A few fixups in error handling: mark pg_re_throw() as noreturn for gcc,

and for other compilers, insert a dummy exit() call so that they understand
PG_RE_THROW() doesn't return.  Insert fflush(stderr) in ExceptionalCondition,
per recent buildfarm evidence that that might not happen automatically on some
platforms.  And const-ify ExceptionalCondition's declaration while at it.

src/backend/utils/error/assert.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/error/assert.c,v 1.33 2007/01/05 22:19:43 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/error/assert.c,v 1.34 2007/05/04 02:01:02 tgl Exp $
  *
  * NOTE
  *	  This should eventually work with elog()
@@ -21,11 +21,14 @@
 
 /*
  * ExceptionalCondition - Handles the failure of an Assert()
+ *
+ * Note: this can't actually return, but we declare it as returning int
+ * because the TrapMacro() macro might get wonky otherwise.
  */
 int
-ExceptionalCondition(char *conditionName,
-					 char *errorType,
-					 char *fileName,
+ExceptionalCondition(const char *conditionName,
+					 const char *errorType,
+					 const char *fileName,
 					 int lineNumber)
 {
 	if (!PointerIsValid(conditionName)
@@ -39,6 +42,9 @@ ExceptionalCondition(char *conditionName,
 					 fileName, lineNumber);
 	}
 
+	/* Usually this shouldn't be needed, but make sure the msg went out */
+	fflush(stderr);
+
 #ifdef SLEEP_ON_ASSERT
 
 	/*

src/backend/utils/error/elog.c

@@ -42,7 +42,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/error/elog.c,v 1.184 2007/05/02 15:32:41 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/error/elog.c,v 1.185 2007/05/04 02:01:02 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1151,6 +1151,16 @@ pg_re_throw(void)
 
 		errfinish(0);
 	}
+
+	/* We mustn't return... */
+	ExceptionalCondition("pg_re_throw tried to return", "FailedAssertion",
+						 __FILE__, __LINE__);
+
+	/*
+	 * Since ExceptionalCondition isn't declared noreturn because of
+	 * TrapMacro(), we need this to keep gcc from complaining.
+	 */
+	abort();
 }
 
 

src/include/postgres.h

@@ -10,7 +10,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1995, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/postgres.h,v 1.79 2007/04/06 04:21:44 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/postgres.h,v 1.80 2007/05/04 02:01:02 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -694,8 +694,9 @@ extern DLLIMPORT bool assert_enabled;
 		Trap(!(condition), "BadState")
 #endif   /* USE_ASSERT_CHECKING */
 
-extern int ExceptionalCondition(char *conditionName, char *errorType,
-					 char *fileName, int lineNumber);
+extern int ExceptionalCondition(const char *conditionName,
+								const char *errorType,
+								const char *fileName, int lineNumber);
 
 /* ----------------------------------------------------------------
  *				Section 4: genbki macros used by catalog/pg_xxx.h files

src/include/utils/elog.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/utils/elog.h,v 1.85 2007/05/02 15:32:42 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/utils/elog.h,v 1.86 2007/05/04 02:01:02 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -222,8 +222,17 @@ extern DLLIMPORT ErrorContextCallback *error_context_stack;
 		error_context_stack = save_context_stack; \
 	} while (0)
 
+/*
+ * gcc understands __attribute__((noreturn)); for other compilers, insert
+ * a useless exit() call so that the compiler gets the point.
+ */
+#ifdef __GNUC__
 #define PG_RE_THROW()  \
 	pg_re_throw()
+#else
+#define PG_RE_THROW()  \
+	(pg_re_throw(), exit(1))
+#endif
 
 extern DLLIMPORT sigjmp_buf *PG_exception_stack;
 
@@ -262,7 +271,7 @@ extern ErrorData *CopyErrorData(void);
 extern void FreeErrorData(ErrorData *edata);
 extern void FlushErrorState(void);
 extern void ReThrowError(ErrorData *edata);
-extern void pg_re_throw(void);
+extern void pg_re_throw(void) __attribute__((noreturn));
 
 
 /* GUC-configurable parameters */