From ce293c982e1b6d9db775e02fefb8905caa4ee748 Mon Sep 17 00:00:00 2001 From: kcbanner Date: Thu, 2 Nov 2023 00:02:37 -0400 Subject: cbe: avoid collisions with builtins and intrinsics Changes: - Add `isMangledIdent` to determine if `fmtIdent` would make any edits to the identifier - Any function that has a mangled identifier is referred to using the mangled identifer within the current file, but if it is exported the first export will be with the non-mangled name. - Add `zig_import` to import a symbol under a different name - Add a level of indirection to float function names. Now, they are referred to as `zig_float_fn__`. The definitions in zig.h are wrapped with `zig_import` to import the symbol under the real name. The specific problem that sparked this change was the combination of `zig_libc_name_f80(name) __##name##x` with the input `fma`, resulting in `__fmax`, which is a new intrinsic in recent versions of cl.exe. With the above changes in place, compiler_rt can output the following: ``` static zig_weak_linkage_fn zig_f80 zig_e___fmax(zig_f80, zig_f80, zig_f80); zig_export(zig_weak_linkage_fn zig_f80 zig_e___fmax(zig_f80, zig_f80, zig_f80), __fmax, "__fmax"); ``` Within compiler_rt, `zig_e___fmax` is used to refer to the function, but consumers will import `__fmax`, which maps to their `zig_float_fn_f80_fma` definition from zig.h. --- src/codegen/c.zig | 71 ++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 47 insertions(+), 24 deletions(-) (limited to 'src') diff --git a/src/codegen/c.zig b/src/codegen/c.zig index 0178ffef9a..17aad238cb 100644 --- a/src/codegen/c.zig +++ b/src/codegen/c.zig @@ -258,6 +258,20 @@ pub fn fmtIdent(ident: []const u8) std.fmt.Formatter(formatIdent) { return .{ .data = ident }; } +// Returns true if `formatIdent` would make any edits to ident. +// This must be kept in sync with `formatIdent`. +pub fn isMangledIdent(ident: []const u8, solo: bool) bool { + if (solo and isReservedIdent(ident)) return true; + for (ident, 0..) |c, i| { + switch (c) { + 'a'...'z', 'A'...'Z', '_' => {}, + '0'...'9' => if (i == 0) return true, + else => return true, + } + } + return false; +} + /// This data is available when outputting .c code for a `InternPool.Index` /// that corresponds to `func`. /// It is not available when generating .h file. @@ -526,6 +540,7 @@ pub const DeclGen = struct { is_naked_fn: bool, /// This is a borrowed reference from `link.C`. fwd_decl: std.ArrayList(u8), + error_msg: ?*Module.ErrorMsg, ctypes: CType.Store, /// Keeps track of anonymous decls that need to be rendered before this @@ -1598,7 +1613,7 @@ pub const DeclGen = struct { switch (name) { .export_index => |export_index| try dg.renderDeclName(w, fn_decl_index, export_index), - .string => |string| try w.writeAll(string), + .string => |string| try w.print("{ }", .{fmtIdent(string)}), } try renderTypeSuffix( @@ -1813,9 +1828,17 @@ pub const DeclGen = struct { fn declIsGlobal(dg: *DeclGen, tv: TypedValue) bool { const mod = dg.module; return switch (mod.intern_pool.indexToKey(tv.val.ip_index)) { - .variable => |variable| mod.decl_exports.contains(variable.decl), + .variable => |variable| { + if (mod.decl_exports.get(variable.decl)) |exports| { + return !isMangledIdent(dg.module.intern_pool.stringToSlice(exports.items[0].opts.name), true); + } else return false; + }, .extern_func => true, - .func => |func| mod.decl_exports.contains(func.owner_decl), + .func => |func| { + if (mod.decl_exports.get(func.owner_decl)) |exports| { + return !isMangledIdent(dg.module.intern_pool.stringToSlice(exports.items[0].opts.name), true); + } else return false; + }, else => unreachable, }; } @@ -1925,9 +1948,9 @@ pub const DeclGen = struct { try mod.markDeclAlive(decl); if (mod.decl_exports.get(decl_index)) |exports| { - try writer.print("{}", .{exports.items[export_index].opts.name.fmt(&mod.intern_pool)}); + try writer.print("{ }", .{fmtIdent(mod.intern_pool.stringToSlice(exports.items[export_index].opts.name))}); } else if (decl.getExternDecl(mod).unwrap()) |extern_decl_index| { - try writer.print("{}", .{mod.declPtr(extern_decl_index).name.fmt(&mod.intern_pool)}); + try writer.print("{ }", .