Mark Terminate() as noreturn

This helps the compiler identify which code paths are taken
rarely, and move them out of the way from hot paths.

Author: magv

configure.ac

@@ -267,6 +267,17 @@ AS_IF([test $ok != yes],
 		[ok=yes;
 		AC_DEFINE([HAVE_POPCNT], [1], [Define to 1 if you have __popcnt function.])])
 	AC_MSG_RESULT($ok)])
+AC_MSG_CHECKING([__attribute__((noreturn))])
+AC_LINK_IFELSE(
+	[AC_LANG_PROGRAM([extern void fatal() __attribute__((noreturn));], [return 0;])],
+	[
+		AC_DEFINE(NORETURN, [__attribute__((noreturn))], [The "noreturn" function attribute.])
+		AC_MSG_RESULT([yes])
+	],
+	[
+		AC_DEFINE(NORETURN, [], [The "noreturn" function attribute.])
+		AC_MSG_RESULT([no])
+	])
 
 # Check for inline
 AC_C_INLINE

sources/declare.h

@@ -410,7 +410,7 @@ static inline ULONG LongAbs(LONG x)
  */
 static inline int UnsignedToInt(unsigned int x)
 {
-	extern void TerminateImpl(int, const char*, int, const char*);
+	extern void TerminateImpl(int, const char*, int, const char*) NORETURN;
 	if ( x <= INT_MAX ) return(x);
 	if ( x >= (unsigned int)INT_MIN )
 		return((int)(x - (unsigned int)INT_MIN) + INT_MIN);
@@ -420,7 +420,7 @@ static inline int UnsignedToInt(unsigned int x)
 
 static inline WORD UWordToWord(UWORD x)
 {
-	extern void TerminateImpl(int, const char*, int, const char*);
+	extern void TerminateImpl(int, const char*, int, const char*) NORETURN;
 	if ( x <= WORD_MAX_VALUE ) return(x);
 	if ( x >= (UWORD)WORD_MIN_VALUE )
 		return((WORD)(x - (UWORD)WORD_MIN_VALUE) + WORD_MIN_VALUE);
@@ -430,7 +430,7 @@ static inline WORD UWordToWord(UWORD x)
 
 static inline LONG ULongToLong(ULONG x)
 {
-	extern void TerminateImpl(int, const char*, int, const char*);
+	extern void TerminateImpl(int, const char*, int, const char*) NORETURN;
 	if ( x <= LONG_MAX_VALUE ) return(x);
 	if ( x >= (ULONG)LONG_MIN_VALUE )
 		return((LONG)(x - (ULONG)LONG_MIN_VALUE) + LONG_MIN_VALUE);
@@ -791,7 +791,7 @@ extern VOID   PositionStream(STREAM *,LONG);
 extern int    ReverseStatements(STREAM *);
 extern int    ProcessOption(UBYTE *,UBYTE *,int);
 extern int    DoSetups(VOID);
-extern VOID   TerminateImpl(int, const char *,int, const char *);
+extern VOID   TerminateImpl(int, const char *,int, const char *) NORETURN;
 extern NAMENODE *GetNode(NAMETREE *,UBYTE *);
 extern int    AddName(NAMETREE *,UBYTE *,WORD,WORD,int *);
 extern int    GetName(NAMETREE *,UBYTE *,WORD *,int);
@@ -990,7 +990,7 @@ extern int    DoPolyratfun(UBYTE *);
 extern int    CompileStatement(UBYTE *);
 extern UBYTE *ToToken(UBYTE *);
 extern int    GetDollar(UBYTE *);
-extern int    MesWork(VOID);
+extern VOID   MesWork(VOID) NORETURN;
 extern int    MesPrint(const char *,...);
 extern int    MesCall(char *);
 extern UBYTE *NumCopy(WORD,UBYTE *);

