Fix building RTS with gcc 2.*; declare all variables at the top of a block

Patch from Audrey Tang.

rts/RaiseAsync.c

@@ -942,10 +942,12 @@ raiseAsync(Capability *cap, StgTSO *tso, StgClosure *exception,
 	}
 
 	case STOP_FRAME:
+	{
 	    // We've stripped the entire stack, the thread is now dead.
 	    tso->what_next = ThreadKilled;
 	    tso->sp = frame + sizeofW(StgStopFrame);
 	    return;
+	}
 
 	case CATCH_FRAME:
 	    // If we find a CATCH_FRAME, and we've got an exception to raise,
@@ -1017,15 +1019,17 @@ raiseAsync(Capability *cap, StgTSO *tso, StgClosure *exception,
 	    // whether the transaction is valid or not because its
 	    // possible validity cannot have caused the exception
 	    // and will not be visible after the abort.
-	    debugTrace(DEBUG_stm, 
-		       "found atomically block delivering async exception");
 
+		{
             StgTRecHeader *trec = tso -> trec;
             StgTRecHeader *outer = stmGetEnclosingTRec(trec);
+	    debugTrace(DEBUG_stm, 
+		       "found atomically block delivering async exception");
             stmAbortTransaction(cap, trec);
 	    stmFreeAbortedTRec(cap, trec);
             tso -> trec = outer;
 	    break;
+	    };
 	    
 	default:
 	    break;

rts/RetainerProfile.c

@@ -864,6 +864,7 @@ pop( StgClosure **c, StgClosure **cp, retainer *r )
 	    // we divide the step counter: the 2 low bits indicate
 	    // which field, and the rest of the bits indicate the
 	    // entry number (starting from zero).
+	    TRecEntry *entry;
 	    nat entry_no = se->info.next.step >> 2;
 	    nat field_no = se->info.next.step & 3;
 	    if (entry_no == ((StgTRecChunk *)se->c)->next_entry_idx) {
@@ -871,7 +872,7 @@ pop( StgClosure **c, StgClosure **cp, retainer *r )
 		popOff();
 		return;
 	    }
-	    TRecEntry *entry = &((StgTRecChunk *)se->c)->entries[entry_no];
+	    entry = &((StgTRecChunk *)se->c)->entries[entry_no];
 	    if (field_no == 0) {
 		*c = (StgClosure *)entry->tvar;
 	    } else if (field_no == 1) {

rts/STM.c

@@ -596,8 +596,9 @@ static void remove_watch_queue_entries_for_trec(Capability *cap,
     StgTVarWatchQueue *pq;
     StgTVarWatchQueue *nq;
     StgTVarWatchQueue *q;
+    StgClosure *saw;
     s = e -> tvar;
-    StgClosure *saw = lock_tvar(trec, s);
+    saw = lock_tvar(trec, s);
     q = (StgTVarWatchQueue *) (e -> new_value);
     TRACE("%p : removing tso=%p from watch queue for tvar=%p", 
 	  trec, 
@@ -943,6 +944,7 @@ StgTRecHeader *stmStartTransaction(Capability *cap,
 
 void stmAbortTransaction(Capability *cap,
                          StgTRecHeader *trec) {
+  StgTRecHeader *et;
   TRACE("%p : stmAbortTransaction", trec);
   ASSERT (trec != NO_TREC);
   ASSERT ((trec -> state == TREC_ACTIVE) || 
@@ -951,7 +953,7 @@ void stmAbortTransaction(Capability *cap,
 
   lock_stm(trec);
 
-  StgTRecHeader *et = trec -> enclosing_trec;
+  et = trec -> enclosing_trec;
   if (et == NO_TREC) {
     // We're a top-level transaction: remove any watch queue entries that
     // we may have.
@@ -1165,13 +1167,13 @@ static void connect_invariant_to_trec(Capability *cap,
 void stmAddInvariantToCheck(Capability *cap, 
 			    StgTRecHeader *trec,
 			    StgClosure *code) {
+  StgAtomicInvariant *invariant;
+  StgInvariantCheckQueue *q;
   TRACE("%p : stmAddInvariantToCheck closure=%p", trec, code);
   ASSERT(trec != NO_TREC);
   ASSERT(trec -> state == TREC_ACTIVE ||
 	 trec -> state == TREC_CONDEMNED);
 
