Commit 2bf6c28bc3

Andrew Kelley <superjoe30@gmail.com>
2016-02-11 09:33:27
ability to cross compile
hello_libc.zig can produce a windows build
1 parent 54a8b6a
src/all_types.hpp
@@ -14,6 +14,7 @@
 #include "hash_map.hpp"
 #include "errmsg.hpp"
 #include "bignum.hpp"
+#include "target.hpp"
 
 struct AstNode;
 struct ImportTableEntry;
@@ -1109,6 +1110,7 @@ struct CodeGen {
         TypeTableEntry *entry_pure_error;
     } builtin_types;
 
+    ZigTarget zig_target;
     LLVMTargetDataRef target_data_ref;
     unsigned pointer_size_bytes;
     bool is_big_endian;
@@ -1120,12 +1122,18 @@ struct CodeGen {
     Buf *libc_static_lib_dir;
     Buf *libc_include_dir;
     Buf *dynamic_linker;
+    Buf *linker_path;
+    Buf triple_str;
     bool is_release_build;
     bool is_test_build;
     LLVMTargetMachineRef target_machine;
     LLVMZigDIFile *dummy_di_file;
+    bool is_native_target;
     Buf *root_source_dir;
     Buf *root_out_name;
+    bool windows_subsystem_windows;
+    bool windows_subsystem_console;
+    bool windows_linker_unicode;
 
     // The function definitions this module includes. There must be a corresponding
     // fn_protos entry.
src/analyze.cpp
@@ -5929,13 +5929,13 @@ bool handle_is_ptr(TypeTableEntry *type_entry) {
 void find_libc_path(CodeGen *g) {
     // later we can handle this better by reporting an error via the normal mechanism
     if (!g->libc_lib_dir || buf_len(g->libc_lib_dir) == 0) {
-        zig_panic("Unable to determine libc lib path. probably need to reconfigure");
+        zig_panic("Unable to determine libc lib path.");
     }
     if (!g->libc_static_lib_dir || buf_len(g->libc_static_lib_dir) == 0) {
-        zig_panic("Unable to determine libc static lib path. probably need to reconfigure");
+        zig_panic("Unable to determine libc static lib path.");
     }
     if (!g->libc_include_dir || buf_len(g->libc_include_dir) == 0) {
-        zig_panic("Unable to determine libc include path. probably need to reconfigure");
+        zig_panic("Unable to determine libc include path.");
     }
 }
 
src/codegen.cpp
@@ -15,12 +15,14 @@
 #include "errmsg.hpp"
 #include "parseh.hpp"
 #include "ast_render.hpp"
+#include "target.hpp"
+#include "link.hpp"
 
 #include <stdio.h>
 #include <errno.h>
 
 
-CodeGen *codegen_create(Buf *root_source_dir) {
+CodeGen *codegen_create(Buf *root_source_dir, const ZigTarget *target) {
     CodeGen *g = allocate<CodeGen>(1);
     g->link_table.init(32);
     g->import_table.init(32);
@@ -33,11 +35,29 @@ CodeGen *codegen_create(Buf *root_source_dir) {
     g->is_test_build = false;
     g->root_source_dir = root_source_dir;
     g->error_value_count = 1;
-    g->dynamic_linker = buf_create_from_str(ZIG_DYNAMIC_LINKER);
 
-    g->libc_lib_dir = buf_create_from_str(ZIG_LIBC_LIB_DIR);
-    g->libc_static_lib_dir = buf_create_from_str(ZIG_LIBC_STATIC_LIB_DIR);
-    g->libc_include_dir = buf_create_from_str(ZIG_LIBC_INCLUDE_DIR);
+    if (target) {
+        // cross compiling, so we can't rely on all the configured stuff since
+        // that's for native compilation
+        g->zig_target = *target;
+        resolve_target_object_format(&g->zig_target);
+
+        g->dynamic_linker = buf_create_from_str("");
+        g->libc_lib_dir = buf_create_from_str("");
+        g->libc_static_lib_dir = buf_create_from_str("");
+        g->libc_include_dir = buf_create_from_str("");
+        g->linker_path = buf_create_from_str("");
+    } else {
+        // native compilation, we can rely on the configuration stuff
+        g->is_native_target = true;
+        get_native_target(&g->zig_target);
+
+        g->dynamic_linker = buf_create_from_str(ZIG_DYNAMIC_LINKER);
+        g->libc_lib_dir = buf_create_from_str(ZIG_LIBC_LIB_DIR);
+        g->libc_static_lib_dir = buf_create_from_str(ZIG_LIBC_STATIC_LIB_DIR);
+        g->libc_include_dir = buf_create_from_str(ZIG_LIBC_INCLUDE_DIR);
+        g->linker_path = buf_create_from_str(ZIG_LD_PATH);
+    }
 
     return g;
 }
@@ -95,10 +115,23 @@ void codegen_set_dynamic_linker(CodeGen *g, Buf *dynamic_linker) {
     g->dynamic_linker = dynamic_linker;
 }
 
+void codegen_set_linker_path(CodeGen *g, Buf *linker_path) {
+    g->linker_path = linker_path;
+}
+
 void codegen_add_lib_dir(CodeGen *g, const char *dir) {
     g->lib_dirs.append(dir);
 }
 
+void codegen_set_windows_subsystem(CodeGen *g, bool mwindows, bool mconsole) {
+    g->windows_subsystem_windows = mwindows;
+    g->windows_subsystem_console = mconsole;
+}
+
+void codegen_set_windows_unicode(CodeGen *g, bool municode) {
+    g->windows_linker_unicode = municode;
+}
+
 static LLVMValueRef gen_expr(CodeGen *g, AstNode *expr_node);
 static LLVMValueRef gen_lvalue(CodeGen *g, AstNode *expr_node, AstNode *node, TypeTableEntry **out_type_entry);
 static LLVMValueRef gen_field_access_expr(CodeGen *g, AstNode *node, bool is_lvalue);
@@ -3502,34 +3535,35 @@ static void init(CodeGen *g, Buf *source_path) {
     g->lib_search_paths.append(g->root_source_dir);
     g->lib_search_paths.append(buf_create_from_str(ZIG_STD_DIR));
 