sources/execute.c

@@ -1118,7 +1118,9 @@ WORD PutBracket(PHEAD WORD *termin)
 	WORD *bbb = 0, *bind, *binst = 0, bwild = 0, *bss = 0, *bns = 0, bset = 0;
 	term1 = AT.WorkPointer+1;
 	term2 = (WORD *)(((UBYTE *)(term1)) + AM.MaxTer);
-	if ( ( (WORD *)(((UBYTE *)(term2)) + AM.MaxTer) ) > AT.WorkTop ) return(MesWork());
+	if ( ( (WORD *)(((UBYTE *)(term2)) + AM.MaxTer) ) > AT.WorkTop ) {
+		MesWork();
+	}
 	if ( AR.BracketOn < 0 ) {
 		t2 = term1; t1 = term2;		/* AntiBracket */
 	}

sources/message.c

@@ -53,7 +53,7 @@ static char hex[] = {'0','1','2','3','4','5','6','7','8','9',
  		#[ Error0 :
 */
 
-VOID Error0(char *s)
+NORETURN VOID Error0(char *s)
 {
 	MesPrint("=== %s",s);
 	Terminate(-1);
@@ -64,7 +64,7 @@ VOID Error0(char *s)
  		#[ Error1 :
 */
 
-VOID Error1(char *s, UBYTE *t)
+NORETURN VOID Error1(char *s, UBYTE *t)
 {
 	MesPrint("@%s %s",s,t);
 	Terminate(-1);
@@ -75,7 +75,7 @@ VOID Error1(char *s, UBYTE *t)
  		#[ Error2 :
 */
 
-VOID Error2(char *s1, char *s2, UBYTE *t)
+NORETURN VOID Error2(char *s1, char *s2, UBYTE *t)
 {
 	MesPrint("@%s%s %s",s1,s2,t);
 	Terminate(-1);
@@ -86,12 +86,11 @@ VOID Error2(char *s1, char *s2, UBYTE *t)
  		#[ MesWork :
 */
 
-int MesWork(VOID)
+NORETURN VOID MesWork(VOID)
 {
 	MesPrint("=== Workspace overflow. %l bytes is not enough.",AM.WorkSize);
 	MesPrint("=== Change parameter WorkSpace in %s",setupfilename);
 	Terminate(-1);
-	return(-1);
 }
 
 /*

sources/parallel.c

@@ -1558,7 +1558,9 @@ int PF_Processor(EXPRESSIONS e, WORD i, WORD LastExpression)
 	}
 #endif
 
-	if ( ( (WORD *)(((UBYTE *)(AT.WorkPointer)) + AM.MaxTer ) ) > AT.WorkTop ) return(MesWork());
+	if ( ( (WORD *)(((UBYTE *)(AT.WorkPointer)) + AM.MaxTer ) ) > AT.WorkTop ) {
+		MesWork();
+	}
 
 	/* For redefine statements. */
 	if ( AC.numpfirstnum > 0 ) {

sources/proces.c

@@ -99,7 +99,9 @@ WORD Processor(VOID)
 	AR.CompressPointer = AR.CompressBuffer;
 	AR.NoCompress = AC.NoCompress;
 	term = AT.WorkPointer;
-	if ( ( (WORD *)(((UBYTE *)(AT.WorkPointer)) + AM.MaxTer) ) > AT.WorkTop ) return(MesWork());
+	if ( ( (WORD *)(((UBYTE *)(AT.WorkPointer)) + AM.MaxTer) ) > AT.WorkTop ) {
+		MesWork();
+	}
 	UpdatePositions();
 	C->rhs[C->numrhs+1] = C->Pointer;
 	AR.KeptInHold = 0;

sources/reshuf.c

@@ -1875,7 +1875,7 @@ WORD DoPartitions(PHEAD WORD *term, WORD level)
 			t2 = twhere+twhere[1];
 			to = termout = AT.WorkPointer;
 			if ( termout + *term + part.numpart*FUNHEAD + AM.MaxTal >= AT.WorkTop ) {
-				return(MesWork());
+				MesWork();
 			}
 			for ( i = 0; i < ncoeffnum; i++ ) coeff[i] = coeffnum[i];
 			ncoeff = ncoeffnum;