{fmtIdent(mod.intern_pool.stringToSlice(mod.declPtr(extern_decl_index).name))}); } else { // MSVC has a limit of 4095 character token length limit, and fmtIdent can (worst case), // expand to 3x the length of its input, but let's cut it off at a much shorter limit. @@ -2564,16 +2587,19 @@ fn genExports(o: *Object) !void { const fwd = o.dg.fwd_decl.writer(); const exports = mod.decl_exports.get(decl_index) orelse return; - if (exports.items.len < 2) return; + + const is_mangled = isMangledIdent(ip.stringToSlice(exports.items[0].opts.name), true); + if (exports.items.len < 2 and !is_mangled) return; switch (ip.indexToKey(tv.val.toIntern())) { .func => { - for (exports.items[1..], 1..) |@"export", i| { + const start_i = 1 - @intFromBool(is_mangled); + for (exports.items[start_i..], start_i..) |@"export", i| { try fwd.writeAll("zig_export("); if (exports.items[i].opts.linkage == .Weak) try fwd.writeAll("zig_weak_linkage_fn "); try o.dg.renderFunctionSignature(fwd, decl_index, .forward, .{ .export_index = @as(u32, @intCast(i)) }); - try fwd.print(", {s}, {s});\n", .{ - fmtStringLiteral(ip.stringToSlice(exports.items[0].opts.name), null), + try fwd.print(", { }, {s});\n", .{ + fmtIdent(ip.stringToSlice(exports.items[0].opts.name)), fmtStringLiteral(ip.stringToSlice(@"export".opts.name), null), }); } @@ -2583,7 +2609,8 @@ fn genExports(o: *Object) !void { unreachable; }, .variable => |variable| { - for (exports.items[1..], 1..) |@"export", i| { + const start_i = 1 - @intFromBool(is_mangled); + for (exports.items[start_i..], start_i..) |@"export", i| { try fwd.writeAll("zig_export("); if (exports.items[i].opts.linkage == .Weak) try fwd.writeAll("zig_weak_linkage "); const alias = ip.stringToSlice(@"export".opts.name); @@ -2595,8 +2622,8 @@ fn genExports(o: *Object) !void { decl.alignment, .complete, ); - try fwd.print(", {s}, {s});\n", .{ - fmtStringLiteral(ip.stringToSlice(exports.items[0].opts.name), null), + try fwd.print(", { }, {s});\n", .{ + fmtIdent(ip.stringToSlice(exports.items[0].opts.name)), fmtStringLiteral(alias, null), }); } @@ -6861,9 +6888,9 @@ fn airReduce(f: *Function, inst: Air.Inst.Index) !CValue { try f.writeCValue(writer, accum, .Other); switch (op) { .float_op => |func| { - try writer.writeAll(" = zig_libc_name_"); + try writer.writeAll(" = zig_float_fn_"); try f.object.dg.renderTypeForBuiltinFnName(writer, scalar_ty); - try writer.print("({s})(", .{func.operation}); + try writer.print("_{s}(", .{func.operation}); try f.writeCValue(writer, accum, .FunctionArgument); try writer.writeAll(", "); try f.writeCValue(writer, operand, .Other); @@ -7195,11 +7222,9 @@ fn unFloatOp(f: *Function, inst: Air.Inst.Index, operand: CValue, ty: Type, oper const v = try Vectorize.start(f, inst, writer, ty); try f.writeCValue(writer, local, .Other); try v.elem(f, writer); - try writer.writeAll(" = zig_libc_name_"); + try writer.writeAll(" = zig_float_fn_"); try f.object.dg.renderTypeForBuiltinFnName(writer, scalar_ty); - try writer.writeByte('('); - try writer.writeAll(operation); - try writer.writeAll(")("); + try writer.print("_{s}(", .{operation}); try f.writeCValue(writer, operand, .FunctionArgument); try v.elem(f, writer); try writer.writeAll(");\n"); @@ -7234,11 +7259,9 @@ fn airBinFloatOp(f: *Function, inst: Air.Inst.Index, operation: []const u8) !CVa const v = try Vectorize.start(f, inst, writer, inst_ty); try f.writeCValue(writer, local, .Other); try v.elem(f, writer); - try writer.writeAll(" = zig_libc_name_"); + try writer.writeAll(" = zig_float_fn_"); try f.object.dg.renderTypeForBuiltinFnName(writer, inst_scalar_ty); - try writer.writeByte('('); - try writer.writeAll(operation); - try writer.writeAll(")("); + try writer.print("_{s}(", .{operation}); try f.writeCValue(writer, lhs, .FunctionArgument); try v.elem(f, writer); try writer.writeAll(", "); @@ -7268,9 +7291,9 @@ fn airMulAdd(f: *Function, inst: Air.Inst.Index) !CValue { const v = try Vectorize.start(f, inst, writer, inst_ty); try f.writeCValue(writer, local, .Other); try v.elem(f, writer); - try writer.writeAll(" = zig_libc_name_"); + try writer.writeAll(" = zig_float_fn_"); try f.object.dg.renderTypeForBuiltinFnName(writer, inst_scalar_ty); - try writer.writeAll("(fma)("); + try writer.writeAll("_fma("); try f.writeCValue(writer, mulend1, .FunctionArgument); try v.elem(f, writer); try writer.writeAll(", "); -- cgit v1.2.3