ability to compile c++ hello world with zig c++

closes #4786

src-self-hosted/clang_options_data.zig

@@ -3752,7 +3752,14 @@ flagpd1("nostdinc++"),
     .psl = false,
 },
 flagpd1("nostdlibinc"),
-flagpd1("nostdlib++"),
+.{
+    .name = "nostdlib++",
+    .syntax = .flag,
+    .zig_equivalent = .nostdlib_cpp,
+    .pd1 = true,
+    .pd2 = false,
+    .psl = false,
+},
 flagpd1("nostdsysteminc"),
 flagpd1("objcmt-atomic-property"),
 flagpd1("objcmt-migrate-all"),

src-self-hosted/stage2.zig

@@ -1273,6 +1273,7 @@ pub const ClangArgIterator = extern struct {
         pic,
         no_pic,
         nostdlib,
+        nostdlib_cpp,
         shared,
         rdynamic,
         wl,

src/all_types.hpp

@@ -2019,6 +2019,7 @@ struct CodeGen {
     ZigLLVMDICompileUnit *compile_unit;
     ZigLLVMDIFile *compile_unit_file;
     LinkLib *libc_link_lib;
+    LinkLib *libcpp_link_lib;
     LLVMTargetDataRef target_data_ref;
     LLVMTargetMachineRef target_machine;
     ZigLLVMDIFile *dummy_di_file;

src/analyze.cpp

@@ -7756,10 +7756,14 @@ LinkLib *create_link_lib(Buf *name) {
 
 LinkLib *add_link_lib(CodeGen *g, Buf *name) {
     bool is_libc = buf_eql_str(name, "c");
+    bool is_libcpp = buf_eql_str(name, "c++") || buf_eql_str(name, "c++abi");
 
     if (is_libc && g->libc_link_lib != nullptr)
         return g->libc_link_lib;
 
+    if (is_libcpp && g->libcpp_link_lib != nullptr)
+        return g->libcpp_link_lib;
+
     for (size_t i = 0; i < g->link_libs_list.length; i += 1) {
         LinkLib *existing_lib = g->link_libs_list.at(i);
         if (buf_eql_buf(existing_lib->name, name)) {
@@ -7772,6 +7776,8 @@ LinkLib *add_link_lib(CodeGen *g, Buf *name) {
 
     if (is_libc)
         g->libc_link_lib = link_lib;
+    if (is_libcpp)
+        g->libcpp_link_lib = link_lib;
 
     return link_lib;
 }

src/codegen.cpp

@@ -8700,6 +8700,7 @@ Buf *codegen_generate_builtin_source(CodeGen *g) {
     buf_appendf(contents, "pub const object_format = ObjectFormat.%s;\n", cur_obj_fmt);
     buf_appendf(contents, "pub const mode = %s;\n", build_mode_to_str(g->build_mode));
     buf_appendf(contents, "pub const link_libc = %s;\n", bool_to_str(g->libc_link_lib != nullptr));
+    buf_appendf(contents, "pub const link_libcpp = %s;\n", bool_to_str(g->libcpp_link_lib != nullptr));
     buf_appendf(contents, "pub const have_error_return_tracing = %s;\n", bool_to_str(g->have_err_ret_tracing));
     buf_appendf(contents, "pub const valgrind_support = %s;\n", bool_to_str(want_valgrind_support(g)));
     buf_appendf(contents, "pub const position_independent_code = %s;\n", bool_to_str(g->have_pic));
@@ -8798,6 +8799,7 @@ static Error define_builtin_compile_vars(CodeGen *g) {
     }
     cache_bool(&cache_hash, g->have_err_ret_tracing);
     cache_bool(&cache_hash, g->libc_link_lib != nullptr);
+    cache_bool(&cache_hash, g->libcpp_link_lib != nullptr);
     cache_bool(&cache_hash, g->valgrind_support);
     cache_bool(&cache_hash, g->link_eh_frame_hdr);
     cache_int(&cache_hash, detect_subsystem(g));
@@ -9205,6 +9207,14 @@ void add_cc_args(CodeGen *g, ZigList<const char *> &args, const char *out_dep_pa
         args.append(g->framework_dirs.at(i));
     }
 
+    if (g->libcpp_link_lib != nullptr) {
+        const char *libcxx_include_path = buf_ptr(buf_sprintf("%s" OS_SEP "libcxx" OS_SEP "include",
+                buf_ptr(g->zig_lib_dir)));
+
+        args.append("-isystem");
+        args.append(libcxx_include_path);
+    }
+
     // According to Rich Felker libc headers are supposed to go before C language headers.
     // However as noted by @dimenus, appending libc headers before c_headers breaks intrinsics
     // and other compiler specific items.

