zig

commit 7aee8a93ebc199dd5ff94387f0906699d795c138 (tree)
parent 3e3c651b670fb45e714db1cfb32428c3ea3cd828
Author: Vexu <git@vexu.eu>
Date:   Tue, 12 May 2020 01:25:24 +0300

Merge pull request #5315 from xackus/fix-bigint_fits_in_bits

stage1: detect underflow in bigint_fits_in_bits
Diffstat:
M
src/bigint.cpp
 | 
1
+
M
test/compile_errors.zig
 | 
8
++++++++

2 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/src/bigint.cpp b/src/bigint.cpp
@@ -243,6 +243,7 @@ bool bigint_fits_in_bits(const BigInt *bn, size_t bit_count, bool is_signed) {
     }
 
     if (!is_signed) {
+        if(bn->is_negative) return false;
         size_t full_bits = bn->digit_count * 64;
         size_t leading_zero_count = bigint_clz(bn, full_bits);
         return bit_count >= full_bits - leading_zero_count;
diff --git a/test/compile_errors.zig b/test/compile_errors.zig
@@ -7411,4 +7411,12 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
     , &[_][]const u8{
         ":5:28: error: expected type '[]u8', found '*const [3:0]u8'",
     });
+
+    cases.add("integer underflow error",
+        \\export fn entry() void {
+        \\    _ = @intToPtr(*c_void, ~@as(usize, @import("std").math.maxInt(usize)) - 1);
+        \\}
+    , &[_][]const u8{
+        ":2:75: error: operation caused overflow",
+    });
 }