start moving `zig cc` to stage2

 * build.zig: repair the ability to link against llvm, clang, and lld
 * move the zig cc arg parsing logic to stage2
   - the preprocessor flag is still TODO
   - the clang arg iterator code is improved to use slices instead of
     raw pointers because it no longer has to deal with an extern
     struct.
 * clean up error printing with a `fatal` function and use log API
   for messages rather than std.debug.print
 * add support for more CLI options to stage2 & update usage text
   - hooking up most of these new options is TODO
 * clean up the way libc and libc++ are detected via command line
   options. target information is used to determine if any of the libc
   candidate names are chosen.
 * add native library directory detection
 * implement the ability to invoke clang from stage2
 * introduce a build_options.have_llvm so we can comptime branch
   on whether LLVM is linked in or not.

1 files changed, 5 insertions, 407 deletions

diff --git a/src/main.cpp b/src/main.cpp
index e2f6a82a12..af3bc4b2a1 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -404,7 +404,6 @@ 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;
@@ -446,18 +445,8 @@ static int main0(int argc, char **argv) {
     bool function_sections = false;
     const char *mcpu = nullptr;
     CodeModel code_model = CodeModelDefault;
-    const char *override_soname = nullptr;
-    bool only_pp_or_asm = false;
-    bool ensure_libc_on_non_freestanding = false;
-    bool ensure_libcpp_on_non_freestanding = false;
-    bool disable_c_depfile = false;
     bool want_native_include_dirs = false;
-    Buf *linker_optimization = nullptr;
-    OptionalBool linker_gc_sections = OptionalBoolNull;
-    OptionalBool linker_allow_shlib_undefined = OptionalBoolNull;
     OptionalBool linker_bind_global_refs_locally = OptionalBoolNull;
-    bool linker_z_nodelete = false;
-    bool linker_z_defs = false;
     size_t stack_size_override = 0;
 
