Drop support for very old GCC versions

They don't support C11 anyway. Additionally, CLang defines a very
conservative __GNUC__ value (which is also configurable via the
-fgnuc-version= command-line argument)

boilerplate/cairo-boilerplate.h

@@ -73,7 +73,7 @@
 #define CAIRO_BOILERPLATE_DEBUG(x)
 #endif
 
-#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 4)
+#if defined (__GNUC__)
 #ifdef __MINGW32__
 #define CAIRO_BOILERPLATE_PRINTF_FORMAT(fmt_index, va_index)            \
 	__attribute__((__format__(__MINGW_PRINTF_FORMAT, fmt_index, va_index)))

src/cairo-compiler-private.h

@@ -54,7 +54,7 @@
 
 #define CAIRO_STACK_ARRAY_LENGTH(T) (CAIRO_STACK_BUFFER_SIZE / sizeof(T))
 
-#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 4)
+#if defined (__GNUC__)
 #ifdef __MINGW32__
 #define CAIRO_PRINTF_FORMAT(fmt_index, va_index)                        \
 	__attribute__((__format__(__MINGW_PRINTF_FORMAT, fmt_index, va_index)))
@@ -67,8 +67,8 @@
 #endif
 
 #define CAIRO_HAS_HIDDEN_SYMBOLS 1
-#if (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 3)) && \
+#if defined(__GNUC__) && \
-    (defined(__ELF__) || defined(__APPLE__)) &&			\
+    (defined(__ELF__) || defined(__APPLE__)) && \
     !defined(__sun)
 #define cairo_private_no_warn	__attribute__((__visibility__("hidden")))
 #elif defined(__SUNPRO_C) && (__SUNPRO_C >= 0x550)
@@ -97,7 +97,7 @@
    indicating that the old function has been deprecated by the new
    function.
 */
-#if __GNUC__ >= 2 && defined(__ELF__)
+#if defined (__GNUC__) && defined(__ELF__)
 # define CAIRO_FUNCTION_ALIAS(old, new)		\
 	extern __typeof (new) old		\
 	__asm__ ("" #old)			\
@@ -126,17 +126,21 @@
  * constant-folding, with 'cairo_const 'also guaranteeing that pointer contents
  * do not change across the function call.
  */
-#if __GNUC__ >= 3
+#if defined (__GNUC__)
 #define cairo_pure __attribute__((pure))
 #define cairo_const __attribute__((const))
 #define cairo_always_inline inline __attribute__((always_inline))
+#elif defined (_MSC_VER)
+#define cairo_pure
+#define cairo_const
+#define cairo_always_inline __forceinline
 #else
 #define cairo_pure
 #define cairo_const
 #define cairo_always_inline inline
 #endif
 
-#if defined(__GNUC__) && (__GNUC__ > 2) && defined(__OPTIMIZE__)
+#if defined(__GNUC__) && defined(__OPTIMIZE__)
 #define likely(expr) (__builtin_expect (!!(expr), 1))
 #define unlikely(expr) (__builtin_expect (!!(expr), 0))
 #else
@@ -144,7 +148,7 @@
 #define unlikely(expr) (expr)
 #endif
 
-#ifndef __GNUC__
+#if !defined(__GNUC__)
 #undef __attribute__
 #define __attribute__(x)
 #endif
@@ -161,18 +165,11 @@
 #define strdup _strdup
 #define unlink _unlink
 #if _MSC_VER < 1900
-  #define vsnprintf _vsnprintf
+  #define vsnprintf _vsnprintf // TODO
   #define snprintf _snprintf
 #endif
 #endif
 
-#ifdef _MSC_VER
-#ifndef __cplusplus
-#undef inline
-#define inline __inline
-#endif
-#endif
-
 #if defined(_MSC_VER) && defined(_M_IX86)
 /* When compiling with /Gy and /OPT:ICF identical functions will be folded in together.
    The CAIRO_ENSURE_UNIQUE macro ensures that a function is always unique and

src/cairo.h

@@ -53,7 +53,7 @@
 #if (defined(_WIN32) || defined(__CYGWIN__)) && !defined(CAIRO_WIN32_STATIC_BUILD)
 # define _cairo_export __declspec(dllexport)
 # define _cairo_import __declspec(dllimport)
-#elif defined(__GNUC__) && (__GNUC__ >= 4)
+#elif defined(__GNUC__)
 # define _cairo_export __attribute__((__visibility__("default")))
 # define _cairo_import
 #else

src/cairoint.h

@@ -175,7 +175,7 @@ do {					\
 static inline int cairo_const
 _cairo_popcount (uint32_t mask)
 {
-#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+#if defined (__GNUC__)
     return __builtin_popcount (mask);
 #else
     register int y;

util/cairo-script/cairo-script-private.h

@@ -98,7 +98,7 @@
 #endif
 
 
-#if __GNUC__ >= 3
+#if defined (__GNUC__)
 #define csi_pure __attribute__((pure))
 #define csi_const __attribute__((const))
 #else
@@ -106,7 +106,7 @@
 #define csi_const
 #endif
 
-#if defined(__GNUC__) && (__GNUC__ > 2) && defined(__OPTIMIZE__)
+#if defined(__GNUC__) && defined(__OPTIMIZE__)
 #define _CSI_BOOLEAN_EXPR(expr)                   \
  __extension__ ({                               \
    int _csi_boolean_var_;                         \
@@ -133,7 +133,7 @@
     (type *)((char *) (ptr) - (char *) &((type *)0)->member)
 #endif
 
-#if (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 3)) && defined(__ELF__) && !defined(__sun)
+#if defined(__GNUC__) && defined(__ELF__) && !defined(__sun)
 #define csi_private_no_warn	__attribute__((__visibility__("hidden")))
 #elif defined(__SUNPRO_C) && (__SUNPRO_C >= 0x550)
 #define csi_private_no_warn	__hidden

util/cairo-trace/trace.c

@@ -100,7 +100,7 @@
  */
 #define CAIRO_BITSWAP8(c) ((((c) * 0x0802LU & 0x22110LU) | ((c) * 0x8020LU & 0x88440LU)) * 0x10101LU >> 16)
 
-#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 4)
+#if defined(__GNUC__)
 #ifdef __MINGW32__
 #define CAIRO_PRINTF_FORMAT(fmt_index, va_index)                        \
 	__attribute__((__format__(__MINGW_PRINTF_FORMAT, fmt_index, va_index)))
@@ -143,7 +143,7 @@ static void *_dlhandle = RTLD_NEXT;
 #endif
 #define BUCKET(b, ptr) (((uintptr_t) (ptr) >> PTR_SHIFT) % ARRAY_LENGTH (b))
 
-#if defined(__GNUC__) && (__GNUC__ > 2) && defined(__OPTIMIZE__)
+#if defined(__GNUC__) && defined(__OPTIMIZE__)
 #define _BOOLEAN_EXPR(expr)                   \
  __extension__ ({                             \
    int _boolean_var_;                         \
@@ -220,7 +220,7 @@ static void _init_trace (void);
 
 #define INIT_TRACE_ONCE() pthread_once (&once_control, _init_trace)
 
-#if __GNUC__ >= 3 && defined(__ELF__) && !defined(__sun)
+#if defined(__GNUC__) && defined(__ELF__) && !defined(__sun)
 # define _enter_trace() INIT_TRACE_ONCE ()
 # define _exit_trace()  do { } while (0)
 # define _should_trace() 1