src/install_files.h

@@ -1841,4 +1841,69 @@ static const char *ZIG_MUSL_COMPAT_TIME32_FILES[] = {
 "musl/compat/time32/wait3_time32.c",
 "musl/compat/time32/wait4_time32.c",
 };
+static const char *ZIG_LIBCXXABI_FILES[] = {
+"src/abort_message.cpp",
+"src/cxa_aux_runtime.cpp",
+"src/cxa_default_handlers.cpp",
+"src/cxa_demangle.cpp",
+"src/cxa_exception.cpp",
+"src/cxa_exception_storage.cpp",
+"src/cxa_guard.cpp",
+"src/cxa_handlers.cpp",
+"src/cxa_noexception.cpp",
+"src/cxa_personality.cpp",
+"src/cxa_thread_atexit.cpp",
+"src/cxa_unexpected.cpp",
+"src/cxa_vector.cpp",
+"src/cxa_virtual.cpp",
+"src/fallback_malloc.cpp",
+"src/private_typeinfo.cpp",
+"src/stdlib_exception.cpp",
+"src/stdlib_new_delete.cpp",
+"src/stdlib_stdexcept.cpp",
+"src/stdlib_typeinfo.cpp",
+};
+static const char *ZIG_LIBCXX_FILES[] = {
+"src/algorithm.cpp",
+"src/any.cpp",
+"src/bind.cpp",
+"src/charconv.cpp",
+"src/chrono.cpp",
+"src/condition_variable.cpp",
+"src/condition_variable_destructor.cpp",
+"src/debug.cpp",
+"src/exception.cpp",
+"src/experimental/memory_resource.cpp",
+"src/filesystem/directory_iterator.cpp",
+"src/filesystem/int128_builtins.cpp",
+"src/filesystem/operations.cpp",
+"src/functional.cpp",
+"src/future.cpp",
+"src/hash.cpp",
+"src/ios.cpp",
+"src/iostream.cpp",
+"src/locale.cpp",
+"src/memory.cpp",
+"src/mutex.cpp",
+"src/mutex_destructor.cpp",
+"src/new.cpp",
+"src/optional.cpp",
+"src/random.cpp",
+"src/regex.cpp",
+"src/shared_mutex.cpp",
+"src/stdexcept.cpp",
+"src/string.cpp",
+"src/strstream.cpp",
+"src/support/solaris/xlocale.cpp",
+"src/support/win32/locale_win32.cpp",
+"src/support/win32/support.cpp",
+"src/support/win32/thread_win32.cpp",
+"src/system_error.cpp",
+"src/thread.cpp",
+"src/typeinfo.cpp",
+"src/utility.cpp",
+"src/valarray.cpp",
+"src/variant.cpp",
+"src/vector.cpp",
+};
 #endif

src/link.cpp

@@ -1107,6 +1107,105 @@ static const char *build_musl(CodeGen *parent, Stage2ProgressNode *progress_node
     return buf_ptr(&child_gen->bin_file_output_path);
 }
 
