Add compile error tests for atomic feature detection

Author: silversquirl

test/cases/compile_errors/atomic_missing_features_wasm32.zig

@@ -0,0 +1,9 @@
+export fn entry() void {
+    var x: u32 = 0;
+    _ = @atomicLoad(u32, &x, .monotonic);
+}
+
+// error
+// target=wasm32-freestanding:baseline
+//
+// :3:16: error: 4-byte @atomicLoad on wasm32 requires the following missing CPU features: atomics

test/cases/compile_errors/atomic_missing_features_x86_64.zig

@@ -0,0 +1,9 @@
+export fn entry() void {
+    var x: u128 = 0;
+    @cmpxchgWeak(u128, &x, 1, 2, .monotonic, .monotonic);
+}
+
+// error
+// target=x86_64-native:baseline
+//
+// :3:16: error: 16-byte @cmpxchgWeak on x86_64 requires the following missing CPU features: cx16

test/cases/compile_errors/atomic_unsupported_op_wasm.zig

@@ -0,0 +1,9 @@
+export fn entry() void {
+    var x: u32 = 0;
+    @atomicRmw(u32, &x, .Min, 1, .monotonic);
+}
+
+// error
+// target=wasm32-freestanding:bleeding_edge
+//
+// :3:16: error: @atoimcRmw(.Min) is not supported on wasm32

test/cases/compile_errors/atomic_unsupported_sizes_aarch64.zig

@@ -0,0 +1,14 @@
+export fn valid() void {
+    var x: u128 = 0;
+    _ = @atomicRmw(u128, &x, .Xchg, 1, .monotonic);
+}
+export fn invalid() void {
+    var x: u256 = 0;
+    _ = @atomicRmw(u256, &x, .Xchg, 1, .monotonic);
+}
+
+// error
+// target=aarch64-native
+//
+// ":7:16: error: {s} does not support @atomicRmw(.Xchg) on this type", .{arch}),
+// ":7:16: note: size of type is 32, but Xchg on {s} requires a value of size 1, 2, 4, 8, or 16", .{arch}),

test/cases/compile_errors/atomic_unsupported_sizes_x86_64.zig

@@ -0,0 +1,14 @@
+export fn rmw() void {
+    var x: u128 = 0;
+    _ = @atomicRmw(u128, &x, .Xchg, 1, .monotonic);
+}
+export fn cmpxchg() void {
+    var x: u256 = 0;
+    _ = @cmpxchgWeak(u256, &x, 0, 1, .monotonic, .monotonic);
+}
+
+// error
+// target=x86_64-native:x86_64_v2
+//
+// ":7:16: error: {s} does not support @atomicRmw(.Xchg) on this type", .{arch}),
+// ":7:16: note: size of type is 32, but Xchg on {s} requires a value of size 1, 2, 4, 8, or 16", .{arch}),

test/cases/compile_errors/atomics_with_invalid_type.zig

@@ -1,18 +1,24 @@
-export fn float() void {
+export fn floatCmpxchg() void {
     var x: f32 = 0;
     _ = @cmpxchgWeak(f32, &x, 1, 2, .seq_cst, .seq_cst);
 }
 
 const NormalStruct = struct { x: u32 };
-export fn normalStruct() void {
-    var x: NormalStruct = 0;
+export fn normalStructCmpxchg() void {
+    var x: NormalStruct = .{ .x = 0 };
     _ = @cmpxchgWeak(NormalStruct, &x, .{ .x = 1 }, .{ .x = 2 }, .seq_cst, .seq_cst);
 }
 
+export fn normalStructLoad() void {
+    var x: NormalStruct = .{ .x = 0 };
+    _ = @atomicLoad(NormalStruct, &x, .seq_cst);
+}
+
 // error
-// backend=stage2
-// target=native
 //
-// :3:22: error: expected bool, integer, enum, packed struct, or pointer type; found 'f32'
-// :8:27: error: expected type 'tmp.NormalStruct', found 'comptime_int'
+// :3:22: error: expected bool, integer, enum, error set, packed struct, or pointer type; found 'f32'
+// :3:22: note: floats are not supported for cmpxchg because float equality differs from bitwise equality
+// :9:22: error: expected bool, integer, enum, error set, packed struct, or pointer type; found 'tmp.NormalStruct'
+// :6:22: note: struct declared here
+// :14:21: error: expected bool, integer, float, enum, error set, packed struct, or pointer type; found 'tmp.NormalStruct'
 // :6:22: note: struct declared here

test/src/Cases.zig

@@ -1069,7 +1069,14 @@ const TestManifest = struct {
     fn getDefaultParser(comptime T: type) ParseFn(T) {
         if (T == std.Target.Query) return struct {
             fn parse(str: []const u8) anyerror!T {
-                return std.Target.Query.parse(.{ .arch_os_abi = str });
+                if (std.mem.indexOfScalar(u8, str, ':')) |idx| {
+                    return std.Target.Query.parse(.{
+                        .arch_os_abi = str[0..idx],
+                        .cpu_features = str[idx + 1 ..],
+                    });
+                } else {
+                    return std.Target.Query.parse(.{ .arch_os_abi = str });
+                }
             }
         }.parse;