FIXED: Handling return values in stack expansion.

Introduce more `bool` to correctly distinguish functions returning
true/false/*_OVERFLOW from those raising exceptions and only returning
true/false.

src/pl-attvar.c

@@ -75,7 +75,7 @@ assignment. The attribute list remains   accessible  through the trailed
 assignment until this is GC'ed.
 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
 
-int
+bool
 PL_get_attr(DECL_LD term_t t, term_t a)
 { Word p = valTermRef(t);
 
@@ -84,10 +84,10 @@ PL_get_attr(DECL_LD term_t t, term_t a)
   { Word ap = valPAttVar(*p);
 
     *valTermRef(a) = makeRefG(ap);	/* reference, so we can assign */
-    succeed;
+    return true;
   }
 
-  fail;
+  return false;
 }
 
 /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -204,7 +204,7 @@ assignAttVar(DECL_LD Word av, Word value)
   return;
 }
 
-int
+bool
 bind_attvar_const(DECL_LD Word p, word c)
 { if ( !hasGlobalSpace(0) )
   { PushPtr(p); PushVal(c);
@@ -249,7 +249,7 @@ alloc_attvar(DECL_LD)
 }
 
 
-int
+bool
 on_attvar_chain(Word avp)
 { GET_LD
   Word p, next;
@@ -532,7 +532,7 @@ apply. The environment has size 1 if there  is a pending exception, 2 if
 a wakeup was saved and 3 if both where saved.
 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
 
-int
+bool
 saveWakeup(DECL_LD wakeup_state *state, int forceframe)
 { state->flags = 0;
   state->outofstack = LD->outofstack;

src/pl-attvar.h

@@ -56,11 +56,11 @@
 #define LDFUNC_DECLARATIONS
 
 void		assignAttVar(Word av, Word value);
-int		bind_attvar_const(Word p, word c);
-int		saveWakeup(wakeup_state *state, int forceframe);
+bool		bind_attvar_const(Word p, word c);
+bool		saveWakeup(wakeup_state *state, int forceframe);
 void		restoreWakeup(wakeup_state *state);
-int		PL_get_attr(term_t t, term_t a);
-int		on_attvar_chain(Word avp);
+bool		PL_get_attr(term_t t, term_t a);
+bool		on_attvar_chain(Word avp);
 Word		alloc_attvar(void);
 
 #undef LDFUNC_DECLARATIONS

src/pl-gc.h

@@ -96,7 +96,7 @@ void		unblockGC(int flags);	/* re-allow garbage collect */
 		 *******************************/
 
 #define ensureLocalSpace_ex(bytes) LDFUNC(ensureLocalSpace_ex, bytes)
-static inline int
+static inline bool
 ensureLocalSpace_ex(DECL_LD size_t bytes)
 { int rc;
 
@@ -109,15 +109,22 @@ ensureLocalSpace_ex(DECL_LD size_t bytes)
   return raiseStackOverflow(rc);
 }
 
-#define ensureStackSpace_ex(gcells, tcells, flags) LDFUNC(ensureStackSpace_ex, gcells, tcells, flags)
-static inline int
+#define ensureStackSpace_ex(gcells, tcells, flags) \
+	LDFUNC(ensureStackSpace_ex, gcells, tcells, flags)
+
+static inline bool
 ensureStackSpace_ex(DECL_LD size_t gcells, size_t tcells, int flags)
-{ if ( hasStackSpace(gcells, tcells) )
+{ int rc;
+
+  if ( hasStackSpace(gcells, tcells) )
     return true;
 
-  return f_ensureStackSpace(gcells+BIND_GLOBAL_SPACE,
-			    tcells+BIND_TRAIL_SPACE,
-			    flags);
+  if ( (rc=f_ensureStackSpace(gcells+BIND_GLOBAL_SPACE,
+			      tcells+BIND_TRAIL_SPACE,
+			      flags)) == true )
+    return true;
+
+  return raiseStackOverflow(rc);
 }
 
 #endif /*_PL_GC_H*/

src/pl-vmi.c

@@ -231,9 +231,7 @@ END_VMH
 	  __rc = ensureStackSpace(g, t);		\
 	  LOAD_REGISTERS(QID);				\
 	  if ( __rc != true )				\
-	  { raiseStackOverflow(__rc);			\
 	    THROW_EXCEPTION;				\
-	  }						\
 	} while(0)
 
 /* Can be used for debugging to always force GC at a place */

src/pl-wam.c

@@ -256,7 +256,8 @@ raiseSignal(PL_local_data_t *ld, int sig)
 
     do
     { alerted = ld->alerted;
-    } while ( !COMPARE_AND_SWAP_INT(&ld->alerted, alerted, alerted|ALERT_SIGNAL) );
+    } while ( !COMPARE_AND_SWAP_INT(&ld->alerted, alerted,
+				    alerted|ALERT_SIGNAL) );
 
     return true;
   }
@@ -268,7 +269,7 @@ raiseSignal(PL_local_data_t *ld, int sig)
 int
 pendingSignal(PL_local_data_t *ld, int sig)
 { if ( IS_VALID_SIGNAL(sig) && ld )
-  { return WSIGMASK_ISSET(ld->signal.pending, sig) ? true : false;
+  { return WSIGMASK_ISSET(ld->signal.pending, sig);
   }
 
   return -1;
@@ -1440,10 +1441,10 @@ callBreakHook(DECL_LD LocalFrame frame, Choice bfr,
 Trail a raw pointer after we know there is insufficient tail space.
 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
 
-int
+bool
 grow_trail_ptr(DECL_LD Word p)
 { PushPtr(p);
-  int rc = ensureGlobalSpace(0, ALLOW_GC);
+  bool rc = ensureGlobalSpace(0, ALLOW_GC);
   PopPtr(p);
   if ( !rc )
     return false;

src/pl-wam.h

@@ -79,7 +79,7 @@ Module		contextModule(LocalFrame fr);
 void		setContextModule(LocalFrame fr, Module context);
 bool		existingChoice(Choice ch);
 bool		existingFrame(LocalFrame fr);
-int		grow_trail_ptr(Word p);
+bool		grow_trail_ptr(Word p);
 bool		handles_unwind(qid_t qid, unsigned int flags);
 #ifdef O_DEBUG
 char *		chp_chars(Choice ch);
@@ -90,7 +90,7 @@ char *		chp_chars(Choice ch);
 #define getProcDefinition(proc)	getLocalProcDefinition(proc->definition)
 
 #define trail_ptr(p) LDFUNC(trail_ptr, p)
-static inline int
+static inline bool
 trail_ptr(DECL_LD Word p)
 { if ( hasTrailSpace(1) )
   { (tTop++)->address = p;