diff --git a/src/clang.zig b/src/clang.zig index 205a3cccc617..d3eacbfec449 100644 --- a/src/clang.zig +++ b/src/clang.zig @@ -470,6 +470,9 @@ pub const FieldDecl = opaque { pub const getAlignedAttribute = ZigClangFieldDecl_getAlignedAttribute; extern fn ZigClangFieldDecl_getAlignedAttribute(*const FieldDecl, *const ASTContext) c_uint; + pub const getPackedAttribute = ZigClangFieldDecl_getPackedAttribute; + extern fn ZigClangFieldDecl_getPackedAttribute(*const FieldDecl) bool; + pub const isAnonymousStructOrUnion = ZigClangFieldDecl_isAnonymousStructOrUnion; extern fn ZigClangFieldDecl_isAnonymousStructOrUnion(*const FieldDecl) bool; @@ -1015,6 +1018,9 @@ pub const VarDecl = opaque { pub const getAlignedAttribute = ZigClangVarDecl_getAlignedAttribute; extern fn ZigClangVarDecl_getAlignedAttribute(*const VarDecl, *const ASTContext) c_uint; + pub const getPackedAttribute = ZigClangVarDecl_getPackedAttribute; + extern fn ZigClangVarDecl_getPackedAttribute(*const VarDecl) bool; + pub const getCleanupAttribute = ZigClangVarDecl_getCleanupAttribute; extern fn ZigClangVarDecl_getCleanupAttribute(*const VarDecl) ?*const FunctionDecl; diff --git a/src/translate_c.zig b/src/translate_c.zig index f969bf1c8b94..e24c78f05250 100644 --- a/src/translate_c.zig +++ b/src/translate_c.zig @@ -878,7 +878,7 @@ fn visitVarDecl(c: *Context, var_decl: *const clang.VarDecl, mangled_name: ?[]co .is_export = is_export, .is_threadlocal = is_threadlocal, .linksection_string = linksection_string, - .alignment = zigAlignment(var_decl.getAlignedAttribute(c.clang_context)), + .alignment = ClangAlignment.forVar(c, var_decl).zigAlignment(), .name = var_name, .type = type_node, .init = init_node, @@ -1096,7 +1096,6 @@ fn transRecordDecl(c: *Context, scope: *Scope, record_decl: *const clang.RecordD break :blk Tag.opaque_literal.init(); }; - const is_packed = record_decl.getPackedAttribute(); var fields = std.ArrayList(ast.Payload.Record.Field).init(c.gpa); defer fields.deinit(); @@ -1153,7 +1152,7 @@ fn transRecordDecl(c: *Context, scope: *Scope, record_decl: *const clang.RecordD const alignment = if (has_flexible_array and field_decl.getFieldIndex() == 0) @intCast(c_uint, record_alignment) else - zigAlignment(field_decl.getAlignedAttribute(c.clang_context)); + ClangAlignment.forField(c, field_decl, record_def).zigAlignment(); if (is_anon) { try c.decl_table.putNoClobber(c.gpa, @ptrToInt(field_decl.getCanonicalDecl()), field_name); @@ -1166,15 +1165,11 @@ fn transRecordDecl(c: *Context, scope: *Scope, record_decl: *const clang.RecordD }); } - if (!c.zig_is_stage1 and is_packed) { - return failDecl(c, record_loc, name, "cannot translate packed record union", .{}); - } - const record_payload = try c.arena.create(ast.Payload.Record); record_payload.* = .{ .base = .{ .tag = ([2]Tag{ .@"struct", .@"union" })[@boolToInt(is_union)] }, .data = .{ - .layout = if (is_packed) .@"packed" else .@"extern", + .layout = .@"extern", .fields = try c.arena.dupe(ast.Payload.Record.Field, fields.items), .functions = try c.arena.dupe(Node, functions.items), .variables = &.