3 files changed, 53 insertions, 0 deletions
diff --git a/src/include/c.h b/src/include/c.h
index 50e1ecfde4d..06f689d3593 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -689,6 +689,47 @@ typedef NameData *Name;
 	} while (0)
 
 
+/*
+ * Macros to support compile-time assertion checks, if the compiler has them.
+ *
+ * If the "condition" (a compile-time-constant expression) evaluates to false,
+ * throw a compile error using the "errmessage" (a string literal).
+ *
+ * gcc 4.6 and up supports _Static_assert(), but it has bizarre syntactic
+ * placement restrictions.  These macros make it safe to use as a statement
+ * or in an expression, respectively.
+ */
+#ifdef HAVE__STATIC_ASSERT
+#define StaticAssertStmt(condition, errmessage) \
+	do { _Static_assert(condition, errmessage); } while(0)
+#define StaticAssertExpr(condition, errmessage) \
+	({ StaticAssertStmt(condition, errmessage); true; })
+#else /* !HAVE__STATIC_ASSERT */
+#define StaticAssertStmt(condition, errmessage)
+#define StaticAssertExpr(condition, errmessage) ((void) true)
+#endif /* HAVE__STATIC_ASSERT */
+
+
+/*
+ * Compile-time checks that a variable (or expression) has the specified type.
+ *
+ * AssertVariableIsOfType() can be used as a statement.
+ * AssertVariableIsOfTypeMacro() is intended for use in macros, eg
+ *		#define foo(x) (AssertVariableIsOfTypeMacro(x, int), bar(x))
+ */
+#ifdef HAVE__BUILTIN_TYPES_COMPATIBLE_P
+#define AssertVariableIsOfType(varname, typename) \
+	StaticAssertStmt(__builtin_types_compatible_p(__typeof__(varname), typename), \
+	CppAsString(varname) " does not have type " CppAsString(typename))
+#define AssertVariableIsOfTypeMacro(varname, typename) \
+	StaticAssertExpr(__builtin_types_compatible_p(__typeof__(varname), typename), \
+	CppAsString(varname) " does not have type " CppAsString(typename))
+#else /* !HAVE__BUILTIN_TYPES_COMPATIBLE_P */
+#define AssertVariableIsOfType(varname, typename)
+#define AssertVariableIsOfTypeMacro(varname, typename) ((void) true)
+#endif /* HAVE__BUILTIN_TYPES_COMPATIBLE_P */
+
+
 /* ----------------------------------------------------------------
  *				Section 7:	random stuff
  * ----------------------------------------------------------------
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 1ffb032835f..58cd5907dd4 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -635,6 +635,12 @@
 /* Define to 1 if you have the <winldap.h> header file. */
 #undef HAVE_WINLDAP_H
 
+/* Define to 1 if your compiler understands __builtin_types_compatible_p. */
+#undef HAVE__BUILTIN_TYPES_COMPATIBLE_P
+
+/* Define to 1 if your compiler understands _Static_assert. */
+#undef HAVE__STATIC_ASSERT
+
 /* Define to the appropriate snprintf format for 64-bit ints. */
 #undef INT64_FORMAT
 
diff --git a/src/include/pg_config.h.win32 b/src/include/pg_config.h.win32
index b7b7c641d3a..4d9cc55c699 100644
--- a/src/include/pg_config.h.win32
+++ b/src/include/pg_config.h.win32
@@ -526,6 +526,12 @@
 /* Define to 1 if you have the <winldap.h> header file. */
 /* #undef HAVE_WINLDAP_H */
 
+/* Define to 1 if your compiler understands __builtin_types_compatible_p. */
+/* #undef HAVE__BUILTIN_TYPES_COMPATIBLE_P */
+
+/* Define to 1 if your compiler understands _Static_assert. */
+/* #undef HAVE__STATIC_ASSERT */
+
 /* Define to the appropriate snprintf format for 64-bit ints, if any. */
 #define INT64_FORMAT "%lld"