Merge pull request #24674 from Justus2308/undef-shift-bitwise

Sema: Improve comptime arithmetic undef handling

test/behavior/bit_shifting.zig

@@ -154,12 +154,6 @@ test "Saturating Shift Left where lhs is of a computed type" {
     try expect(value.exponent == 0);
 }
 
-comptime {
-    var image: [1]u8 = undefined;
-    _ = ℑ
-    _ = @shlExact(@as(u16, image[0]), 8);
-}
-
 test "Saturating Shift Left" {
     if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_c) return error.SkipZigTest;

test/cases/compile_errors/saturating_shl_does_not_allow_negative_rhs.zig

@@ -30,7 +30,9 @@ export fn d(rhs: @Vector(3, i32)) void {
 //
 // :2:25: error: shift by negative amount '-1'
 // :7:12: error: shift by negative amount '-2'
-// :11:47: error: shift by negative amount '-3' at index '0'
-// :16:27: error: shift by negative amount '-4' at index '1'
+// :11:47: error: shift by negative amount '-3'
+// :11:47: note: when computing vector element at index '0'
+// :16:27: error: shift by negative amount '-4'
+// :16:27: note: when computing vector element at index '1'
 // :20:25: error: shift by signed type 'i32'
 // :24:40: error: shift by signed type '@Vector(3, i32)'

test/cases/compile_errors/shift_by_larger_than_usize.zig

@@ -0,0 +1,9 @@
+export fn f() usize {
+    const a = comptime 0 <<| (1 << @bitSizeOf(usize));
+    return a;
+}
+
+// error
+// target=x86_64-linux
+//
+// :2:30: error: this implementation only supports comptime shift amounts of up to 2^64 - 1 bits

test/cases/compile_errors/shlExact_shifts_out_1_bits.zig

@@ -7,4 +7,4 @@ comptime {
 // backend=stage2
 // target=native
 //
-// :2:15: error: operation caused overflow
+// :2:15: error: overflow of integer type 'u8' with value '340'

test/cases/compile_errors/shl_exact_on_undefined_value.zig

@@ -0,0 +1,11 @@
+comptime {
+    var a: i64 = undefined;
+    var b: u6 = undefined;
+    _ = &a;
+    _ = &b;
+    _ = @shlExact(a, b);
+}
+
+// error
+//
+// :6:19: error: use of undefined value here causes illegal behavior

test/cases/compile_errors/shl_on_undefined_value.zig

@@ -0,0 +1,11 @@
+comptime {
+    var a: i64 = undefined;
+    var b: u6 = undefined;
+    _ = &a;
+    _ = &b;
+    _ = a << b;
+}
+
+// error
+//
+// :6:9: error: use of undefined value here causes illegal behavior

test/cases/compile_errors/shl_with_overflow_on_undefined_value.zig

@@ -0,0 +1,11 @@
+comptime {
+    var a: i64 = undefined;
+    var b: u6 = undefined;
+    _ = &a;
+    _ = &b;
+    _ = @shlWithOverflow(a, b);
+}
+
+// error
+//
+// :6:26: error: use of undefined value here causes illegal behavior

test/cases/compile_errors/shr_exact_on_undefined_value.zig

@@ -0,0 +1,11 @@
+comptime {
+    var a: i64 = undefined;
+    var b: u6 = undefined;
+    _ = &a;
+    _ = &b;
+    _ = @shrExact(a, b);
+}
+
+// error
+//
+// :6:19: error: use of undefined value here causes illegal behavior

test/cases/compile_errors/shr_on_undefined_value.zig

@@ -0,0 +1,11 @@
+comptime {
+    var a: i64 = undefined;
+    var b: u6 = undefined;
+    _ = &a;
+    _ = &b;
+    _ = a >> b;
+}
+
+// error
+//
+// :6:9: error: use of undefined value here causes illegal behavior