     ZigList<const char *> llvm_argv = {0};
@@ -585,355 +574,10 @@ static int main0(int argc, char **argv) {
         return stage2_fmt(argc, argv);
     } else if (argc >= 2 && strcmp(argv[1], "env") == 0) {
         return stage2_env(argc, argv);
-    } 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);
-        want_native_include_dirs = true;
-
-        bool c_arg = false;
-        Stage2ClangArgIterator it;
-        stage2_clang_arg_iterator(&it, argc, argv);
-        bool is_shared_lib = false;
-        ZigList<Buf *> linker_args = {};
-        while (it.has_next) {
-            if ((err = stage2_clang_arg_next(&it))) {
-                fprintf(stderr, "unable to parse command line parameters: %s\n", err_str(err));
-                return EXIT_FAILURE;
-            }
-            switch (it.kind) {
-                case Stage2ClangArgTarget: // example: -target riscv64-linux-unknown
-                    target_string = it.only_arg;
-                    break;
-                case Stage2ClangArgO: // -o
-                    emit_bin_override_path = it.only_arg;
-                    enable_cache = CacheOptOn;
-                    break;
-                case Stage2ClangArgC: // -c
-                    c_arg = true;
-                    break;
-                case Stage2ClangArgOther:
-                    for (size_t i = 0; i < it.other_args_len; i += 1) {
-                        clang_argv.append(it.other_args_ptr[i]);
-                    }
-                    break;
-                case Stage2ClangArgPositional: {
-                    FileExt file_ext = classify_file_ext(it.only_arg, strlen(it.only_arg));
-                    switch (file_ext) {
-                        case FileExtAsm:
-                        case FileExtC:
-                        case FileExtCpp:
-                        case FileExtLLVMIr:
-                        case FileExtLLVMBitCode:
-                        case FileExtHeader: {
-                            CFile *c_file = heap::c_allocator.create<CFile>();
-                            c_file->source_path = it.only_arg;
-                            c_source_files.append(c_file);
-                            break;
-                        }
-                        case FileExtUnknown:
-                            objects.append(it.only_arg);
-                            break;
-                    }
-                    break;
-                }
-                case Stage2ClangArgL: // -l
-                    if (strcmp(it.only_arg, "c") == 0) {
-                        have_libc = true;
-                        link_libs.append("c");
-                    } else if (strcmp(it.only_arg, "c++") == 0 ||
-                        strcmp(it.only_arg, "stdc++") == 0)
-                    {
-                        have_libcpp = true;
-                        link_libs.append("c++");
-                    } else {
-                        link_libs.append(it.only_arg);
-                    }
-                    break;
-                case Stage2ClangArgIgnore:
-                    break;
-                case Stage2ClangArgDriverPunt:
-                    // Never mind what we're doing, just pass the args directly. For example --help.
-                    return ZigClang_main(argc, argv);
-                case Stage2ClangArgPIC:
-                    want_pic = WantPICEnabled;
-                    break;
-                case Stage2ClangArgNoPIC:
-                    want_pic = WantPICDisabled;
-                    break;
-                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;
-                    break;
-                case Stage2ClangArgRDynamic:
-                    rdynamic = true;
-                    break;
-                case Stage2ClangArgWL: {
-                    const char *arg = it.only_arg;
-                    for (;;) {
-                        size_t pos = 0;
-                        while (arg[pos] != ',' && arg[pos] != 0) pos += 1;
-                        linker_args.append(buf_create_from_mem(arg, pos));
-                        if (arg[pos] == 0) break;
-                        arg += pos + 1;
-                    }
-                    break;
-                }
-                case Stage2ClangArgPreprocessOrAsm:
-                    // this handles both -E and -S
-                    only_pp_or_asm = true;
-                    for (size_t i = 0; i < it.other_args_len; i += 1) {
-                        clang_argv.append(it.other_args_ptr[i]);
-                    }
-                    break;
-                case Stage2ClangArgOptimize:
-                    // alright what release mode do they want?
-                    if (strcmp(it.only_arg, "Os") == 0) {
-                        build_mode = BuildModeSmallRelease;
-                    } else if (strcmp(it.only_arg, "O2") == 0 ||
-                            strcmp(it.only_arg, "O3") == 0 ||
-                            strcmp(it.only_arg, "O4") == 0)
-                    {
-                        build_mode = BuildModeFastRelease;
-                    } else if (strcmp(it.only_arg, "Og") == 0 ||
-                            strcmp(it.only_arg, "O0") == 0)
-                    {
-                        build_mode = BuildModeDebug;
-                    } else {
