diff options
Diffstat (limited to 'src/cmd/gc/gen.c')
| -rw-r--r-- | src/cmd/gc/gen.c | 55 |
1 files changed, 27 insertions, 28 deletions
diff --git a/src/cmd/gc/gen.c b/src/cmd/gc/gen.c index 1c05a0ba6..46373f8b8 100644 --- 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 |