comp: add support for -fdata-sections

lib/std/Build/Step/Compile.zig

@@ -123,6 +123,10 @@ link_emit_relocs: bool = false,
 /// safely garbage-collected during the linking phase.
 link_function_sections: bool = false,
 
+/// Place every data in its own section so that unused ones may be
+/// safely garbage-collected during the linking phase.
+link_data_sections: bool = false,
+
 /// Remove functions and data that are unreachable by the entry point or
 /// exported symbols.
 link_gc_sections: ?bool = null,
@@ -1647,6 +1651,9 @@ fn make(step: *Step, prog_node: *std.Progress.Node) !void {
     if (self.link_function_sections) {
         try zig_args.append("-ffunction-sections");
     }
+    if (self.link_data_sections) {
+        try zig_args.append("-fdata-sections");
+    }
     if (self.link_gc_sections) |x| {
         try zig_args.append(if (x) "--gc-sections" else "--no-gc-sections");
     }

src/Compilation.zig

@@ -623,6 +623,7 @@ pub const InitOptions = struct {
     formatted_panics: ?bool = null,
     rdynamic: bool = false,
     function_sections: bool = false,
+    data_sections: bool = false,
     no_builtin: bool = false,
     is_native_os: bool,
     is_native_abi: bool,
@@ -1193,6 +1194,7 @@ pub fn create(gpa: Allocator, options: InitOptions) !*Compilation {
         cache.hash.add(omit_frame_pointer);
         cache.hash.add(link_mode);
         cache.hash.add(options.function_sections);
+        cache.hash.add(options.data_sections);
         cache.hash.add(options.no_builtin);
         cache.hash.add(strip);
         cache.hash.add(link_libc);
@@ -1572,6 +1574,7 @@ pub fn create(gpa: Allocator, options: InitOptions) !*Compilation {
             .is_native_os = options.is_native_os,
             .is_native_abi = options.is_native_abi,
             .function_sections = options.function_sections,
+            .data_sections = options.data_sections,
             .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,
@@ -4903,6 +4906,10 @@ pub fn addCCArgs(
         try argv.append("-ffunction-sections");
     }
 
+    if (comp.bin_file.options.data_sections) {
+        try argv.append("-fdata-sections");
+    }
+
     if (comp.bin_file.options.no_builtin) {
         try argv.append("-fno-builtin");
     }
@@ -6405,6 +6412,7 @@ fn buildOutputFromZig(
         .optimize_mode = comp.compilerRtOptMode(),
         .link_mode = .Static,
         .function_sections = true,
+        .data_sections = true,
         .no_builtin = true,
         .want_sanitize_c = false,
         .want_stack_check = false,

