zig cc: add --hash-style linker parameter

This is only relevant for ELF files.

I also fixed a bug where passing a zig source file to `zig cc` would
incorrectly punt to clang because it thought there were no positional
arguments.

7 files changed, 39 insertions, 7 deletions

diff --git a/src/Compilation.zig b/src/Compilation.zig
index dec98ed781..b804227bb9 100644
--- a/src/Compilation.zig
+++ b/src/Compilation.zig
@@ -791,6 +791,7 @@ pub const InitOptions = struct {
     /// infinite recursion.
     skip_linker_dependencies: bool = false,
     parent_compilation_link_libc: bool = false,
+    hash_style: link.HashStyle = .both,
     entry: ?[]const u8 = null,
     stack_size_override: ?u64 = null,
     image_base_override: ?u64 = null,
@@ -1610,6 +1611,7 @@ pub fn create(gpa: Allocator, options: InitOptions) !*Compilation {
             .is_test = options.is_test,
             .wasi_exec_model = wasi_exec_model,
             .use_stage1 = use_stage1,
+            .hash_style = options.hash_style,
             .enable_link_snapshots = options.enable_link_snapshots,
             .native_darwin_sdk = options.native_darwin_sdk,
             .install_name = options.install_name,
@@ -2227,7 +2229,7 @@ fn prepareWholeEmitSubPath(arena: Allocator, opt_emit: ?EmitLoc) error{OutOfMemo
 /// to remind the programmer to update multiple related pieces of code that
 /// are in different locations. Bump this number when adding or deleting
 /// anything from the link cache manifest.
-pub const link_hash_implementation_version = 1;
+pub const link_hash_implementation_version = 2;
 
 fn addNonIncrementalStuffToCacheManifest(comp: *Compilation, man: *Cache.Manifest) !void {
     const gpa = comp.gpa;
@@ -2237,7 +2239,7 @@ fn addNonIncrementalStuffToCacheManifest(comp: *Compilation, man: *Cache.Manifes
     defer arena_allocator.deinit();
     const arena = arena_allocator.allocator();
 
-    comptime assert(link_hash_implementation_version == 1);
+    comptime assert(link_hash_implementation_version == 2);
 
     if (comp.bin_file.options.module) |mod| {
         const main_zig_file = try mod.main_pkg.root_src_directory.join(arena, &[_][]const u8{
@@ -2308,6 +2310,7 @@ fn addNonIncrementalStuffToCacheManifest(comp: *Compilation, man: *Cache.Manifes
     man.hash.add(comp.bin_file.options.z_noexecstack);
     man.hash.add(comp.bin_file.options.z_now);
     man.hash.add(comp.bin_file.options.z_relro);
+    man.hash.add(comp.bin_file.options.hash_style);
     man.hash.add(comp.bin_file.options.include_compiler_rt);
     if (comp.bin_file.options.link_libc) {
         man.hash.add(comp.bin_file.options.libc_installation != null);
diff --git a/src/link.zig b/src/link.zig
index 817cb4c052..883d79de34 100644
--- a/src/link.zig
+++ b/src/link.zig
@@ -146,6 +146,7 @@ pub const Options = struct {
     disable_lld_caching: bool,
     is_test: bool,
     use_stage1: bool,
+    hash_style: HashStyle,
     major_subsystem_version: ?u32,
     minor_subsystem_version: ?u32,
     gc_sections: ?bool = null,
@@ -191,6 +192,8 @@ pub const Options = struct {
     }
 };
 
+pub const HashStyle = enum { sysv, gnu, both };
+
 pub const File = struct {
     tag: Tag,
     options: Options,
diff --git a/src/link/Coff.zig b/src/link/Coff.zig
index 20a76f49a2..152e078b66 100644
--- a/src/link/Coff.zig
+++ b/src/link/Coff.zig
@@ -941,7 +941,7 @@ fn linkWithLLD(self: *Coff, comp: *Compilation) !void {
         man = comp.cache_parent.obtain();
         self.base.releaseLock();
 
-        comptime assert(Compilation.link_hash_implementation_version == 1);
+        comptime assert(Compilation.link_hash_implementation_version == 2);
 
         for (self.base.options.objects) |obj| {
             _ = try man.addFile(obj.path, null);
diff --git a/src/link/Elf.zig b/src/link/Elf.zig
index 15fff6db79..8a9d98189a 100644
--- a/src/link/Elf.zig
+++ b/src/link/Elf.zig
@@ -1413,7 +1413,7 @@ fn linkWithLLD(self: *Elf, comp: *Compilation) !void {
         // We are about to obtain this lock, so here we give other processes a chance first.
         self.base.releaseLock();
 
