From 0df7ed79d304afc7d379482005e892979d4a5e4d Mon Sep 17 00:00:00 2001 From: Jakub Konka Date: Fri, 24 Jun 2022 20:25:16 +0200 Subject: [PATCH] macho: implement -search_dylibs_first linker option --- lib/std/build.zig | 11 ++++ src/Compilation.zig | 3 + src/link.zig | 3 + src/link/MachO.zig | 141 +++++++++++++++++++++++++++----------------- src/main.zig | 12 +++- 5 files changed, 114 insertions(+), 56 deletions(-) diff --git a/lib/std/build.zig b/lib/std/build.zig index 57304242cd..0b49087747 100644 --- a/lib/std/build.zig +++ b/lib/std/build.zig @@ -1586,6 +1586,13 @@ pub const LibExeObjStep = struct { /// (Darwin) Size of the pagezero segment. pagezero_size: ?u64 = null, + /// (Darwin) Search strategy for searching system libraries. Either `paths_first` or `dylibs_first`. + /// The former lowers to `-search_paths_first` linker option, while the latter to `-search_dylibs_first` + /// option. + /// By default, if no option is specified, the linker assumes `paths_first` as the default + /// search strategy. + search_strategy: ?enum { paths_first, dylibs_first } = null, + /// Position Independent Code force_pic: ?bool = null, @@ -2650,6 +2657,10 @@ pub const LibExeObjStep = struct { const size = try std.fmt.allocPrint(builder.allocator, "{x}", .{pagezero_size}); try zig_args.appendSlice(&[_][]const u8{ "-pagezero_size", size }); } + if (self.search_strategy) |strat| switch (strat) { + .paths_first => try zig_args.append("-search_paths_first"), + .dylibs_first => try zig_args.append("-search_dylibs_first"), + }; if (self.bundle_compiler_rt) |x| { if (x) { diff --git a/src/Compilation.zig b/src/Compilation.zig index 8cb93b5473..cbd36216ae 100644 --- a/src/Compilation.zig +++ b/src/Compilation.zig @@ -905,6 +905,8 @@ pub const InitOptions = struct { entitlements: ?[]const u8 = null, /// (Darwin) size of the __PAGEZERO segment pagezero_size: ?u64 = null, + /// (Darwin) search strategy for system libraries + search_strategy: ?link.File.MachO.SearchStrategy = null, }; fn addPackageTableToCacheHash( @@ -1745,6 +1747,7 @@ pub fn create(gpa: Allocator, options: InitOptions) !*Compilation { .install_name = options.install_name, .entitlements = options.entitlements, .pagezero_size = options.pagezero_size, + .search_strategy = options.search_strategy, }); errdefer bin_file.destroy(); comp.* = .{ diff --git a/src/link.zig b/src/link.zig index c78fb8c2c5..cfcb112e9b 100644 --- a/src/link.zig +++ b/src/link.zig @@ -190,6 +190,9 @@ pub const Options = struct { /// (Darwin) size of the __PAGEZERO segment pagezero_size: ?u64 = null, + /// (Darwin) search strategy for system libraries + search_strategy: ?File.MachO.SearchStrategy = null, + pub fn effectiveOutputMode(options: Options) std.builtin.OutputMode { return if (options.use_lld) .Obj else options.output_mode; } diff --git a/src/link/MachO.zig b/src/link/MachO.zig index 0c44901d29..bade8caa0c 100644 --- a/src/link/MachO.zig +++ b/src/link/MachO.zig @@ -47,6 +47,11 @@ pub const DebugSymbols = @import("MachO/DebugSymbols.zig"); pub const base_tag: File.Tag = File.Tag.macho; +pub const SearchStrategy = enum { + paths_first, + dylibs_first, +}; + base: File, /// If this is not null, an object file is created by LLVM and linked with LLD afterwards. @@ -784,18 +789,43 @@ pub fn flushModule(self: *MachO, comp: *Compilation, prog_node: *std.Progress.No } var libs = std.ArrayList([]const u8).init(arena); - for (search_lib_names.items) |lib_name| { - // Assume ld64 default: -search_paths_first - // Look in each directory for a dylib (stub first), and then for archive - // TODO implement alternative: -search_dylibs_first - for (&[_][]const u8{ ".tbd", ".dylib", ".a" }) |ext| { - if (try resolveLib(arena, lib_dirs.items, lib_name, ext)) |full_path| { - try libs.append(full_path); - break; - } - } else { - log.warn("library not found for '-l{s}'", .