+static const char *build_libcxxabi(CodeGen *parent, Stage2ProgressNode *progress_node) {
+    CodeGen *child_gen = create_child_codegen(parent, nullptr, OutTypeLib, nullptr, "c++abi", progress_node);
+    codegen_add_link_lib(child_gen, buf_create_from_str("c"));
+
+    ZigList<CFile *> c_source_files = {0};
+
+    const char *cxxabi_include_path = buf_ptr(buf_sprintf("%s" OS_SEP "libcxxabi" OS_SEP "include",
+                buf_ptr(parent->zig_lib_dir)));
+    const char *cxx_include_path = buf_ptr(buf_sprintf("%s" OS_SEP "libcxx" OS_SEP "include",
+                buf_ptr(parent->zig_lib_dir)));
+
+    for (size_t i = 0; i < array_length(ZIG_LIBCXXABI_FILES); i += 1) {
+        const char *rel_src_path = ZIG_LIBCXXABI_FILES[i];
+
+        CFile *c_file = heap::c_allocator.create<CFile>();
+        c_file->source_path = buf_ptr(buf_sprintf("%s" OS_SEP "libcxxabi" OS_SEP "%s",
+                    buf_ptr(parent->zig_lib_dir), rel_src_path));
+
+        c_file->args.append("-DHAVE___CXA_THREAD_ATEXIT_IMPL");
+        c_file->args.append("-D_LIBCPP_DISABLE_EXTERN_TEMPLATE");
+        c_file->args.append("-D_LIBCPP_ENABLE_CXX17_REMOVED_UNEXPECTED_FUNCTIONS");
+        c_file->args.append("-D_LIBCXXABI_BUILDING_LIBRARY");
+
+        c_file->args.append("-I");
+        c_file->args.append(cxxabi_include_path);
+
+        c_file->args.append("-I");
+        c_file->args.append(cxx_include_path);
+
+        c_file->args.append("-O3");
+        c_file->args.append("-DNDEBUG");
+        c_file->args.append("-fPIC");
+        c_file->args.append("-nostdinc++");
+        c_file->args.append("-fstrict-aliasing");
+        c_file->args.append("-funwind-tables");
+        c_file->args.append("-D_DEBUG");
+        c_file->args.append("-UNDEBUG");
+        c_file->args.append("-std=c++11");
+
+        c_source_files.append(c_file);
+    }
+
+
+    child_gen->c_source_files = c_source_files;
+    codegen_build_and_link(child_gen);
+    return buf_ptr(&child_gen->bin_file_output_path);
+}
+
+static const char *build_libcxx(CodeGen *parent, Stage2ProgressNode *progress_node) {
+    CodeGen *child_gen = create_child_codegen(parent, nullptr, OutTypeLib, nullptr, "c++", progress_node);
+    codegen_add_link_lib(child_gen, buf_create_from_str("c"));
+
+    ZigList<CFile *> c_source_files = {0};
+
+    const char *cxxabi_include_path = buf_ptr(buf_sprintf("%s" OS_SEP "libcxxabi" OS_SEP "include",
+                buf_ptr(parent->zig_lib_dir)));
+    const char *cxx_include_path = buf_ptr(buf_sprintf("%s" OS_SEP "libcxx" OS_SEP "include",
+                buf_ptr(parent->zig_lib_dir)));
+
+    for (size_t i = 0; i < array_length(ZIG_LIBCXX_FILES); i += 1) {
+        const char *rel_src_path = ZIG_LIBCXX_FILES[i];
+
+        Buf *src_path_buf = buf_create_from_str(rel_src_path);
+        if (buf_starts_with_str(src_path_buf, "src/support/win32") && parent->zig_target->os != OsWindows) {
+            continue;
+        }
+
+        CFile *c_file = heap::c_allocator.create<CFile>();
+        c_file->source_path = buf_ptr(buf_sprintf("%s" OS_SEP "libcxx" OS_SEP "%s",
+                    buf_ptr(parent->zig_lib_dir), rel_src_path));
+
+        c_file->args.append("-DNDEBUG");
+        c_file->args.append("-D_LIBCPP_BUILDING_LIBRARY");
+        c_file->args.append("-D_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER");
+        c_file->args.append("-DLIBCXX_BUILDING_LIBCXXABI");
+
+        c_file->args.append("-I");
+        c_file->args.append(cxx_include_path);
+
+        c_file->args.append("-I");
+        c_file->args.append(cxxabi_include_path);
+
+        c_file->args.append("-O3");
+        c_file->args.append("-DNDEBUG");
+        c_file->args.append("-fPIC");
+        c_file->args.append("-nostdinc++");
+        c_file->args.append("-fvisibility-inlines-hidden");
+        c_file->args.append("-std=c++14");
+        c_file->args.append("-Wno-user-defined-literals");
+
+        c_source_files.append(c_file);
+    }
+
+
+    child_gen->c_source_files = c_source_files;
+    codegen_build_and_link(child_gen);
+    return buf_ptr(&child_gen->bin_file_output_path);
+}
+
 static void add_msvcrt_os_dep(CodeGen *parent, CodeGen *child_gen, const char *src_path) {
     CFile *c_file = heap::c_allocator.create<CFile>();
     c_file->source_path = buf_ptr(buf_sprintf("%s" OS_SEP "libc" OS_SEP "mingw" OS_SEP "%s",
@@ -1770,6 +1869,10 @@ static void construct_linker_job_elf(LinkJob *lj) {
             // libc is linked specially
             continue;
         }
+        if (buf_eql_str(link_lib->name, "c++") || buf_eql_str(link_lib->name, "c++abi")) {
+            // libc++ is linked specially
+            continue;
+        }
         if (g->libc == nullptr && target_is_libc_lib_name(g->zig_target, buf_ptr(link_lib->name))) {
             // these libraries are always linked below when targeting glibc
             continue;
@@ -1785,6 +1888,11 @@ static void construct_linker_job_elf(LinkJob *lj) {
         lj->args.append(buf_ptr(arg));
     }
 
+    // libc++ dep
+    if (g->libcpp_link_lib != nullptr && g->out_type != OutTypeObj) {
+        lj->args.append(build_libcxxabi(g, lj->build_dep_prog_node));
+        lj->args.append(build_libcxx(g, lj->build_dep_prog_node));
+    }
 
