Commit 5f4c3e6557

Andrew Kelley <andrew@ziglang.org>
2019-05-11 05:35:46
stage2 translate-c: simple function definitions
See #1964
1 parent dbb5da1
src/translate_c.cpp
@@ -1277,15 +1277,15 @@ static AstNode *trans_qual_type(Context *c, ZigClangQualType qt, ZigClangSourceL
     return trans_type(c, ZigClangQualType_getTypePtr(qt), source_loc);
 }
 
-static int trans_compound_stmt_inline(Context *c, TransScope *scope, const clang::CompoundStmt *stmt,
+static int trans_compound_stmt_inline(Context *c, TransScope *scope, const ZigClangCompoundStmt *stmt,
         AstNode *block_node, TransScope **out_node_scope)
 {
     assert(block_node->type == NodeTypeBlock);
-    for (clang::CompoundStmt::const_body_iterator it = stmt->body_begin(), end_it = stmt->body_end();
-            it != end_it; ++it)
+    for (ZigClangCompoundStmt_const_body_iterator it = ZigClangCompoundStmt_body_begin(stmt),
+        end_it = ZigClangCompoundStmt_body_end(stmt); it != end_it; ++it)
     {
         AstNode *child_node;
-        scope = trans_stmt(c, scope, bitcast(*it), &child_node);
+        scope = trans_stmt(c, scope, *it, &child_node);
         if (scope == nullptr)
             return ErrorUnexpected;
         if (child_node != nullptr)
@@ -1297,7 +1297,7 @@ static int trans_compound_stmt_inline(Context *c, TransScope *scope, const clang
     return ErrorNone;
 }
 
-static AstNode *trans_compound_stmt(Context *c, TransScope *scope, const clang::CompoundStmt *stmt,
+static AstNode *trans_compound_stmt(Context *c, TransScope *scope, const ZigClangCompoundStmt *stmt,
         TransScope **out_node_scope)
 {
     TransScopeBlock *child_scope_block = trans_scope_block_create(c, scope);
@@ -1309,7 +1309,7 @@ static AstNode *trans_compound_stmt(Context *c, TransScope *scope, const clang::
 static AstNode *trans_stmt_expr(Context *c, ResultUsed result_used, TransScope *scope,
         const clang::StmtExpr *stmt, TransScope **out_node_scope)
 {
-    AstNode *block = trans_compound_stmt(c, scope, stmt->getSubStmt(), out_node_scope);
+    AstNode *block = trans_compound_stmt(c, scope, (const ZigClangCompoundStmt *)stmt->getSubStmt(), out_node_scope);
     if (block == nullptr)
         return block;
     assert(block->type == NodeTypeBlock);
@@ -3220,7 +3220,7 @@ static AstNode *trans_switch_stmt(Context *c, TransScope *parent_scope, const cl
     AstNode *body_node;
     const ZigClangStmt *body_stmt = bitcast(stmt->getBody());
     if (ZigClangStmt_getStmtClass(body_stmt) == ZigClangStmt_CompoundStmtClass) {
-        if (trans_compound_stmt_inline(c, &switch_scope->base, (const clang::CompoundStmt *)body_stmt,
+        if (trans_compound_stmt_inline(c, &switch_scope->base, (const ZigClangCompoundStmt *)body_stmt,
                                        block_scope->node, nullptr))
         {
             return nullptr;
@@ -3399,7 +3399,7 @@ static int trans_stmt_extra(Context *c, TransScope *scope, const ZigClangStmt *s
                     trans_return_stmt(c, scope, (const clang::ReturnStmt *)stmt));
         case ZigClangStmt_CompoundStmtClass:
             return wrap_stmt(out_node, out_child_scope, scope,
-                    trans_compound_stmt(c, scope, (const clang::CompoundStmt *)stmt, out_node_scope));
+                    trans_compound_stmt(c, scope, (const ZigClangCompoundStmt *)stmt, out_node_scope));
         case ZigClangStmt_IntegerLiteralClass:
             return wrap_stmt(out_node, out_child_scope, scope,
                     trans_integer_literal(c, result_used, (const clang::IntegerLiteral *)stmt));
src/zig_clang.cpp
@@ -1292,6 +1292,14 @@ static clang::APValue::LValueBase bitcast(ZigClangAPValueLValueBase src) {
     return dest;
 }
 