-                        for (size_t i = 0; i < it.other_args_len; i += 1) {
-                            clang_argv.append(it.other_args_ptr[i]);
-                        }
-                    }
-                    break;
-                case Stage2ClangArgDebug:
-                    strip = false;
-                    if (strcmp(it.only_arg, "-g") == 0) {
-                        // we handled with strip = false above
-                    } else {
-                        for (size_t i = 0; i < it.other_args_len; i += 1) {
-                            clang_argv.append(it.other_args_ptr[i]);
-                        }
-                    }
-                    break;
-                case Stage2ClangArgSanitize:
-                    if (strcmp(it.only_arg, "undefined") == 0) {
-                        want_sanitize_c = WantCSanitizeEnabled;
-                    } else {
-                        for (size_t i = 0; i < it.other_args_len; i += 1) {
-                            clang_argv.append(it.other_args_ptr[i]);
-                        }
-                    }
-                    break;
-                case Stage2ClangArgLinkerScript:
-                    linker_script = it.only_arg;
-                    break;
-                case Stage2ClangArgVerboseCmds:
-                    verbose_cc = true;
-                    verbose_link = true;
-                    break;
-                case Stage2ClangArgForLinker:
-                    linker_args.append(buf_create_from_str(it.only_arg));
-                    break;
-                case Stage2ClangArgLinkerInputZ:
-                    linker_args.append(buf_create_from_str("-z"));
-                    linker_args.append(buf_create_from_str(it.only_arg));
-                    break;
-                case Stage2ClangArgLibDir:
-                    lib_dirs.append(it.only_arg);
-                    break;
-                case Stage2ClangArgMCpu:
-                    mcpu = it.only_arg;
-                    break;
-                case Stage2ClangArgDepFile:
-                    disable_c_depfile = true;
-                    for (size_t i = 0; i < it.other_args_len; i += 1) {
-                        clang_argv.append(it.other_args_ptr[i]);
-                    }
-                    break;
-                case Stage2ClangArgFrameworkDir:
-                    framework_dirs.append(it.only_arg);
-                    break;
-                case Stage2ClangArgFramework:
-                    frameworks.append(it.only_arg);
-                    break;
-                case Stage2ClangArgNoStdLibInc:
-                    want_native_include_dirs = false;
-                    break;
-            }
-        }
-        // Parse linker args
-        for (size_t i = 0; i < linker_args.length; i += 1) {
-            Buf *arg = linker_args.at(i);
-            if (buf_eql_str(arg, "-soname")) {
-                i += 1;
-                if (i >= linker_args.length) {
-                    fprintf(stderr, "expected linker arg after '%s'\n", buf_ptr(arg));
-                    return EXIT_FAILURE;
-                }
-                Buf *soname_buf = linker_args.at(i);
-                override_soname = buf_ptr(soname_buf);
-                // use it as --name
-                // example: libsoundio.so.2
-                size_t prefix = 0;
-                if (buf_starts_with_str(soname_buf, "lib")) {
-                    prefix = 3;
-                }
-                size_t end = buf_len(soname_buf);
-                if (buf_ends_with_str(soname_buf, ".so")) {
-                    end -= 3;
-                } else {
-                    bool found_digit = false;
-                    while (end > 0 && isdigit(buf_ptr(soname_buf)[end - 1])) {
-                        found_digit = true;
-                        end -= 1;
-                    }
-                    if (found_digit && end > 0 && buf_ptr(soname_buf)[end - 1] == '.') {
-                        end -= 1;
-                    } else {
-                        end = buf_len(soname_buf);
-                    }
-                    if (buf_ends_with_str(buf_slice(soname_buf, prefix, end), ".so")) {
-                        end -= 3;
-                    }
-                }
-                out_name = buf_ptr(buf_slice(soname_buf, prefix, end));
-            } else if (buf_eql_str(arg, "-rpath")) {
-                i += 1;
-                if (i >= linker_args.length) {
-                    fprintf(stderr, "expected linker arg after '%s'\n", buf_ptr(arg));
-                    return EXIT_FAILURE;
-                }
-                Buf *rpath = linker_args.at(i);
-                rpath_list.append(buf_ptr(rpath));
-            } else if (buf_eql_str(arg, "-I") ||
-                buf_eql_str(arg, "--dynamic-linker") ||
-                buf_eql_str(arg, "-dynamic-linker"))
-            {
-                i += 1;
-                if (i >= linker_args.length) {
-                    fprintf(stderr, "expected linker arg after '%s'\n", buf_ptr(arg));
-                    return EXIT_FAILURE;
-                }
-                dynamic_linker = buf_ptr(linker_args.at(i));
-            } else if (buf_eql_str(arg, "-E") ||
-                buf_eql_str(arg, "--export-dynamic") ||
-                buf_eql_str(arg, "-export-dynamic"))