{}, @@ -1851,12 +1846,62 @@ fn transCStyleCastExprClass( return maybeSuppressResult(c, scope, result_used, cast_node); } -/// Clang reports the alignment in bits, we use bytes -/// Clang uses 0 for "no alignment specified", we use null -fn zigAlignment(bit_alignment: c_uint) ?c_uint { - if (bit_alignment == 0) return null; - return bit_alignment / 8; -} +/// The alignment of a variable or field +const ClangAlignment = struct { + /// Clang reports the alignment in bits, we use bytes + /// Clang uses 0 for "no alignment specified", we use null + bit_alignment: c_uint, + /// If the field or variable is marked as 'packed' + /// + /// According to the GCC variable attribute docs, this impacts alignment + /// https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html + /// + /// > The packed attribute specifies that a structure member + /// > should have the smallest possible alignment + /// + /// Note also that specifying the 'packed' attribute on a structure + /// implicitly packs all its fields (making their alignment 1). + /// + /// This will be null if the AST node doesn't support packing (functions) + is_packed: ?bool, + + /// Get the alignment for a field, optionally taking into account the parent record + pub fn forField(c: *const Context, field: *const clang.FieldDecl, parent: ?*const clang.RecordDecl) ClangAlignment { + const parent_packed = if (parent) |record| record.getPackedAttribute() else false; + // NOTE: According to GCC docs, parent attribute packed implies child attribute packed + return ClangAlignment{ + .bit_alignment = field.getAlignedAttribute(c.clang_context), + .is_packed = field.getPackedAttribute() or parent_packed, + }; + } + + pub fn forVar(c: *const Context, var_decl: *const clang.VarDecl) ClangAlignment { + return ClangAlignment{ + .bit_alignment = var_decl.getAlignedAttribute(c.clang_context), + .is_packed = var_decl.getPackedAttribute(), + }; + } + + pub fn forFunc(c: *const Context, fun: *const clang.FunctionDecl) ClangAlignment { + return ClangAlignment{ + .bit_alignment = fun.getAlignedAttribute(c.clang_context), + .is_packed = null, // not supported by GCC/clang (or meaningful), + }; + } + + /// Translate the clang alignment info into a zig alignment + /// + /// Returns null if there is no special alignment info + pub fn zigAlignment(self: ClangAlignment) ?c_uint { + if (self.bit_alignment != 0) { + return self.bit_alignment / 8; + } else if (self.is_packed orelse false) { + return 1; + } else { + return null; + } + } +}; fn transDeclStmtOne( c: *Context, @@ -1910,7 +1955,7 @@ fn transDeclStmtOne( .is_export = false, .is_threadlocal = var_decl.getTLSKind() != .None, .linksection_string = null, - .alignment = zigAlignment(var_decl.getAlignedAttribute(c.clang_context)), + .alignment = ClangAlignment.forVar(c, var_decl).zigAlignment(), .name = var_name, .type = type_node, .init = init_node, @@ -5054,7 +5099,7 @@ fn finishTransFnProto( break :blk null; }; - const alignment = if (fn_decl) |decl| zigAlignment(decl.getAlignedAttribute(c.clang_context)) else null; + const alignment = if (fn_decl) |decl| ClangAlignment.forFunc(c, decl).zigAlignment() else null; const explicit_callconv = if ((is_inline or is_export or is_extern) and cc == .C) null else cc; diff --git a/src/zig_clang.cpp b/src/zig_clang.cpp index 223dc29067be..bd06ead4b0b6 100644 --- a/src/zig_clang.cpp +++ b/src/zig_clang.cpp @@ -1941,10 +1941,7 @@ const char* ZigClangVarDecl_getSectionAttribute(const struct ZigClangVarDecl *se bool ZigClangRecordDecl_getPackedAttribute(const ZigClangRecordDecl *zig_record_decl) { const clang::RecordDecl *record_decl = reinterpret_cast(zig_record_decl); - if (record_decl->getAttr()) { - return true; - } - return false; + return record_decl->hasAttr(); } unsigned ZigClangVarDecl_getAlignedAttribute(const struct ZigClangVarDecl *self, const ZigClangASTContext* ctx) { @@ -1985,6 +1982,16 @@ unsigned ZigClangFunctionDecl_getAlignedAttribute(const struct ZigClangFunctionD return 0; } +bool ZigClangVarDecl_getPackedAttribute(const