Altered SUBSYSTEM option handling when linking in msvc mode; Added preliminary UEFI support.

CMakeLists.txt

@@ -590,6 +590,7 @@ set(ZIG_STD_FILES
     "os/freebsd/x86_64.zig"
     "os/path.zig"
     "os/time.zig"
+    "os/uefi/index.zig"
     "os/windows/advapi32.zig"
     "os/windows/error.zig"
     "os/windows/index.zig"

src-self-hosted/target.zig

@@ -520,7 +520,7 @@ pub const Target = union(enum) {
                 => return 64,
             },
 
-            builtin.Os.windows => switch (id) {
+            builtin.Os.windows, builtin.Os.uefi => switch (id) {
                 CInt.Id.Short,
                 CInt.Id.UShort,
                 => return 16,

src/all_types.hpp

@@ -1754,8 +1754,7 @@ struct CodeGen {
     bool strip_debug_symbols;
     bool is_test_build;
     bool is_native_target;
-    bool windows_subsystem_windows;
+    ZigLLVM_MSVCSubsystemType msvc_subsystem;
-    bool windows_subsystem_console;
     bool linker_rdynamic;
     bool no_rosegment_workaround;
     bool each_lib_rpath;

src/analyze.cpp

@@ -3203,24 +3203,25 @@ void add_fn_export(CodeGen *g, ZigFn *fn_table_entry, Buf *symbol_name, GlobalLi
     if (ccc) {
         if (buf_eql_str(symbol_name, "main") && g->libc_link_lib != nullptr) {
             g->have_c_main = true;
-            g->windows_subsystem_windows = false;
+            g->msvc_subsystem = ZigLLVM_MSVC_CONSOLE;
-            g->windows_subsystem_console = true;
         } else if (buf_eql_str(symbol_name, "WinMain") &&
             g->zig_target.os == OsWindows)
         {
             g->have_winmain = true;
-            g->windows_subsystem_windows = true;
+            g->msvc_subsystem = ZigLLVM_MSVC_WINDOWS;
-            g->windows_subsystem_console = false;
         } else if (buf_eql_str(symbol_name, "WinMainCRTStartup") &&
             g->zig_target.os == OsWindows)
         {
             g->have_winmain_crt_startup = true;
+            g->msvc_subsystem = ZigLLVM_MSVC_WINDOWS;
         } else if (buf_eql_str(symbol_name, "DllMainCRTStartup") &&
             g->zig_target.os == OsWindows)
         {
             g->have_dllmain_crt_startup = true;
+            g->msvc_subsystem = ZigLLVM_MSVC_WINDOWS;
         }
     }
+
     FnExport *fn_export = fn_table_entry->export_list.add_one();
     memset(fn_export, 0, sizeof(FnExport));
     buf_init_from_buf(&fn_export->name, symbol_name);
@@ -4376,8 +4377,7 @@ ImportTableEntry *add_source_file(CodeGen *g, PackageTableEntry *package, Buf *r
             if (is_pub && ok_cc) {
                 if (buf_eql_str(proto_name, "main")) {
                     g->have_pub_main = true;
-                    g->windows_subsystem_windows = false;
+                    g->msvc_subsystem = ZigLLVM_MSVC_CONSOLE;
-                    g->windows_subsystem_console = true;
                 } else if (buf_eql_str(proto_name, "panic")) {
                     g->have_pub_panic = true;
                 }

src/codegen.cpp

@@ -291,11 +291,6 @@ void codegen_add_framework(CodeGen *g, const char *framework) {
     g->darwin_frameworks.append(buf_create_from_str(framework));
 }
 