-    LLVMInitializeAllTargets();
-    LLVMInitializeAllTargetMCs();
-    LLVMInitializeAllAsmPrinters();
-    LLVMInitializeAllAsmParsers();
-    LLVMInitializeNativeTarget();
-
-    char *native_triple = LLVMGetDefaultTargetTriple();
-
     g->module = LLVMModuleCreateWithName(buf_ptr(source_path));
 
-    LLVMSetTarget(g->module, native_triple);
+    get_target_triple(&g->triple_str, &g->zig_target);
+
+    LLVMSetTarget(g->module, buf_ptr(&g->triple_str));
 
     LLVMTargetRef target_ref;
     char *err_msg = nullptr;
-    if (LLVMGetTargetFromTriple(native_triple, &target_ref, &err_msg)) {
-        zig_panic("unable to get target from triple: %s", err_msg);
+    if (LLVMGetTargetFromTriple(buf_ptr(&g->triple_str), &target_ref, &err_msg)) {
+        zig_panic("unable to create target based on: %s", buf_ptr(&g->triple_str));
     }
 
 
-    char *native_cpu = LLVMZigGetHostCPUName();
-    char *native_features = LLVMZigGetNativeFeatures();
-
     LLVMCodeGenOptLevel opt_level = g->is_release_build ? LLVMCodeGenLevelAggressive : LLVMCodeGenLevelNone;
 
     LLVMRelocMode reloc_mode = g->is_static ? LLVMRelocStatic : LLVMRelocPIC;
 
-    g->target_machine = LLVMCreateTargetMachine(target_ref, native_triple,
-            native_cpu, native_features, opt_level, reloc_mode, LLVMCodeModelDefault);
+    const char *target_specific_cpu_args;
+    const char *target_specific_features;
+    if (g->is_native_target) {
+        target_specific_cpu_args = LLVMZigGetHostCPUName();
+        target_specific_features = LLVMZigGetNativeFeatures();
+    } else {
+        target_specific_cpu_args = "";
+        target_specific_features = "";
+    }
+
+    g->target_machine = LLVMCreateTargetMachine(target_ref, buf_ptr(&g->triple_str),
+            target_specific_cpu_args, target_specific_features, opt_level, reloc_mode, LLVMCodeModelDefault);
 
     g->target_data_ref = LLVMGetTargetMachineData(g->target_machine);
 
@@ -3902,7 +3936,7 @@ static void to_c_type(CodeGen *g, AstNode *type_node, Buf *out_buf) {
     }
 }
 
-static void generate_h_file(CodeGen *g) {
+void codegen_generate_h_file(CodeGen *g) {
     assert(!g->is_test_build);
 
