Commit 794beafb9c

Veikka Tuominen <git@vexu.eu>
2022-07-20 11:30:11
Sema: validate extern struct field types earlier
`validateExternType` does not require the type to be resolved so we can check it earlier. Only doing it in `resolveTypeFully` lead to worse or missing compile errors.
1 parent 821e406
src/Sema.zig
@@ -14559,13 +14559,23 @@ fn zirStructInitAnon(
         var runtime_src: ?LazySrcLoc = null;
         var extra_index = extra.end;
         for (types) |*field_ty, i| {
+            const init_src = src; // TODO better source location
             const item = sema.code.extraData(Zir.Inst.StructInitAnon.Item, extra_index);
             extra_index = item.end;
 
             names[i] = sema.code.nullTerminatedString(item.data.field_name);
             const init = try sema.resolveInst(item.data.init);
             field_ty.* = sema.typeOf(init);
-            const init_src = src; // TODO better source location
+            if (types[i].zigTypeTag() == .Opaque) {
+                const msg = msg: {
+                    const msg = try sema.errMsg(block, init_src, "opaque types have unknown size and therefore cannot be directly embedded in structs", .{});
+                    errdefer msg.destroy(sema.gpa);
+
+                    try sema.addDeclaredHereNote(msg, types[i]);
+                    break :msg msg;
+                };
+                return sema.failWithOwnedErrorMsg(block, msg);
+            }
             if (try sema.resolveMaybeUndefVal(block, init_src, init)) |init_val| {
                 values[i] = init_val;
             } else {
@@ -14742,9 +14752,19 @@ fn zirArrayInitAnon(
     const opt_runtime_src = rs: {
         var runtime_src: ?LazySrcLoc = null;
         for (operands) |operand, i| {
+            const operand_src = src; // TODO better source location
             const elem = try sema.resolveInst(operand);
             types[i] = sema.typeOf(elem);
-            const operand_src = src; // TODO better source location
+            if (types[i].zigTypeTag() == .Opaque) {
+                const msg = msg: {
+                    const msg = try sema.errMsg(block, operand_src, "opaque types have unknown size and therefore cannot be directly embedded in structs", .{});
+                    errdefer msg.destroy(sema.gpa);
+
+                    try sema.addDeclaredHereNote(msg, types[i]);
+                    break :msg msg;
+                };
+                return sema.failWithOwnedErrorMsg(block, msg);
+            }
             if (try sema.resolveMaybeUndefVal(block, operand_src, elem)) |val| {
                 values[i] = val;
             } else {
@@ -18641,6 +18661,8 @@ const ExternPosition = enum {
     other,
 };
 
+/// Returns true if `ty` is allowed in extern types.
+/// Does *NOT* require `ty` to be resolved in any way.
 fn validateExternType(sema: *Sema, ty: Type, position: ExternPosition) CompileError!bool {
     switch (ty.zigTypeTag()) {
         .Type,
@@ -25214,20 +25236,6 @@ fn resolveStructFully(
         struct_obj.status = .fully_resolved_wip;
         for (struct_obj.fields.values()) |field| {
             try sema.resolveTypeFully(block, src, field.ty);
-
-            if (struct_obj.layout == .Extern and !(try sema.validateExternType(field.ty, .other))) {
-                const msg = msg: {
-                    const msg = try sema.errMsg(block, src, "extern structs cannot contain fields of type '{}'", .{field.ty.fmt(sema.mod)});
-                    errdefer msg.destroy(sema.gpa);
-
-                    const src_decl = sema.mod.declPtr(block.src_decl);
-                    try sema.explainWhyTypeIsNotExtern(block, src, msg, src.toSrcLoc(src_decl), field.ty, .other);
-
-                    try sema.addDeclaredHereNote(msg, field.ty);
-                    break :msg msg;
-                };
-                return sema.failWithOwnedErrorMsg(block, msg);
-            }
         }
         struct_obj.status = .fully_resolved;
     }
@@ -25261,20 +25269,6 @@ fn resolveUnionFully(
         union_obj.status = .fully_resolved_wip;
         for (union_obj.fields.values()) |field| {
             try sema.resolveTypeFully(block, src, field.ty);
-
-            if (union_obj.layout == .Extern and !(try sema.validateExternType(field.ty, .union_field))) {
-                const msg = msg: {
-                    const msg = try sema.errMsg(block, src, "extern unions cannot contain fields of type '{}'", .{field.ty.fmt(sema.mod)});
-                    errdefer msg.destroy(sema.gpa);
-
-                    const src_decl = sema.mod.declPtr(block.src_decl);
-                    try sema.explainWhyTypeIsNotExtern(block, src, msg, src.toSrcLoc(src_decl), field.ty, .union_field);
-
-                    try sema.addDeclaredHereNote(msg, field.ty);
-                    break :msg msg;
-                };
-                return sema.failWithOwnedErrorMsg(block, msg);
-            }
         }
         union_obj.status = .fully_resolved;
     }
@@ -25612,6 +25606,33 @@ fn semaStructFields(mod: *Module, struct_obj: *Module.Struct) CompileError!void
         const field = &struct_obj.fields.values()[i];
         field.ty = try field_ty.copy(decl_arena_allocator);
 
