1 files changed, 102 insertions, 1 deletions
diff --git a/upb/port_def.inc b/upb/port_def.inc
index fe975a0..1b343d8 100644
--- a/upb/port_def.inc
+++ b/upb/port_def.inc
@@ -1,4 +1,25 @@
-
+/*
+* This is where we define macros used across upb.
+*
+* All of these macros are undef'd in port_undef.inc to avoid leaking them to
+* users.
+*
+* The correct usage is:
+*
+*   #include "upb/foobar.h"
+*   #include "upb/baz.h"
+*
+*   // MUST be last included header.
+*   #include "upb/port_def.inc"
+*
+*   // Code for this file.
+*   // <...>
+*
+*   // Can be omitted for .c files, required for .h.
+*   #include "upb/port_undef.inc"
+*
+* This file is private and must not be included by users!
+*/
 #ifndef UINTPTR_MAX
 #error must include stdint.h first
 #endif
@@ -20,3 +41,83 @@
 #define UPB_WRITE_ONEOF(msg, fieldtype, offset, value, case_offset, case_val) \
   UPB_FIELD_AT(msg, int, case_offset) = case_val;                             \
   UPB_FIELD_AT(msg, fieldtype, offset) = value;
+
+/* UPB_INLINE: inline if possible, emit standalone code if required. */
+#ifdef __cplusplus
+#define UPB_INLINE inline
+#elif defined (__GNUC__)
+#define UPB_INLINE static __inline__
+#else
+#define UPB_INLINE static
+#endif
+
+/* Hints to the compiler about likely/unlikely branches. */
+#define UPB_LIKELY(x) __builtin_expect((x),1)
+
+/* Define UPB_BIG_ENDIAN manually if you're on big endian and your compiler
+ * doesn't provide these preprocessor symbols. */
+#if defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
+#define UPB_BIG_ENDIAN
+#endif
+
+/* Macros for function attributes on compilers that support them. */
+#ifdef __GNUC__
+#define UPB_FORCEINLINE __inline__ __attribute__((always_inline))
+#define UPB_NOINLINE __attribute__((noinline))
+#define UPB_NORETURN __attribute__((__noreturn__))
+#else  /* !defined(__GNUC__) */
+#define UPB_FORCEINLINE
+#define UPB_NOINLINE
+#define UPB_NORETURN
+#endif
+
+#if __STDC_VERSION__ >= 199901L || __cplusplus >= 201103L
+/* C99/C++11 versions. */
+#include <stdio.h>
+#define _upb_snprintf snprintf
+#define _upb_vsnprintf vsnprintf
+#define _upb_va_copy(a, b) va_copy(a, b)
+#elif defined __GNUC__
+/* A few hacky workarounds for functions not in C89.
+ * For internal use only!
+ * TODO(haberman): fix these by including our own implementations, or finding
+ * another workaround.
+ */
+#define _upb_snprintf __builtin_snprintf
+#define _upb_vsnprintf __builtin_vsnprintf
+#define _upb_va_copy(a, b) __va_copy(a, b)
+#else
+#error Need implementations of [v]snprintf and va_copy
+#endif
+
+#ifdef __cplusplus
+#if __cplusplus >= 201103L || defined(__GXX_EXPERIMENTAL_CXX0X__) || \
+    (defined(_MSC_VER) && _MSC_VER >= 1900)
+// C++11 is present
+#else
+#error upb requires C++11 for C++ support
+#endif
+#endif
+
+#define UPB_MAX(x, y) ((x) > (y) ? (x) : (y))
+#define UPB_MIN(x, y) ((x) < (y) ? (x) : (y))
+
+#define UPB_UNUSED(var) (void)var
+
+/* UPB_ASSERT(): in release mode, we use the expression without letting it be
+ * evaluated.  This prevents "unused variable" warnings. */
+#ifdef NDEBUG
+#define UPB_ASSERT(expr) do {} while (false && (expr))
+#else
+#define UPB_ASSERT(expr) assert(expr)
+#endif
+
+/* UPB_ASSERT_DEBUGVAR(): assert that uses functions or variables that only
+ * exist in debug mode.  This turns into regular assert. */
+#define UPB_ASSERT_DEBUGVAR(expr) assert(expr)
+
+#ifdef __GNUC__
+#define UPB_UNREACHABLE() do { assert(0); __builtin_unreachable(); } while(0)
+#else
+#define UPB_UNREACHABLE() do { assert(0); } while(0)
+#endif