     Buf *h_file_out_path = buf_sprintf("%s.h", buf_ptr(g->root_out_name));
@@ -3989,258 +4023,3 @@ static void generate_h_file(CodeGen *g) {
     if (fclose(out_h))
         zig_panic("unable to close h file: %s", strerror(errno));
 }
-
-static const char *get_libc_file(CodeGen *g, const char *file) {
-    Buf *out_buf = buf_alloc();
-    os_path_join(g->libc_lib_dir, buf_create_from_str(file), out_buf);
-    return buf_ptr(out_buf);
-}
-
-static const char *get_libc_static_file(CodeGen *g, const char *file) {
-    Buf *out_buf = buf_alloc();
-    os_path_join(g->libc_static_lib_dir, buf_create_from_str(file), out_buf);
-    return buf_ptr(out_buf);
-}
-
-static Buf *build_o(CodeGen *parent_gen, const char *oname) {
-    Buf *source_basename = buf_sprintf("%s.zig", oname);
-    Buf *std_dir_path = buf_create_from_str(ZIG_STD_DIR);
-
-    CodeGen *child_gen = codegen_create(std_dir_path);
-    child_gen->link_libc = parent_gen->link_libc;
-
-    codegen_set_is_release(child_gen, parent_gen->is_release_build);
-
-    codegen_set_strip(child_gen, parent_gen->strip_debug_symbols);
-    codegen_set_is_static(child_gen, parent_gen->is_static);
-
-    codegen_set_out_type(child_gen, OutTypeObj);
-    codegen_set_out_name(child_gen, buf_create_from_str(oname));
-
-    codegen_set_verbose(child_gen, parent_gen->verbose);
-    codegen_set_errmsg_color(child_gen, parent_gen->err_color);
-
-    Buf *full_path = buf_alloc();
-    os_path_join(std_dir_path, source_basename, full_path);
-    Buf source_code = BUF_INIT;
-    if (os_fetch_file_path(full_path, &source_code)) {
-        zig_panic("unable to fetch file: %s\n", buf_ptr(full_path));
-    }
-
-    codegen_add_root_code(child_gen, std_dir_path, source_basename, &source_code);
-    Buf *o_out = buf_sprintf("%s.o", oname);
-    codegen_link(child_gen, buf_ptr(o_out));
-
-    return o_out;
-}
-
-void codegen_link(CodeGen *g, const char *out_file) {
-    bool is_optimized = g->is_release_build;
-    if (is_optimized) {
-        if (g->verbose) {
-            fprintf(stderr, "\nOptimization:\n");
-            fprintf(stderr, "---------------\n");
-        }
-
-        LLVMZigOptimizeModule(g->target_machine, g->module);
-
-        if (g->verbose) {
-            LLVMDumpModule(g->module);
-        }
-    }
-    if (g->verbose) {
-        fprintf(stderr, "\nLink:\n");
-        fprintf(stderr, "-------\n");
-    }
-
-    if (!out_file) {
-        assert(g->root_out_name);
-        out_file = buf_ptr(g->root_out_name);
-    }
-
-    Buf out_file_o = BUF_INIT;
-    buf_init_from_str(&out_file_o, out_file);
-
-    if (g->out_type != OutTypeObj) {
-        buf_append_str(&out_file_o, ".o");
-    }
-
-    char *err_msg = nullptr;
-    if (LLVMTargetMachineEmitToFile(g->target_machine, g->module, buf_ptr(&out_file_o),
-                LLVMObjectFile, &err_msg))
-    {
-        zig_panic("unable to write object file: %s", err_msg);
-    }
-
-    if (g->out_type == OutTypeObj) {
-        if (g->verbose) {
-            fprintf(stderr, "OK\n");
-        }
-        return;
-    }
-
-    if (g->out_type == OutTypeLib && g->is_static) {
-        // invoke `ar`
-        // example:
-        // # static link into libfoo.a
-        // ar rcs libfoo.a foo1.o foo2.o
-        zig_panic("TODO invoke ar");
-        return;
-    }
-
-    bool link_in_crt = (g->link_libc && g->out_type == OutTypeExe);
-    if (link_in_crt) {
-        find_libc_path(g);
-    }
-
-
-
-    // invoke `ld`
-    ZigList<const char *> args = {0};
-
-    // TODO make this target dependent
-    args.append("-m");
-    args.append("elf_x86_64");
-
-    if (g->is_static) {
-        args.append("-static");
-    }
-
-    args.append("-o");
-    args.append(out_file);
-
-    if (link_in_crt) {
-        const char *crt1o;
-        const char *crtbegino;
-        if (g->is_static) {
-            crt1o = "crt1.o";
-            crtbegino = "crtbeginT.o";
-        } else {
-            crt1o = "Scrt1.o";
-            crtbegino = "crtbegin.o";
-        }
-        args.append(get_libc_file(g, crt1o));
-        args.append(get_libc_file(g, "crti.o"));
-        args.append(get_libc_static_file(g, crtbegino));
-    }
-
-    for (int i = 0; i < g->lib_dirs.length; i += 1) {
-        const char *lib_dir = g->lib_dirs.at(i);
-        args.append("-L");
-        args.append(lib_dir);
-    }
-
-    if (g->link_libc) {
-        args.append("-L");
-        args.append(buf_ptr(g->libc_lib_dir));
-
-        args.append("-L");
-        args.append(buf_ptr(g->libc_static_lib_dir));
-    }
-
-    if (g->dynamic_linker && buf_len(g->dynamic_linker) > 0) {
-        args.append("-dynamic-linker");
-        args.append(buf_ptr(g->dynamic_linker));
-    } else {
-        args.append("-dynamic-linker");
-        args.append(buf_ptr(get_dynamic_linker(g->target_machine)));
-    }
-
-    if (g->out_type == OutTypeLib) {
-        Buf *out_lib_so = buf_sprintf("lib%s.so.%d.%d.%d",
-                buf_ptr(g->root_out_name), g->version_major, g->version_minor, g->version_patch);
-        Buf *soname = buf_sprintf("lib%s.so.%d", buf_ptr(g->root_out_name), g->version_major);
-        args.append("-shared");
-        args.append("-soname");
-        args.append(buf_ptr(soname));
-        out_file = buf_ptr(out_lib_so);
-    }
-
-    // .o files
-    args.append((const char *)buf_ptr(&out_file_o));
-
-    if (g->is_test_build) {
-        const char *test_runner_name = g->link_libc ? "test_runner_libc" : "test_runner_nolibc";
-        Buf *test_runner_o_path = build_o(g, test_runner_name);
-        args.append(buf_ptr(test_runner_o_path));
-    }
-
-    if (!g->link_libc && (g->out_type == OutTypeExe || g->out_type == OutTypeLib)) {
-        Buf *builtin_o_path = build_o(g, "builtin");
-        args.append(buf_ptr(builtin_o_path));
-    }
-
-    auto it = g->link_table.entry_iterator();
-    for (;;) {
-        auto *entry = it.next();
-        if (!entry)
-            break;
-
-        // we handle libc explicitly, don't do it here
-        if (!buf_eql_str(entry->key, "c")) {
-            Buf *arg = buf_sprintf("-l%s", buf_ptr(entry->key));
-            args.append(buf_ptr(arg));
-        }
-    }
-
-
-    // libc dep
-    if (g->link_libc) {
-        if (g->is_static) {
-            args.append("--start-group");
-            args.append("-lgcc");
-            args.append("-lgcc_eh");
-            args.append("-lc");
-            args.append("--end-group");
-        } else {
-            args.append("-lgcc");
-            args.append("--as-needed");
-            args.append("-lgcc_s");
-            args.append("--no-as-needed");
-            args.append("-lc");
-            args.append("-lgcc");
-            args.append("--as-needed");
-            args.append("-lgcc_s");
-            args.append("--no-as-needed");
-        }
-    }
-
-    // crt end
-    if (link_in_crt) {
-        args.append(get_libc_static_file(g, "crtend.o"));
-        args.append(get_libc_file(g, "crtn.o"));
-    }
-
-    if (g->verbose) {
-        fprintf(stderr, "ld");
-        for (int i = 0; i < args.length; i += 1) {
-            fprintf(stderr, " %s", args.at(i));
-        }
-        fprintf(stderr, "\n");
-    }
-
-    int return_code;
-    Buf ld_stderr = BUF_INIT;
-    Buf ld_stdout = BUF_INIT;
-    os_exec_process("ld", args, &return_code, &ld_stderr, &ld_stdout);
-
-    if (return_code != 0) {
-        fprintf(stderr, "ld failed with return code %d\n", return_code);
-        fprintf(stderr, "ld ");
-        for (int i = 0; i < args.length; i += 1) {
-            fprintf(stderr, "%s ", args.at(i));
-        }
-        fprintf(stderr, "\n%s\n", buf_ptr(&ld_stderr));
-        exit(1);
-    } else if (buf_len(&ld_stderr)) {
-        fprintf(stderr, "%s\n", buf_ptr(&ld_stderr));
-    }
-
-    if (g->out_type == OutTypeLib) {
-        generate_h_file(g);
-    }
-
-    if (g->verbose) {
-        fprintf(stderr, "OK\n");
-    }
-}
src/codegen.hpp
@@ -10,10 +10,11 @@
 
 #include "parser.hpp"
 #include "errmsg.hpp"
+#include "target.hpp"
 
 #include <stdio.h>
 
-CodeGen *codegen_create(Buf *root_source_dir);
+CodeGen *codegen_create(Buf *root_source_dir, const ZigTarget *target);
 
 void codegen_set_clang_argv(CodeGen *codegen, const char **args, int len);
 void codegen_set_is_release(CodeGen *codegen, bool is_release);
@@ -29,13 +30,16 @@ void codegen_set_libc_lib_dir(CodeGen *codegen, Buf *libc_lib_dir);
 void codegen_set_libc_static_lib_dir(CodeGen *g, Buf *libc_static_lib_dir);
 void codegen_set_libc_include_dir(CodeGen *codegen, Buf *libc_include_dir);
 void codegen_set_dynamic_linker(CodeGen *g, Buf *dynamic_linker);
+void codegen_set_linker_path(CodeGen *g, Buf *linker_path);
+void codegen_set_windows_subsystem(CodeGen *g, bool mwindows, bool mconsole);
+void codegen_set_windows_unicode(CodeGen *g, bool municode);
 void codegen_add_lib_dir(CodeGen *codegen, const char *dir);
 
 void codegen_add_root_code(CodeGen *g, Buf *source_dir, Buf *source_basename, Buf *source_code);
 