-            {
-                rdynamic = true;
-            } else if (buf_eql_str(arg, "--version-script")) {
-                i += 1;
-                if (i >= linker_args.length) {
-                    fprintf(stderr, "expected linker arg after '%s'\n", buf_ptr(arg));
-                    return EXIT_FAILURE;
-                }
-                version_script = linker_args.at(i);
-            } else if (buf_starts_with_str(arg, "-O")) {
-                linker_optimization = arg;
-            } else if (buf_eql_str(arg, "--gc-sections")) {
-                linker_gc_sections = OptionalBoolTrue;
-            } else if (buf_eql_str(arg, "--no-gc-sections")) {
-                linker_gc_sections = OptionalBoolFalse;
-            } else if (buf_eql_str(arg, "--allow-shlib-undefined") ||
-                       buf_eql_str(arg, "-allow-shlib-undefined"))
-            {
-                linker_allow_shlib_undefined = OptionalBoolTrue;
-            } else if (buf_eql_str(arg, "--no-allow-shlib-undefined") ||
-                       buf_eql_str(arg, "-no-allow-shlib-undefined"))
-            {
-                linker_allow_shlib_undefined = OptionalBoolFalse;
-            } else if (buf_eql_str(arg, "-Bsymbolic")) {
-                linker_bind_global_refs_locally = OptionalBoolTrue;
-            } else if (buf_eql_str(arg, "-z")) {
-                i += 1;
-                if (i >= linker_args.length) {
-                    fprintf(stderr, "expected linker arg after '%s'\n", buf_ptr(arg));
-                    return EXIT_FAILURE;
-                }
-                Buf *z_arg = linker_args.at(i);
-                if (buf_eql_str(z_arg, "nodelete")) {
-                    linker_z_nodelete = true;
-                } else if (buf_eql_str(z_arg, "defs")) {
-                    linker_z_defs = true;
-                } else {
-                    fprintf(stderr, "warning: unsupported linker arg: -z %s\n", buf_ptr(z_arg));
-                }
-            } else if (buf_eql_str(arg, "--major-image-version")) {
-                i += 1;
-                if (i >= linker_args.length) {
-                    fprintf(stderr, "expected linker arg after '%s'\n", buf_ptr(arg));
-                    return EXIT_FAILURE;
-                }
-                ver_major = atoi(buf_ptr(linker_args.at(i)));
-            } else if (buf_eql_str(arg, "--minor-image-version")) {
-                i += 1;
-                if (i >= linker_args.length) {
-                    fprintf(stderr, "expected linker arg after '%s'\n", buf_ptr(arg));
-                    return EXIT_FAILURE;
-                }
-                ver_minor = atoi(buf_ptr(linker_args.at(i)));
-            } else if (buf_eql_str(arg, "--stack")) {
-                i += 1;
-                if (i >= linker_args.length) {
-                    fprintf(stderr, "expected linker arg after '%s'\n", buf_ptr(arg));
-                    return EXIT_FAILURE;
-                }
-                stack_size_override = atoi(buf_ptr(linker_args.at(i)));
-            } else {
-                fprintf(stderr, "warning: unsupported linker arg: %s\n", buf_ptr(arg));
-            }
-        }
-
-        if (want_sanitize_c == WantCSanitizeEnabled && build_mode == BuildModeFastRelease) {
-            build_mode = BuildModeSafeRelease;
-        }
-
-        if (only_pp_or_asm) {
-            cmd = CmdBuild;
-            out_type = OutTypeObj;
-            emit_bin = false;
-            // Transfer "objects" into c_source_files
-            for (size_t i = 0; i < objects.length; i += 1) {
-                CFile *c_file = heap::c_allocator.create<CFile>();
-                c_file->source_path = objects.at(i);
-                c_source_files.append(c_file);
-            }
-            for (size_t i = 0; i < c_source_files.length; i += 1) {
-                Buf *src_path;
-                if (emit_bin_override_path != nullptr) {
-                    src_path = buf_create_from_str(emit_bin_override_path);
-                } else {
-                    src_path = buf_create_from_str(c_source_files.at(i)->source_path);
-                }
-                Buf basename = BUF_INIT;
-                os_path_split(src_path, nullptr, &basename);
-                c_source_files.at(i)->preprocessor_only_basename = buf_ptr(&basename);
-            }
-        } else if (!c_arg) {
-            cmd = CmdBuild;
-            if (is_shared_lib) {
-                out_type = OutTypeLib;
-            } else {
-                out_type = OutTypeExe;
-            }
-            if (emit_bin_override_path == nullptr) {
-                emit_bin_override_path = "a.out";
-                enable_cache = CacheOptOn;
-            }
-        } else {
-            cmd = CmdBuild;
-            out_type = OutTypeObj;
-        }
-        if (c_source_files.length == 0 && objects.length == 0) {
-            // For example `zig cc` and no args should print the "no input files" message.
-            return ZigClang_main(argc, argv);
-        }
+    } else if (argc >= 2 && strcmp(argv[1], "cc") == 0) {
+        return stage2_cc(argc, argv, false);
+    } else if (argc >= 2 && strcmp(argv[1], "c++") == 0) {
+        return stage2_cc(argc, argv, true);
     } else for (int i = 1; i < argc; i += 1) {
         char *arg = argv[i];
 
