Merge pull request #4971 from Vexu/const-ref

Fix missing const on address of literal

lib/std/json.zig

@@ -1327,12 +1327,13 @@ test "Value.jsonStringify" {
     {
         var buffer: [10]u8 = undefined;
         var fbs = std.io.fixedBufferStream(&buffer);
+        var vals = [_]Value{
+            .{ .Integer = 1 },
+            .{ .Integer = 2 },
+            .{ .Integer = 3 },
+        };
         try (Value{
-            .Array = Array.fromOwnedSlice(undefined, &[_]Value{
-                .{ .Integer = 1 },
-                .{ .Integer = 2 },
-                .{ .Integer = 3 },
-            }),
+            .Array = Array.fromOwnedSlice(undefined, &vals),
         }).jsonStringify(.{}, fbs.outStream());
         testing.expectEqualSlices(u8, fbs.getWritten(), "[1,2,3]");
     }

lib/std/testing.zig

@@ -7,7 +7,8 @@ pub const FailingAllocator = @import("testing/failing_allocator.zig").FailingAll
 pub const allocator = &allocator_instance.allocator;
 pub var allocator_instance = LeakCountAllocator.init(&base_allocator_instance.allocator);
 
-pub const failing_allocator = &FailingAllocator.init(&base_allocator_instance.allocator, 0).allocator;
+pub const failing_allocator = &failing_allocator_instance.allocator;
+pub var failing_allocator_instance = FailingAllocator.init(&base_allocator_instance.allocator, 0);
 
 pub var base_allocator_instance = std.heap.ThreadSafeFixedBufferAllocator.init(allocator_mem[0..]);
 var allocator_mem: [1024 * 1024]u8 = undefined;

src/all_types.hpp

@@ -3519,8 +3519,6 @@ struct IrInstSrcRef {
     IrInstSrc base;
 
     IrInstSrc *value;
-    bool is_const;
-    bool is_volatile;
 };
 
 struct IrInstGenRef {

src/ir.cpp

@@ -3290,13 +3290,9 @@ static IrInstSrc *ir_build_import(IrBuilderSrc *irb, Scope *scope, AstNode *sour
     return &instruction->base;
 }
 
-static IrInstSrc *ir_build_ref_src(IrBuilderSrc *irb, Scope *scope, AstNode *source_node, IrInstSrc *value,
-        bool is_const, bool is_volatile)
-{
+static IrInstSrc *ir_build_ref_src(IrBuilderSrc *irb, Scope *scope, AstNode *source_node, IrInstSrc *value) {
     IrInstSrcRef *instruction = ir_build_instruction<IrInstSrcRef>(irb, scope, source_node);
     instruction->value = value;
-    instruction->is_const = is_const;
-    instruction->is_volatile = is_volatile;
 
     ir_ref_instruction(value, irb->current_basic_block);
 
@@ -5938,7 +5934,7 @@ static IrInstSrc *ir_gen_symbol(IrBuilderSrc *irb, Scope *scope, AstNode *node,
     } else {
         IrInstSrc *value = ir_build_const_type(irb, scope, node, primitive_type);
         if (lval == LValPtr) {
-            return ir_build_ref_src(irb, scope, node, value, false, false);
+            return ir_build_ref_src(irb, scope, node, value);
         } else {
             return ir_expr_wrap(irb, scope, value, result_loc);
         }
@@ -7486,7 +7482,7 @@ static IrInstSrc *ir_lval_wrap(IrBuilderSrc *irb, Scope *scope, IrInstSrc *value
     if (lval == LValPtr) {
         // We needed a pointer to a value, but we got a value. So we create
         // an instruction which just makes a pointer of it.
-        return ir_build_ref_src(irb, scope, value->base.source_node, value, false, false);
+        return ir_build_ref_src(irb, scope, value->base.source_node, value);
     } else if (result_loc != nullptr) {
         return ir_expr_wrap(irb, scope, value, result_loc);
     } else {
@@ -23348,7 +23344,16 @@ static IrInstGen *ir_analyze_instruction_ref(IrAnalyze *ira, IrInstSrcRef *ref_i
     IrInstGen *value = ref_instruction->value->child;
     if (type_is_invalid(value->value->type))
         return ira->codegen->invalid_inst_gen;
-    return ir_get_ref(ira, &ref_instruction->base.base, value, ref_instruction->is_const, ref_instruction->is_volatile);
+
+    bool is_const = false;
+    bool is_volatile = false;
+
+    ZigValue *child_value = value->value;
+    if (child_value->special == ConstValSpecialStatic) {
+        is_const = true;
+    }
+
+    return ir_get_ref(ira, &ref_instruction->base.base, value, is_const, is_volatile);
 }
 
 static IrInstGen *ir_analyze_union_init(IrAnalyze *ira, IrInst* source_instruction,

src/ir_print.cpp

@@ -1476,9 +1476,7 @@ static void ir_print_import(IrPrintSrc *irp, IrInstSrcImport *instruction) {
 }
 
 static void ir_print_ref(IrPrintSrc *irp, IrInstSrcRef *instruction) {
-    const char *const_str = instruction->is_const ? "const " : "";
-    const char *volatile_str = instruction->is_volatile ? "volatile " : "";
-    fprintf(irp->f, "%s%sref ", const_str, volatile_str);
+    fprintf(irp->f, "ref ");
     ir_print_other_inst_src(irp, instruction->value);
 }
 

test/compile_errors.zig

@@ -2,6 +2,34 @@ const tests = @import("tests.zig");
 const std = @import("std");
 