-  StgAtomicInvariant *invariant;
-  StgInvariantCheckQueue *q;
 
   // 1. Allocate an StgAtomicInvariant, set last_execution to NO_TREC
   //    to signal that this is a new invariant in the current atomic block
@@ -1200,6 +1202,7 @@ void stmAddInvariantToCheck(Capability *cap,
  */
 
 StgInvariantCheckQueue *stmGetInvariantsToCheck(Capability *cap, StgTRecHeader *trec) {
+  StgTRecChunk *c;
   TRACE("%p : stmGetInvariantsToCheck, head was %p", 
 	trec,
 	trec -> invariants_to_check);
@@ -1211,7 +1214,7 @@ StgInvariantCheckQueue *stmGetInvariantsToCheck(Capability *cap, StgTRecHeader *
   ASSERT(trec -> enclosing_trec == NO_TREC);
 
   lock_stm(trec);
-  StgTRecChunk *c = trec -> current_chunk;
+  c = trec -> current_chunk;
   while (c != END_STM_CHUNK_LIST) {
     unsigned int i;
     for (i = 0; i < c -> next_entry_idx; i ++) {
@@ -1223,15 +1226,15 @@ StgInvariantCheckQueue *stmGetInvariantsToCheck(Capability *cap, StgTRecHeader *
 	// Pick up any invariants on the TVar being updated
 	// by entry "e"
 
-	TRACE("%p : checking for invariants on %p", trec, s);
 	StgTVarWatchQueue *q;
+	TRACE("%p : checking for invariants on %p", trec, s);
 	for (q = s -> first_watch_queue_entry;
 	     q != END_STM_WATCH_QUEUE;
 	     q = q -> next_queue_entry) {
 	  if (watcher_is_invariant(q)) {
-	    TRACE("%p : Touching invariant %p", trec, q -> closure);
 	    StgBool found = FALSE;
 	    StgInvariantCheckQueue *q2;
+	    TRACE("%p : Touching invariant %p", trec, q -> closure);
 	    for (q2 = trec -> invariants_to_check;
 		 q2 != END_INVARIANT_CHECK_QUEUE;
 		 q2 = q2 -> next_queue_entry) {
@@ -1243,8 +1246,8 @@ StgInvariantCheckQueue *stmGetInvariantsToCheck(Capability *cap, StgTRecHeader *
 	    }
 	    
 	    if (!found) {
-	      TRACE("%p : Not already found %p", trec, q -> closure);
 	      StgInvariantCheckQueue *q3;
+	      TRACE("%p : Not already found %p", trec, q -> closure);
 	      q3 = alloc_stg_invariant_check_queue(cap,
 						   (StgAtomicInvariant*) q -> closure);
 	      q3 -> next_queue_entry = trec -> invariants_to_check;
@@ -1273,6 +1276,8 @@ StgInvariantCheckQueue *stmGetInvariantsToCheck(Capability *cap, StgTRecHeader *
 StgBool stmCommitTransaction(Capability *cap, StgTRecHeader *trec) {
   int result;
   StgInt64 max_commits_at_start = max_commits;
+  StgBool touched_invariants;
+  StgBool use_read_phase;
 
   TRACE("%p : stmCommitTransaction()", trec);
   ASSERT (trec != NO_TREC);
@@ -1286,7 +1291,7 @@ StgBool stmCommitTransaction(Capability *cap, StgTRecHeader *trec) {
   // touched_invariants is true if we've written to a TVar with invariants 
   // attached to it, or if we're trying to add a new invariant to the system.
 
