Commit cb4c488cbd

Vexu <git@vexu.eu>
2020-03-10 14:57:57
translate-c support struct field alignment
1 parent 4cace8f
Changed files (5)
src/zig_clang.cpp
@@ -1615,6 +1615,16 @@ unsigned ZigClangVarDecl_getAlignedAttribute(const struct ZigClangVarDecl *self,
     return 0;
 }
 
+unsigned ZigClangFieldDecl_getAlignedAttribute(const struct ZigClangFieldDecl *self, const ZigClangASTContext* ctx) {
+    auto casted_self = reinterpret_cast<const clang::FieldDecl *>(self);
+    auto casted_ctx = const_cast<clang::ASTContext *>(reinterpret_cast<const clang::ASTContext *>(ctx));
+    if (const clang::AlignedAttr *AA = casted_self->getAttr<clang::AlignedAttr>()) {
+        return AA->getAlignment(*casted_ctx);
+    }
+    // Zero means no explicit alignment factor was specified
+    return 0;
+}
+
 unsigned ZigClangFunctionDecl_getAlignedAttribute(const struct ZigClangFunctionDecl *self, const ZigClangASTContext* ctx) {
     auto casted_self = reinterpret_cast<const clang::FunctionDecl *>(self);
     auto casted_ctx = const_cast<clang::ASTContext *>(reinterpret_cast<const clang::ASTContext *>(ctx));
src/zig_clang.h
@@ -865,6 +865,7 @@ ZIG_EXTERN_C const struct ZigClangVarDecl *ZigClangVarDecl_getCanonicalDecl(cons
 ZIG_EXTERN_C const char* ZigClangVarDecl_getSectionAttribute(const struct ZigClangVarDecl *self, size_t *len);
 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 struct ZigClangQualType ZigClangParmVarDecl_getOriginalType(const struct ZigClangParmVarDecl *self);
 
src-self-hosted/clang.zig
@@ -765,6 +765,7 @@ pub extern fn ZigClangTagDecl_isThisDeclarationADefinition(self: *const ZigClang
 pub extern fn ZigClangEnumType_getDecl(record_ty: ?*const struct_ZigClangEnumType) *const struct_ZigClangEnumDecl;
 pub extern fn ZigClangRecordDecl_getCanonicalDecl(record_decl: ?*const struct_ZigClangRecordDecl) ?*const struct_ZigClangTagDecl;
 pub extern fn ZigClangFieldDecl_getCanonicalDecl(field_decl: ?*const struct_ZigClangFieldDecl) ?*const struct_ZigClangFieldDecl;
+pub extern fn ZigClangFieldDecl_getAlignedAttribute(field_decl: ?*const struct_ZigClangFieldDecl, *const ZigClangASTContext) c_uint;
 pub extern fn ZigClangEnumDecl_getCanonicalDecl(self: ?*const struct_ZigClangEnumDecl) ?*const struct_ZigClangTagDecl;
 pub extern fn ZigClangTypedefNameDecl_getCanonicalDecl(self: ?*const struct_ZigClangTypedefNameDecl) ?*const struct_ZigClangTypedefNameDecl;
 pub extern fn ZigClangFunctionDecl_getCanonicalDecl(self: ?*const struct_ZigClangFunctionDecl) ?*const struct_ZigClangFunctionDecl;
src-self-hosted/translate_c.zig
@@ -632,7 +632,7 @@ fn visitVarDecl(c: *Context, var_decl: *const ZigClangVarDecl) Error!void {
     const align_expr = blk: {
         const alignment = ZigClangVarDecl_getAlignedAttribute(var_decl, rp.c.clang_context);
         if (alignment != 0) {
-            _ = try appendToken(rp.c, .Keyword_linksection, "align");
+            _ = try appendToken(rp.c, .Keyword_align, "align");
             _ = try appendToken(rp.c, .LParen, "(");
             // Clang reports the alignment in bits
             const expr = try transCreateNodeInt(rp.c, alignment / 8);
@@ -827,6 +827,20 @@ fn transRecordDecl(c: *Context, record_decl: *const ZigClangRecordDecl) Error!?*
                 else => |e| return e,
             };
 
+            const align_expr = blk: {
+                const alignment = ZigClangFieldDecl_getAlignedAttribute(field_decl, rp.c.clang_context);
+                if (alignment != 0) {
+                    _ = try appendToken(rp.c, .Keyword_align, "align");
+                    _ = try appendToken(rp.c, .LParen, "(");
+                    // Clang reports the alignment in bits
+                    const expr = try transCreateNodeInt(rp.c, alignment / 8);
+                    _ = try appendToken(rp.c, .RParen, ")");
+
+                    break :blk expr;
+                }
+                break :blk null;
+            };
+
             const field_node = try c.a().create(ast.Node.ContainerField);
             field_node.* = .{
                 .doc_comments = null,
@@ -834,7 +848,7 @@ fn transRecordDecl(c: *Context, record_decl: *const ZigClangRecordDecl) Error!?*
                 .name_token = field_name,
                 .type_expr = field_type,
                 .value_expr = null,
-                .align_expr = null,
+                .align_expr = align_expr,
             };
 
             if (is_anon) {
@@ -4607,7 +4621,7 @@ fn finishTransFnProto(
         if (fn_decl) |decl| {
             const alignment = ZigClangFunctionDecl_getAlignedAttribute(decl, rp.c.clang_context);
             if (alignment != 0) {
-                _ = try appendToken(rp.c, .Keyword_linksection, "align");
+                _ = try appendToken(rp.c, .Keyword_align, "align");
                 _ = try appendToken(rp.c, .LParen, "(");
                 // Clang reports the alignment in bits
                 const expr = try transCreateNodeInt(rp.c, alignment / 8);
test/translate_c.zig
@@ -3,6 +3,16 @@ const std = @import("std");
 const CrossTarget = std.zig.CrossTarget;
 
 pub fn addCases(cases: *tests.TranslateCContext) void {
+    cases.add("struct with aligned fields",
+        \\struct foo {
+        \\    __attribute__((aligned(1))) short bar;
+        \\};
+    , &[_][]const u8{
+        \\pub const struct_foo = extern struct {
+        \\    bar: c_short align(1),
+        \\};
+    });
+
     cases.add("structs with VLAs are rejected",
         \\struct foo { int x; int y[]; };
         \\struct bar { int x; int y[0]; };