Commit 4e5a88b288
src/link/Coff.zig
@@ -940,7 +940,7 @@ fn linkWithLLD(self: *Coff, comp: *Compilation) !void {
}
}
}
- man.hash.addStringSet(self.base.options.system_libs);
+ link.hashAddSystemLibs(&man.hash, self.base.options.system_libs);
man.hash.addOptional(self.base.options.subsystem);
man.hash.add(self.base.options.is_test);
man.hash.add(self.base.options.tsaware);
src/link/Elf.zig
@@ -1345,7 +1345,7 @@ fn linkWithLLD(self: *Elf, comp: *Compilation) !void {
}
man.hash.addOptionalBytes(self.base.options.soname);
man.hash.addOptional(self.base.options.version);
- man.hash.addStringSet(self.base.options.system_libs);
+ link.hashAddSystemLibs(&man.hash, self.base.options.system_libs);
man.hash.add(allow_shlib_undefined);
man.hash.add(self.base.options.bind_global_refs_locally);
man.hash.add(self.base.options.tsan);
@@ -1550,7 +1550,9 @@ fn linkWithLLD(self: *Elf, comp: *Compilation) !void {
for (self.base.options.system_libs.keys()) |link_lib| {
test_path.shrinkRetainingCapacity(0);
const sep = fs.path.sep_str;
- try test_path.writer().print("{s}" ++ sep ++ "lib{s}.so", .{ lib_dir_path, link_lib });
+ try test_path.writer().print("{s}" ++ sep ++ "lib{s}.so", .{
+ lib_dir_path, link_lib,
+ });
fs.cwd().access(test_path.items, .{}) catch |err| switch (err) {
error.FileNotFound => continue,
else => |e| return e,
@@ -1627,16 +1629,42 @@ fn linkWithLLD(self: *Elf, comp: *Compilation) !void {
// Shared libraries.
if (is_exe_or_dyn_lib) {
const system_libs = self.base.options.system_libs.keys();
- try argv.ensureUnusedCapacity(system_libs.len);
- for (system_libs) |link_lib| {
- // By this time, we depend on these libs being dynamically linked libraries and not static libraries
- // (the check for that needs to be earlier), but they could be full paths to .so files, in which
- // case we want to avoid prepending "-l".
+ const system_libs_values = self.base.options.system_libs.values();
+
+ // Worst-case, we need an --as-needed argument for every lib, as well
+ // as one before and one after.
+ try argv.ensureUnusedCapacity(system_libs.len * 2 + 2);
+ argv.appendAssumeCapacity("--as-needed");
+ var as_needed = true;
+
+ for (system_libs) |link_lib, i| {
+ const lib_as_needed = !system_libs_values[i].needed;
+ switch ((@as(u2, @boolToInt(lib_as_needed)) << 1) | @boolToInt(as_needed)) {
+ 0b00, 0b11 => {},
+ 0b01 => {
+ argv.appendAssumeCapacity("--no-as-needed");
+ as_needed = false;
+ },
+ 0b10 => {
+ argv.appendAssumeCapacity("--as-needed");
+ as_needed = true;
+ },
+ }
+
+ // By this time, we depend on these libs being dynamically linked
+ // libraries and not static libraries (the check for that needs to be earlier),
+ // but they could be full paths to .so files, in which case we
+ // want to avoid prepending "-l".
const ext = Compilation.classifyFileExt(link_lib);
const arg = if (ext == .shared_library) link_lib else try std.fmt.allocPrint(arena, "-l{s}", .{link_lib});
argv.appendAssumeCapacity(arg);
}
+ if (!as_needed) {
+ argv.appendAssumeCapacity("--as-needed");
+ as_needed = true;
+ }
+
// libc++ dep
if (self.base.options.link_libcpp) {
try argv.append(comp.libcxxabi_static_lib.?.full_object_path);
src/link/MachO.zig
@@ -471,7 +471,7 @@ pub fn flushModule(self: *MachO, comp: *Compilation) !void {
if (is_dyn_lib) {
man.hash.addOptional(self.base.options.version);
}
- man.hash.addStringSet(self.base.options.system_libs);
+ link.hashAddSystemLibs(&man.hash, self.base.options.system_libs);
man.hash.addOptionalBytes(self.base.options.sysroot);
// We don't actually care whether it's a cache hit or miss; we just need the digest and the lock.
