stage2: cleanups to --compress-debug-sections

 * make the setting in the linker backend be non-optional; by this time
   all defaults are supposed to be resolved.
 * integrate with `zig cc`
 * change the CLI parsing to match C compiler parsing, allowing
   `--compress-debug-sections` alone to choose a default encoding of
   zlib.

Author: andrewrk

src/Compilation.zig

@@ -1688,7 +1688,7 @@ pub fn create(gpa: Allocator, options: InitOptions) !*Compilation {
             .no_builtin = options.no_builtin,
             .allow_shlib_undefined = options.linker_allow_shlib_undefined,
             .bind_global_refs_locally = options.linker_bind_global_refs_locally orelse false,
-            .compress_debug_sections = options.linker_compress_debug_sections,
+            .compress_debug_sections = options.linker_compress_debug_sections orelse .none,
             .import_memory = options.linker_import_memory orelse false,
             .import_table = options.linker_import_table,
             .export_table = options.linker_export_table,
@@ -2461,7 +2461,7 @@ fn addNonIncrementalStuffToCacheManifest(comp: *Compilation, man: *Cache.Manifes
     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.addOptional(comp.bin_file.options.compress_debug_sections);
+    man.hash.add(comp.bin_file.options.compress_debug_sections);
     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);

src/clang_options_data.zig

@@ -2308,7 +2308,7 @@ flagpd1("compiler-options-dump"),
 .{
     .name = "compress-debug-sections",
     .syntax = .flag,
-    .zig_equivalent = .other,
+    .zig_equivalent = .compress_debug_sections,
     .pd1 = true,
     .pd2 = true,
     .psl = false,
@@ -3834,7 +3834,7 @@ m("mavx512cd"),
 m("mavx512dq"),
 m("mavx512er"),
 m("mavx512f"),
-flagpd1("mavx512fp16"),
+m("mavx512fp16"),
 m("mavx512ifma"),
 m("mavx512pf"),
 m("mavx512vbmi"),
@@ -3867,7 +3867,7 @@ flagpd1("mconstructor-aliases"),
 flagpd1("mcpu=?"),
 m("mcrbits"),
 m("mcrc"),
-flagpd1("mcrc32"),
+m("mcrc32"),
 m("mcumode"),
 m("mcx16"),
 sepd1("mdebug-pass"),
@@ -3892,8 +3892,8 @@ flagpd1("mfancy-math-387"),
 flagpd1("mfentry"),
 flagpd1("mfix4300"),
 flagpd1("mfix-and-continue"),
-flagpd1("mfix-cmse-cve-2021-35465"),
-flagpd1("mfix-cortex-a53-835769"),
+m("mfix-cmse-cve-2021-35465"),
+m("mfix-cortex-a53-835769"),
 m("mfloat128"),
 sepd1("mfloat-abi"),
 m("mfma"),
@@ -3913,8 +3913,8 @@ flagpd1("mglobal-merge"),
 flagpd1("mgpopt"),
 m("mhard-float"),
 m("mhvx"),
-flagpd1("mhvx-ieee-fp"),
-flagpd1("mhvx-qfloat"),
+m("mhvx-ieee-fp"),
+m("mhvx-qfloat"),
 m("mhreset"),
 m("mhtm"),
 flagpd1("miamcu"),
@@ -4005,7 +4005,7 @@ m("mno-avx512cd"),
 m("mno-avx512dq"),
 m("mno-avx512er"),
 m("mno-avx512f"),
-flagpd1("mno-avx512fp16"),
+m("mno-avx512fp16"),
 m("mno-avx512ifma"),
 m("mno-avx512pf"),
 m("mno-avx512vbmi"),
@@ -4019,7 +4019,7 @@ flagpd1("mno-backchain"),
 m("mno-bmi"),
 m("mno-bmi2"),
 flagpd1("mno-branch-likely"),
-flagpd1("mno-bti-at-return-twice"),
+m("mno-bti-at-return-twice"),
 m("mno-bulk-memory"),
 flagpd1("mno-check-zero-division"),
 m("mno-cldemote"),
@@ -4032,7 +4032,7 @@ flagpd1("mno-constant-cfstrings"),
 flagpd1("mno-constructor-aliases"),
 m("mno-crbits"),
 m("mno-crc"),
-flagpd1("mno-crc32"),
+m("mno-crc32"),
 m("mno-cumode"),
 m("mno-cx16"),
 m("mno-dsp"),
@@ -4044,8 +4044,8 @@ flagpd1("mnoexecstack"),
 m("mno-execute-only"),
 flagpd1("mno-extern-sdata"),
 m("mno-f16c"),
-flagpd1("mno-fix-cmse-cve-2021-35465"),
-flagpd1("mno-fix-cortex-a53-835769"),
+m("mno-fix-cmse-cve-2021-35465"),
+m("mno-fix-cortex-a53-835769"),
 m("mno-float128"),
 m("mno-fma"),
 m("mno-fma4"),
@@ -4058,8 +4058,8 @@ m("mno-ginv"),
 flagpd1("mno-global-merge"),
 flagpd1("mno-gpopt"),
 m("mno-hvx"),
-flagpd1("mno-hvx-ieee-fp"),
-flagpd1("mno-hvx-qfloat"),
+m("mno-hvx-ieee-fp"),
+m("mno-hvx-qfloat"),
 m("mno-hreset"),
 m("mno-htm"),
 flagpd1("mno-iamcu"),
@@ -4137,7 +4137,7 @@ m("mno-reference-types"),
 m("mno-relax"),
 flagpd1("mno-relax-all"),
 flagpd1("mno-relax-pic-calls"),
-flagpd1("mno-relaxed-simd"),
+m("mno-relaxed-simd"),
 flagpd1("mno-restrict-it"),
 m("mno-retpoline"),
 m("mno-retpoline-external-thunk"),
@@ -4259,7 +4259,7 @@ flagpd1("mrelax-pic-calls"),
     .pd2 = true,
     .psl = false,
 },
-flagpd1("mrelaxed-simd"),
+m("mrelaxed-simd"),
 sepd1("mrelocation-model"),
 flagpd1("mrestrict-it"),
 m("mretpoline"),
@@ -4323,7 +4323,7 @@ m("mv66"),
 m("mv67"),
 flagpd1("mv67t"),
 m("mv68"),
-flagpd1("mv69"),
+m("mv69"),
 m("mvaes"),
 m("mvirt"),
 m("mvpclmulqdq"),
@@ -5087,7 +5087,7 @@ joinpd1("msign-return-address-key="),
 .{
     .name = "compress-debug-sections=",
     .syntax = .joined,
-    .zig_equivalent = .other,
+    .zig_equivalent = .compress_debug_sections,
     .pd1 = true,
     .pd2 = true,
     .psl = false,