struct ZigClangVarDecl *self) { + auto casted_self = reinterpret_cast(self); + return casted_self->hasAttr(); +} + +bool ZigClangFieldDecl_getPackedAttribute(const struct ZigClangFieldDecl *self) { + auto casted_self = reinterpret_cast(self); + return casted_self->hasAttr(); +} + ZigClangQualType ZigClangParmVarDecl_getOriginalType(const struct ZigClangParmVarDecl *self) { return bitcast(reinterpret_cast(self)->getOriginalType()); } diff --git a/src/zig_clang.h b/src/zig_clang.h index 5d556700e653..fab5b83b2d98 100644 --- a/src/zig_clang.h +++ b/src/zig_clang.h @@ -1101,6 +1101,8 @@ ZIG_EXTERN_C const struct ZigClangFunctionDecl *ZigClangVarDecl_getCleanupAttrib ZIG_EXTERN_C unsigned ZigClangVarDecl_getAlignedAttribute(const struct ZigClangVarDecl *self, const ZigClangASTContext* ctx); ZIG_EXTERN_C unsigned ZigClangFunctionDecl_getAlignedAttribute(const struct ZigClangFunctionDecl *self, const ZigClangASTContext* ctx); ZIG_EXTERN_C unsigned ZigClangFieldDecl_getAlignedAttribute(const struct ZigClangFieldDecl *self, const ZigClangASTContext* ctx); +ZIG_EXTERN_C bool ZigClangVarDecl_getPackedAttribute(const struct ZigClangVarDecl *self); +ZIG_EXTERN_C bool ZigClangFieldDecl_getPackedAttribute(const struct ZigClangFieldDecl *self); ZIG_EXTERN_C const struct ZigClangStringLiteral *ZigClangFileScopeAsmDecl_getAsmString(const struct ZigClangFileScopeAsmDecl *self); diff --git a/test/run_translated_c.zig b/test/run_translated_c.zig index e62c33eaa840..71654afba4f9 100644 --- a/test/run_translated_c.zig +++ b/test/run_translated_c.zig @@ -250,20 +250,18 @@ pub fn addCases(cases: *tests.RunTranslatedCContext) void { \\} , ""); - if (@import("builtin").zig_backend == .stage1) { - cases.add("struct initializer - packed", - \\#define _NO_CRT_STDIO_INLINE 1 - \\#include - \\#include - \\struct s {uint8_t x,y; - \\ uint32_t z;} __attribute__((packed)) s0 = {1, 2}; - \\int main() { - \\ /* sizeof nor offsetof currently supported */ - \\ if (((intptr_t)&s0.z - (intptr_t)&s0.x) != 2) abort(); - \\ return 0; - \\} - , ""); - } + cases.add("struct initializer - packed", + \\#define _NO_CRT_STDIO_INLINE 1 + \\#include + \\#include + \\struct s {uint8_t x,y; + \\ uint32_t z;} __attribute__((packed)) s0 = {1, 2}; + \\int main() { + \\ /* sizeof nor offsetof currently supported */ + \\ if (((intptr_t)&s0.z - (intptr_t)&s0.x) != 2) abort(); + \\ return 0; + \\} + , ""); cases.add("cast signed array index to unsigned", \\#include diff --git a/test/translate_c.zig b/test/translate_c.zig index 0e38444ad2af..755f61435bfc 100644 --- a/test/translate_c.zig +++ b/test/translate_c.zig @@ -728,22 +728,20 @@ pub fn addCases(cases: *tests.TranslateCContext) void { \\} }); - if (builtin.zig_backend == .stage1) { - cases.add("struct initializer - packed", - \\struct {int x,y,z;} __attribute__((packed)) s0 = {1, 2}; - , &[_][]const u8{ - \\const struct_unnamed_1 = packed struct { - \\ x: c_int, - \\ y: c_int, - \\ z: c_int, - \\}; - \\pub export var s0: struct_unnamed_1 = struct_unnamed_1{ - \\ .x = @as(c_int, 1), - \\ .y = @as(c_int, 2), - \\ .z = 0, - \\}; - }); - } + cases.add("struct initializer - packed", + \\struct {int x,y,z;} __attribute__((packed)) s0 = {1, 2}; + , &[_][]const u8{ + \\const struct_unnamed_1 = extern struct { + \\ x: c_int align(1), + \\ y: c_int align(1), + \\ z: c_int align(1), + \\}; + \\pub export var s0: struct_unnamed_1 = struct_unnamed_1{ + \\ .x = @as(c_int, 1), + \\ .y = @as(c_int, 2), + \\ .z = 0, + \\}; + }); // Test case temporarily disabled: // https://github.com/ziglang/zig/issues/12055