+static_assert(sizeof(ZigClangCompoundStmt_const_body_iterator) == sizeof(clang::CompoundStmt::const_body_iterator), "");
+static ZigClangCompoundStmt_const_body_iterator bitcast(clang::CompoundStmt::const_body_iterator src) {
+    ZigClangCompoundStmt_const_body_iterator dest;
+    memcpy(&dest, static_cast<void *>(&src), sizeof(ZigClangCompoundStmt_const_body_iterator));
+    return dest;
+}
+
+
 ZigClangSourceLocation ZigClangSourceManager_getSpellingLoc(const ZigClangSourceManager *self,
         ZigClangSourceLocation Loc)
 {
@@ -1811,3 +1819,13 @@ struct ZigClangQualType ZigClangFunctionProtoType_getParamType(const struct ZigC
     auto casted = reinterpret_cast<const clang::FunctionProtoType *>(self);
     return bitcast(casted->getParamType(index));
 }
+
+ZigClangCompoundStmt_const_body_iterator ZigClangCompoundStmt_body_begin(const struct ZigClangCompoundStmt *self) {
+    auto casted = reinterpret_cast<const clang::CompoundStmt *>(self);
+    return bitcast(casted->body_begin());
+}
+
+ZigClangCompoundStmt_const_body_iterator ZigClangCompoundStmt_body_end(const struct ZigClangCompoundStmt *self) {
+    auto casted = reinterpret_cast<const clang::CompoundStmt *>(self);
+    return bitcast(casted->body_end());
+}
src/zig_clang.h
@@ -102,6 +102,8 @@ struct ZigClangVarDecl;
 struct ZigClangWhileStmt;
 struct ZigClangFunctionType;
 
