
     ":" ALSO_TRIPLET(CONFIG_SYSROOT "/usr/local/include") \
-    ":" ALSO_TRIPLET(CONFIG_SYSROOT "/usr/include")
+    ":" ALSO_TRIPLET(CONFIG_SYSROOT CONFIG_USR_INCLUDE)
 # endif
 #endif
 

tests/tests2/Makefile

@@ -15,9 +15,6 @@ endif
 ifdef CONFIG_OSX
  SKIP += 40_stdio.test 42_function_pointer.test
  SKIP += 113_btdll.test # no shared lib support yet
- FLAGS += -w
- SDK := `xcrun --show-sdk-path`
- TCCFLAGS += -I$(SDK)/usr/include
 endif
 ifeq ($(ARCH),x86_64)
  SKIP += 73_arm64.test