src/clang_options_data.zig

@@ -2282,6 +2282,22 @@ flagpd1("fopenmp-is-device"),
     .pd2 = false,
     .psl = true,
 },
+.{
+    .name = "Qgather-",
+    .syntax = .flag,
+    .zig_equivalent = .other,
+    .pd1 = true,
+    .pd2 = false,
+    .psl = true,
+},
+.{
+    .name = "Qscatter-",
+    .syntax = .flag,
+    .zig_equivalent = .other,
+    .pd1 = true,
+    .pd2 = false,
+    .psl = true,
+},
 sepd1("Xmicrosoft-visualc-tools-root"),
 sepd1("Xmicrosoft-visualc-tools-version"),
 sepd1("Xmicrosoft-windows-sdk-root"),
@@ -2727,7 +2743,14 @@ flagpd1("fcxx-modules"),
 flagpd1("fc++-static-destructors"),
 flagpd1("fd-lines-as-code"),
 flagpd1("fd-lines-as-comments"),
-flagpd1("fdata-sections"),
+.{
+    .name = "fdata-sections",
+    .syntax = .flag,
+    .zig_equivalent = .data_sections,
+    .pd1 = true,
+    .pd2 = false,
+    .psl = false,
+},
 sepd1("fdebug-compilation-dir"),
 flagpd1("fdebug-dump-all"),
 flagpd1("fdebug-dump-parse-tree"),
@@ -3130,7 +3153,14 @@ flagpd1("fno-cxx-modules"),
 flagpd1("fno-c++-static-destructors"),
 flagpd1("fno-d-lines-as-code"),
 flagpd1("fno-d-lines-as-comments"),
-flagpd1("fno-data-sections"),
+.{
+    .name = "fno-data-sections",
+    .syntax = .flag,
+    .zig_equivalent = .no_data_sections,
+    .pd1 = true,
+    .pd2 = false,
+    .psl = false,
+},
 flagpd1("fno-debug-info-for-profiling"),
 flagpd1("fno-debug-macro"),
 flagpd1("fno-debug-pass-manager"),
@@ -4080,7 +4110,7 @@ flagpd1("malign-double"),
 m("maltivec"),
 flagpd1("mamdgpu-ieee"),
 m("mamx-bf16"),
-flagpd1("mamx-complex"),
+m("mamx-complex"),
 m("mamx-fp16"),
 m("mamx-int8"),
 m("mamx-tile"),
@@ -4109,7 +4139,7 @@ m("mavx512vpopcntdq"),
 m("mavxifma"),
 m("mavxneconvert"),
 m("mavxvnni"),
-flagpd1("mavxvnniint16"),
+m("mavxvnniint16"),
 m("mavxvnniint8"),
 flagpd1("mbackchain"),
 flagpd1("mbig-endian"),
@@ -4264,7 +4294,7 @@ m("mno-aes"),
 m("mno-altivec"),
 flagpd1("mno-amdgpu-ieee"),
 m("mno-amx-bf16"),
-flagpd1("mno-amx-complex"),
+m("mno-amx-complex"),
 m("mno-amx-fp16"),
 m("mno-amx-int8"),
 m("mno-amx-tile"),
@@ -4290,7 +4320,7 @@ m("mno-avx512vpopcntdq"),
 m("mno-avxifma"),
 m("mno-avxneconvert"),
 m("mno-avxvnni"),
-flagpd1("mno-avxvnniint16"),
+m("mno-avxvnniint16"),
 m("mno-avxvnniint8"),
 flagpd1("mno-backchain"),
 m("mno-bmi"),
@@ -4336,6 +4366,7 @@ m("mno-fpu"),
 m("mno-fsgsbase"),
 m("mno-fsmuld"),
 m("mno-fxsr"),
+flagpd1("mno-gather"),
 m("mno-gfni"),
 m("mno-ginv"),
 flagpd1("mno-global-merge"),
@@ -4433,16 +4464,17 @@ flagpd1("mno-rtd"),
 m("mno-rtm"),
 m("mno-sahf"),
 m("mno-save-restore"),
+flagpd1("mno-scatter"),
 m("mno-serialize"),
 m("mno-seses"),
 m("mno-sgx"),
 m("mno-sha"),
-flagpd1("mno-sha512"),
+m("mno-sha512"),
 m("mno-shstk"),
 m("mno-sign-ext"),
 m("mno-simd128"),
 flagpd1("mno-skip-rax-setup"),
-flagpd1("mno-sm3"),
+m("mno-sm3"),
 m("mno-sm4"),
 m("mno-soft-float"),
 m("mno-spe"),
@@ -4568,14 +4600,14 @@ m("msecure-plt"),
 m("mserialize"),
 m("msgx"),
 m("msha"),
-flagpd1("msha512"),
+m("msha512"),
 m("mshstk"),
 m("msign-ext"),
 flagpd1("msim"),
 m("msimd128"),
 m("msingle-float"),
 flagpd1("mskip-rax-setup"),
-flagpd1("msm3"),
+m("msm3"),
 m("msm4"),
 sepd1("msmall-data-limit"),
 m("msoft-float"),

src/codegen/llvm.zig

@@ -955,6 +955,7 @@ pub const Object = struct {
                 reloc_mode,
                 code_model,
                 options.function_sections,
+                options.data_sections,
                 float_abi,
                 if (target_util.llvmMachineAbi(options.target)) |s| s.ptr else null,
             );

src/codegen/llvm/bindings.zig

@@ -919,6 +919,7 @@ pub const TargetMachine = opaque {
         Reloc: RelocMode,
         CodeModel: CodeModel,
         function_sections: bool,
+        data_sections: bool,
         float_abi: ABIType,
         abi_name: ?[*:0]const u8,
     ) *TargetMachine;

src/link.zig

@@ -139,6 +139,7 @@ pub const Options = struct {
     link_libunwind: bool,
     darwin_sdk_layout: ?DarwinSdkLayout,
     function_sections: bool,
+    data_sections: bool,
     no_builtin: bool,
     eh_frame_hdr: bool,
     emit_relocs: bool,

