2 files changed, 32 insertions, 2 deletions
diff --git a/src/include/c.h b/src/include/c.h
index 04fd23577de..6d4495bdd9f 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -333,6 +333,36 @@
 #endif
 
 /*
+ * pg_assume(expr) states that we assume `expr` to evaluate to true. In assert
+ * enabled builds pg_assume() is turned into an assertion, in optimized builds
+ * we try to clue the compiler into the fact that `expr` is true.
+ *
+ * This is useful for two purposes:
+ *
+ * 1) Avoid compiler warnings by telling the compiler about assumptions the
+ *	  code makes. This is particularly useful when building with optimizations
+ *	  and w/o assertions.
+ *
+ * 2) Help the compiler to generate more efficient code
+ *
+ * It is unspecified whether `expr` is evaluated, therefore it better be
+ * side-effect free.
+ */
+#if defined(USE_ASSERT_CHECKING)
+#define pg_assume(expr) Assert(expr)
+#elif defined(HAVE__BUILTIN_UNREACHABLE)
+#define pg_assume(expr) \
+	do { \
+		if (!(expr)) \
+			__builtin_unreachable(); \
+	} while (0)
+#elif defined(_MSC_VER)
+#define pg_assume(expr) __assume(expr)
+#else
+#define pg_assume(expr) ((void) 0)
+#endif
+
+/*
  * Hints to the compiler about the likelihood of a branch. Both likely() and
  * unlikely() return the boolean value of the contained expression.
  *
diff --git a/src/include/utils/pg_locale.h b/src/include/utils/pg_locale.h
index 1cd7c76a0a7..931f5b3b880 100644
--- a/src/include/utils/pg_locale.h
+++ b/src/include/utils/pg_locale.h
@@ -214,8 +214,8 @@ extern void report_newlocale_failure(const char *localename);
 
 /* These functions convert from/to libc's wchar_t, *not* pg_wchar_t */
 extern size_t wchar2char(char *to, const wchar_t *from, size_t tolen,
-						 pg_locale_t locale);
+						 locale_t loc);
 extern size_t char2wchar(wchar_t *to, size_t tolen,
-						 const char *from, size_t fromlen, pg_locale_t locale);
+						 const char *from, size_t fromlen, locale_t loc);
 
 #endif							/* _PG_LOCALE_ */