authorgravatar for 14938807+xackus@users.noreply.github.comxackus <14938807+xackus@users.noreply.github.com> 2020-07-05 17:58:21+02:00
committergravatar for 14938807+xackus@users.noreply.github.comxackus <14938807+xackus@users.noreply.github.com> 2020-07-05 17:58:21+02:00
log51f8c306d9fa32c849b26c2d95a45901a02f448e
tree80a09b965eaa0ff2849f3eafc7405eb9af3146ff
parent0ae1157e4553d6f54e0d489daebb006c402e0f63

stage1: add missing runtime safety for @intCast unsigned -> signed of same bit count

2 files changed, 16 insertions(+), 4 deletions(-)

src/codegen.cpp+6-4
......@@ -1535,9 +1535,11 @@ static LLVMValueRef gen_widen_or_shorten(CodeGen *g, bool want_runtime_safety, Z
15351535 zig_unreachable();
15361536 }
15371537
1538 if (actual_type->id == ZigTypeIdInt &&
1539 !wanted_type->data.integral.is_signed && actual_type->data.integral.is_signed &&
1540 want_runtime_safety)
1538 if (actual_type->id == ZigTypeIdInt && want_runtime_safety && (
1539 // negative to unsigned
1540 (!wanted_type->data.integral.is_signed && actual_type->data.integral.is_signed) ||
1541 // unsigned would become negative
1542 (wanted_type->data.integral.is_signed && !actual_type->data.integral.is_signed && actual_bits == wanted_bits)))
15411543 {
15421544 LLVMValueRef zero = LLVMConstNull(get_llvm_type(g, actual_type));
15431545 LLVMValueRef ok_bit = LLVMBuildICmp(g->builder, LLVMIntSGE, expr_val, zero, "");
......@@ -1547,7 +1549,7 @@ static LLVMValueRef gen_widen_or_shorten(CodeGen *g, bool want_runtime_safety, Z
15471549 LLVMBuildCondBr(g->builder, ok_bit, ok_block, fail_block);
15481550
15491551 LLVMPositionBuilderAtEnd(g->builder, fail_block);
1550 gen_safety_crash(g, PanicMsgIdCastNegativeToUnsigned);
1552 gen_safety_crash(g, actual_type->data.integral.is_signed ? PanicMsgIdCastNegativeToUnsigned : PanicMsgIdCastTruncatedData);
15511553
15521554 LLVMPositionBuilderAtEnd(g->builder, ok_block);
15531555 }
test/runtime_safety.zig+10
......@@ -757,6 +757,16 @@ pub fn addCases(cases: *tests.CompareOutputContext) void {
757757 \\}
758758 );
759759
760 cases.addRuntimeSafety("unsigned integer not fitting in cast to signed integer - same bit count",
761 \\pub fn panic(message: []const u8, stack_trace: ?*@import("builtin").StackTrace) noreturn {
762 \\ @import("std").os.exit(126);
763 \\}
764 \\pub fn main() void {
765 \\ var value: u8 = 245;
766 \\ var casted = @intCast(i8, value);
767 \\}
768 );
769
760770 cases.addRuntimeSafety("unwrap error",
761771 \\pub fn panic(message: []const u8, stack_trace: ?*@import("builtin").StackTrace) noreturn {
762772 \\ if (@import("std").mem.eql(u8, message, "attempt to unwrap error: Whatever")) {