-void codegen_link(CodeGen *g, const char *out_file);
-
 void codegen_parseh(CodeGen *g, Buf *src_dirname, Buf *src_basename, Buf *source_code);
 void codegen_render_ast(CodeGen *g, FILE *f, int indent_size);
 
+void codegen_generate_h_file(CodeGen *g);
+
 #endif
src/config.h.in
@@ -11,6 +11,7 @@
 #define ZIG_LIBC_INCLUDE_DIR "@ZIG_LIBC_INCLUDE_DIR@"
 #define ZIG_LIBC_LIB_DIR "@ZIG_LIBC_LIB_DIR@"
 #define ZIG_LIBC_STATIC_LIB_DIR "@ZIG_LIBC_STATIC_LIB_DIR@"
+#define ZIG_LD_PATH "@ZIG_LD_PATH@"
 #define ZIG_DYNAMIC_LINKER "@ZIG_DYNAMIC_LINKER@"
 
 #cmakedefine ZIG_LLVM_OLD_CXX_ABI
src/link.cpp
@@ -0,0 +1,518 @@
+/*
+ * Copyright (c) 2015 Andrew Kelley
+ *
+ * This file is part of zig, which is MIT licensed.
+ * See http://opensource.org/licenses/MIT
+ */
+
+#include "link.hpp"
+#include "os.hpp"
+#include "config.h"
+#include "codegen.hpp"
+#include "analyze.hpp"
+
+struct LinkJob {
+    CodeGen *codegen;
+    Buf out_file;
+    ZigList<const char *> args;
+    bool link_in_crt;
+    Buf out_file_o;
+};
+
+static const char *get_libc_file(CodeGen *g, const char *file) {
+    Buf *out_buf = buf_alloc();
+    os_path_join(g->libc_lib_dir, buf_create_from_str(file), out_buf);
+    return buf_ptr(out_buf);
+}
+
+static const char *get_libc_static_file(CodeGen *g, const char *file) {
+    Buf *out_buf = buf_alloc();
+    os_path_join(g->libc_static_lib_dir, buf_create_from_str(file), out_buf);
+    return buf_ptr(out_buf);
+}
+
+static Buf *build_o(CodeGen *parent_gen, const char *oname) {
+    Buf *source_basename = buf_sprintf("%s.zig", oname);
+    Buf *std_dir_path = buf_create_from_str(ZIG_STD_DIR);
+
+    ZigTarget *child_target = parent_gen->is_native_target ? nullptr : &parent_gen->zig_target;
+    CodeGen *child_gen = codegen_create(std_dir_path, child_target);
+    child_gen->link_libc = parent_gen->link_libc;
+
+    codegen_set_is_release(child_gen, parent_gen->is_release_build);
+
+    codegen_set_strip(child_gen, parent_gen->strip_debug_symbols);
+    codegen_set_is_static(child_gen, parent_gen->is_static);
+
+    codegen_set_out_type(child_gen, OutTypeObj);
+    codegen_set_out_name(child_gen, buf_create_from_str(oname));
+
+    codegen_set_verbose(child_gen, parent_gen->verbose);
+    codegen_set_errmsg_color(child_gen, parent_gen->err_color);
+
+    Buf *full_path = buf_alloc();
+    os_path_join(std_dir_path, source_basename, full_path);
+    Buf source_code = BUF_INIT;
+    if (os_fetch_file_path(full_path, &source_code)) {
+        zig_panic("unable to fetch file: %s\n", buf_ptr(full_path));
+    }
+
+    codegen_add_root_code(child_gen, std_dir_path, source_basename, &source_code);
+    Buf *o_out = buf_sprintf("%s.o", oname);
+    codegen_link(child_gen, buf_ptr(o_out));
+
+    return o_out;
+}
+
+static const char *get_o_file_extension(CodeGen *g) {
+    if (g->zig_target.environ == ZigLLVM_MSVC) {
+        return ".obj";
+    } else {
+        return ".o";
+    }
+}
+
+static const char *get_exe_file_extension(CodeGen *g) {
+    if (g->zig_target.os == ZigLLVM_Win32) {
+        return ".exe";
+    } else {
+        return "";
+    }
+}
+
+static void construct_linker_job_linux(LinkJob *lj) {
+    CodeGen *g = lj->codegen;
+
+    lj->args.append("-m");
+    lj->args.append("elf_x86_64");
+
+    if (g->is_static) {
+        lj->args.append("-static");
+    }
+
+    lj->args.append("-o");
+    lj->args.append(buf_ptr(&lj->out_file));
+
+    if (lj->link_in_crt) {
+        const char *crt1o;
+        const char *crtbegino;
+        if (g->is_static) {
+            crt1o = "crt1.o";
+            crtbegino = "crtbeginT.o";
+        } else {
+            crt1o = "Scrt1.o";
+            crtbegino = "crtbegin.o";
+        }
+        lj->args.append(get_libc_file(g, crt1o));
+        lj->args.append(get_libc_file(g, "crti.o"));
+        lj->args.append(get_libc_static_file(g, crtbegino));
+    }
+
+    for (int i = 0; i < g->lib_dirs.length; i += 1) {
+        const char *lib_dir = g->lib_dirs.at(i);
+        lj->args.append("-L");
+        lj->args.append(lib_dir);
+    }
+
+    if (g->link_libc) {
+        lj->args.append("-L");
+        lj->args.append(buf_ptr(g->libc_lib_dir));
+
+        lj->args.append("-L");
+        lj->args.append(buf_ptr(g->libc_static_lib_dir));
+    }
+
+    if (g->dynamic_linker && buf_len(g->dynamic_linker) > 0) {
+        lj->args.append("-dynamic-linker");
+        lj->args.append(buf_ptr(g->dynamic_linker));
+    } else {
+        lj->args.append("-dynamic-linker");
+        lj->args.append(buf_ptr(get_dynamic_linker(g->target_machine)));
+    }
+
+    if (g->out_type == OutTypeLib) {
+        buf_resize(&lj->out_file, 0);
+        buf_appendf(&lj->out_file, "lib%s.so.%d.%d.%d",
+                buf_ptr(g->root_out_name), g->version_major, g->version_minor, g->version_patch);
+        Buf *soname = buf_sprintf("lib%s.so.%d", buf_ptr(g->root_out_name), g->version_major);
+        lj->args.append("-shared");
+        lj->args.append("-soname");
+        lj->args.append(buf_ptr(soname));
+    }
+
+    // .o files
+    lj->args.append((const char *)buf_ptr(&lj->out_file_o));
+
+    if (g->is_test_build) {
+        const char *test_runner_name = g->link_libc ? "test_runner_libc" : "test_runner_nolibc";
+        Buf *test_runner_o_path = build_o(g, test_runner_name);
+        lj->args.append(buf_ptr(test_runner_o_path));
+    }
+
+    if (!g->link_libc && (g->out_type == OutTypeExe || g->out_type == OutTypeLib)) {
+        Buf *builtin_o_path = build_o(g, "builtin");
+        lj->args.append(buf_ptr(builtin_o_path));
+    }
+
+    auto it = g->link_table.entry_iterator();
+    for (;;) {
+        auto *entry = it.next();
+        if (!entry)
+            break;
+
+        // we handle libc explicitly, don't do it here
+        if (!buf_eql_str(entry->key, "c")) {
+            Buf *arg = buf_sprintf("-l%s", buf_ptr(entry->key));
+            lj->args.append(buf_ptr(arg));
+        }
+    }
+
+
+    // libc dep
+    if (g->link_libc) {
+        if (g->is_static) {