src/Cache.zig
@@ -90,14 +90,6 @@ pub const HashHelper = struct {
for (list_of_bytes) |bytes| hh.addBytes(bytes);
}
- pub fn addStringSet(hh: *HashHelper, hm: std.StringArrayHashMapUnmanaged(void)) void {
- const keys = hm.keys();
- hh.add(keys.len);
- for (keys) |key| {
- hh.addBytes(key);
- }
- }
-
/// Convert the input value into bytes and record it as a dependency of the process being cached.
pub fn add(hh: *HashHelper, x: anytype) void {
switch (@TypeOf(x)) {
src/Compilation.zig
@@ -627,6 +627,8 @@ pub const ClangPreprocessorMode = enum {
stdout,
};
+pub const SystemLib = link.SystemLib;
+
pub const InitOptions = struct {
zig_lib_directory: Directory,
local_cache_directory: Directory,
@@ -672,7 +674,8 @@ pub const InitOptions = struct {
link_objects: []const []const u8 = &[0][]const u8{},
framework_dirs: []const []const u8 = &[0][]const u8{},
frameworks: []const []const u8 = &[0][]const u8{},
- system_libs: []const []const u8 = &[0][]const u8{},
+ system_lib_names: []const []const u8 = &.{},
+ system_lib_infos: []const SystemLib = &.{},
/// These correspond to the WASI libc emulated subcomponents including:
/// * process clocks
/// * getpid
@@ -935,7 +938,7 @@ pub fn create(gpa: *Allocator, options: InitOptions) !*Compilation {
if (options.link_objects.len != 0 or
options.c_source_files.len != 0 or
options.frameworks.len != 0 or
- options.system_libs.len != 0 or
+ options.system_lib_names.len != 0 or
options.link_libc or options.link_libcpp or
link_eh_frame_hdr or
options.link_emit_relocs or
@@ -1003,7 +1006,7 @@ pub fn create(gpa: *Allocator, options: InitOptions) !*Compilation {
break :dl true;
}
const any_dyn_libs: bool = x: {
- if (options.system_libs.len != 0)
+ if (options.system_lib_names.len != 0)
break :x true;
for (options.link_objects) |obj| {
switch (classifyFileExt(obj)) {
@@ -1050,7 +1053,7 @@ pub fn create(gpa: *Allocator, options: InitOptions) !*Compilation {
options.target,
options.is_native_abi,
link_libc,
- options.system_libs.len != 0 or options.frameworks.len != 0,
+ options.system_lib_names.len != 0 or options.frameworks.len != 0,
options.libc_installation,
);
@@ -1372,11 +1375,11 @@ pub fn create(gpa: *Allocator, options: InitOptions) !*Compilation {
};
};
- var system_libs: std.StringArrayHashMapUnmanaged(void) = .{};
+ var system_libs: std.StringArrayHashMapUnmanaged(SystemLib) = .{};
errdefer system_libs.deinit(gpa);
- try system_libs.ensureTotalCapacity(gpa, options.system_libs.len);
- for (options.system_libs) |lib_name| {
- system_libs.putAssumeCapacity(lib_name, {});
+ try system_libs.ensureTotalCapacity(gpa, options.system_lib_names.len);
+ for (options.system_lib_names) |lib_name, i| {
+ system_libs.putAssumeCapacity(lib_name, options.system_lib_infos[i]);
}
const bin_file = try link.File.openPath(gpa, .{
src/link.zig
@@ -18,6 +18,22 @@ const wasi_libc = @import("wasi_libc.zig");
const Air = @import("Air.zig");
const Liveness = @import("Liveness.zig");
+pub const SystemLib = struct {
+ needed: bool = false,
+};
+
+pub fn hashAddSystemLibs(
