break and continue fixes

labeled break/continue was using
first loop with any label,
not first loop with the right label.

R=ken
OCL=32453
CL=32458

diff --git a/src/cmd/6g/gobj.c b/src/cmd/6g/gobj.c
index 1d7c07eba02257dfd4d38cdb4b4bf8208bef67e2..6199d2f2f01fce5b05729fb5c7859c086fe6fb36 100644 (file)
--- a/src/cmd/6g/gobj.c
+++ b/src/cmd/6g/gobj.c
@@ -97,6 +97,8 @@ zaddr(Biobuf *b, Addr *a, int s)
        switch(a->type) {
 
        case D_BRANCH:
+               if(a->branch == nil)
+                       fatal("unpatched branch");
                a->offset = a->branch->loc;
 
        default:

diff --git a/src/cmd/8g/gobj.c b/src/cmd/8g/gobj.c
index 96762375f2308912d2d36879d8ff67ac4868d57a..683c77d40c46a1ee127038387e173ce450ca8610 100644 (file)
--- a/src/cmd/8g/gobj.c
+++ b/src/cmd/8g/gobj.c
@@ -97,6 +97,8 @@ zaddr(Biobuf *b, Addr *a, int s)
        switch(a->type) {
 
        case D_BRANCH:
+               if(a->branch == nil)
+                       fatal("unpatched branch");
                a->offset = a->branch->loc;
 
        default:

diff --git a/src/cmd/gc/gen.c b/src/cmd/gc/gen.c
index 1c05a0ba6c077e6b5104af202194e4c00e82ca0a..46373f8b82b1c2cc63c8cd6d81aed8ab87e6c6ae 100644 (file)
--- a/src/cmd/gc/gen.c
+++ b/src/cmd/gc/gen.c
@@ -162,7 +162,14 @@ gen(Node *n)
        case OFALL:
        case OXCASE:
        case OXFALL:
+               break;
+
        case OEMPTY:
+               // insert no-op so that
+               //      L:; for { }
+               // does not treat L as a label for the loop.
+               if(labellist && labellist->label == p3)
+                       gused(N);
                break;
 
        case OBLOCK:
@@ -181,9 +188,11 @@ gen(Node *n)
        case OBREAK:
                if(n->left != N) {
                        for(lab=labellist; lab!=L; lab=lab->link) {
-                               if(lab->breakpc != P) {
+                               if(lab->sym == n->left->sym) {
+                                       if(lab->breakpc == P)
+                                               yyerror("invalid break label %S", n->left->sym);
                                        gjmp(lab->breakpc);
-                                       break;
+                                       goto donebreak;
                                }
                        }
                        if(lab == L)
@@ -195,26 +204,30 @@ gen(Node *n)
                        break;
                }
                gjmp(breakpc);
+       donebreak:
                break;
 
        case OCONTINUE:
                if(n->left != N) {
                        for(lab=labellist; lab!=L; lab=lab->link) {
-                               if(lab->continpc != P) {
+                               if(lab->sym == n->left->sym) {
+                                       if(lab->continpc == P)
+                                               yyerror("invalid continue label %S", n->left->sym);
                                        gjmp(lab->continpc);
-                                       break;
+                                       goto donecont;
                                }
                        }
                        if(lab == L)
-                               yyerror("break label not defined: %S", n->left->sym);
+                               yyerror("continue label not defined: %S", n->left->sym);
                        break;
                }
 
                if(continpc == P) {
-                       yyerror("gen: continue is not in a loop");
+                       yyerror("continue is not in a loop");
                        break;
                }
                gjmp(continpc);
+       donecont:
                break;
 
        case OFOR:
@@ -224,14 +237,10 @@ gen(Node *n)
                scontin = continpc;
                continpc = pc;
 