     // libc dep
     if (g->libc_link_lib != nullptr && g->out_type != OutTypeObj) {

src/main.cpp

@@ -412,6 +412,7 @@ static int main0(int argc, char **argv) {
     ZigList<const char *> framework_dirs = {0};
     ZigList<const char *> frameworks = {0};
     bool have_libc = false;
+    bool have_libcpp = false;
     const char *target_string = nullptr;
     bool rdynamic = false;
     const char *linker_script = nullptr;
@@ -456,6 +457,7 @@ static int main0(int argc, char **argv) {
     const char *override_soname = nullptr;
     bool only_preprocess = false;
     bool ensure_libc_on_non_freestanding = false;
+    bool ensure_libcpp_on_non_freestanding = false;
 
     ZigList<const char *> llvm_argv = {0};
     llvm_argv.append("zig (LLVM option parsing)");
@@ -580,10 +582,11 @@ static int main0(int argc, char **argv) {
         return (term.how == TerminationIdClean) ? term.code : -1;
     } else if (argc >= 2 && strcmp(argv[1], "fmt") == 0) {
         return stage2_fmt(argc, argv);
-    } else if (argc >= 2 && strcmp(argv[1], "cc") == 0) {
+    } else if (argc >= 2 && (strcmp(argv[1], "cc") == 0 || strcmp(argv[1], "c++") == 0)) {
         emit_h = false;
         strip = true;
         ensure_libc_on_non_freestanding = true;
+        ensure_libcpp_on_non_freestanding = (strcmp(argv[1], "c++") == 0);
 
         bool c_arg = false;
         Stage2ClangArgIterator it;
@@ -632,6 +635,8 @@ static int main0(int argc, char **argv) {
                 case Stage2ClangArgL: // -l
                     if (strcmp(it.only_arg, "c") == 0)
                         have_libc = true;
+                    if (strcmp(it.only_arg, "c++") == 0)
+                        have_libcpp = true;
                     link_libs.append(it.only_arg);
                     break;
                 case Stage2ClangArgIgnore:
@@ -648,6 +653,9 @@ static int main0(int argc, char **argv) {
                 case Stage2ClangArgNoStdLib:
                     ensure_libc_on_non_freestanding = false;
                     break;
+                case Stage2ClangArgNoStdLibCpp:
+                    ensure_libcpp_on_non_freestanding = false;
+                    break;
                 case Stage2ClangArgShared:
                     is_dynamic = true;
                     is_shared_lib = true;
@@ -916,6 +924,8 @@ static int main0(int argc, char **argv) {
                 const char *l = &arg[2];
                 if (strcmp(l, "c") == 0)
                     have_libc = true;
+                if (strcmp(l, "c++") == 0)
+                    have_libcpp = true;
                 link_libs.append(l);
             } else if (arg[1] == 'I' && arg[2] != 0) {
                 clang_argv.append("-I");
@@ -1057,6 +1067,8 @@ static int main0(int argc, char **argv) {
                 } else if (strcmp(arg, "--library") == 0 || strcmp(arg, "-l") == 0) {
                     if (strcmp(argv[i], "c") == 0)
                         have_libc = true;
+                    if (strcmp(argv[i], "c++") == 0)
+                        have_libcpp = true;
                     link_libs.append(argv[i]);
                 } else if (strcmp(arg, "--forbid-library") == 0) {
                     forbidden_link_libs.append(argv[i]);
@@ -1221,6 +1233,10 @@ static int main0(int argc, char **argv) {
         have_libc = true;
         link_libs.append("c");
     }
+    if (!have_libcpp && ensure_libcpp_on_non_freestanding && target.os != OsFreestanding) {
+        have_libcpp = true;
+        link_libs.append("c++");
+    }
 
     Buf zig_triple_buf = BUF_INIT;
     target_triple_zig(&zig_triple_buf, &target);

src/stage2.h

@@ -334,6 +334,7 @@ enum Stage2ClangArg {
     Stage2ClangArgPIC,
     Stage2ClangArgNoPIC,
     Stage2ClangArgNoStdLib,
+    Stage2ClangArgNoStdLibCpp,
     Stage2ClangArgShared,
     Stage2ClangArgRDynamic,
     Stage2ClangArgWL,

tools/update_clang_options.zig

@@ -62,6 +62,10 @@ const known_options = [_]KnownOpt{
         .name = "no-standard-libraries",
         .ident = "nostdlib",
     },
+    .{
+        .name = "nostdlib++",
+        .ident = "nostdlib_cpp",
+    },
     .{
         .name = "shared",
         .ident = "shared",