+typedef struct ZigClangStmt *const * ZigClangCompoundStmt_const_body_iterator;
+
 enum ZigClangBO {
     ZigClangBO_PtrMemD,
     ZigClangBO_PtrMemI,
@@ -820,4 +822,9 @@ ZIG_EXTERN_C struct ZigClangQualType ZigClangFunctionType_getReturnType(const st
 ZIG_EXTERN_C bool ZigClangFunctionProtoType_isVariadic(const struct ZigClangFunctionProtoType *self);
 ZIG_EXTERN_C unsigned ZigClangFunctionProtoType_getNumParams(const struct ZigClangFunctionProtoType *self);
 ZIG_EXTERN_C struct ZigClangQualType ZigClangFunctionProtoType_getParamType(const struct ZigClangFunctionProtoType *self, unsigned i);
+
+
+ZIG_EXTERN_C ZigClangCompoundStmt_const_body_iterator ZigClangCompoundStmt_body_begin(const struct ZigClangCompoundStmt *self);
+ZIG_EXTERN_C ZigClangCompoundStmt_const_body_iterator ZigClangCompoundStmt_body_end(const struct ZigClangCompoundStmt *self);
+
 #endif
src-self-hosted/clang.zig
@@ -12,7 +12,7 @@ pub const struct_ZigClangCStyleCastExpr = @OpaqueType();
 pub const struct_ZigClangCallExpr = @OpaqueType();
 pub const struct_ZigClangCaseStmt = @OpaqueType();
 pub const struct_ZigClangCompoundAssignOperator = @OpaqueType();
-pub const struct_ZigClangCompoundStmt = @OpaqueType();
+pub const ZigClangCompoundStmt = @OpaqueType();
 pub const struct_ZigClangConditionalOperator = @OpaqueType();
 pub const struct_ZigClangConstantArrayType = @OpaqueType();
 pub const struct_ZigClangContinueStmt = @OpaqueType();
@@ -33,7 +33,7 @@ pub const struct_ZigClangFieldDecl = @OpaqueType();
 pub const struct_ZigClangFileID = @OpaqueType();
 pub const struct_ZigClangForStmt = @OpaqueType();
 pub const struct_ZigClangFullSourceLoc = @OpaqueType();
-pub const struct_ZigClangFunctionDecl = @OpaqueType();
+pub const ZigClangFunctionDecl = @OpaqueType();
 pub const struct_ZigClangFunctionProtoType = @OpaqueType();
 pub const struct_ZigClangIfStmt = @OpaqueType();
 pub const struct_ZigClangImplicitCastExpr = @OpaqueType();
@@ -488,12 +488,12 @@ pub extern fn ZigClangQualType_isRestrictQualified(arg0: struct_ZigClangQualType
 pub extern fn ZigClangType_getTypeClass(self: ?*const struct_ZigClangType) ZigClangTypeClass;
 pub extern fn ZigClangType_isVoidType(self: ?*const struct_ZigClangType) bool;
 pub extern fn ZigClangType_getTypeClassName(self: *const struct_ZigClangType) [*]const u8;
-pub extern fn ZigClangStmt_getBeginLoc(self: ?*const struct_ZigClangStmt) struct_ZigClangSourceLocation;
+pub extern fn ZigClangStmt_getBeginLoc(self: *const struct_ZigClangStmt) struct_ZigClangSourceLocation;
 pub extern fn ZigClangStmt_getStmtClass(self: ?*const struct_ZigClangStmt) ZigClangStmtClass;
 pub extern fn ZigClangStmt_classof_Expr(self: ?*const struct_ZigClangStmt) bool;
 pub extern fn ZigClangExpr_getStmtClass(self: ?*const struct_ZigClangExpr) ZigClangStmtClass;
 pub extern fn ZigClangExpr_getType(self: ?*const struct_ZigClangExpr) struct_ZigClangQualType;
-pub extern fn ZigClangExpr_getBeginLoc(self: ?*const struct_ZigClangExpr) struct_ZigClangSourceLocation;
+pub extern fn ZigClangExpr_getBeginLoc(self: *const struct_ZigClangExpr) struct_ZigClangSourceLocation;
 pub extern fn ZigClangAPValue_getKind(self: ?*const struct_ZigClangAPValue) ZigClangAPValueKind;
 pub extern fn ZigClangAPValue_getInt(self: ?*const struct_ZigClangAPValue) ?*const struct_ZigClangAPSInt;
 pub extern fn ZigClangAPValue_getArrayInitializedElts(self: ?*const struct_ZigClangAPValue) c_uint;
@@ -510,11 +510,12 @@ pub extern fn ZigClangAPSInt_getNumWords(self: ?*const struct_ZigClangAPSInt) c_
 pub extern fn ZigClangAPValueLValueBase_dyn_cast_Expr(self: struct_ZigClangAPValueLValueBase) ?*const struct_ZigClangExpr;
 pub extern fn ZigClangASTUnit_delete(arg0: ?*struct_ZigClangASTUnit) void;
 
-pub extern fn ZigClangFunctionDecl_getType(self: *const struct_ZigClangFunctionDecl) struct_ZigClangQualType;
-pub extern fn ZigClangFunctionDecl_getLocation(self: *const struct_ZigClangFunctionDecl) struct_ZigClangSourceLocation;
-pub extern fn ZigClangFunctionDecl_hasBody(self: *const struct_ZigClangFunctionDecl) bool;
-pub extern fn ZigClangFunctionDecl_getStorageClass(self: *const struct_ZigClangFunctionDecl) ZigClangStorageClass;
-pub extern fn ZigClangFunctionDecl_getParamDecl(self: *const struct_ZigClangFunctionDecl, i: c_uint) *const struct_ZigClangParmVarDecl;
+pub extern fn ZigClangFunctionDecl_getType(self: *const ZigClangFunctionDecl) struct_ZigClangQualType;
+pub extern fn ZigClangFunctionDecl_getLocation(self: *const ZigClangFunctionDecl) struct_ZigClangSourceLocation;
+pub extern fn ZigClangFunctionDecl_hasBody(self: *const ZigClangFunctionDecl) bool;
+pub extern fn ZigClangFunctionDecl_getStorageClass(self: *const ZigClangFunctionDecl) ZigClangStorageClass;
+pub extern fn ZigClangFunctionDecl_getParamDecl(self: *const ZigClangFunctionDecl, i: c_uint) *const struct_ZigClangParmVarDecl;
+pub extern fn ZigClangFunctionDecl_getBody(self: *const ZigClangFunctionDecl) *const struct_ZigClangStmt;
 
 pub extern fn ZigClangBuiltinType_getKind(self: *const struct_ZigClangBuiltinType) ZigClangBuiltinTypeKind;
 