-void codegen_set_windows_subsystem(CodeGen *g, bool mwindows, bool mconsole) {
-    g->windows_subsystem_windows = mwindows;
-    g->windows_subsystem_console = mconsole;
-}
-
 void codegen_set_mmacosx_version_min(CodeGen *g, Buf *mmacosx_version_min) {
     g->mmacosx_version_min = mmacosx_version_min;
 }
@@ -7273,7 +7268,7 @@ static void init(CodeGen *g) {
         // LLVM creates invalid binaries on Windows sometimes.
         // See https://github.com/ziglang/zig/issues/508
         // As a workaround we do not use target native features on Windows.
-        if (g->zig_target.os == OsWindows) {
+        if (g->zig_target.os == OsWindows || g->zig_target.os == OsUefi) {
             target_specific_cpu_args = "";
             target_specific_features = "";
         } else {
@@ -7519,6 +7514,7 @@ static void gen_root_source(CodeGen *g) {
     report_errors_and_maybe_exit(g);
 
     if (!g->is_test_build && g->zig_target.os != OsFreestanding &&
+        g->zig_target.os != OsZen && g->zig_target.os != OsUefi &&
         !g->have_c_main && !g->have_winmain && !g->have_winmain_crt_startup &&
         ((g->have_pub_main && g->out_type == OutTypeObj) || g->out_type == OutTypeExe))
     {
@@ -8079,8 +8075,7 @@ static Error check_cache(CodeGen *g, Buf *manifest_dir, Buf *digest) {
     cache_bool(ch, g->strip_debug_symbols);
     cache_bool(ch, g->is_test_build);
     cache_bool(ch, g->is_native_target);
-    cache_bool(ch, g->windows_subsystem_windows);
+    cache_int(ch, g->msvc_subsystem);
-    cache_bool(ch, g->windows_subsystem_console);
     cache_bool(ch, g->linker_rdynamic);
     cache_bool(ch, g->no_rosegment_workaround);
     cache_bool(ch, g->each_lib_rpath);

src/codegen.hpp

@@ -33,7 +33,6 @@ void codegen_set_libc_include_dir(CodeGen *codegen, Buf *libc_include_dir);
 void codegen_set_msvc_lib_dir(CodeGen *g, Buf *msvc_lib_dir);
 void codegen_set_kernel32_lib_dir(CodeGen *codegen, Buf *kernel32_lib_dir);
 void codegen_set_dynamic_linker(CodeGen *g, Buf *dynamic_linker);
-void codegen_set_windows_subsystem(CodeGen *g, bool mwindows, bool mconsole);
 void codegen_add_lib_dir(CodeGen *codegen, const char *dir);
 void codegen_add_forbidden_lib(CodeGen *codegen, Buf *lib);
 LinkLib *codegen_add_link_lib(CodeGen *codegen, Buf *lib);

src/ir.cpp

@@ -17872,7 +17872,13 @@ static IrInstruction *ir_analyze_instruction_c_import(IrAnalyze *ira, IrInstruct
     if (type_is_invalid(cimport_result->value.type))
         return ira->codegen->invalid_instruction;
 
+    if (ira->codegen->msvc_subsystem != ZigLLVM_MSVC_EFI_APPLICATION &&
+		ira->codegen->msvc_subsystem != ZigLLVM_MSVC_EFI_BOOT_SERVICE_DRIVER &&
+		ira->codegen->msvc_subsystem != ZigLLVM_MSVC_EFI_ROM &&
+		ira->codegen->msvc_subsystem != ZigLLVM_MSVC_EFI_RUNTIME_DRIVER) {
+
 		find_libc_include_path(ira->codegen);
+	}
 
     ImportTableEntry *child_import = allocate<ImportTableEntry>(1);
     child_import->decls_scope = create_decls_scope(ira->codegen, node, nullptr, nullptr, child_import);

src/link.cpp

@@ -455,7 +455,7 @@ static void construct_linker_job_coff(LinkJob *lj) {
 
     lj->args.append("-NOLOGO");
 
-    if (!g->strip_debug_symbols) {
+    if (!g->strip_debug_symbols && g->zig_target.os != Os::OsUefi) {
         lj->args.append("-DEBUG");
     }
 
@@ -466,11 +466,6 @@ static void construct_linker_job_coff(LinkJob *lj) {
 
     coff_append_machine_arg(g, &lj->args);
 