src/main.zig

@@ -453,6 +453,8 @@ const usage_build_generic =
     \\  -fno-builtin              Disable implicit builtin knowledge of functions
     \\  -ffunction-sections       Places each function in a separate section
     \\  -fno-function-sections    All functions go into same section
+    \\  -fdata-sections           Places each data in a separate section
+    \\  -fno-data-sections        All data go into same section
     \\  -fstrip                   Omit debug symbols
     \\  -fno-strip                Keep debug symbols
     \\  -fformatted-panics        Enable formatted safety panics
@@ -793,6 +795,7 @@ fn buildOutputType(
     var strip: ?bool = null;
     var formatted_panics: ?bool = null;
     var function_sections = false;
+    var data_sections = false;
     var no_builtin = false;
     var listen: Listen = .none;
     var debug_compile_errors = false;
@@ -1459,6 +1462,10 @@ fn buildOutputType(
                         function_sections = true;
                     } else if (mem.eql(u8, arg, "-fno-function-sections")) {
                         function_sections = false;
+                    } else if (mem.eql(u8, arg, "-fdata-sections")) {
+                        data_sections = true;
+                    } else if (mem.eql(u8, arg, "-fno-data-sections")) {
+                        data_sections = false;
                     } else if (mem.eql(u8, arg, "-fbuiltin")) {
                         no_builtin = false;
                     } else if (mem.eql(u8, arg, "-fno-builtin")) {
@@ -1780,6 +1787,8 @@ fn buildOutputType(
                     .no_omit_frame_pointer => omit_frame_pointer = false,
                     .function_sections => function_sections = true,
                     .no_function_sections => function_sections = false,
+                    .data_sections => data_sections = true,
+                    .no_data_sections => data_sections = false,
                     .builtin => no_builtin = false,
                     .no_builtin => no_builtin = true,
                     .color_diagnostics => color = .on,
@@ -3475,6 +3484,7 @@ fn buildOutputType(
         .formatted_panics = formatted_panics,
         .single_threaded = single_threaded,
         .function_sections = function_sections,
+        .data_sections = data_sections,
         .no_builtin = no_builtin,
         .self_exe_path = self_exe_path,
         .thread_pool = &thread_pool,
@@ -5589,6 +5599,8 @@ pub const ClangArgIterator = struct {
         no_omit_frame_pointer,
         function_sections,
         no_function_sections,
+        data_sections,
+        no_data_sections,
         builtin,
         no_builtin,
         color_diagnostics,

src/zig_llvm.cpp

@@ -82,7 +82,8 @@ static const bool assertions_on = false;
 
 LLVMTargetMachineRef ZigLLVMCreateTargetMachine(LLVMTargetRef T, const char *Triple,
     const char *CPU, const char *Features, LLVMCodeGenOptLevel Level, LLVMRelocMode Reloc,
-    LLVMCodeModel CodeModel, bool function_sections, ZigLLVMABIType float_abi, const char *abi_name)
+    LLVMCodeModel CodeModel, bool function_sections, bool data_sections, ZigLLVMABIType float_abi, 
+    const char *abi_name)
 {
     std::optional<Reloc::Model> RM;
     switch (Reloc){
@@ -130,6 +131,7 @@ LLVMTargetMachineRef ZigLLVMCreateTargetMachine(LLVMTargetRef T, const char *Tri
     TargetOptions opt;
 
     opt.FunctionSections = function_sections;
+    opt.DataSections = data_sections;
     switch (float_abi) {
         case ZigLLVMABITypeDefault:
             opt.FloatABIType = FloatABI::Default;

src/zig_llvm.h

@@ -57,7 +57,8 @@ enum ZigLLVMABIType {
 
 ZIG_EXTERN_C LLVMTargetMachineRef ZigLLVMCreateTargetMachine(LLVMTargetRef T, const char *Triple,
     const char *CPU, const char *Features, LLVMCodeGenOptLevel Level, LLVMRelocMode Reloc,
-    LLVMCodeModel CodeModel, bool function_sections, enum ZigLLVMABIType float_abi, const char *abi_name);
+    LLVMCodeModel CodeModel, bool function_sections, bool data_sections, enum ZigLLVMABIType float_abi, 
+    const char *abi_name);
 
 ZIG_EXTERN_C void ZigLLVMSetOptBisectLimit(LLVMContextRef context_ref, int limit);
 

tools/update_clang_options.zig

@@ -332,6 +332,14 @@ const known_options = [_]KnownOpt{
         .name = "fno-function-sections",
         .ident = "no_function_sections",
     },
+    .{
+        .name = "fdata-sections",
+        .ident = "data_sections",
+    },
+    .{
+        .name = "fno-data-sections",
+        .ident = "no_data_sections",
+    },
     .{
         .name = "fbuiltin",
         .ident = "builtin",