@@ -543,7 +544,6 @@ pub const ZigClangCStyleCastExpr = struct_ZigClangCStyleCastExpr;
 pub const ZigClangCallExpr = struct_ZigClangCallExpr;
 pub const ZigClangCaseStmt = struct_ZigClangCaseStmt;
 pub const ZigClangCompoundAssignOperator = struct_ZigClangCompoundAssignOperator;
-pub const ZigClangCompoundStmt = struct_ZigClangCompoundStmt;
 pub const ZigClangConditionalOperator = struct_ZigClangConditionalOperator;
 pub const ZigClangConstantArrayType = struct_ZigClangConstantArrayType;
 pub const ZigClangContinueStmt = struct_ZigClangContinueStmt;
@@ -564,7 +564,6 @@ pub const ZigClangFieldDecl = struct_ZigClangFieldDecl;
 pub const ZigClangFileID = struct_ZigClangFileID;
 pub const ZigClangForStmt = struct_ZigClangForStmt;
 pub const ZigClangFullSourceLoc = struct_ZigClangFullSourceLoc;
-pub const ZigClangFunctionDecl = struct_ZigClangFunctionDecl;
 pub const ZigClangFunctionProtoType = struct_ZigClangFunctionProtoType;
 pub const ZigClangIfStmt = struct_ZigClangIfStmt;
 pub const ZigClangImplicitCastExpr = struct_ZigClangImplicitCastExpr;
@@ -860,3 +859,8 @@ pub const ZigClangStorageClass = extern enum {
     Auto,
     Register,
 };
+
+pub const ZigClangCompoundStmt_const_body_iterator = [*c]const *struct_ZigClangStmt;
+
+pub extern fn ZigClangCompoundStmt_body_begin(self: *const ZigClangCompoundStmt) ZigClangCompoundStmt_const_body_iterator;
+pub extern fn ZigClangCompoundStmt_body_end(self: *const ZigClangCompoundStmt) ZigClangCompoundStmt_const_body_iterator;
src-self-hosted/translate_c.zig
@@ -3,6 +3,7 @@
 
 const std = @import("std");
 const builtin = @import("builtin");
+const assert = std.debug.assert;
 const ast = std.zig.ast;
 const Token = std.zig.Token;
 use @import("clang.zig");
@@ -21,6 +22,10 @@ pub const Error = error{
     OutOfMemory,
     UnsupportedType,
 };
+pub const TransError = error{
+    OutOfMemory,
+    UnsupportedTranslation,
+};
 
 const DeclTable = std.HashMap(usize, void, addrHash, addrEql);
 
@@ -61,6 +66,27 @@ const Scope = struct {
 
     const Block = struct {
         base: Scope,
+        block_node: *ast.Node.Block,
+
+        /// Don't forget to set rbrace token later
+        fn create(c: *Context, parent: *Scope, lbrace_tok: ast.TokenIndex) !*Block {
+            const block = try c.a().create(Block);
+            block.* = Block{
+                .base = Scope{
+                    .id = Id.Block,
+                    .parent = parent,
+                },
+                .block_node = try c.a().create(ast.Node.Block),
+            };
+            block.block_node.* = ast.Node.Block{
+                .base = ast.Node{ .id = ast.Node.Id.Block },
+                .label = null,
+                .lbrace = lbrace_tok,
+                .statements = ast.Node.Block.StatementList.init(c.a()),
+                .rbrace = undefined,
+            };
+            return block;
+        }
     };
 
     const Root = struct {
@@ -72,6 +98,12 @@ const Scope = struct {
     };
 };
 
+const TransResult = struct {
+    node: *ast.Node,
+    node_scope: *Scope,
+    child_scope: *Scope,
+};
+
 const Context = struct {
     tree: *ast.Tree,
     source_buffer: *std.Buffer,
@@ -170,6 +202,14 @@ pub fn translate(
 