-    if (g->windows_subsystem_windows) {
-        lj->args.append("/SUBSYSTEM:windows");
-    } else if (g->windows_subsystem_console) {
-        lj->args.append("/SUBSYSTEM:console");
-    }
     // The commented out stuff is from when we linked with MinGW
     // Now that we're linking with LLD it remains to be determined
     // how to handle --target-environ gnu
@@ -499,18 +494,47 @@ static void construct_linker_job_coff(LinkJob *lj) {
     //    }
     //}
 
-    lj->args.append(buf_ptr(buf_sprintf("-OUT:%s", buf_ptr(&g->output_file_path))));
 
-    if (g->libc_link_lib != nullptr) {
+    // These are n actual command lines from LINK.EXE UEFI builds (app & driver) to be used as guidance cleaning
-        lj->args.append(buf_ptr(buf_sprintf("-LIBPATH:%s", buf_ptr(g->msvc_lib_dir))));
+    // up a bit for building the COFF linker args:
-        lj->args.append(buf_ptr(buf_sprintf("-LIBPATH:%s", buf_ptr(g->kernel32_lib_dir))));
+    // /OUT:"J:\coding\nebulae\k\x64\Release\k.efi" /LTCG:incremental /Driver /PDB:"J:\coding\nebulae\k\x64\Release\k.pdb" "UefiApplicationEntryPoint.lib" "UefiRuntimeLib.lib" "UefiHiiLib.lib" "UefiHiiServicesLib.lib" "UefiSortLib.lib" "UefiShellLib.lib" "GlueLib.lib" "BaseLib.lib" "BaseDebugPrintErrorLevelLib.lib" "BasePrintLib.lib" "UefiLib.lib" "UefiBootServicesTableLib.lib" "UefiRuntimeServicesTableLib.lib" "UefiDevicePathLibDevicePathProtocol.lib" "UefiDebugLibConOut.lib" "UefiMemoryLib.lib" "UefiMemoryAllocationLib.lib" "BaseSynchronizationLib.lib" "UefiFileHandleLib.lib" /IMPLIB:"J:\coding\nebulae\k\x64\Release\k.lib" /DEBUG:FASTLINK /BASE:"0" /MACHINE:X64 /ENTRY:"EfiMain" /OPT:REF /SAFESEH:NO /SUBSYSTEM:EFI_APPLICATION /MERGE:".rdata=.data" /NOLOGO /ALIGN:32 /NODEFAULTLIB /SECTION:".xdata,D" 
+    // /OUT:"J:\coding\VisualUefi\samples\x64\Release\UefiDriver.efi" /LTCG:incremental /Driver /PDB:"J:\coding\VisualUefi\samples\x64\Release\UefiDriver.pdb" "UefiDriverEntryPoint.lib" "UefiHiiLib.lib" "UefiHiiServicesLib.lib" "UefiSortLib.lib" "UefiShellLib.lib" "GlueLib.lib" "BaseLib.lib" "BaseDebugPrintErrorLevelLib.lib" "BasePrintLib.lib" "UefiLib.lib" "UefiBootServicesTableLib.lib" "UefiRuntimeServicesTableLib.lib" "UefiDevicePathLibDevicePathProtocol.lib" "UefiDebugLibConOut.lib" "UefiMemoryLib.lib" "UefiMemoryAllocationLib.lib" "BaseSynchronizationLib.lib" "UefiFileHandleLib.lib" /IMPLIB:"J:\coding\VisualUefi\samples\x64\Release\UefiDriver.lib" /DEBUG:FASTLINK /BASE:"0" /MACHINE:X64 /ENTRY:"EfiMain" /OPT:REF /SAFESEH:NO /SUBSYSTEM:EFI_BOOT_SERVICE_DRIVER /MERGE:".rdata=.data" /NOLOGO /ALIGN:32 /NODEFAULTLIB /SECTION:".xdata,D" 
     
