Merge pull request #3115 from ziglang/fix-field-alignment-kludge

fix field alignment kludge by implementing lazy values

3 files changed, 101 insertions, 44 deletions

diff --git a/test/compile_errors.zig b/test/compile_errors.zig
index a6a1d0219b..bc2d43706f 100644
--- a/test/compile_errors.zig
+++ b/test/compile_errors.zig
@@ -2,6 +2,33 @@ const tests = @import("tests.zig");
 const builtin = @import("builtin");
 
 pub fn addCases(cases: *tests.CompileErrorContext) void {
+    cases.add(
+        "alignment of enum field specified",
+        \\const Number = enum {
+        \\    a,
+        \\    b align(i32),
+        \\};
+        \\export fn entry1() void {
+        \\    var x: Number = undefined;
+        \\}
+    ,
+        "tmp.zig:3:13: error: structs and unions, not enums, support field alignment",
+        "tmp.zig:1:16: note: consider 'union(enum)' here",
+    );
+
+    cases.add(
+        "bad alignment type",
+        \\export fn entry1() void {
+        \\    var x: []align(true) i32 = undefined;
+        \\}
+        \\export fn entry2() void {
+        \\    var x: *align(f64(12.34)) i32 = undefined;
+        \\}
+    ,
+        "tmp.zig:2:20: error: expected type 'u29', found 'bool'",
+        "tmp.zig:5:22: error: fractional component prevents float value 12.340000 from being casted to type 'u29'",
+    );
+
     cases.addCase(x: {
         var tc = cases.create("variable in inline assembly template cannot be found",
             \\export fn entry() void {
@@ -10,7 +37,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
             \\        : [bar] "=r" (-> usize)
             \\    );
             \\}
-        , "tmp.zig:2:14: error: could not find 'foo' in the inputs or outputs.");
+        , "tmp.zig:2:14: error: could not find 'foo' in the inputs or outputs");
         tc.target = tests.Target{
             .Cross = tests.CrossTarget{
                 .arch = .x86_64,
@@ -53,8 +80,8 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\}
     ,
         "tmp.zig:8:1: error: '@Frame(rangeSum)' depends on itself",
-        "tmp.zig:15:33: note: when analyzing type '@Frame(rangeSumIndirect)' here",
-        "tmp.zig:26:25: note: when analyzing type '@Frame(rangeSum)' here",
+        "tmp.zig:15:33: note: when analyzing type '@Frame(rangeSum)' here",
+        "tmp.zig:26:25: note: when analyzing type '@Frame(rangeSumIndirect)' here",
     );
 
     cases.add(
@@ -245,7 +272,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
     ,
         "tmp.zig:4:1: error: unable to determine async function frame of 'amain'",
         "tmp.zig:5:10: note: analysis of function 'other' depends on the frame",
-        "tmp.zig:8:13: note: depends on the frame here",
+        "tmp.zig:8:13: note: referenced here",
     );
 
     cases.add(
@@ -258,7 +285,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\}
     ,
         "tmp.zig:4:1: error: cannot resolve '@Frame(amain)': function not fully analyzed yet",
-        "tmp.zig:5:13: note: depends on its own frame here",
+        "tmp.zig:5:13: note: referenced here",
     );
 
     cases.add(
@@ -404,7 +431,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\    const foo: Foo = undefined;
         \\}
     ,
-        "tmp.zig:2:8: error: expected type 'type', found '(undefined)'",
+        "tmp.zig:2:8: error: use of undefined value here causes undefined behavior",
     );
 
     cases.add(
@@ -470,7 +497,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
     );
 
     cases.add(
-        "Generic function where return type is self-referenced",
+        "generic function where return type is self-referenced",
         \\fn Foo(comptime T: type) Foo(T) {
         \\    return struct{ x: T };
         \\}
@@ -481,7 +508,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\}
     ,
         "tmp.zig:1:29: error: evaluation exceeded 1000 backwards branches",
-        "tmp.zig:1:29: note: called from here",
+        "tmp.zig:5:18: note: referenced here",
     );
 