-        comptime assert(Compilation.link_hash_implementation_version == 1);
+        comptime assert(Compilation.link_hash_implementation_version == 2);
 
         try man.addOptionalFile(self.base.options.linker_script);
         try man.addOptionalFile(self.base.options.version_script);
@@ -1447,6 +1447,7 @@ fn linkWithLLD(self: *Elf, comp: *Compilation) !void {
         man.hash.add(self.base.options.z_noexecstack);
         man.hash.add(self.base.options.z_now);
         man.hash.add(self.base.options.z_relro);
+        man.hash.add(self.base.options.hash_style);
         // strip does not need to go into the linker hash because it is part of the hash namespace
         if (self.base.options.link_libc) {
             man.hash.add(self.base.options.libc_installation != null);
@@ -1558,6 +1559,12 @@ fn linkWithLLD(self: *Elf, comp: *Compilation) !void {
             try argv.append(entry);
         }
 
+        switch (self.base.options.hash_style) {
+            .gnu => try argv.append("--hash-style=gnu"),
+            .sysv => try argv.append("--hash-style=sysv"),
+            .both => {}, // this is the default
+        }
+
         if (self.base.options.output_mode == .Exe) {
             try argv.append("-z");
             try argv.append(try std.fmt.allocPrint(arena, "stack-size={d}", .{stack_size}));
diff --git a/src/link/MachO.zig b/src/link/MachO.zig
index cd1d197010..a9950fcc8d 100644
--- a/src/link/MachO.zig
+++ b/src/link/MachO.zig
@@ -497,7 +497,7 @@ pub fn flushModule(self: *MachO, comp: *Compilation) !void {
         // We are about to obtain this lock, so here we give other processes a chance first.
         self.base.releaseLock();
 
-        comptime assert(Compilation.link_hash_implementation_version == 1);
+        comptime assert(Compilation.link_hash_implementation_version == 2);
 
         for (self.base.options.objects) |obj| {
             _ = try man.addFile(obj.path, null);
diff --git a/src/link/Wasm.zig b/src/link/Wasm.zig
index 9a9c6c464c..7d01ef4083 100644
--- a/src/link/Wasm.zig
+++ b/src/link/Wasm.zig
@@ -1203,7 +1203,7 @@ fn linkWithLLD(self: *Wasm, comp: *Compilation) !void {
         // We are about to obtain this lock, so here we give other processes a chance first.
         self.base.releaseLock();
 
-        comptime assert(Compilation.link_hash_implementation_version == 1);
+        comptime assert(Compilation.link_hash_implementation_version == 2);
 
         for (self.base.options.objects) |obj| {
             _ = try man.addFile(obj.path, null);
diff --git a/src/main.zig b/src/main.zig
index 3f74a64c36..b32da74ef6 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -676,6 +676,7 @@ fn buildOutputType(
     var enable_link_snapshots: bool = false;
     var native_darwin_sdk: ?std.zig.system.darwin.DarwinSDK = null;
     var install_name: ?[]const u8 = null;
+    var hash_style: link.HashStyle = .both;
 
     // 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
@@ -1790,6 +1791,19 @@ fn buildOutputType(
                         .path = linker_args.items[i],
                         .must_link = true,
                     });
+                } else if (mem.eql(u8, arg, "-hash-style") or
+                    mem.eql(u8, arg, "--hash-style"))
+                {
+                    i += 1;
+                    if (i >= linker_args.items.len) {
+                        fatal("expected linker arg after '{s}'", .{arg});
+                    }
+                    const next_arg = linker_args.items[i];
+                    hash_style = std.meta.stringToEnum(link.HashStyle, next_arg) orelse {
+                        fatal("expected [sysv|gnu|both] after --hash-style, found '{s}'", .{
+                            next_arg,
+                        });
+                    };
                 } else {
                     warn("unsupported linker arg: {s}", .{arg});
                 }
@@ -1859,8 +1873,12 @@ fn buildOutputType(
                     }
                 },
             }
-            if (c_source_files.items.len == 0 and link_objects.items.len == 0) {
+            if (c_source_files.items.len == 0 and
+                link_objects.items.len == 0 and
+                root_src_file == null)
+            {
                 // For example `zig cc` and no args should print the "no input files" message.
+                // There could be other reasons to punt to clang, for example, --help.
                 return punt_to_clang(arena, all_args);
             }
         },
@@ -2503,6 +2521,7 @@ fn buildOutputType(
         .use_lld = use_lld,
         .use_clang = use_clang,
         .use_stage1 = use_stage1,
+        .hash_style = hash_style,
         .rdynamic = rdynamic,
         .linker_script = linker_script,
         .version_script = version_script,