-               // define break and cotinue labels
-               for(lab=labellist; lab!=L; lab=lab->link) {
-                       if(lab->label != p3)
-                               break;
-                       if(lab->op == OLABEL) {
-                               lab->breakpc = breakpc;
-                               lab->continpc = continpc;
-                       }
+               // define break and continue labels
+               if((lab = labellist) != L && lab->label == p3 && lab->op == OLABEL) {
+                       lab->breakpc = breakpc;
+                       lab->continpc = continpc;
                }
 
                gen(n->nincr);                          // contin:      incr
@@ -268,13 +277,8 @@ gen(Node *n)
                breakpc = gjmp(P);              // break:       goto done
 
                // define break label
-               for(lab=labellist; lab!=L; lab=lab->link) {
-                       if(lab->label != p3)
-                               break;
-                       if(lab->op == OLABEL) {
-                               lab->breakpc = breakpc;
-                       }
-               }
+               if((lab = labellist) != L && lab->label == p3 && lab->op == OLABEL)
+                       lab->breakpc = breakpc;
 
                patch(p1, pc);                          // test:
                genlist(n->nbody);                              //              switch(test) body
@@ -288,13 +292,8 @@ gen(Node *n)
                breakpc = gjmp(P);              // break:       goto done
 
                // define break label
-               for(lab=labellist; lab!=L; lab=lab->link) {
-                       if(lab->label != p3)
-                               break;
-                       if(lab->op == OLABEL) {
-                               lab->breakpc = breakpc;
-                       }
-               }
+               if((lab = labellist) != L && lab->label == p3 && lab->op == OLABEL)
+                       lab->breakpc = breakpc;
 
                patch(p1, pc);                          // test:
                genlist(n->nbody);                              //              select() body

diff --git a/test/bugs/bug136.go b/test/fixedbugs/bug136.go
similarity index 100%
rename from test/bugs/bug136.go
rename to test/fixedbugs/bug136.go

diff --git a/test/fixedbugs/bug178.go b/test/fixedbugs/bug178.go
new file mode 100644 (file)
index 0000000..4f58634
--- /dev/null
+++ b/test/fixedbugs/bug178.go
@@ -0,0 +1,27 @@
+// $G $D/$F.go && $L $F.$A && ./$A.out
+
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+func main() {
+L:
+       for i := 0; i < 1; i++ {
+L1:
+               for {
+                       break L;
+               }
+               panic("BUG: not reached - break");
+       }
+
+L2:
+       for i := 0; i < 1; i++ {
+L3:
+               for {
+                       continue L2;
+               }
+               panic("BUG: not reached - continue");
+       }
+}

diff --git a/test/fixedbugs/bug179.go b/test/fixedbugs/bug179.go
new file mode 100644 (file)
index 0000000..690b012
--- /dev/null
+++ b/test/fixedbugs/bug179.go
@@ -0,0 +1,24 @@
+// errchk $G -e $D/$F.go
+
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+func main() {
+L:
+       for {
+               for {
+                       break L2;       // ERROR "L2"
+                       continue L2;    // ERROR "L2"
+               }
+       }
+
+L1:
+       x := 1;
+       for {
+               break L1;       // ERROR "L1"
+               continue L1;    // ERROR "L1"
+       }
+}

diff --git a/test/golden.out b/test/golden.out
index be5f7482bbb6111469a3f3b760bc25b2cbc63a1e..a92efaffec032cc7d9c1af4d0878f931088b71b2 100644 (file)
--- a/test/golden.out
+++ b/test/golden.out
@@ -88,9 +88,6 @@ panic PC=xxx
 =========== bugs/bug132.go
 BUG: compilation succeeds incorrectly
 
-=========== bugs/bug136.go
-BUG: should not compile
-
 =========== bugs/bug159.go
 abc: expected 4 5 6 got 4 4 -4
 BUG: bug159
@@ -227,6 +224,9 @@ fixedbugs/bug133.dir/bug2.go:11: undefined: bug0.T field i
 fixedbugs/bug133.dir/bug2.go:11: illegal types for operand: RETURN
        int
 
+=========== fixedbugs/bug136.go
+fixedbugs/bug136.go:9: invalid break label L
+
 =========== fixedbugs/bug148.go
 2 3
 interface is main.T, not main.T·bug148·1