+        if (struct_obj.layout == .Extern and !(try sema.validateExternType(field.ty, .other))) {
+            const msg = msg: {
+                const tree = try sema.getAstTree(&block_scope);
+                const fields_src = enumFieldSrcLoc(decl, tree.*, struct_obj.node_offset, i);
+                const msg = try sema.errMsg(&block_scope, fields_src, "extern structs cannot contain fields of type '{}'", .{field.ty.fmt(sema.mod)});
+                errdefer msg.destroy(sema.gpa);
+
+                try sema.explainWhyTypeIsNotExtern(&block_scope, fields_src, msg, fields_src.toSrcLoc(decl), field.ty, .other);
+
+                try sema.addDeclaredHereNote(msg, field.ty);
+                break :msg msg;
+            };
+            return sema.failWithOwnedErrorMsg(&block_scope, msg);
+        }
+        if (field_ty.zigTypeTag() == .Opaque) {
+            const msg = msg: {
+                const tree = try sema.getAstTree(&block_scope);
+                const field_src = enumFieldSrcLoc(decl, tree.*, struct_obj.node_offset, i);
+                const msg = try sema.errMsg(&block_scope, field_src, "opaque types have unknown size and therefore cannot be directly embedded in structs", .{});
+                errdefer msg.destroy(sema.gpa);
+
+                try sema.addDeclaredHereNote(msg, field_ty);
+                break :msg msg;
+            };
+            return sema.failWithOwnedErrorMsg(&block_scope, msg);
+        }
+
         if (zir_field.align_body_len > 0) {
             const body = zir.extra[extra_index..][0..zir_field.align_body_len];
             extra_index += body.len;
@@ -25909,6 +25930,33 @@ fn semaUnionFields(mod: *Module, union_obj: *Module.Union) CompileError!void {
             }
         }
 
+        if (union_obj.layout == .Extern and !(try sema.validateExternType(field_ty, .union_field))) {
+            const msg = msg: {
+                const tree = try sema.getAstTree(&block_scope);
+                const field_src = enumFieldSrcLoc(decl, tree.*, union_obj.node_offset, field_i);
+                const msg = try sema.errMsg(&block_scope, field_src, "extern unions cannot contain fields of type '{}'", .{field_ty.fmt(sema.mod)});
+                errdefer msg.destroy(sema.gpa);
+
+                try sema.explainWhyTypeIsNotExtern(&block_scope, field_src, msg, field_src.toSrcLoc(decl), field_ty, .union_field);
+
+                try sema.addDeclaredHereNote(msg, field_ty);
+                break :msg msg;
+            };
+            return sema.failWithOwnedErrorMsg(&block_scope, msg);
+        }
+        if (field_ty.zigTypeTag() == .Opaque) {
+            const msg = msg: {
+                const tree = try sema.getAstTree(&block_scope);
+                const field_src = enumFieldSrcLoc(decl, tree.*, union_obj.node_offset, field_i);
+                const msg = try sema.errMsg(&block_scope, field_src, "opaque types have unknown size and therefore cannot be directly embedded in unions", .{});
+                errdefer msg.destroy(sema.gpa);
+
+                try sema.addDeclaredHereNote(msg, field_ty);
+                break :msg msg;
+            };
+            return sema.failWithOwnedErrorMsg(&block_scope, msg);
+        }
+
         gop.value_ptr.* = .{
             .ty = try field_ty.copy(decl_arena_allocator),
             .abi_align = 0,
test/behavior/bugs/1310.zig
@@ -4,7 +4,7 @@ const builtin = @import("builtin");
 
 pub const VM = ?[*]const struct_InvocationTable_;
 pub const struct_InvocationTable_ = extern struct {
-    GetVM: ?fn (?[*]VM) callconv(.C) c_int,
+    GetVM: ?*const fn (?[*]VM) callconv(.C) c_int,
 };
 
 pub const struct_VM_ = extern struct {
@@ -23,5 +23,7 @@ fn agent_callback(_vm: [*]VM, options: [*]u8) callconv(.C) i32 {
 }
 
 test "fixed" {
+    if (builtin.zig_backend == .stage1) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_c) return error.SkipZigTest;
     try expect(agent_callback(undefined, undefined) == 11);
 }
test/behavior/align.zig
@@ -299,7 +299,7 @@ test "implicitly decreasing fn alignment" {
     try testImplicitlyDecreaseFnAlign(alignedBig, 5678);
 }
 