{lib_name}); - lib_not_found = true; + + // Assume ld64 default -search_paths_first if no strategy specified. + const search_strategy = self.base.options.search_strategy orelse .paths_first; + outer: for (search_lib_names.items) |lib_name| { + switch (search_strategy) { + .paths_first => { + // Look in each directory for a dylib (stub first), and then for archive + for (lib_dirs.items) |dir| { + for (&[_][]const u8{ ".tbd", ".dylib", ".a" }) |ext| { + if (try resolveLib(arena, dir, lib_name, ext)) |full_path| { + try libs.append(full_path); + continue :outer; + } + } + } else { + log.warn("library not found for '-l{s}'", .{lib_name}); + lib_not_found = true; + } + }, + .dylibs_first => { + // First, look for a dylib in each search dir + for (lib_dirs.items) |dir| { + for (&[_][]const u8{ ".tbd", ".dylib" }) |ext| { + if (try resolveLib(arena, dir, lib_name, ext)) |full_path| { + try libs.append(full_path); + continue :outer; + } + } + } else for (lib_dirs.items) |dir| { + if (try resolveLib(arena, dir, lib_name, ".a")) |full_path| { + try libs.append(full_path); + } else { + log.warn("library not found for '-l{s}'", .{lib_name}); + lib_not_found = true; + } + } + }, } } @@ -811,19 +841,23 @@ pub fn flushModule(self: *MachO, comp: *Compilation, prog_node: *std.Progress.No if (self.base.options.sysroot != null) blk: { // Try stub file first. If we hit it, then we're done as the stub file // re-exports every single symbol definition. - if (try resolveLib(arena, lib_dirs.items, "System", ".tbd")) |full_path| { - try libs.append(full_path); - libsystem_available = true; - break :blk; + for (lib_dirs.items) |dir| { + if (try resolveLib(arena, dir, "System", ".tbd")) |full_path| { + try libs.append(full_path); + libsystem_available = true; + break :blk; + } } // If we didn't hit the stub file, try .dylib next. However, libSystem.dylib // doesn't export libc.dylib which we'll need to resolve subsequently also. - if (try resolveLib(arena, lib_dirs.items, "System", ".dylib")) |libsystem_path| { - if (try resolveLib(arena, lib_dirs.items, "c", ".dylib")) |libc_path| { - try libs.append(libsystem_path); - try libs.append(libc_path); - libsystem_available = true; - break :blk; + for (lib_dirs.items) |dir| { + if (try resolveLib(arena, dir, "System", ".dylib")) |libsystem_path| { + if (try resolveLib(arena, dir, "c", ".dylib")) |libc_path| { + try libs.append(libsystem_path); + try libs.append(libc_path); + libsystem_available = true; + break :blk; + } } } } @@ -847,11 +881,13 @@ pub fn flushModule(self: *MachO, comp: *Compilation, prog_node: *std.Progress.No } } - for (self.base.options.frameworks) |framework| { - for (&[_][]const u8{ ".tbd", ".dylib", "" }) |ext| { - if (try resolveFramework(arena, framework_dirs.items, framework, ext)) |full_path| { - try libs.append(full_path); - break; + outer: for (self.base.options.frameworks) |framework| { + for (framework_dirs.items) |dir| { + for (&[_][]const u8{ ".tbd", ".dylib", "" }) |ext| { + if (try resolveFramework(arena, dir, framework, ext)) |full_path| { + try libs.append(full_path); + continue :outer; + } } } else { log.warn("framework not found for '-framework {s}'", .{framework}); @@ -934,6 +970,11 @@ pub fn flushModule(self: *MachO, comp: *Compilation, prog_node: *std.Progress.No try argv.append(try std.fmt.allocPrint(arena, "0x{x}", .{pagezero_size})); } + if (self.base.options.search_strategy) |strat| switch (strat) { + .paths_first => try argv.append("-search_paths_first"), + .dylibs_first => try argv.append("-search_dylibs_first"), + }; + if (self.base.options.entry) |entry| { try argv.append("-e"); try argv.append(entry); @@ -1183,51 +1224,41 @@ fn resolveSearchDir( fn resolveLib( arena: Allocator, - search_dirs: []const []const u8, + search_dir: []const u8, name: []const u8, ext: []const u8, ) !?[]const u8 { const search_name = try std.fmt.allocPrint(arena, "lib{s}{s}", .{ name, ext }); + const full_path = try fs.path.join(arena, &[_][]const u8{ search_dir, search_name }); - for (search_dirs) |dir| { - const full_path = try fs.path.join(arena, &[_][]const u8{ dir, search_name }); + // Check if the file exists. + const tmp = fs.cwd().openFile(full_path, .