From: Ian Lance Taylor <iant@golang.org>
Date: Thu, 8 Nov 2012 01:34:06 +0000 (-0800)
Subject: cmd/gc: warn about slice indexes larger than int in typecheck pass
X-Git-Tag: go1.1rc2~1926
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=e3977f0d3a20ec7311b939fd2e60d78f4c6031ef;p=gostls13.git

cmd/gc: warn about slice indexes larger than int in typecheck pass

Fixes GOARCH=386 build.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6810098
---

diff --git a/src/cmd/gc/typecheck.c b/src/cmd/gc/typecheck.c
index 9b42772393..2d1dbd75f1 100644
--- a/src/cmd/gc/typecheck.c
+++ b/src/cmd/gc/typecheck.c
@@ -828,6 +828,10 @@ reswitch:
 					yyerror("invalid %s index %N (index must be non-negative)", why, n->right);
 				} else if(isfixedarray(t) && t->bound > 0 && mpgetfix(n->right->val.u.xval) >= t->bound)
 					yyerror("invalid array index %N (out of bounds for %d-element array)", n->right, t->bound);
+				else if(mpcmpfixfix(n->right->val.u.xval, maxintval[TINT]) > 0) {
+					why = isfixedarray(t) ? "array" : "slice";
+					yyerror("invalid %s index %N (index too large)", why, n->right);
+				}
 			}
 			break;
 
@@ -947,6 +951,8 @@ reswitch:
 					yyerror("invalid slice index %N (index must be non-negative)", n->right->left);
 				else if(tp != nil && tp->bound > 0 && mpgetfix(n->right->left->val.u.xval) > tp->bound)
 					yyerror("invalid slice index %N (out of bounds for %d-element array)", n->right->left, tp->bound);
+				else if(mpcmpfixfix(n->right->left->val.u.xval, maxintval[TINT]) > 0)
+					yyerror("invalid slice index %N (index too large)", n->right->left);
 			}
 		}
 		if(n->right->right != N) {
@@ -961,6 +967,8 @@ reswitch:
 					yyerror("invalid slice index %N (index must be non-negative)", n->right->right);
 				else if(tp != nil && tp->bound > 0 && mpgetfix(n->right->right->val.u.xval) > tp->bound)
 					yyerror("invalid slice index %N (out of bounds for %d-element array)", n->right->right, tp->bound);
+				else if(mpcmpfixfix(n->right->right->val.u.xval, maxintval[TINT]) > 0)
+					yyerror("invalid slice index %N (index too large)", n->right->right);
 			}
 		}
 		goto ret;