+            lj->args.append("--start-group");
+            lj->args.append("-lgcc");
+            lj->args.append("-lgcc_eh");
+            lj->args.append("-lc");
+            lj->args.append("--end-group");
+        } else {
+            lj->args.append("-lgcc");
+            lj->args.append("--as-needed");
+            lj->args.append("-lgcc_s");
+            lj->args.append("--no-as-needed");
+            lj->args.append("-lc");
+            lj->args.append("-lgcc");
+            lj->args.append("--as-needed");
+            lj->args.append("-lgcc_s");
+            lj->args.append("--no-as-needed");
+        }
+    }
+
+    // crt end
+    if (lj->link_in_crt) {
+        lj->args.append(get_libc_static_file(g, "crtend.o"));
+        lj->args.append(get_libc_file(g, "crtn.o"));
+    }
+}
+
+static bool is_target_cyg_mingw(const ZigTarget *target) {
+    return (target->os == ZigLLVM_Win32 && target->environ == ZigLLVM_Cygnus) ||
+        (target->os == ZigLLVM_Win32 && target->environ == ZigLLVM_GNU);
+}
+
+static void construct_linker_job_mingw(LinkJob *lj) {
+    CodeGen *g = lj->codegen;
+
+    if (g->zig_target.arch.arch == ZigLLVM_x86) {
+        lj->args.append("-m");
+        lj->args.append("i386pe");
+    } else if (g->zig_target.arch.arch == ZigLLVM_x86_64) {
+        lj->args.append("-m");
+        lj->args.append("i386pep");
+    } else if (g->zig_target.arch.arch == ZigLLVM_arm) {
+        lj->args.append("-m");
+        lj->args.append("thumb2pe");
+    }
+
+    if (g->windows_subsystem_windows) {
+        lj->args.append("--subsystem");
+        lj->args.append("windows");
+    } else if (g->windows_subsystem_console) {
+        lj->args.append("--subsystem");
+        lj->args.append("console");
+    }
+
+    bool dll = g->out_type == OutTypeLib;
+    bool shared = !g->is_static && dll;
+    if (g->is_static) {
+        lj->args.append("-Bstatic");
+    } else {
+        if (dll) {
+            lj->args.append("--dll");
+        } else if (shared) {
+            lj->args.append("--shared");
+        }
+        lj->args.append("-Bdynamic");
+        if (dll || shared) {
+            lj->args.append("-e");
+            if (g->zig_target.arch.arch == ZigLLVM_x86) {
+                lj->args.append("_DllMainCRTStartup@12");
+            } else {
+                lj->args.append("DllMainCRTStartup");
+            }
+            lj->args.append("--enable-auto-image-base");
+        }
+    }
+
+    lj->args.append("-o");
+    lj->args.append(buf_ptr(&lj->out_file));
+
+    if (lj->link_in_crt) {
+        if (shared || dll) {
+            lj->args.append(get_libc_file(g, "dllcrt2.o"));
+        } else {
+            if (g->windows_linker_unicode) {
+                lj->args.append(get_libc_file(g, "crt2u.o"));
+            } else {
+                lj->args.append(get_libc_file(g, "crt2.o"));
+            }
+        }
+        lj->args.append(get_libc_static_file(g, "crtbegin.o"));
+    }
+
+    for (int i = 0; i < g->lib_dirs.length; i += 1) {
+        const char *lib_dir = g->lib_dirs.at(i);
+        lj->args.append("-L");
+        lj->args.append(lib_dir);
+    }
+
+    if (g->link_libc) {
+        lj->args.append("-L");
+        lj->args.append(buf_ptr(g->libc_lib_dir));
+
+        lj->args.append("-L");
+        lj->args.append(buf_ptr(g->libc_static_lib_dir));
+    }
+
+    lj->args.append((const char *)buf_ptr(&lj->out_file_o));
+
+    if (g->link_libc) {
+        if (g->is_static) {
+            lj->args.append("--start-group");
+        }
+
+        lj->args.append("-lmingw32");
+
+        lj->args.append("-lgcc");
+        bool is_android = (g->zig_target.environ == ZigLLVM_Android);
+        bool is_cyg_ming = is_target_cyg_mingw(&g->zig_target);
+        if (!g->is_static && !is_android) {
+            if (!is_cyg_ming) {
+                lj->args.append("--as-needed");
+            }
+            //lj->args.append("-lgcc_s");
+            if (!is_cyg_ming) {
+                lj->args.append("--no-as-needed");
+            }
+        }
+        if (g->is_static && !is_android) {
+            //lj->args.append("-lgcc_eh");
+        }
+        if (is_android && !g->is_static) {
+            lj->args.append("-ldl");
+        }
+
+        lj->args.append("-lmoldname");
+        lj->args.append("-lmingwex");
+        lj->args.append("-lmsvcrt");
+
+
+        if (g->windows_subsystem_windows) {
+            lj->args.append("-lgdi32");
+            lj->args.append("-lcomdlg32");
+        }
+        lj->args.append("-ladvapi32");
+        lj->args.append("-lshell32");
+        lj->args.append("-luser32");
+        lj->args.append("-lkernel32");
+
+        if (g->is_static) {
+            lj->args.append("--end-group");
+        }
+
+        if (lj->link_in_crt) {
+            lj->args.append(get_libc_static_file(g, "crtend.o"));
+        }
+    }
+}
+
+static void construct_linker_job(LinkJob *lj) {
+    switch (lj->codegen->zig_target.os) {
+        case ZigLLVM_UnknownOS:
+             zig_unreachable();
+        case ZigLLVM_Linux:
+             if (lj->codegen->zig_target.arch.arch == ZigLLVM_hexagon) {
+                zig_panic("TODO construct hexagon_TC linker job");
+             } else {
+                return construct_linker_job_linux(lj);
+             }
+        case ZigLLVM_CloudABI:
+             zig_panic("TODO construct CloudABI linker job");
+        case ZigLLVM_Darwin:
+        case ZigLLVM_MacOSX:
+        case ZigLLVM_IOS:
+             zig_panic("TODO construct DarwinClang linker job");
+        case ZigLLVM_DragonFly:
+             zig_panic("TODO construct DragonFly linker job");
+        case ZigLLVM_OpenBSD:
+             zig_panic("TODO construct OpenBSD linker job");
+        case ZigLLVM_Bitrig:
+             zig_panic("TODO construct Bitrig linker job");
+        case ZigLLVM_NetBSD:
+             zig_panic("TODO construct NetBSD linker job");
+        case ZigLLVM_FreeBSD:
+             zig_panic("TODO construct FreeBSD linker job");
+        case ZigLLVM_Minix:
+             zig_panic("TODO construct Minix linker job");
+        case ZigLLVM_NaCl:
+             zig_panic("TODO construct NaCl_TC linker job");
+        case ZigLLVM_Solaris:
+             zig_panic("TODO construct Solaris linker job");
+        case ZigLLVM_Win32:
+            switch (lj->codegen->zig_target.environ) {
+                default:
+                    if (lj->codegen->zig_target.oformat == ZigLLVM_ELF) {
+                        zig_panic("TODO construct Generic_ELF linker job");
+                    } else if (lj->codegen->zig_target.oformat == ZigLLVM_MachO) {
+                        zig_panic("TODO construct MachO linker job");
+                    } else {
+                        zig_panic("TODO construct Generic_GCC linker job");
+                    }
+                case ZigLLVM_GNU:
+                    return construct_linker_job_mingw(lj);
+                case ZigLLVM_Itanium:
+                    zig_panic("TODO construct CrossWindowsToolChain linker job");
+                case ZigLLVM_MSVC:
+                case ZigLLVM_UnknownEnvironment:
+                    zig_panic("TODO construct MSVC linker job");
+             }
+        case ZigLLVM_CUDA:
+             zig_panic("TODO construct Cuda linker job");
+        default:
+             // Of these targets, Hexagon is the only one that might have
+             // an OS of Linux, in which case it got handled above already.
+             if (lj->codegen->zig_target.arch.arch == ZigLLVM_tce) {
+                zig_panic("TODO construct TCE linker job");
+             } else if (lj->codegen->zig_target.arch.arch == ZigLLVM_hexagon) {
+                zig_panic("TODO construct Hexagon_TC linker job");
+             } else if (lj->codegen->zig_target.arch.arch == ZigLLVM_xcore) {
+                zig_panic("TODO construct XCore linker job");
+             } else if (lj->codegen->zig_target.arch.arch == ZigLLVM_shave) {
+                zig_panic("TODO construct SHAVE linker job");
+             } else if (lj->codegen->zig_target.oformat == ZigLLVM_ELF) {
+                zig_panic("TODO construct Generic_ELF linker job");
+             } else if (lj->codegen->zig_target.oformat == ZigLLVM_MachO) {
+                zig_panic("TODO construct MachO linker job");
+             } else {
+                zig_panic("TODO construct Generic_GCC linker job");
+             }
+
+    }
+}
+
+static void ensure_we_have_linker_path(CodeGen *g) {
+    if (!g->linker_path || buf_len(g->linker_path) == 0) {
+        zig_panic("zig does not know the path to the linker");
+    }
+}
+
+void codegen_link(CodeGen *g, const char *out_file) {
+    LinkJob lj = {0};
+    lj.codegen = g;
+    if (out_file) {
+        buf_init_from_str(&lj.out_file, out_file);
+    } else {
+        buf_resize(&lj.out_file, 0);
+    }
+
+    bool is_optimized = g->is_release_build;
+    if (is_optimized) {
+        if (g->verbose) {
+            fprintf(stderr, "\nOptimization:\n");
+            fprintf(stderr, "---------------\n");
+        }
+
+        LLVMZigOptimizeModule(g->target_machine, g->module);
+
+        if (g->verbose) {
+            LLVMDumpModule(g->module);
+        }
+    }
+    if (g->verbose) {
+        fprintf(stderr, "\nLink:\n");
+        fprintf(stderr, "-------\n");
+    }
+
+    if (buf_len(&lj.out_file) == 0) {
+        assert(g->root_out_name);
+        buf_init_from_buf(&lj.out_file, g->root_out_name);
+        buf_append_str(&lj.out_file, get_exe_file_extension(g));
+    }
+
+    buf_init_from_buf(&lj.out_file_o, &lj.out_file);
+
+    if (g->out_type != OutTypeObj) {
+        const char *o_ext = get_o_file_extension(g);
+        buf_append_str(&lj.out_file_o, o_ext);
+    }
+
+    char *err_msg = nullptr;
+    if (LLVMTargetMachineEmitToFile(g->target_machine, g->module, buf_ptr(&lj.out_file_o),
+                LLVMObjectFile, &err_msg))
+    {
+        zig_panic("unable to write object file: %s", err_msg);
+    }
+
+    if (g->out_type == OutTypeObj) {
+        if (g->verbose) {
+            fprintf(stderr, "OK\n");
+        }
+        return;
+    }
+
+    if (g->out_type == OutTypeLib && g->is_static) {
+        // invoke `ar`
+        // example:
+        // # static link into libfoo.a
+        // ar rcs libfoo.a foo1.o foo2.o
+        zig_panic("TODO invoke ar");
+        return;
+    }
+
+    lj.link_in_crt = (g->link_libc && g->out_type == OutTypeExe);
+    if (lj.link_in_crt) {
+        find_libc_path(g);
+    }
+
+
+
+    // invoke `ld`
+    ensure_we_have_linker_path(g);
+
+    construct_linker_job(&lj);
+
+
+    if (g->verbose) {
+        fprintf(stderr, "%s", buf_ptr(g->linker_path));
+        for (int i = 0; i < lj.args.length; i += 1) {
+            fprintf(stderr, " %s", lj.args.at(i));
+        }
+        fprintf(stderr, "\n");
+    }
+
+    int return_code;
+    Buf ld_stderr = BUF_INIT;
+    Buf ld_stdout = BUF_INIT;
+    os_exec_process(buf_ptr(g->linker_path), lj.args, &return_code, &ld_stderr, &ld_stdout);
+
+    if (return_code != 0) {
+        fprintf(stderr, "linker failed with return code %d\n", return_code);
+        fprintf(stderr, "%s ", buf_ptr(g->linker_path));
+        for (int i = 0; i < lj.args.length; i += 1) {
+            fprintf(stderr, "%s ", lj.args.at(i));
+        }
+        fprintf(stderr, "\n%s\n", buf_ptr(&ld_stderr));
+        exit(1);
+    } else if (buf_len(&ld_stderr)) {
+        fprintf(stderr, "%s\n", buf_ptr(&ld_stderr));
+    }
+
+    if (g->out_type == OutTypeLib) {
+        codegen_generate_h_file(g);
+    }
+
+    if (g->verbose) {
+        fprintf(stderr, "OK\n");
+    }
+}
src/link.hpp
@@ -0,0 +1,17 @@
+/*
+ * Copyright (c) 2015 Andrew Kelley
+ *
+ * This file is part of zig, which is MIT licensed.
+ * See http://opensource.org/licenses/MIT
+ */
+
+#ifndef ZIG_LINK_HPP
+#define ZIG_LINK_HPP
+
+#include "all_types.hpp"
+
+void codegen_link(CodeGen *g, const char *out_file);
+
+
+#endif
+
src/main.cpp
@@ -11,6 +11,7 @@
 #include "os.hpp"
 #include "error.hpp"
 #include "target.hpp"
+#include "link.hpp"
 