-        lj->args.append(buf_ptr(buf_sprintf("-LIBPATH:%s", buf_ptr(g->libc_lib_dir))));
+    // Sorry for the goto(s) :)
-        if (g->libc_static_lib_dir != nullptr) {
+    switch (g->msvc_subsystem) {
-            lj->args.append(buf_ptr(buf_sprintf("-LIBPATH:%s", buf_ptr(g->libc_static_lib_dir))));
+        case ZigLLVM_MSVC_CONSOLE:
-        }
+            lj->args.append("/SUBSYSTEM:console");
+            goto building_nt;
+        case ZigLLVM_MSVC_EFI_APPLICATION:
+            lj->args.append("/SUBSYSTEM:efi_application");
+            goto building_uefi;
+        case ZigLLVM_MSVC_EFI_BOOT_SERVICE_DRIVER:
+            lj->args.append("/SUBSYSTEM:efi_boot_service_driver");
+            goto building_uefi;
+        case ZigLLVM_MSVC_EFI_ROM:
+            lj->args.append("/SUBSYSTEM:efi_rom");
+            goto building_uefi;
+        case ZigLLVM_MSVC_EFI_RUNTIME_DRIVER:
+            lj->args.append("/SUBSYSTEM:efi_runtime_driver");
+            goto building_uefi;
+        case ZigLLVM_MSVC_NATIVE:
+            lj->args.append("/SUBSYSTEM:native");
+            goto building_nt;
+        case ZigLLVM_MSVC_POSIX:
+            lj->args.append("/SUBSYSTEM:posix");
+            goto building_nt;
+        case ZigLLVM_MSVC_WINDOWS:
+            lj->args.append("/SUBSYSTEM:windows");
+            goto building_nt;
+        case ZigLLVM_MSVC_NONE:
+            goto continuing_build;
     }
 
+building_uefi:
+    lj->args.append("/BASE:\"0\" /ENTRY:\"EfiMain\" /OPT:REF /SAFESEH:NO /MERGE:\".rdata=.data\" /ALIGN:32 /NODEFAULTLIB /SECTION:\".xdata,D\"");
+    goto continuing_build;
+
+building_nt:
     if (lj->link_in_crt) {
         const char *lib_str = g->is_static ? "lib" : "";
         const char *d_str = (g->build_mode == BuildModeDebug) ? "d" : "";
@@ -547,16 +571,30 @@ static void construct_linker_job_coff(LinkJob *lj) {
         // msvcrt depends on kernel32
         lj->args.append("kernel32.lib");
     } else {
-        lj->args.append("-NODEFAULTLIB");
+        lj->args.append("/NODEFAULTLIB");
         if (!is_library) {
             if (g->have_winmain) {
-                lj->args.append("-ENTRY:WinMain");
+                lj->args.append("/ENTRY:WinMain");
             } else {
-                lj->args.append("-ENTRY:WinMainCRTStartup");
+                lj->args.append("/ENTRY:WinMainCRTStartup");
             }
         }
     }
 
+continuing_build:
+
+    lj->args.append(buf_ptr(buf_sprintf("-OUT:%s", buf_ptr(&g->output_file_path))));
+
+    if (g->libc_link_lib != nullptr) {
+        lj->args.append(buf_ptr(buf_sprintf("-LIBPATH:%s", buf_ptr(g->msvc_lib_dir))));
+        lj->args.append(buf_ptr(buf_sprintf("-LIBPATH:%s", buf_ptr(g->kernel32_lib_dir))));
+
+        lj->args.append(buf_ptr(buf_sprintf("-LIBPATH:%s", buf_ptr(g->libc_lib_dir))));
+        if (g->libc_static_lib_dir != nullptr) {
+            lj->args.append(buf_ptr(buf_sprintf("-LIBPATH:%s", buf_ptr(g->libc_static_lib_dir))));
+        }
+    }
+
     if (is_library && !g->is_static) {
         lj->args.append("-DLL");
     }