     _ = try appendToken(&context, .Eof, "");
     tree.source = source_buffer.toOwnedSlice();
+    if (false) {
+        std.debug.warn("debug source:\n{}\n==EOF==\ntokens:\n", tree.source);
+        var i: usize = 0;
+        while (i < tree.tokens.len) : (i += 1) {
+            const token = tree.tokens.at(i);
+            std.debug.warn("{}\n", token);
+        }
+    }
     return tree;
 }
 
@@ -213,29 +253,107 @@ fn visitFnDecl(c: *Context, fn_decl: *const ZigClangFunctionDecl) Error!void {
     const fn_decl_loc = ZigClangFunctionDecl_getLocation(fn_decl);
     const fn_qt = ZigClangFunctionDecl_getType(fn_decl);
     const fn_type = ZigClangQualType_getTypePtr(fn_qt);
+    var scope = &c.global_scope.base;
+    const decl_ctx = FnDeclContext{
+        .fn_name = fn_name,
+        .has_body = ZigClangFunctionDecl_hasBody(fn_decl),
+        .storage_class = ZigClangFunctionDecl_getStorageClass(fn_decl),
+        .scope = &scope,
+    };
     const proto_node = switch (ZigClangType_getTypeClass(fn_type)) {
-        .FunctionProto => transFnProto(
-            rp,
-            @ptrCast(*const ZigClangFunctionProtoType, fn_type),
-            fn_decl_loc,
-            fn_decl,
-            fn_name,
-        ) catch |err| switch (err) {
-            error.UnsupportedType => {
-                return failDecl(c, fn_decl_loc, fn_name, "unable to resolve prototype of function");
-            },
-            else => return err,
+        .FunctionProto => blk: {
+            const fn_proto_type = @ptrCast(*const ZigClangFunctionProtoType, fn_type);
+            break :blk transFnProto(rp, fn_proto_type, fn_decl_loc, decl_ctx) catch |err| switch (err) {
+                error.UnsupportedType => {
+                    return failDecl(c, fn_decl_loc, fn_name, "unable to resolve prototype of function");
+                },
+                error.OutOfMemory => return error.OutOfMemory,
+            };
         },
         .FunctionNoProto => return failDecl(c, fn_decl_loc, fn_name, "TODO support functions with no prototype"),
         else => unreachable,
     };
 
-    if (!ZigClangFunctionDecl_hasBody(fn_decl)) {
+    if (!decl_ctx.has_body) {
         const semi_tok = try appendToken(c, .Semicolon, ";");
         return addTopLevelDecl(c, fn_name, &proto_node.base);
     }
 
-    try emitWarning(c, fn_decl_loc, "TODO implement function body translation");
+    // actual function definition with body
+    const body_stmt = ZigClangFunctionDecl_getBody(fn_decl);
+    const result = transStmt(rp, scope, body_stmt, .unused, .r_value) catch |err| switch (err) {
+        error.OutOfMemory => return error.OutOfMemory,
+        error.UnsupportedTranslation => return failDecl(c, fn_decl_loc, fn_name, "unable to translate function"),
+    };
+    assert(result.node.id == ast.Node.Id.Block);
+    proto_node.body_node = result.node;
+
+    return addTopLevelDecl(c, fn_name, &proto_node.base);
+}
+
+const ResultUsed = enum {
+    used,
+    unused,
+};
+
+const LRValue = enum {
+    l_value,
+    r_value,
+};
+
+fn transStmt(
+    rp: RestorePoint,
+    scope: *Scope,
+    stmt: *const ZigClangStmt,
+    result_used: ResultUsed,
+    lrvalue: LRValue,
+) !TransResult {
+    const sc = ZigClangStmt_getStmtClass(stmt);
+    switch (sc) {
+        .CompoundStmtClass => return transCompoundStmt(rp, scope, @ptrCast(*const ZigClangCompoundStmt, stmt)),
+        else => {
+            return revertAndWarn(
+                rp,
+                error.UnsupportedTranslation,
+                ZigClangStmt_getBeginLoc(stmt),
+                "TODO implement translation of stmt class {}",
+                @tagName(sc),
+            );
+        },
+    }
+}
+
+fn transCompoundStmtInline(
+    rp: RestorePoint,
+    parent_scope: *Scope,
+    stmt: *const ZigClangCompoundStmt,
+    block_node: *ast.Node.Block,
+) TransError!TransResult {
+    var it = ZigClangCompoundStmt_body_begin(stmt);
+    const end_it = ZigClangCompoundStmt_body_end(stmt);
+    var scope = parent_scope;
+    while (it != end_it) : (it += 1) {
+        const result = try transStmt(rp, scope, it.*, .unused, .r_value);
+        scope = result.child_scope;
+        try block_node.statements.push(result.node);
+    }
+    return TransResult{
+        .node = &block_node.base,
+        .child_scope = scope,
+        .node_scope = scope,
+    };
+}
+
+fn transCompoundStmt(rp: RestorePoint, scope: *Scope, stmt: *const ZigClangCompoundStmt) !TransResult {
+    const lbrace_tok = try appendToken(rp.c, .LBrace, "{");
+    const block_scope = try Scope.Block.create(rp.c, scope, lbrace_tok);
+    const inline_result = try transCompoundStmtInline(rp, &block_scope.base, stmt, block_scope.block_node);
+    block_scope.block_node.rbrace = try appendToken(rp.c, .RBrace, "}");
+    return TransResult{
+        .node = &block_scope.block_node.base,
+        .node_scope = inline_result.node_scope,
+        .child_scope = inline_result.child_scope,
+    };
 }
 
