Parser: fix spurious unsigned overflows

Vexu · Dec 3, 2023 · a11ab45 · a11ab45
1 parent a0555b0
commit a11ab45
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Showing 2 changed files with 14 additions and 4 deletions.
diff --git a/src/aro/Parser.zig b/src/aro/Parser.zig
@@ -6445,9 +6445,11 @@ fn addExpr(p: *Parser) Error!Result {
         const lhs_ty = lhs.ty;
         if (try lhs.adjustTypes(minus.?, &rhs, p, if (plus != null) .add else .sub)) {
             if (plus != null) {
-                if (try lhs.val.add(lhs.val, rhs.val, lhs.ty, p.comp)) try p.errOverflow(plus.?, lhs);
+                if (try lhs.val.add(lhs.val, rhs.val, lhs.ty, p.comp) and
+                    lhs.ty.signedness(p.comp) != .unsigned) try p.errOverflow(plus.?, lhs);
             } else {
-                if (try lhs.val.sub(lhs.val, rhs.val, lhs.ty, p.comp)) try p.errOverflow(minus.?, lhs);
+                if (try lhs.val.sub(lhs.val, rhs.val, lhs.ty, p.comp) and
+                    lhs.ty.signedness(p.comp) != .unsigned) try p.errOverflow(minus.?, lhs);
             }
         }
         if (lhs.ty.specifier != .invalid and lhs_ty.isPtr() and !lhs_ty.isVoidStar() and lhs_ty.elemType().hasIncompleteSize()) {
@@ -6484,9 +6486,11 @@ fn mulExpr(p: *Parser) Error!Result {
 
         if (try lhs.adjustTypes(percent.?, &rhs, p, if (tag == .mod_expr) .integer else .arithmetic)) {
             if (mul != null) {
-                if (try lhs.val.mul(lhs.val, rhs.val, lhs.ty, p.comp)) try p.errOverflow(mul.?, lhs);
+                if (try lhs.val.mul(lhs.val, rhs.val, lhs.ty, p.comp) and
+                    lhs.ty.signedness(p.comp) != .unsigned) try p.errOverflow(mul.?, lhs);
             } else if (div != null) {
-                if (try lhs.val.div(lhs.val, rhs.val, lhs.ty, p.comp)) try p.errOverflow(mul.?, lhs);
+                if (try lhs.val.div(lhs.val, rhs.val, lhs.ty, p.comp) and
+                    lhs.ty.signedness(p.comp) != .unsigned) try p.errOverflow(mul.?, lhs);
             } else {
                 var res = try Value.rem(lhs.val, rhs.val, lhs.ty, p.comp);
                 if (res.opt_ref == .none) {

diff --git a/test/cases/arithmetic overflow.c b/test/cases/arithmetic overflow.c
@@ -0,0 +1,6 @@
+_Static_assert(0xFFFFFFFF + 1 == 0, "'");
+_Static_assert(1 + 0xFFFFFFFF == 0, "'");
+_Static_assert(0 - 0x00000001 == 0xFFFFFFFF, "'");
+_Static_assert(0x00000000 - 0x00000001 == 0xFFFFFFFF, "'");
+_Static_assert(0x80000000 * 2 == 0, "'");
+_Static_assert(2 * 0x80000000 == 0, "'");