src/link.zig

@@ -123,7 +123,7 @@ pub const Options = struct {
     nxcompat: bool,
     dynamicbase: bool,
     linker_optimization: u8,
-    compress_debug_sections: ?CompressDebugSections,
+    compress_debug_sections: CompressDebugSections,
     bind_global_refs_locally: bool,
     import_memory: bool,
     import_table: bool,

src/link/Elf.zig

@@ -1351,7 +1351,7 @@ fn linkWithLLD(self: *Elf, comp: *Compilation, prog_node: *std.Progress.Node) !v
         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.addOptional(self.base.options.compress_debug_sections);
+        man.hash.add(self.base.options.compress_debug_sections);
         man.hash.add(self.base.options.tsan);
         man.hash.addOptionalBytes(self.base.options.sysroot);
         man.hash.add(self.base.options.linker_optimization);
@@ -1755,9 +1755,9 @@ fn linkWithLLD(self: *Elf, comp: *Compilation, prog_node: *std.Progress.Node) !v
             try argv.append("--allow-shlib-undefined");
         }
 
-        if (self.base.options.compress_debug_sections) |how| {
-            const arg = try std.fmt.allocPrint(arena, "--compress-debug-sections={s}", .{@tagName(how)});
-            try argv.append(arg);
+        switch (self.base.options.compress_debug_sections) {
+            .none => {},
+            .zlib => try argv.append("--compress-debug-sections=zlib"),
         }
 
         if (self.base.options.bind_global_refs_locally) {

src/main.zig

@@ -443,8 +443,9 @@ const usage_build_generic =
     \\  -dynamic                       Force output to be dynamically linked
     \\  -static                        Force output to be statically linked
     \\  -Bsymbolic                     Bind global references locally
-    \\  --compress-debug-sections=     Compress DWARF debug sections
-    \\      none|zlib
+    \\  --compress-debug-sections=[e]  Debug section compression settings
+    \\      none                       No compression
+    \\      zlib                       Compression with deflate/inflate
     \\  --subsystem [subsystem]        (Windows) /SUBSYSTEM:<subsystem> to the linker
     \\  --stack [size]                 Override default stack size
     \\  --image-base [addr]            Set base address for executable image
@@ -946,6 +947,8 @@ fn buildOutputType(
                         linker_compress_debug_sections = std.meta.stringToEnum(link.CompressDebugSections, param) orelse {
                             fatal("expected --compress-debug-sections=[none|zlib], found '{s}'", .{param});
                         };
+                    } else if (mem.eql(u8, arg, "--compress-debug-sections")) {
+                        linker_compress_debug_sections = link.CompressDebugSections.zlib;
                     } else if (mem.eql(u8, arg, "-pagezero_size")) {
                         const next_arg = args_iter.next() orelse {
                             fatal("expected parameter after {s}", .{arg});
@@ -1648,6 +1651,15 @@ fn buildOutputType(
                     .weak_library => try system_libs.put(it.only_arg, .{ .weak = true }),
                     .weak_framework => try frameworks.put(gpa, it.only_arg, .{ .weak = true }),
                     .headerpad_max_install_names => headerpad_max_install_names = true,
+                    .compress_debug_sections => {
+                        if (it.only_arg.len == 0) {
+                            linker_compress_debug_sections = .zlib;
+                        } else {
+                            linker_compress_debug_sections = std.meta.stringToEnum(link.CompressDebugSections, it.only_arg) orelse {
+                                fatal("expected [none|zlib] after --compress-debug-sections, found '{s}'", .{it.only_arg});
+                            };
+                        }
+                    },
                 }
             }
             // Parse linker args.
@@ -4617,6 +4629,7 @@ pub const ClangArgIterator = struct {
         weak_library,
         weak_framework,
         headerpad_max_install_names,
+        compress_debug_sections,
     };
 
     const Args = struct {

tools/update_clang_options.zig

@@ -460,6 +460,14 @@ const known_options = [_]KnownOpt{
         .name = "headerpad_max_install_names",
         .ident = "headerpad_max_install_names",
     },
+    .{
+        .name = "compress-debug-sections",
+        .ident = "compress_debug_sections",
+    },
+    .{
+        .name = "compress-debug-sections=",
+        .ident = "compress_debug_sections",
+    },
 };
 
 const blacklisted_options = [_][]const u8{};