     cases.add(
@@ -645,7 +672,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\const A = struct { a : A, };
         \\export fn entry() usize { return @sizeOf(A); }
     ,
-        "tmp.zig:1:11: error: struct 'A' contains itself",
+        "tmp.zig:1:11: error: struct 'A' depends on itself",
     );
 
     cases.add(
@@ -655,7 +682,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\const C = struct { a : A, };
         \\export fn entry() usize { return @sizeOf(A); }
     ,
-        "tmp.zig:1:11: error: struct 'A' contains itself",
+        "tmp.zig:1:11: error: struct 'A' depends on itself",
     );
 
     cases.add(
@@ -670,7 +697,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\    return @sizeOf(@typeOf(foo.x));
         \\}
     ,
-        "tmp.zig:1:13: error: struct 'Foo' contains itself",
+        "tmp.zig:1:13: error: struct 'Foo' depends on itself",
         "tmp.zig:8:28: note: referenced here",
     );
 
@@ -689,7 +716,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\}
     ,
         "tmp.zig:7:9: error: dependency loop detected",
-        "tmp.zig:2:19: note: called from here",
+        "tmp.zig:2:19: note: referenced here",
         "tmp.zig:10:21: note: referenced here",
     );
 
@@ -703,7 +730,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\    var s: Foo = Foo.E;
         \\}
     ,
-        "tmp.zig:1:17: error: 'Foo' depends on itself",
+        "tmp.zig:1:17: error: enum 'Foo' depends on itself",
     );
 
     cases.add(
@@ -866,7 +893,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         break :x tc;
     });
 
-    cases.addTest(
+    cases.add(
         "export generic function",
         \\export fn foo(num: var) i32 {
         \\    return 0;
@@ -875,17 +902,17 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         "tmp.zig:1:15: error: parameter of type 'var' not allowed in function with calling convention 'ccc'",
     );
 
-    cases.addTest(
+    cases.add(
         "C pointer to c_void",
         \\export fn a() void {
         \\    var x: *c_void = undefined;
         \\    var y: [*c]c_void = x;
         \\}
     ,
-        "tmp.zig:3:12: error: C pointers cannot point opaque types",
+        "tmp.zig:3:16: error: C pointers cannot point opaque types",
     );
 
-    cases.addTest(
+    cases.add(
         "directly embedding opaque type in struct and union",
         \\const O = @OpaqueType();
         \\const Foo = struct {
@@ -906,7 +933,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         "tmp.zig:7:10: error: opaque types have unknown size and therefore cannot be directly embedded in unions",
     );
 
-    cases.addTest(
+    cases.add(
         "implicit cast between C pointer and Zig pointer - bad const/align/child",
         \\export fn a() void {
         \\    var x: [*c]u8 = undefined;
@@ -942,7 +969,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         "tmp.zig:23:22: error: expected type '[*c]u32', found '*u8'",
     );
 
-    cases.addTest(
+    cases.add(
         "implicit casting null c pointer to zig pointer",
         \\comptime {
         \\    var c_ptr: [*c]u8 = 0;
@@ -952,7 +979,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         "tmp.zig:3:24: error: null pointer casted to type '*u8'",
     );
 
-    cases.addTest(
+    cases.add(
         "implicit casting undefined c pointer to zig pointer",
         \\comptime {
         \\    var c_ptr: [*c]u8 = undefined;
@@ -962,7 +989,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         "tmp.zig:3:24: error: use of undefined value here causes undefined behavior",
     );
 
-    cases.addTest(
+    cases.add(
         "implicit casting C pointers which would mess up null semantics",
         \\export fn entry() void {
         \\    var slice: []const u8 = "aoeu";
@@ -987,7 +1014,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         "tmp.zig:13:35: note: mutable '[*c]const u8' allows illegal null values stored to type '[*]u8'",
     );
 
-    cases.addTest(
+    cases.add(
         "implicit casting too big integers to C pointers",
         \\export fn a() void {
         \\    var ptr: [*c]u8 = (1 << 64) + 1;
@@ -1001,14 +1028,14 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         "tmp.zig:6:23: error: integer type 'u65' too big for implicit @intToPtr to type '[*c]u8'",
     );
 