+ hh: *Cache.HashHelper,
+ hm: std.StringArrayHashMapUnmanaged(SystemLib),
+) void {
+ const keys = hm.keys();
+ hh.add(keys.len);
+ hh.addListOfBytes(keys);
+ for (hm.values()) |value| {
+ hh.add(value.needed);
+ }
+}
+
pub const producer_string = if (builtin.is_test) "zig test" else "zig " ++ build_options.version;
pub const Emit = struct {
@@ -121,7 +137,7 @@ pub const Options = struct {
objects: []const []const u8,
framework_dirs: []const []const u8,
frameworks: []const []const u8,
- system_libs: std.StringArrayHashMapUnmanaged(void),
+ system_libs: std.StringArrayHashMapUnmanaged(SystemLib),
wasi_emulated_libs: []const wasi_libc.CRTFile,
lib_dirs: []const []const u8,
rpath_list: []const []const u8,
src/main.zig
@@ -387,7 +387,9 @@ const usage_build_generic =
\\ -ffunction-sections Places each function in a separate section
\\
\\Link Options:
- \\ -l[lib], --library [lib] Link against system library
+ \\ -l[lib], --library [lib] Link against system library (only if actually used)
+ \\ -needed-l[lib], Link against system library (even if unused)
+ \\ --needed-library [lib]
\\ -L[d], --library-directory [d] Add a directory to the library search path
\\ -T[script], --script [script] Use a custom linker script
\\ --version-script [path] Provide a version .map file
@@ -655,7 +657,7 @@ fn buildOutputType(
var wasi_exec_model: ?std.builtin.WasiExecModel = null;
var enable_link_snapshots: bool = false;
- var system_libs = std.ArrayList([]const u8).init(gpa);
+ var system_libs = std.StringArrayHashMap(Compilation.SystemLib).init(gpa);
defer system_libs.deinit();
var wasi_emulated_libs = std.ArrayList(wasi_libc.CRTFile).init(gpa);
@@ -860,10 +862,14 @@ fn buildOutputType(
version_script = args[i];
} else if (mem.eql(u8, arg, "--library") or mem.eql(u8, arg, "-l")) {
if (i + 1 >= args.len) fatal("expected parameter after {s}", .{arg});
- // We don't know whether this library is part of libc or libc++ until we resolve the target.
- // So we simply append to the list for now.
+ // We don't know whether this library is part of libc or libc++ until
+ // we resolve the target, so we simply append to the list for now.
i += 1;
- try system_libs.append(args[i]);
+ try system_libs.put(args[i], .{ .needed = false });
+ } else if (mem.eql(u8, arg, "--needed-library") or mem.eql(u8, arg, "-needed-l")) {
+ if (i + 1 >= args.len) fatal("expected parameter after {s}", .{arg});
+ i += 1;
+ try system_libs.put(args[i], .{ .needed = true });
} else if (mem.eql(u8, arg, "-D") or
mem.eql(u8, arg, "-isystem") or
mem.eql(u8, arg, "-I") or
@@ -1164,9 +1170,11 @@ fn buildOutputType(
} else if (mem.startsWith(u8, arg, "-F")) {
try framework_dirs.append(arg[2..]);
} else if (mem.startsWith(u8, arg, "-l")) {
- // We don't know whether this library is part of libc or libc++ until we resolve the target.
- // So we simply append to the list for now.
- try system_libs.append(arg[2..]);
+ // We don't know whether this library is part of libc or libc++ until
+ // we resolve the target, so we simply append to the list for now.