{}) catch |err| switch (err) { + error.FileNotFound => return null, + else => |e| return e, + }; + defer tmp.close(); - // Check if the file exists. - const tmp = fs.cwd().openFile(full_path, .{}) catch |err| switch (err) { - error.FileNotFound => continue, - else => |e| return e, - }; - defer tmp.close(); - - return full_path; - } - - return null; + return full_path; } fn resolveFramework( arena: Allocator, - search_dirs: []const []const u8, + search_dir: []const u8, name: []const u8, ext: []const u8, ) !?[]const u8 { const search_name = try std.fmt.allocPrint(arena, "{s}{s}", .{ name, ext }); const prefix_path = try std.fmt.allocPrint(arena, "{s}.framework", .{name}); + const full_path = try fs.path.join(arena, &[_][]const u8{ search_dir, prefix_path, search_name }); - for (search_dirs) |dir| { - const full_path = try fs.path.join(arena, &[_][]const u8{ dir, prefix_path, search_name }); + // Check if the file exists. + const tmp = fs.cwd().openFile(full_path, .{}) catch |err| switch (err) { + error.FileNotFound => return null, + else => |e| return e, + }; + defer tmp.close(); - // Check if the file exists. - const tmp = fs.cwd().openFile(full_path, .{}) catch |err| switch (err) { - error.FileNotFound => continue, - else => |e| return e, - }; - defer tmp.close(); - - return full_path; - } - - return null; + return full_path; } fn parseObject(self: *MachO, path: []const u8) !bool { diff --git a/src/main.zig b/src/main.zig index b2b795d25f..9cf50e1193 100644 --- a/src/main.zig +++ b/src/main.zig @@ -448,6 +448,8 @@ const usage_build_generic = \\ -install_name=[value] (Darwin) add dylib's install name \\ --entitlements [path] (Darwin) add path to entitlements file for embedding in code signature \\ -pagezero_size [value] (Darwin) size of the __PAGEZERO segment in hexadecimal notation + \\ -search_paths_first (Darwin) search each dir in library search paths for `libx.dylib` then `libx.a` + \\ -search_dylibs_first (Darwin) search `libx.dylib` in each dir in library search paths, then `libx.a` \\ --import-memory (WebAssembly) import memory from the environment \\ --import-table (WebAssembly) import function table from the host environment \\ --export-table (WebAssembly) export function table to the host environment @@ -696,6 +698,7 @@ fn buildOutputType( var hash_style: link.HashStyle = .both; var entitlements: ?[]const u8 = null; var pagezero_size: ?u64 = null; + var search_strategy: ?link.File.MachO.SearchStrategy = null; // e.g. -m3dnow or -mno-outline-atomics. They correspond to std.Target llvm cpu feature names. // This array is populated by zig cc frontend and then has to be converted to zig-style @@ -917,6 +920,10 @@ fn buildOutputType( pagezero_size = std.fmt.parseUnsigned(u64, eatIntPrefix(next_arg, 16), 16) catch |err| { fatal("unable to parse '{s}': {s}", .{ arg, @errorName(err) }); }; + } else if (mem.eql(u8, arg, "-search_paths_first")) { + search_strategy = .paths_first; + } else if (mem.eql(u8, arg, "-search_dylibs_first")) { + search_strategy = .dylibs_first; } else if (mem.eql(u8, arg, "-T") or mem.eql(u8, arg, "--script")) { linker_script = args_iter.next() orelse { fatal("expected parameter after {s}", .{arg}); @@ -1476,7 +1483,9 @@ fn buildOutputType( { force_static_libs = true; } else if (mem.eql(u8, linker_arg, "-search_paths_first")) { - // ignore, since it's the default behavior in both ld64 and zld + search_strategy = .paths_first; + } else if (mem.eql(u8, linker_arg, "-search_dylibs_first")) { + search_strategy = .dylibs_first; } else { try linker_args.append(linker_arg); } @@ -2784,6 +2793,7 @@ fn buildOutputType( .install_name = install_name, .entitlements = entitlements, .pagezero_size = pagezero_size, + .search_strategy = search_strategy, }) catch |err| switch (err) { error.LibCUnavailable => { const target = target_info.target;