-    cases.addTest(
+    cases.add(
         "C pointer pointing to non C ABI compatible type or has align attr",
         \\const Foo = struct {};
         \\export fn a() void {
         \\    const T = [*c]Foo;
         \\}
     ,
-        "tmp.zig:3:15: error: C pointers cannot point to non-C-ABI-compatible type 'Foo'",
+        "tmp.zig:3:19: error: C pointers cannot point to non-C-ABI-compatible type 'Foo'",
     );
 
     cases.addCase(x: {
@@ -1029,7 +1056,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         break :x tc;
     });
 
-    cases.addTest(
+    cases.add(
         "assign to invalid dereference",
         \\export fn entry() void {
         \\    'a'.* = 1;
@@ -1038,7 +1065,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         "tmp.zig:2:8: error: attempt to dereference non-pointer type 'comptime_int'",
     );
 
-    cases.addTest(
+    cases.add(
         "take slice of invalid dereference",
         \\export fn entry() void {
         \\    const x = 'a'.*[0..];
@@ -1047,7 +1074,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         "tmp.zig:2:18: error: attempt to dereference non-pointer type 'comptime_int'",
     );
 
-    cases.addTest(
+    cases.add(
         "@truncate undefined value",
         \\export fn entry() void {
         \\    var z = @truncate(u8, u16(undefined));
@@ -1091,7 +1118,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\    return 5678;
         \\}
     ,
-        "tmp.zig:2:12: error: `&&` is invalid. Note that `and` is boolean AND.",
+        "tmp.zig:2:12: error: `&&` is invalid. Note that `and` is boolean AND",
     );
 
     cases.add(
@@ -1935,7 +1962,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         "unknown length pointer to opaque",
         \\export const T = [*]@OpaqueType();
     ,
-        "tmp.zig:1:18: error: unknown-length pointer to opaque",
+        "tmp.zig:1:21: error: unknown-length pointer to opaque",
     );
 
     cases.add(
@@ -2924,7 +2951,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\fn a() *noreturn {}
         \\export fn entry() void { _ = a(); }
     ,
-        "tmp.zig:1:8: error: pointer to noreturn not allowed",
+        "tmp.zig:1:9: error: pointer to noreturn not allowed",
     );
 
     cases.add(
@@ -3596,7 +3623,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
     );
 
     cases.add(
-        "non constant expression in array size outside function",
+        "non constant expression in array size",
         \\const Foo = struct {
         \\    y: [get()]u8,
         \\};
@@ -3606,8 +3633,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\export fn entry() usize { return @sizeOf(@typeOf(Foo)); }
     ,
         "tmp.zig:5:25: error: unable to evaluate constant expression",
-        "tmp.zig:2:12: note: called from here",
-        "tmp.zig:2:8: note: called from here",
+        "tmp.zig:2:12: note: referenced here",
     );
 
     cases.add(
@@ -3701,7 +3727,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\export fn entry() usize { return @sizeOf(@typeOf(y)); }
     ,
         "tmp.zig:3:14: error: division by zero",
-        "tmp.zig:1:14: note: called from here",
+        "tmp.zig:1:14: note: referenced here",
     );
 
     cases.add(
@@ -4133,7 +4159,8 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\export fn entry() usize { return @sizeOf(@typeOf(seventh_fib_number)); }
     ,
         "tmp.zig:3:21: error: evaluation exceeded 1000 backwards branches",
-        "tmp.zig:3:21: note: called from here",
+        "tmp.zig:1:37: note: referenced here",
+        "tmp.zig:6:50: note: referenced here",
     );
 
     cases.add(
@@ -4174,7 +4201,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\export fn entry() usize { return @sizeOf(@typeOf(a)); }
     ,
         "tmp.zig:6:26: error: unable to evaluate constant expression",
-        "tmp.zig:4:17: note: called from here",
+        "tmp.zig:4:17: note: referenced here",
     );
 
