Merge branch 'LemonBoy-fix-4749'

Closes #4750
Closes #4749

lib/std/zig/parser_test.zig

@@ -1509,6 +1509,8 @@ test "zig fmt: error set declaration" {
         \\const Error = error{OutOfMemory};
         \\const Error = error{};
         \\
+        \\const Error = error{ OutOfMemory, OutOfTime };
+        \\
     );
 }
 

lib/std/zig/render.zig

@@ -1268,25 +1268,51 @@ fn renderExpression(
             }
 
             try renderToken(tree, stream, err_set_decl.error_token, indent, start_col, Space.None); // error
-            try renderToken(tree, stream, lbrace, indent, start_col, Space.Newline); // {
-            const new_indent = indent + indent_delta;
 
-            var it = err_set_decl.decls.iterator(0);
-            while (it.next()) |node| {
-                try stream.writeByteNTimes(' ', new_indent);
+            const src_has_trailing_comma = blk: {
+                const maybe_comma = tree.prevToken(err_set_decl.rbrace_token);
+                break :blk tree.tokens.at(maybe_comma).id == .Comma;
+            };
 
-                if (it.peek()) |next_node| {
-                    try renderExpression(allocator, stream, tree, new_indent, start_col, node.*, Space.None);
-                    try renderToken(tree, stream, tree.nextToken(node.*.lastToken()), new_indent, start_col, Space.Newline); // ,
+            if (src_has_trailing_comma) {
+                try renderToken(tree, stream, lbrace, indent, start_col, Space.Newline); // {
+                const new_indent = indent + indent_delta;
 
-                    try renderExtraNewline(tree, stream, start_col, next_node.*);
-                } else {
-                    try renderExpression(allocator, stream, tree, new_indent, start_col, node.*, Space.Comma);
+                var it = err_set_decl.decls.iterator(0);
+                while (it.next()) |node| {
+                    try stream.writeByteNTimes(' ', new_indent);
+
+                    if (it.peek()) |next_node| {
+                        try renderExpression(allocator, stream, tree, new_indent, start_col, node.*, Space.None);
+                        try renderToken(tree, stream, tree.nextToken(node.*.lastToken()), new_indent, start_col, Space.Newline); // ,
+
+                        try renderExtraNewline(tree, stream, start_col, next_node.*);
+                    } else {
+                        try renderExpression(allocator, stream, tree, new_indent, start_col, node.*, Space.Comma);
+                    }
                 }
-            }
 
-            try stream.writeByteNTimes(' ', indent);
-            return renderToken(tree, stream, err_set_decl.rbrace_token, indent, start_col, space); // }
+                try stream.writeByteNTimes(' ', indent);
+                return renderToken(tree, stream, err_set_decl.rbrace_token, indent, start_col, space); // }
+            } else {
+                try renderToken(tree, stream, lbrace, indent, start_col, Space.Space); // {
+
+                var it = err_set_decl.decls.iterator(0);
+                while (it.next()) |node| {
+                    if (it.peek()) |next_node| {
+                        try renderExpression(allocator, stream, tree, indent, start_col, node.*, Space.None);
+
+                        const comma_token = tree.nextToken(node.*.lastToken());
+                        assert(tree.tokens.at(comma_token).id == .Comma);
+                        try renderToken(tree, stream, comma_token, indent, start_col, Space.Space); // ,
+                        try renderExtraNewline(tree, stream, start_col, next_node.*);
+                    } else {
+                        try renderExpression(allocator, stream, tree, indent, start_col, node.*, Space.Space);
+                    }
+                }
+
+                return renderToken(tree, stream, err_set_decl.rbrace_token, indent, start_col, space); // }
+            }
         },
 
         .ErrorTag => {
@@ -1589,8 +1615,7 @@ fn renderExpression(
                 }
             } else {
                 var it = switch_case.items.iterator(0);
-                while (true) {
-                    const node = it.next().?;
+                while (it.next()) |node| {
                     if (it.peek()) |next_node| {
                         try renderExpression(allocator, stream, tree, indent, start_col, node.*, Space.None);
 
@@ -1601,7 +1626,6 @@ fn renderExpression(
                     } else {
                         try renderExpression(allocator, stream, tree, indent, start_col, node.*, Space.Comma);
                         try stream.writeByteNTimes(' ', indent);
-                        break;
                     }
                 }
             }

src/analyze.cpp

@@ -803,13 +803,7 @@ ZigType *get_array_type(CodeGen *g, ZigType *child_type, uint64_t array_size, Zi
     }
     buf_appendf(&entry->name, "]%s", buf_ptr(&child_type->name));
 
-    size_t full_array_size;
-    if (array_size == 0) {
-        full_array_size = 0;
-    } else {
-        full_array_size = array_size + ((sentinel != nullptr) ? 1 : 0);
-    }
-
+    size_t full_array_size = array_size + ((sentinel != nullptr) ? 1 : 0);
     entry->size_in_bits = child_type->size_in_bits * full_array_size;
     entry->abi_align = child_type->abi_align;
     entry->abi_size = child_type->abi_size * full_array_size;
@@ -1197,7 +1191,8 @@ Error type_val_resolve_zero_bits(CodeGen *g, ZigValue *type_val, ZigType *parent
             LazyValueArrayType *lazy_array_type =
                 reinterpret_cast<LazyValueArrayType *>(type_val->data.x_lazy);
 
-            if (lazy_array_type->length < 1) {
+            // The sentinel counts as an extra element
+            if (lazy_array_type->length == 0 && lazy_array_type->sentinel == nullptr) {
                 *is_zero_bits = true;
                 return ErrorNone;
             }
@@ -1452,7 +1447,7 @@ static OnePossibleValue type_val_resolve_has_one_possible_value(CodeGen *g, ZigV
         case LazyValueIdArrayType: {
             LazyValueArrayType *lazy_array_type =
                 reinterpret_cast<LazyValueArrayType *>(type_val->data.x_lazy);
-            if (lazy_array_type->length < 1)
+            if (lazy_array_type->length == 0)
                 return OnePossibleValueYes;
             return type_val_resolve_has_one_possible_value(g, lazy_array_type->elem_type->value);
         }

src/codegen.cpp

@@ -3584,7 +3584,9 @@ static bool value_is_all_undef(CodeGen *g, ZigValue *const_val) {
                 }
                 return true;
             } else if (const_val->type->id == ZigTypeIdArray) {
-                return value_is_all_undef_array(g, const_val, const_val->type->data.array.len);
+                const size_t full_len = const_val->type->data.array.len +
+                    (const_val->type->data.array.sentinel != nullptr);
+                return value_is_all_undef_array(g, const_val, full_len);
             } else if (const_val->type->id == ZigTypeIdVector) {
                 return value_is_all_undef_array(g, const_val, const_val->type->data.vector.len);
             } else {

test/stage1/behavior/array.zig

@@ -376,3 +376,23 @@ test "type deduction for array subscript expression" {
     S.doTheTest();
     comptime S.doTheTest();
 }
+
+test "sentinel element count towards the ABI size calculation" {
+    const S = struct {
+        fn doTheTest() void {
+            const T = packed struct {
+                fill_pre: u8 = 0x55,
+                data: [0:0]u8 = undefined,
+                fill_post: u8 = 0xAA,
+            };
+            var x = T{};
+            var as_slice = mem.asBytes(&x);
+            expectEqual(@as(usize, 3), as_slice.len);
+            expectEqual(@as(u8, 0x55), as_slice[0]);
+            expectEqual(@as(u8, 0xAA), as_slice[2]);
+        }
+    };
+
+    S.doTheTest();
+    comptime S.doTheTest();
+}