src/main.cpp

@@ -90,9 +90,7 @@ static int print_full_usage(const char *arg0) {
         "  -rdynamic                    add all symbols to the dynamic symbol table\n"
         "  -rpath [path]                add directory to the runtime library search path\n"
         "  --no-rosegment               compromise security to workaround valgrind bug\n"
-        "  -mconsole                    (windows) --subsystem console to the linker\n"
+        "  --msvc-subsystem [subsystem] (windows/uefi) /SUBSYSTEM:<subsystem> to the linker\n"        "  -framework [name]            (darwin) link against framework\n"
-        "  -mwindows                    (windows) --subsystem windows to the linker\n"
-        "  -framework [name]            (darwin) link against framework\n"
         "  -mios-version-min [ver]      (darwin) set iOS deployment target\n"
         "  -mmacosx-version-min [ver]   (darwin) set Mac OS X deployment target\n"
         "  --ver-major [ver]            dynamic library semver major version\n"
@@ -395,6 +393,7 @@ int main(int argc, char **argv) {
     int runtime_args_start = -1;
     bool no_rosegment_workaround = false;
     bool system_linker_hack = false;
+    ZigLLVM_MSVCSubsystemType msvc_subsystem_type = ZigLLVM_MSVC_NONE;
 
     if (argc >= 2 && strcmp(argv[1], "build") == 0) {
         Buf zig_exe_path_buf = BUF_INIT;
@@ -540,6 +539,32 @@ int main(int argc, char **argv) {
                 verbose_llvm_ir = true;
             } else if (strcmp(arg, "--verbose-cimport") == 0) {
                 verbose_cimport = true;
+                       } else if (strcmp(arg, "--msvc-subsystem") == 0) {
+                if (i + 1 >= argc) {
+                    fprintf(stderr, "Expected 1 argument after --msvc-subsystem\n");
+                    return print_error_usage(arg0);
+                }
+                i += 1;
+                if (stricmp(argv[i], "CONSOLE") == 0) {
+                   msvc_subsystem_type = ZigLLVM_MSVC_CONSOLE;
+                } else if (stricmp(argv[i], "WINDOWS") == 0) {
+                    msvc_subsystem_type = ZigLLVM_MSVC_WINDOWS;
+                } else if (stricmp(argv[i], "POSIX") == 0) {
+                    msvc_subsystem_type = ZigLLVM_MSVC_POSIX;
+                } else if (stricmp(argv[i], "NATIVE") == 0) {
+                    msvc_subsystem_type = ZigLLVM_MSVC_NATIVE;
+                } else if (stricmp(argv[i], "EFI_APPLICATION") == 0) {
+                    msvc_subsystem_type = ZigLLVM_MSVC_EFI_APPLICATION;
+                } else if (stricmp(argv[i], "EFI_BOOT_SERVICE_DRIVER") == 0) {
+                    msvc_subsystem_type = ZigLLVM_MSVC_EFI_BOOT_SERVICE_DRIVER;
+                } else if (stricmp(argv[i], "EFI_ROM") == 0) {
+                    msvc_subsystem_type = ZigLLVM_MSVC_EFI_ROM;
+                } else if (stricmp(argv[i], "EFI_RUNTIME_DRIVER") == 0) {
+                    msvc_subsystem_type = ZigLLVM_MSVC_EFI_RUNTIME_DRIVER;
+                } else {
+                    fprintf(stderr, "Unknown format %s for --msvc-subsystem argument\n", argv[i]);
+                    return EXIT_FAILURE;
+                }
             } else if (strcmp(arg, "-mwindows") == 0) {
                 mwindows = true;
             } else if (strcmp(arg, "-mconsole") == 0) {
@@ -849,6 +874,8 @@ int main(int argc, char **argv) {
                 buf_out_name = buf_create_from_str("run");
             }
             CodeGen *g = codegen_create(zig_root_source_file, target, out_type, build_mode, get_zig_lib_dir());
+            g->msvc_subsystem = msvc_subsystem_type;
+
             if (disable_pic) {
                 if (out_type != OutTypeLib || !is_static) {
                     fprintf(stderr, "--disable-pic only applies to static libraries");
@@ -909,7 +936,6 @@ int main(int argc, char **argv) {
                 codegen_add_rpath(g, rpath_list.at(i));
             }
 