     cases.add(
@@ -4257,7 +4284,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\export fn entry() usize { return @sizeOf(@typeOf(y)); }
     ,
         "tmp.zig:3:12: error: negation caused overflow",
-        "tmp.zig:1:14: note: called from here",
+        "tmp.zig:1:14: note: referenced here",
     );
 
     cases.add(
@@ -4270,7 +4297,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\export fn entry() usize { return @sizeOf(@typeOf(y)); }
     ,
         "tmp.zig:3:14: error: operation caused overflow",
-        "tmp.zig:1:14: note: called from here",
+        "tmp.zig:1:14: note: referenced here",
     );
 
     cases.add(
@@ -4283,7 +4310,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\export fn entry() usize { return @sizeOf(@typeOf(y)); }
     ,
         "tmp.zig:3:14: error: operation caused overflow",
-        "tmp.zig:1:14: note: called from here",
+        "tmp.zig:1:14: note: referenced here",
     );
 
     cases.add(
@@ -4296,7 +4323,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\export fn entry() usize { return @sizeOf(@typeOf(y)); }
     ,
         "tmp.zig:3:14: error: operation caused overflow",
-        "tmp.zig:1:14: note: called from here",
+        "tmp.zig:1:14: note: referenced here",
     );
 
     cases.add(
@@ -4388,7 +4415,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\}
     ,
         "tmp.zig:3:7: error: unable to evaluate constant expression",
-        "tmp.zig:16:19: note: called from here",
+        "tmp.zig:16:19: note: referenced here",
     );
 
     cases.add(
@@ -4717,7 +4744,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\}
     ,
         "tmp.zig:10:14: error: unable to evaluate constant expression",
-        "tmp.zig:6:20: note: called from here",
+        "tmp.zig:6:20: note: referenced here",
     );
 
     cases.add(
@@ -5864,7 +5891,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\}
     ,
         "tmp.zig:4:25: error: aoeu",
-        "tmp.zig:1:36: note: called from here",
+        "tmp.zig:1:36: note: referenced here",
         "tmp.zig:12:20: note: referenced here",
     );
 
@@ -5939,7 +5966,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\    var x: MultipleChoice = undefined;
         \\}
     ,
-        "tmp.zig:2:14: error: non-enum union field assignment",
+        "tmp.zig:2:14: error: untagged union field assignment",
         "tmp.zig:1:24: note: consider 'union(enum)' here",
     );
 
diff --git a/test/stage1/behavior/align.zig b/test/stage1/behavior/align.zig
index f607ac59d2..677ae85b68 100644
--- a/test/stage1/behavior/align.zig
+++ b/test/stage1/behavior/align.zig
@@ -290,3 +290,18 @@ test "read 128-bit field from default aligned struct in global memory" {
     expect((@ptrToInt(&default_aligned_global.badguy) % 16) == 0);
     expect(12 == default_aligned_global.badguy);
 }
+
+test "struct field explicit alignment" {
+    const S = struct {
+        const Node = struct {
+            next: *Node,
+            massive_byte: u8 align(64),
+        };
+    };
+
+    var node: S.Node = undefined;
+    node.massive_byte = 100;
+    expect(node.massive_byte == 100);
+    comptime expect(@typeOf(&node.massive_byte) == *align(64) u8);
+    expect(@ptrToInt(&node.massive_byte) % 64 == 0);
+}
diff --git a/test/stage1/behavior/misc.zig b/test/stage1/behavior/misc.zig
index ab58f2ed08..c122b18e0a 100644
--- a/test/stage1/behavior/misc.zig
+++ b/test/stage1/behavior/misc.zig
@@ -706,3 +706,18 @@ test "result location zero sized array inside struct field implicit cast to slic
     var foo = E{ .entries = [_]u32{} };
     expect(foo.entries.len == 0);
 }
+
+var global_foo: *i32 = undefined;
+
+test "global variable assignment with optional unwrapping with var initialized to undefined" {
+    const S = struct {
+        var data: i32 = 1234;
+        fn foo() ?*i32 {
+            return &data;
+        }
+    };
+    global_foo = S.foo() orelse {
+        @panic("bad");
+    };
+    expect(global_foo.* == 1234);
+}