 pub fn addCases(cases: *tests.CompileErrorContext) void {
+    cases.addTest("reference to const data",
+        \\export fn foo() void {
+        \\    var ptr = &[_]u8{0,0,0,0};
+        \\    ptr[1] = 2;
+        \\}
+        \\export fn bar() void {
+        \\    var ptr = &@as(u32, 2);
+        \\    ptr.* = 2;
+        \\}
+        \\export fn baz() void {
+        \\    var ptr = &true;
+        \\    ptr.* = false;
+        \\}
+        \\export fn qux() void {
+        \\    const S = struct{
+        \\        x: usize,
+        \\        y: usize,
+        \\    };
+        \\    var ptr = &S{.x=1,.y=2};
+        \\    ptr.x = 2;
+        \\}
+    , &[_][]const u8{
+        "tmp.zig:3:14: error: cannot assign to constant",
+        "tmp.zig:7:13: error: cannot assign to constant",
+        "tmp.zig:11:13: error: cannot assign to constant",
+        "tmp.zig:19:13: error: cannot assign to constant",
+    });
+
     cases.addTest("cast between ?T where T is not a pointer",
         \\pub const fnty1 = ?fn (i8) void;
         \\pub const fnty2 = ?fn (u64) void;
@@ -969,7 +997,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\    const x = 1 << &@as(u8, 10);
         \\}
     , &[_][]const u8{
-        "tmp.zig:2:21: error: shift amount has to be an integer type, but found '*u8'",
+        "tmp.zig:2:21: error: shift amount has to be an integer type, but found '*const u8'",
         "tmp.zig:2:17: note: referenced here",
     });
 
@@ -978,7 +1006,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\    const x = &@as(u8, 1) << 10;
         \\}
     , &[_][]const u8{
-        "tmp.zig:2:16: error: bit shifting operation expected integer type, found '*u8'",
+        "tmp.zig:2:16: error: bit shifting operation expected integer type, found '*const u8'",
         "tmp.zig:2:27: note: referenced here",
     });
 
@@ -6005,7 +6033,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\    fn bar(self: *const Foo) void {}
         \\};
     , &[_][]const u8{
-        "tmp.zig:2:4: error: variable of type '*comptime_int' must be const or comptime",
+        "tmp.zig:2:4: error: variable of type '*const comptime_int' must be const or comptime",
         "tmp.zig:5:4: error: variable of type '(undefined)' must be const or comptime",
         "tmp.zig:8:4: error: variable of type 'comptime_int' must be const or comptime",
         "tmp.zig:11:4: error: variable of type 'comptime_float' must be const or comptime",
@@ -6849,12 +6877,12 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\    const word: u16 = @bitCast(u16, bytes[0..]);
         \\}
         \\export fn foo2() void {
-        \\    var bytes: []u8 = &[_]u8{1, 2};
+        \\    var bytes: []const u8 = &[_]u8{1, 2};
         \\    const word: u16 = @bitCast(u16, bytes);
         \\}
     , &[_][]const u8{
         "tmp.zig:3:42: error: unable to @bitCast from pointer type '*[2]u8'",
-        "tmp.zig:7:32: error: destination type 'u16' has size 2 but source type '[]u8' has size 16",
+        "tmp.zig:7:32: error: destination type 'u16' has size 2 but source type '[]const u8' has size 16",
         "tmp.zig:7:37: note: referenced here",
     });
 

test/stage1/behavior/for.zig

@@ -161,8 +161,8 @@ test "for copies its payload" {
 
 test "for on slice with allowzero ptr" {
     const S = struct {
-        fn doTheTest(slice: []u8) void {
-            var ptr = @ptrCast([*]allowzero u8, slice.ptr)[0..slice.len];
+        fn doTheTest(slice: []const u8) void {
+            var ptr = @ptrCast([*]const allowzero u8, slice.ptr)[0..slice.len];
             for (ptr) |x, i| expect(x == i + 1);
             for (ptr) |*x, i| expect(x.* == i + 1);
         }

test/stage1/behavior/pointers.zig

@@ -253,7 +253,7 @@ test "pointer sentinel with enums" {
         };
 
         fn doTheTest() void {
-            var ptr: [*:.sentinel]Number = &[_:.sentinel]Number{ .one, .two, .two, .one };
+            var ptr: [*:.sentinel]const Number = &[_:.sentinel]Number{ .one, .two, .two, .one };
             expect(ptr[4] == .sentinel); // TODO this should be comptime expect, see #3731
         }
     };
@@ -264,7 +264,7 @@ test "pointer sentinel with enums" {
 test "pointer sentinel with optional element" {
     const S = struct {
         fn doTheTest() void {
-            var ptr: [*:null]?i32 = &[_:null]?i32{ 1, 2, 3, 4 };
+            var ptr: [*:null]const ?i32 = &[_:null]?i32{ 1, 2, 3, 4 };
             expect(ptr[4] == null); // TODO this should be comptime expect, see #3731
         }
     };
@@ -276,7 +276,7 @@ test "pointer sentinel with +inf" {
     const S = struct {
         fn doTheTest() void {
             const inf = std.math.inf_f32;
-            var ptr: [*:inf]f32 = &[_:inf]f32{ 1.1, 2.2, 3.3, 4.4 };
+            var ptr: [*:inf]const f32 = &[_:inf]f32{ 1.1, 2.2, 3.3, 4.4 };
             expect(ptr[4] == inf); // TODO this should be comptime expect, see #3731
         }
     };

test/stage1/behavior/slice.zig

@@ -218,9 +218,9 @@ test "slice syntax resulting in pointer-to-array" {
         }
 
         fn testPointer0() void {
-            var pointer: [*]u0 = &[1]u0{0};
+            var pointer: [*]const u0 = &[1]u0{0};
             var slice = pointer[0..1];
-            comptime expect(@TypeOf(slice) == *[1]u0);
+            comptime expect(@TypeOf(slice) == *const [1]u0);
             expect(slice[0] == 0);
         }