 #include <stdio.h>
 
@@ -31,26 +32,27 @@ static int usage(const char *arg0) {
         "  --output [file]              override destination path\n"
         "  --verbose                    turn on compiler debug output\n"
         "  --color [auto|off|on]        enable or disable colored error messages\n"
-        "  --libc-lib-dir [path]        set the C compiler data path\n"
-        "  --libc-static-lib-dir [path] set the C compiler data path\n"
-        "  --libc-include-dir [path]    set the C compiler data path\n"
+        "  --libc-lib-dir [path]        directory where libc crt1.o resides\n"
+        "  --libc-static-lib-dir [path] directory where libc crtbeginT.o resides\n"
+        "  --libc-include-dir [path]    directory where libc stdlib.h resides\n"
         "  --dynamic-linker [path]      set the path to ld.so\n"
+        "  --ld-path [path]             set the path to the linker\n"
         "  -isystem [dir]               add additional search path for other .h files\n"
         "  -dirafter [dir]              same as -isystem but do it last\n"
         "  --library-path [dir]         add a directory to the library search path\n"
+        "  --target-arch [name]         specify target architecture\n"
+        "  --target-os [name]           specify target operating system\n"
+        "  --target-environ [name]      specify target environment\n"
+        "  -mwindows                    (windows only) --subsystem windows to the linker\n"
+        "  -mconsole                    (windows only) --subsystem console to the linker\n"
+        "  -municode                    (windows only) link with unicode\n"
     , arg0);
     return EXIT_FAILURE;
 }
 
 static int print_target_list(FILE *f) {
-    ZigLLVM_ArchType native_arch_type;
-    ZigLLVM_SubArchType native_sub_arch_type;
-    ZigLLVM_VendorType native_vendor_type;
-    ZigLLVM_OSType native_os_type;
-    ZigLLVM_EnvironmentType native_environ_type;
-
-    ZigLLVMGetNativeTarget(&native_arch_type, &native_sub_arch_type, &native_vendor_type,
-            &native_os_type, &native_environ_type);
+    ZigTarget native;
+    get_native_target(&native);
 
     fprintf(f, "Architectures:\n");
     int arch_count = target_arch_count();
@@ -58,7 +60,7 @@ static int print_target_list(FILE *f) {
         const ArchType *arch = get_target_arch(arch_i);
         const char *sub_arch_str = (arch->sub_arch == ZigLLVM_NoSubArch) ?
             "" : ZigLLVMGetSubArchTypeName(arch->sub_arch);
-        const char *native_str = (native_arch_type == arch->arch && native_sub_arch_type == arch->sub_arch) ?
+        const char *native_str = (native.arch.arch == arch->arch && native.arch.sub_arch == arch->sub_arch) ?
             " (native)" : "";
         fprintf(f, "  %s%s%s\n", ZigLLVMGetArchTypeName(arch->arch), sub_arch_str, native_str);
     }
@@ -67,15 +69,15 @@ static int print_target_list(FILE *f) {
     int os_count = target_os_count();
     for (int i = 0; i < os_count; i += 1) {
         ZigLLVM_OSType os_type = get_target_os(i);
-        const char *native_str = (native_os_type == os_type) ? " (native)" : "";
+        const char *native_str = (native.os == os_type) ? " (native)" : "";
         fprintf(f, "  %s%s\n", get_target_os_name(os_type), native_str);
     }
 
-    fprintf(f, "\nABIs:\n");
+    fprintf(f, "\nEnvironments:\n");
     int environ_count = target_environ_count();
     for (int i = 0; i < environ_count; i += 1) {
         ZigLLVM_EnvironmentType environ_type = get_target_environ(i);
-        const char *native_str = (native_environ_type == environ_type) ? " (native)" : "";
+        const char *native_str = (native.environ == environ_type) ? " (native)" : "";
         fprintf(f, "  %s%s\n", ZigLLVMGetEnvironmentTypeName(environ_type), native_str);
     }
 
