Added function-section functionality

src-self-hosted/llvm.zig

@@ -283,6 +283,7 @@ extern fn ZigLLVMTargetMachineEmitToFile(
     error_message: *[*]u8,
     is_debug: bool,
     is_small: bool,
+    function_sections: bool,
 ) bool;
 
 pub const BuildCall = ZigLLVMBuildCall;

src/all_types.hpp

@@ -1908,6 +1908,7 @@ struct CodeGen {
     bool have_pic;
     bool have_dynamic_link; // this is whether the final thing will be dynamically linked. see also is_dynamic
     bool have_stack_probing;
+    bool function_sections;
 
     Buf *mmacosx_version_min;
     Buf *mios_version_min;

src/codegen.cpp

@@ -7042,7 +7042,7 @@ static void zig_llvm_emit_output(CodeGen *g) {
         case EmitFileTypeBinary:
             if (ZigLLVMTargetMachineEmitToFile(g->target_machine, g->module, buf_ptr(output_path),
                         ZigLLVM_EmitBinary, &err_msg, g->build_mode == BuildModeDebug, is_small,
-                        g->enable_time_report))
+                        g->enable_time_report, g->function_sections))
             {
                 zig_panic("unable to write object file %s: %s", buf_ptr(output_path), err_msg);
             }
@@ -7058,7 +7058,7 @@ static void zig_llvm_emit_output(CodeGen *g) {
         case EmitFileTypeAssembly:
             if (ZigLLVMTargetMachineEmitToFile(g->target_machine, g->module, buf_ptr(output_path),
                         ZigLLVM_EmitAssembly, &err_msg, g->build_mode == BuildModeDebug, is_small,
-                        g->enable_time_report))
+                        g->enable_time_report, g->function_sections))
             {
                 zig_panic("unable to write assembly file %s: %s", buf_ptr(output_path), err_msg);
             }
@@ -7068,7 +7068,7 @@ static void zig_llvm_emit_output(CodeGen *g) {
         case EmitFileTypeLLVMIr:
             if (ZigLLVMTargetMachineEmitToFile(g->target_machine, g->module, buf_ptr(output_path),
                         ZigLLVM_EmitLLVMIr, &err_msg, g->build_mode == BuildModeDebug, is_small,
-                        g->enable_time_report))
+                        g->enable_time_report, g->function_sections))
             {
                 zig_panic("unable to write llvm-ir file %s: %s", buf_ptr(output_path), err_msg);
             }
@@ -8735,6 +8735,7 @@ Error create_c_object_cache(CodeGen *g, CacheHash **out_cache_hash, bool verbose
     for (size_t arg_i = 0; arg_i < g->clang_argv_len; arg_i += 1) {
         cache_str(cache_hash, g->clang_argv[arg_i]);
     }
+    cache_bool(cache_hash, g->function_sections);
 
     *out_cache_hash = cache_hash;
     return ErrorNone;

src/link.cpp

@@ -791,6 +791,8 @@ static Buf *build_a_raw(CodeGen *parent_gen, const char *aname, Buf *full_path,
         new_link_lib->provided_explicitly = parent_gen->libc_link_lib->provided_explicitly;
     }
 
+    child_gen->function_sections = true;
+
     codegen_build_and_link(child_gen);
     return &child_gen->output_file_path;
 }

src/main.cpp

@@ -85,6 +85,7 @@ static int print_full_usage(const char *arg0, FILE *file, int return_code) {
         "  -isystem [dir]               add additional search path for other .h files\n"
         "  -mllvm [arg]                 forward an arg to LLVM's option processing\n"
         "  --override-std-dir [arg]     use an alternate Zig standard library\n"
+        "  -ffunction-sections          places each function in a seperate section\n"
         "\n"
         "Link Options:\n"
         "  --bundle-compiler-rt [path]  for static libraries, include compiler-rt symbols\n"
@@ -450,6 +451,7 @@ int main(int argc, char **argv) {
     ValgrindSupport valgrind_support = ValgrindSupportAuto;
     WantPIC want_pic = WantPICAuto;
     WantStackCheck want_stack_check = WantStackCheckAuto;
+    bool function_sections = false;
 
     ZigList<const char *> llvm_argv = {0};
     llvm_argv.append("zig (LLVM option parsing)");
@@ -688,6 +690,8 @@ int main(int argc, char **argv) {
                     return EXIT_FAILURE;
                 }
                 cur_pkg = cur_pkg->parent;
+            } else if (strcmp(arg, "-ffunction-sections") == 0) {
+                function_sections = true;
             } else if (i + 1 >= argc) {
                 fprintf(stderr, "Expected another argument after %s\n", arg);
                 return print_error_usage(arg0);
@@ -1101,6 +1105,7 @@ int main(int argc, char **argv) {
             g->bundle_compiler_rt = bundle_compiler_rt;
             codegen_set_errmsg_color(g, color);
             g->system_linker_hack = system_linker_hack;
+            g->function_sections = function_sections;
 
             for (size_t i = 0; i < lib_dirs.length; i += 1) {
                 codegen_add_lib_dir(g, lib_dirs.at(i));

src/zig_llvm.cpp

@@ -95,7 +95,7 @@ static const bool assertions_on = false;
 
 bool ZigLLVMTargetMachineEmitToFile(LLVMTargetMachineRef targ_machine_ref, LLVMModuleRef module_ref,
         const char *filename, ZigLLVM_EmitOutputType output_type, char **error_message, bool is_debug,
-        bool is_small, bool time_report)
+        bool is_small, bool time_report, bool function_sections)
 {
     TimePassesIsEnabled = time_report;
 
@@ -108,6 +108,8 @@ bool ZigLLVMTargetMachineEmitToFile(LLVMTargetMachineRef targ_machine_ref, LLVMM
     TargetMachine* target_machine = reinterpret_cast<TargetMachine*>(targ_machine_ref);
     target_machine->setO0WantsFastISel(true);
 
+    target_machine->Options.FunctionSections = function_sections;
+
     Module* module = unwrap(module_ref);
 
     PassManagerBuilder *PMBuilder = new(std::nothrow) PassManagerBuilder();

src/zig_llvm.h

@@ -56,7 +56,7 @@ enum ZigLLVM_EmitOutputType {
 
 ZIG_EXTERN_C bool ZigLLVMTargetMachineEmitToFile(LLVMTargetMachineRef targ_machine_ref, LLVMModuleRef module_ref,
         const char *filename, enum ZigLLVM_EmitOutputType output_type, char **error_message, bool is_debug,
-        bool is_small, bool time_report);
+        bool is_small, bool time_report, bool function_sections);
 
 ZIG_EXTERN_C LLVMTypeRef ZigLLVMTokenTypeInContext(LLVMContextRef context_ref);