 fn addTopLevelDecl(c: *Context, name: []const u8, decl_node: *ast.Node) !void {
@@ -299,7 +417,7 @@ fn transType(rp: RestorePoint, ty: *const ZigClangType, source_loc: ZigClangSour
         },
         .FunctionProto => {
             const fn_proto_ty = @ptrCast(*const ZigClangFunctionProtoType, ty);
-            const fn_proto = try transFnProto(rp, fn_proto_ty, source_loc, null, null);
+            const fn_proto = try transFnProto(rp, fn_proto_ty, source_loc, null);
             return &fn_proto.base;
         },
         else => {
@@ -309,12 +427,18 @@ fn transType(rp: RestorePoint, ty: *const ZigClangType, source_loc: ZigClangSour
     }
 }
 
+const FnDeclContext = struct {
+    fn_name: []const u8,
+    has_body: bool,
+    storage_class: ZigClangStorageClass,
+    scope: **Scope,
+};
+
 fn transFnProto(
     rp: RestorePoint,
     fn_proto_ty: *const ZigClangFunctionProtoType,
     source_loc: ZigClangSourceLocation,
-    opt_fn_decl: ?*const ZigClangFunctionDecl,
-    fn_name: ?[]const u8,
+    fn_decl_context: ?FnDeclContext,
 ) !*ast.Node.FnProto {
     const fn_ty = @ptrCast(*const ZigClangFunctionType, fn_proto_ty);
     const cc = switch (ZigClangFunctionType_getCallConv(fn_ty)) {
@@ -351,13 +475,11 @@ fn transFnProto(
     const pub_tok = try appendToken(rp.c, .Keyword_pub, "pub");
     const cc_tok = if (cc == .Stdcall) try appendToken(rp.c, .Keyword_stdcallcc, "stdcallcc") else null;
     const is_export = exp: {
-        const fn_decl = opt_fn_decl orelse break :exp false;
-        const has_body = ZigClangFunctionDecl_hasBody(fn_decl);
-        const storage_class = ZigClangFunctionDecl_getStorageClass(fn_decl);
-        break :exp switch (storage_class) {
+        const decl_ctx = fn_decl_context orelse break :exp false;
+        break :exp switch (decl_ctx.storage_class) {
             .None => switch (rp.c.mode) {
                 .import => false,
-                .translate => has_body,
+                .translate => decl_ctx.has_body,
             },
             .Extern, .Static => false,
             .PrivateExtern => return revertAndWarn(rp, error.UnsupportedType, source_loc, "unsupported storage class: private extern"),
@@ -372,7 +494,7 @@ fn transFnProto(
     else
         null;
     const fn_tok = try appendToken(rp.c, .Keyword_fn, "fn");
-    const name_tok = if (fn_name) |n| try appendToken(rp.c, .Identifier, "{}", n) else null;
+    const name_tok = if (fn_decl_context) |ctx| try appendToken(rp.c, .Identifier, ctx.fn_name) else null;
     const lparen_tok = try appendToken(rp.c, .LParen, "(");
     const var_args_tok = if (is_var_args) try appendToken(rp.c, .Ellipsis3, "...") else null;
     const rparen_tok = try appendToken(rp.c, .RParen, ")");
@@ -390,7 +512,7 @@ fn transFnProto(
                         try emitWarning(rp.c, source_loc, "unsupported function proto return type");
                         return err;
                     },
-                    else => return err,
+                    error.OutOfMemory => return error.OutOfMemory,
                 };
             }
         }
@@ -430,17 +552,17 @@ fn revertAndWarn(
 }
 