+ try system_libs.put(arg["-l".len..], .{ .needed = false });
+ } else if (mem.startsWith(u8, arg, "-needed-l")) {
+ try system_libs.put(arg["-needed-l".len..], .{ .needed = true });
} else if (mem.startsWith(u8, arg, "-D") or
mem.startsWith(u8, arg, "-I"))
{
@@ -1230,6 +1238,7 @@ fn buildOutputType(
var linker_args = std.ArrayList([]const u8).init(arena);
var it = ClangArgIterator.init(arena, all_args);
var emit_llvm = false;
+ var needed = false;
while (it.has_next) {
it.next() catch |err| {
fatal("unable to parse command line parameters: {s}", .{@errorName(err)});
@@ -1262,9 +1271,9 @@ fn buildOutputType(
},
.l => {
// -l
- // We don't know whether this library is part of libc or libc++ until we resolve the target.
- // So we simply append to the list for now.
- try system_libs.append(it.only_arg);
+ // We don't know whether this library is part of libc or libc++ until
+ // we resolve the target, so we simply append to the list for now.
+ try system_libs.put(it.only_arg, .{ .needed = needed });
},
.ignore => {},
.driver_punt => {
@@ -1302,8 +1311,13 @@ fn buildOutputType(
continue;
}
}
-
- try linker_args.append(linker_arg);
+ if (mem.eql(u8, linker_arg, "--as-needed")) {
+ needed = false;
+ } else if (mem.eql(u8, linker_arg, "--no-as-needed")) {
+ needed = true;
+ } else {
+ try linker_args.append(linker_arg);
+ }
}
},
.optimize => {
@@ -1725,21 +1739,22 @@ fn buildOutputType(
// existence via flags instead.
{
var i: usize = 0;
- while (i < system_libs.items.len) {
- const lib_name = system_libs.items[i];
+ while (i < system_libs.count()) {
+ const lib_name = system_libs.keys()[i];
+
if (target_util.is_libc_lib_name(target_info.target, lib_name)) {
link_libc = true;
- _ = system_libs.orderedRemove(i);
+ _ = system_libs.orderedRemove(lib_name);
continue;
}
if (target_util.is_libcpp_lib_name(target_info.target, lib_name)) {
link_libcpp = true;
- _ = system_libs.orderedRemove(i);
+ _ = system_libs.orderedRemove(lib_name);
continue;
}
if (mem.eql(u8, lib_name, "unwind")) {
link_libunwind = true;
- _ = system_libs.orderedRemove(i);
+ _ = system_libs.orderedRemove(lib_name);
continue;
}
if (std.fs.path.isAbsolute(lib_name)) {
@@ -1748,7 +1763,7 @@ fn buildOutputType(
if (target_info.target.os.tag == .wasi) {
if (wasi_libc.getEmulatedLibCRTFile(lib_name)) |crt_file| {
try wasi_emulated_libs.append(crt_file);
- _ = system_libs.orderedRemove(i);
+ _ = system_libs.orderedRemove(lib_name);
continue;
}
}
@@ -1777,7 +1792,7 @@ fn buildOutputType(
const is_darwin_on_darwin = (comptime builtin.target.isDarwin()) and cross_target.isDarwin();
if (sysroot == null and (cross_target.isNativeOs() or is_darwin_on_darwin) and
- (system_libs.items.len != 0 or want_native_include_dirs))
+ (system_libs.count() != 0 or want_native_include_dirs))
{
const paths = std.zig.system.NativePaths.detect(arena, target_info) catch |err| {
fatal("unable to detect native system paths: {s}", .{@errorName(err)});
@@ -2144,7 +2159,8 @@ fn buildOutputType(
.link_objects = link_objects.items,
.framework_dirs = framework_dirs.items,
.frameworks = frameworks.items,
- .system_libs = system_libs.items,
+ .system_lib_names = system_libs.keys(),
+ .system_lib_infos = system_libs.values(),
.wasi_emulated_libs = wasi_emulated_libs.items,
.link_libc = link_libc,
.link_libcpp = link_libcpp,