-  StgBool touched_invariants = (trec -> invariants_to_check != END_INVARIANT_CHECK_QUEUE);
+  touched_invariants = (trec -> invariants_to_check != END_INVARIANT_CHECK_QUEUE);
 
   // If we have touched invariants then (i) lock the invariant, and (ii) add
   // the invariant's read set to our own.  Step (i) is needed to serialize
@@ -1298,18 +1303,20 @@ StgBool stmCommitTransaction(Capability *cap, StgTRecHeader *trec) {
   // invariant from both tvars).
 
   if (touched_invariants) {
-    TRACE("%p : locking invariants", trec);
     StgInvariantCheckQueue *q = trec -> invariants_to_check;
+    TRACE("%p : locking invariants", trec);
     while (q != END_INVARIANT_CHECK_QUEUE) {
+      StgTRecHeader *inv_old_trec;
+      StgAtomicInvariant *inv;
       TRACE("%p : locking invariant %p", trec, q -> invariant);
-      StgAtomicInvariant *inv = q -> invariant;
+      inv = q -> invariant;
       if (!lock_inv(inv)) {
         TRACE("%p : failed to lock %p", trec, inv);
         trec -> state = TREC_CONDEMNED;
         break;
       }
 
-      StgTRecHeader *inv_old_trec = inv -> last_execution;
+      inv_old_trec = inv -> last_execution;
       if (inv_old_trec != NO_TREC) {
 	StgTRecChunk *c = inv_old_trec -> current_chunk;
 	while (c != END_STM_CHUNK_LIST) {
@@ -1336,7 +1343,7 @@ StgBool stmCommitTransaction(Capability *cap, StgTRecHeader *trec) {
   // invariants and TVars are managed by the TVar watch queues which are
   // protected by the TVar's locks.
 
-  StgBool use_read_phase = ((config_use_read_phase) && (!touched_invariants));
+  use_read_phase = ((config_use_read_phase) && (!touched_invariants));
 
   result = validate_and_acquire_ownership(trec, (!use_read_phase), TRUE);
   if (result) {
@@ -1344,12 +1351,13 @@ StgBool stmCommitTransaction(Capability *cap, StgTRecHeader *trec) {
     ASSERT (trec -> state == TREC_ACTIVE);
 
     if (use_read_phase) {
+      StgInt64 max_commits_at_end;
+      StgInt64 max_concurrent_commits;
       TRACE("%p : doing read check", trec);
       result = check_read_only(trec);
       TRACE("%p : read-check %s", trec, result ? "succeeded" : "failed");
 
-      StgInt64 max_commits_at_end = max_commits;
-      StgInt64 max_concurrent_commits;
+      max_commits_at_end = max_commits;
       max_concurrent_commits = ((max_commits_at_end - max_commits_at_start) +
                                 (n_capabilities * TOKEN_BATCH_SIZE));
       if (((max_concurrent_commits >> 32) > 0) || shake()) {

rts/Schedule.c

@@ -3109,10 +3109,10 @@ findRetryFrameHelper (StgTSO *tso)
 	return CATCH_RETRY_FRAME;
       
     case CATCH_STM_FRAME: {
-        debugTrace(DEBUG_stm,
-		   "found CATCH_STM_FRAME at %p during retry", p);
         StgTRecHeader *trec = tso -> trec;
 	StgTRecHeader *outer = stmGetEnclosingTRec(trec);
+        debugTrace(DEBUG_stm,
+		   "found CATCH_STM_FRAME at %p during retry", p);
         debugTrace(DEBUG_stm, "trec=%p outer=%p", trec, outer);
 	stmAbortTransaction(tso -> cap, trec);
 	stmFreeAbortedTRec(tso -> cap, trec);

rts/sm/GC.c

@@ -199,12 +199,12 @@ GarbageCollect ( rtsBool force_major_gc )
   lnat oldgen_saved_blocks = 0;
   nat g, s, i;
 
-  ACQUIRE_SM_LOCK;
-
 #ifdef PROFILING
   CostCentreStack *prev_CCS;
 #endif
 
+  ACQUIRE_SM_LOCK;
+
   debugTrace(DEBUG_gc, "starting GC");
 
 #if defined(RTS_USER_SIGNALS)