sema: add compile error for OOB by-length slice of array

2 files changed, 40 insertions, 0 deletions

diff --git a/test/cases/compile_errors/slice_of_array_by-length_oversized.zig b/test/cases/compile_errors/slice_of_array_by-length_oversized.zig
new file mode 100644
index 0000000000..e482197d1a
--- /dev/null
+++ b/test/cases/compile_errors/slice_of_array_by-length_oversized.zig
@@ -0,0 +1,19 @@
+export fn entry1() void {
+    var buf: [5]u8 = undefined;
+    var a: u32 = 6;
+    _ = &a;
+    _ = buf[a..][0..10];
+}
+
+export fn entry2() void {
+    var buf: [5]u8 = undefined;
+    const a: u32 = 6;
+    _ = buf[a..][0..10];
+}
+
+// error
+// backend=stage2
+// target=native
+//
+// :5:21: error: length 10 out of bounds for array of length 5
+// :11:21: error: length 10 out of bounds for array of length 5
diff --git a/test/cases/safety/array slice by-length oversized.zig b/test/cases/safety/array slice by-length oversized.zig
new file mode 100644
index 0000000000..a8b33e428a
--- /dev/null
+++ b/test/cases/safety/array slice by-length oversized.zig
@@ -0,0 +1,21 @@
+const std = @import("std");
+
+pub fn panic(message: []const u8, stack_trace: ?*std.builtin.StackTrace, _: ?usize) noreturn {
+    _ = stack_trace;
+    if (std.mem.eql(u8, message, "index out of bounds: index 12, len 5")) {
+        std.process.exit(0);
+    }
+    std.process.exit(1);
+}
+
+pub fn main() !void {
+    var buf: [5]u8 = undefined;
+    var a: u32 = 6;
+    _ = &a;
+    _ = buf[a..][0..a];
+    return error.TestFailed;
+}
+
+// run
+// backend=llvm
+// target=native