 fn emitWarning(c: *Context, loc: ZigClangSourceLocation, comptime format: []const u8, args: ...) !void {
-    _ = try appendToken(c, .LineComment, "// {}: warning: " ++ format, c.locStr(loc), args);
+    _ = try appendTokenFmt(c, .LineComment, "// {}: warning: " ++ format, c.locStr(loc), args);
 }
 
 fn failDecl(c: *Context, loc: ZigClangSourceLocation, name: []const u8, comptime format: []const u8, args: ...) !void {
     // const name = @compileError(msg);
     const const_tok = try appendToken(c, .Keyword_const, "const");
-    const name_tok = try appendToken(c, .Identifier, "{}", name);
+    const name_tok = try appendToken(c, .Identifier, name);
     const eq_tok = try appendToken(c, .Equal, "=");
     const builtin_tok = try appendToken(c, .Builtin, "@compileError");
     const lparen_tok = try appendToken(c, .LParen, "(");
-    const msg_tok = try appendToken(c, .StringLiteral, "\"" ++ format ++ "\"", args);
+    const msg_tok = try appendTokenFmt(c, .StringLiteral, "\"" ++ format ++ "\"", args);
     const rparen_tok = try appendToken(c, .RParen, ")");
     const semi_tok = try appendToken(c, .Semicolon, ";");
 
@@ -480,16 +602,20 @@ fn failDecl(c: *Context, loc: ZigClangSourceLocation, name: []const u8, comptime
     try c.tree.root_node.decls.push(&var_decl_node.base);
 }
 
-fn appendToken(c: *Context, token_id: Token.Id, comptime format: []const u8, args: ...) !ast.TokenIndex {
+fn appendToken(c: *Context, token_id: Token.Id, bytes: []const u8) !ast.TokenIndex {
+    return appendTokenFmt(c, token_id, "{}", bytes);
+}
+
+fn appendTokenFmt(c: *Context, token_id: Token.Id, comptime format: []const u8, args: ...) !ast.TokenIndex {
     const S = struct {
-        fn callback(context: *Context, bytes: []const u8) Error!void {
+        fn callback(context: *Context, bytes: []const u8) error{OutOfMemory}!void {
             return context.source_buffer.append(bytes);
         }
     };
     const start_index = c.source_buffer.len();
     errdefer c.source_buffer.shrink(start_index);
 
-    try std.fmt.format(c, Error, S.callback, format, args);
+    try std.fmt.format(c, error{OutOfMemory}, S.callback, format, args);
     const end_index = c.source_buffer.len();
     const token_index = c.tree.tokens.len;
     const new_token = try c.tree.tokens.addOne();
@@ -506,7 +632,7 @@ fn appendToken(c: *Context, token_id: Token.Id, comptime format: []const u8, arg
 }
 
 fn appendIdentifier(c: *Context, name: []const u8) !*ast.Node {
-    const token_index = try appendToken(c, .Identifier, "{}", name);
+    const token_index = try appendToken(c, .Identifier, name);
     const identifier = try c.a().create(ast.Node.Identifier);
     identifier.* = ast.Node.Identifier{
         .base = ast.Node{ .id = ast.Node.Id.Identifier },
test/translate_c.zig
@@ -11,6 +11,12 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\pub extern fn bar() c_int;
     );
 
+    cases.add_both("simple function definition",
+        \\void foo(void) {};
+    ,
+        \\pub export fn foo() void {}
+    );
+
     /////////////// Cases that pass for only stage2 ////////////////
     // (none)