-fn testImplicitlyDecreaseFnAlign(ptr: *align(1) const fn () i32, answer: i32) !void {
+fn testImplicitlyDecreaseFnAlign(ptr: *const fn () align(1) i32, answer: i32) !void {
     try expect(ptr() == answer);
 }
 
@@ -325,7 +325,7 @@ test "@alignCast functions" {
 fn fnExpectsOnly1(ptr: *const fn () align(1) i32) i32 {
     return fnExpects4(@alignCast(4, ptr));
 }
-fn fnExpects4(ptr: *align(4) const fn () i32) i32 {
+fn fnExpects4(ptr: *const fn () align(4) i32) i32 {
     return ptr();
 }
 fn simple4() align(4) i32 {
test/cases/compile_errors/stage1/obj/directly_embedding_opaque_type_in_struct_and_union.zig
@@ -1,29 +0,0 @@
-const O = opaque {};
-const Foo = struct {
-    o: O,
-};
-const Bar = union {
-    One: i32,
-    Two: O,
-};
-export fn a() void {
-    var foo: Foo = undefined;
-    _ = foo;
-}
-export fn b() void {
-    var bar: Bar = undefined;
-    _ = bar;
-}
-export fn c() void {
-    var baz: *opaque {} = undefined;
-    const qux = .{baz.*};
-    _ = qux;
-}
-
-// error
-// backend=stage1
-// target=native
-//
-// tmp.zig:3:5: error: opaque types have unknown size and therefore cannot be directly embedded in structs
-// tmp.zig:7:5: error: opaque types have unknown size and therefore cannot be directly embedded in unions
-// tmp.zig:19:22: error: opaque types have unknown size and therefore cannot be directly embedded in structs
test/cases/compile_errors/directly_embedding_opaque_type_in_struct_and_union.zig
@@ -0,0 +1,38 @@
+const O = opaque {};
+const Foo = struct {
+    o: O,
+};
+const Bar = union {
+    One: i32,
+    Two: O,
+};
+export fn a() void {
+    var foo: Foo = undefined;
+    _ = foo;
+}
+export fn b() void {
+    var bar: Bar = undefined;
+    _ = bar;
+}
+export fn c() void {
+    const baz = &@as(opaque {}, undefined);
+    const qux = .{baz.*};
+    _ = qux;
+}
+export fn d() void {
+    const baz = &@as(opaque {}, undefined);
+    const qux = .{ .a = baz.* };
+    _ = qux;
+}
+
+// error
+// backend=stage2
+// target=native
+//
+// :3:5: error: opaque types have unknown size and therefore cannot be directly embedded in structs
+// :1:11: note: opaque declared here
+// :7:5: error: opaque types have unknown size and therefore cannot be directly embedded in unions
+// :19:18: error: opaque types have unknown size and therefore cannot be directly embedded in structs
+// :18:22: note: opaque declared here
+// :24:18: error: opaque types have unknown size and therefore cannot be directly embedded in structs
+// :23:22: note: opaque declared here
test/cases/compile_errors/extern_struct_with_extern-compatible_but_inferred_integer_tag_type.zig
@@ -39,7 +39,7 @@ export fn entry() void {
 // backend=stage2
 // target=native
 //
-// :33:8: error: extern structs cannot contain fields of type 'tmp.E'
-// :33:8: note: enum tag type 'u9' is not extern compatible
-// :33:8: note: only integers with power of two bits are extern compatible
+// :31:5: error: extern structs cannot contain fields of type 'tmp.E'
+// :31:5: note: enum tag type 'u9' is not extern compatible
+// :31:5: note: only integers with power of two bits are extern compatible
 // :1:15: note: enum declared here
test/cases/compile_errors/extern_struct_with_non-extern-compatible_integer_tag_type.zig
@@ -11,7 +11,7 @@ export fn entry() void {
 // backend=stage2
 // target=native
 //
-// :5:8: error: extern structs cannot contain fields of type 'tmp.E'
-// :5:8: note: enum tag type 'u31' is not extern compatible
-// :5:8: note: only integers with power of two bits are extern compatible
+// :3:5: error: extern structs cannot contain fields of type 'tmp.E'
+// :3:5: note: enum tag type 'u31' is not extern compatible
+// :3:5: note: only integers with power of two bits are extern compatible
 // :1:15: note: enum declared here
test/cases/compile_errors/invalid_optional_type_in_extern_struct.zig
@@ -7,5 +7,5 @@ export fn testf(fluff: *stroo) void { _ = fluff; }
 // backend=stage2
 // target=native
 //
-// :4:8: error: extern structs cannot contain fields of type '?[*c]u8'
-// :4:8: note: only pointer like optionals are extern compatible
+// :2:5: error: extern structs cannot contain fields of type '?[*c]u8'
+// :2:5: note: only pointer like optionals are extern compatible