-            codegen_set_windows_subsystem(g, mwindows, mconsole);
             codegen_set_rdynamic(g, rdynamic);
             g->no_rosegment_workaround = no_rosegment_workaround;
             if (mmacosx_version_min && mios_version_min) {

src/target.cpp

@@ -174,6 +174,7 @@ static const Os os_list[] = {
     OsContiki,
     OsAMDPAL,
     OsZen,
+    OsUefi,
 };
 
 // Coordinate with zig_llvm.h
@@ -315,6 +316,8 @@ ZigLLVM_OSType get_llvm_os_type(Os os_type) {
             return ZigLLVM_Contiki;
         case OsAMDPAL:
             return ZigLLVM_AMDPAL;
+        case OsUefi:
+            return ZigLLVM_Uefi;
     }
     zig_unreachable();
 }
@@ -756,6 +759,7 @@ uint32_t target_c_type_size_in_bits(const ZigTarget *target, CIntType id) {
                 case CIntTypeCount:
                     zig_unreachable();
             }
+        case OsUefi:
         case OsWindows:
             switch (id) {
                 case CIntTypeShort:
@@ -803,7 +807,7 @@ uint32_t target_c_type_size_in_bits(const ZigTarget *target, CIntType id) {
 }
 
 const char *target_o_file_ext(ZigTarget *target) {
-    if (target->env_type == ZigLLVM_MSVC || target->os == OsWindows) {
+    if (target->env_type == ZigLLVM_MSVC || (target->os == OsWindows || target->os == OsUefi)) {
         return ".obj";
     } else {
         return ".o";
@@ -821,13 +825,15 @@ const char *target_llvm_ir_file_ext(ZigTarget *target) {
 const char *target_exe_file_ext(ZigTarget *target) {
     if (target->os == OsWindows) {
         return ".exe";
+    } else if (target->os == OsUefi) {
+        return ".efi";
     } else {
         return "";
     }
 }
 
 const char *target_lib_file_ext(ZigTarget *target, bool is_static, size_t version_major, size_t version_minor, size_t version_patch) {
-    if (target->os == OsWindows) {
+    if (target->os == OsWindows || target->os == OsUefi) {
         if (is_static) {
             return ".lib";
         } else {

src/target.hpp

@@ -51,6 +51,7 @@ enum Os {
     OsContiki,
     OsAMDPAL,
     OsZen,
+    OsUefi,
 };
 
 struct ZigTarget {
@@ -59,6 +60,7 @@ struct ZigTarget {
     Os os;
     ZigLLVM_EnvironmentType env_type;
     ZigLLVM_ObjectFormatType oformat;
+    ZigLLVM_MSVCSubsystemType msvc_subsystem = ZigLLVM_MSVC_NONE;
 };
 
 enum CIntType {

src/translate_c.cpp

@@ -4749,8 +4749,10 @@ Error parse_h_file(ImportTableEntry *import, ZigList<ErrorMsg *> *errors, const
     clang_argv.append("-isystem");
     clang_argv.append(buf_ptr(codegen->zig_c_headers_dir));
 
+    if (codegen->libc_include_dir) {
         clang_argv.append("-isystem");
         clang_argv.append(buf_ptr(codegen->libc_include_dir));
+    }
 
     // windows c runtime requires -D_DEBUG if using debug libraries
     if (codegen->build_mode == BuildModeDebug) {

src/zig_llvm.cpp

@@ -690,8 +690,15 @@ const char *ZigLLVMGetVendorTypeName(ZigLLVM_VendorType vendor) {
 }
 
 const char *ZigLLVMGetOSTypeName(ZigLLVM_OSType os) {
+    switch (os) {
+	case ZigLLVM_Zen:
+		return "unknown";
+	case ZigLLVM_Uefi:
+		return "windows";
+	default:
 		return (const char*)Triple::getOSTypeName((Triple::OSType)os).bytes_begin();
 	}
+}
 
 const char *ZigLLVMGetEnvironmentTypeName(ZigLLVM_EnvironmentType env_type) {
     return (const char*)Triple::getEnvironmentTypeName((Triple::EnvironmentType)env_type).bytes_begin();