@@ -1038,7 +682,6 @@ static int main0(int argc, char **argv) {
                     have_libc = true;
                     link_libs.append("c");
                 } else if (strcmp(l, "c++") == 0 || strcmp(l, "stdc++") == 0) {
-                    have_libcpp = true;
                     link_libs.append("c++");
                 } else {
                     link_libs.append(l);
@@ -1185,7 +828,6 @@ static int main0(int argc, char **argv) {
                         have_libc = true;
                         link_libs.append("c");
                     } else if (strcmp(argv[i], "c++") == 0 || strcmp(argv[i], "stdc++") == 0) {
-                        have_libcpp = true;
                         link_libs.append("c++");
                     } else {
                         link_libs.append(argv[i]);
@@ -1351,15 +993,6 @@ static int main0(int argc, char **argv) {
         return print_error_usage(arg0);
     }
 
-    if (!have_libc && ensure_libc_on_non_freestanding && target.os != OsFreestanding) {
-        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);
 
@@ -1616,20 +1249,10 @@ static int main0(int argc, char **argv) {
             g->system_linker_hack = system_linker_hack;
             g->function_sections = function_sections;
             g->code_model = code_model;
-            g->disable_c_depfile = disable_c_depfile;
 
-            g->linker_optimization = linker_optimization;
-            g->linker_gc_sections = linker_gc_sections;
-            g->linker_allow_shlib_undefined = linker_allow_shlib_undefined;
             g->linker_bind_global_refs_locally = linker_bind_global_refs_locally;
-            g->linker_z_nodelete = linker_z_nodelete;
-            g->linker_z_defs = linker_z_defs;
             g->stack_size_override = stack_size_override;
 
-            if (override_soname) {
-                g->override_soname = buf_create_from_str(override_soname);
-            }
-
             for (size_t i = 0; i < lib_dirs.length; i += 1) {
                 codegen_add_lib_dir(g, lib_dirs.at(i));
             }
@@ -1713,37 +1336,12 @@ static int main0(int argc, char **argv) {
                         buf_replace(g->output_dir, '/', '\\');
 #endif
                         Buf *dest_path = buf_create_from_str(emit_bin_override_path);
-                        Buf *source_path;
-                        if (only_pp_or_asm) {
-                            source_path = buf_alloc();
-                            Buf *pp_only_basename = buf_create_from_str(
-                                    c_source_files.at(0)->preprocessor_only_basename);
-                            os_path_join(g->output_dir, pp_only_basename, source_path);
-
-                        } else {
-                            source_path = &g->bin_file_output_path;
-                        }
+                        Buf *source_path = &g->bin_file_output_path;
                         if ((err = os_update_file(source_path, dest_path))) {
                             fprintf(stderr, "unable to copy %s to %s: %s\n", buf_ptr(source_path),
                                     buf_ptr(dest_path), err_str(err));
                             return main_exit(root_progress_node, EXIT_FAILURE);
                         }
-                    } else if (only_pp_or_asm) {
-#if defined(ZIG_OS_WINDOWS)
-                        buf_replace(g->c_artifact_dir, '/', '\\');
-#endif
-                        // dump the preprocessed output to stdout
-                        for (size_t i = 0; i < c_source_files.length; i += 1) {
-                            Buf *source_path = buf_alloc();
-                            Buf *pp_only_basename = buf_create_from_str(
-                                    c_source_files.at(i)->preprocessor_only_basename);
-                            os_path_join(g->c_artifact_dir, pp_only_basename, source_path);
-                            if ((err = os_dump_file(source_path, stdout))) {
-                                fprintf(stderr, "unable to read %s: %s\n", buf_ptr(source_path),
-                                        err_str(err));
-                                return main_exit(root_progress_node, EXIT_FAILURE);
-                            }
-                        }
                     } else if (g->enable_cache) {
 #if defined(ZIG_OS_WINDOWS)
                         buf_replace(&g->bin_file_output_path, '/', '\\');