src/zig_llvm.h

@@ -10,6 +10,7 @@
 
 #include <stdbool.h>
 #include <stddef.h>
+#include <stdint.h>
 #include <llvm-c/Core.h>
 #include <llvm-c/Analysis.h>
 #include <llvm-c/Target.h>
@@ -357,8 +358,8 @@ enum ZigLLVM_OSType {
     ZigLLVM_Mesa3D,
     ZigLLVM_Contiki,
     ZigLLVM_AMDPAL,     // AMD PAL Runtime
-
+    ZigLLVM_Uefi,
-    ZigLLVM_LastOSType = ZigLLVM_AMDPAL
+    ZigLLVM_LastOSType = ZigLLVM_Uefi
 };
 
 // Synchronize with target.cpp::environ_list
@@ -397,6 +398,19 @@ enum ZigLLVM_ObjectFormatType {
     ZigLLVM_Wasm,
 };
 
+// For MSVC-supported subsystems
+enum ZigLLVM_MSVCSubsystemType {
+    ZigLLVM_MSVC_NONE,
+    ZigLLVM_MSVC_CONSOLE,
+    ZigLLVM_MSVC_WINDOWS,
+    ZigLLVM_MSVC_POSIX,
+    ZigLLVM_MSVC_NATIVE,
+    ZigLLVM_MSVC_EFI_APPLICATION,
+    ZigLLVM_MSVC_EFI_BOOT_SERVICE_DRIVER,
+    ZigLLVM_MSVC_EFI_ROM,
+    ZigLLVM_MSVC_EFI_RUNTIME_DRIVER,                                         
+};
+
 ZIG_EXTERN_C const char *ZigLLVMGetArchTypeName(enum ZigLLVM_ArchType arch);
 ZIG_EXTERN_C const char *ZigLLVMGetSubArchTypeName(enum ZigLLVM_SubArchType sub_arch);
 ZIG_EXTERN_C const char *ZigLLVMGetVendorTypeName(enum ZigLLVM_VendorType vendor);

std/debug/index.zig

@@ -1135,7 +1135,7 @@ pub const DebugInfo = switch (builtin.os) {
             return self.ofiles.allocator;
         }
     },
-    builtin.Os.windows => struct {
+    builtin.Os.uefi, builtin.Os.windows => struct {
         pdb: pdb.Pdb,
         coff: *coff.Coff,
         sect_contribs: []pdb.SectionContribEntry,

std/os/index.zig

@@ -18,6 +18,7 @@ test "std.os" {
     _ = @import("test.zig");
     _ = @import("time.zig");
     _ = @import("windows/index.zig");
+    _ = @import("uefi/index.zig");
     _ = @import("get_app_data_dir.zig");
 }
 
@@ -26,6 +27,8 @@ pub const darwin = @import("darwin.zig");
 pub const linux = @import("linux/index.zig");
 pub const freebsd = @import("freebsd/index.zig");
 pub const zen = @import("zen.zig");
+pub const uefi = @import("uefi/index.zig");
+
 pub const posix = switch (builtin.os) {
     Os.linux => linux,
     Os.macosx, Os.ios => darwin,
@@ -33,6 +36,7 @@ pub const posix = switch (builtin.os) {
     Os.zen => zen,
     else => @compileError("Unsupported OS"),
 };
+
 pub const net = @import("net.zig");
 
 pub const ChildProcess = @import("child_process.zig").ChildProcess;
@@ -187,6 +191,9 @@ pub fn abort() noreturn {
             }
             windows.ExitProcess(3);
         },
+        Os.uefi => {
+            while (true) {}
+        },
         else => @compileError("Unsupported OS"),
     }
 }

std/special/panic.zig

@@ -10,7 +10,7 @@ pub fn panic(msg: []const u8, error_return_trace: ?*builtin.StackTrace) noreturn
     @setCold(true);
     switch (builtin.os) {
         // TODO: fix panic in zen.
-        builtin.Os.freestanding, builtin.Os.zen => {
+        builtin.Os.freestanding, builtin.Os.zen, builtin.Os.uefi => {
             while (true) {}
         },
         else => {