@@ -107,9 +109,16 @@ int main(int argc, char **argv) {
     const char *libc_static_lib_dir = nullptr;
     const char *libc_include_dir = nullptr;
     const char *dynamic_linker = nullptr;
+    const char *linker_path = nullptr;
     ZigList<const char *> clang_argv = {0};
     ZigList<const char *> lib_dirs = {0};
     int err;
+    const char *target_arch = nullptr;
+    const char *target_os = nullptr;
+    const char *target_environ = nullptr;
+    bool mwindows = false;
+    bool mconsole = false;
+    bool municode = false;
 
     for (int i = 1; i < argc; i += 1) {
         char *arg = argv[i];
@@ -123,6 +132,12 @@ int main(int argc, char **argv) {
                 is_static = true;
             } else if (strcmp(arg, "--verbose") == 0) {
                 verbose = true;
+            } else if (strcmp(arg, "-mwindows") == 0) {
+                mwindows = true;
+            } else if (strcmp(arg, "-mconsole") == 0) {
+                mconsole = true;
+            } else if (strcmp(arg, "-municode") == 0) {
+                municode = true;
             } else if (i + 1 >= argc) {
                 return usage(arg0);
             } else {
@@ -161,6 +176,8 @@ int main(int argc, char **argv) {
                     libc_include_dir = argv[i];
                 } else if (strcmp(arg, "--dynamic-linker") == 0) {
                     dynamic_linker = argv[i];
+                } else if (strcmp(arg, "--ld-path") == 0) {
+                    linker_path = argv[i];
                 } else if (strcmp(arg, "-isystem") == 0) {
                     clang_argv.append("-isystem");
                     clang_argv.append(argv[i]);
@@ -169,7 +186,14 @@ int main(int argc, char **argv) {
                     clang_argv.append(argv[i]);
                 } else if (strcmp(arg, "--library-path") == 0) {
                     lib_dirs.append(argv[i]);
+                } else if (strcmp(arg, "--target-arch") == 0) {
+                    target_arch = argv[i];
+                } else if (strcmp(arg, "--target-os") == 0) {
+                    target_os = argv[i];
+                } else if (strcmp(arg, "--target-environ") == 0) {
+                    target_environ = argv[i];
                 } else {
+                    fprintf(stderr, "Invalid argument: %s\n", arg);
                     return usage(arg0);
                 }
             }
@@ -216,6 +240,36 @@ int main(int argc, char **argv) {
             if (!in_file)
                 return usage(arg0);
 
+            init_all_targets();
+
+            ZigTarget alloc_target;
+            ZigTarget *target;
+            if (!target_arch && !target_os && !target_environ) {
+                target = nullptr;
+            } else {
+                target = &alloc_target;
+                get_unknown_target(target);
+                if (target_arch) {
+                    if (parse_target_arch(target_arch, &target->arch)) {
+                        fprintf(stderr, "invalid --target-arch argument\n");
+                        return usage(arg0);
+                    }
+                }
+                if (target_os) {
+                    if (parse_target_os(target_os, &target->os)) {
+                        fprintf(stderr, "invalid --target-os argument\n");
+                        return usage(arg0);
+                    }
+                }
+                if (target_environ) {
+                    if (parse_target_environ(target_environ, &target->environ)) {
+                        fprintf(stderr, "invalid --target-environ argument\n");
+                        return usage(arg0);
+                    }
+                }
+            }
+
+
             Buf in_file_buf = BUF_INIT;
             buf_init_from_str(&in_file_buf, in_file);
 
@@ -237,7 +291,7 @@ int main(int argc, char **argv) {
                 }
             }
 
-            CodeGen *g = codegen_create(&root_source_dir);
+            CodeGen *g = codegen_create(&root_source_dir, target);
             codegen_set_is_release(g, is_release_build);
             codegen_set_is_test(g, cmd == CmdTest);
 
@@ -262,6 +316,8 @@ int main(int argc, char **argv) {
                 codegen_set_libc_include_dir(g, buf_create_from_str(libc_include_dir));
             if (dynamic_linker)
                 codegen_set_dynamic_linker(g, buf_create_from_str(dynamic_linker));
+            if (linker_path)
+                codegen_set_linker_path(g, buf_create_from_str(linker_path));
             codegen_set_verbose(g, verbose);
             codegen_set_errmsg_color(g, color);
 
@@ -269,6 +325,9 @@ int main(int argc, char **argv) {
                 codegen_add_lib_dir(g, lib_dirs.at(i));
             }
 
+            codegen_set_windows_subsystem(g, mwindows, mconsole);
+            codegen_set_windows_unicode(g, municode);
+
             if (cmd == CmdBuild) {
                 codegen_add_root_code(g, &root_source_dir, &root_source_name, &root_source_code);
                 codegen_link(g, out_file);
src/parseh.cpp
@@ -1540,6 +1540,11 @@ int parse_h_file(ImportTableEntry *import, ZigList<ErrorMsg *> *errors, const ch
     clang_argv.append("-Xclang");
     clang_argv.append("-detailed-preprocessing-record");
 
+    if (!c->codegen->is_native_target) {
+        clang_argv.append("-target");
+        clang_argv.append(buf_ptr(&c->codegen->triple_str));
+    }
+
     clang_argv.append(target_file);
 
     // to make the [start...end] argument work
src/target.cpp
@@ -7,6 +7,9 @@
 
 #include "target.hpp"
 #include "util.hpp"
+#include "error.hpp"
+
+#include <stdio.h>
 
 static const ArchType arch_list[] = {
     {ZigLLVM_arm, ZigLLVM_ARMSubArch_v8_1a},
@@ -158,3 +161,127 @@ int target_environ_count(void) {
 ZigLLVM_EnvironmentType get_target_environ(int index) {
     return environ_list[index];
 }
+
+void get_native_target(ZigTarget *target) {
+    ZigLLVMGetNativeTarget(
+            &target->arch.arch,
+            &target->arch.sub_arch,
+            &target->vendor,
+            &target->os,
+            &target->environ,
+            &target->oformat);
+}
+
+void get_unknown_target(ZigTarget *target) {
+    target->arch.arch = ZigLLVM_UnknownArch;
+    target->arch.sub_arch = ZigLLVM_NoSubArch;
+    target->vendor = ZigLLVM_UnknownVendor;
+    target->os = ZigLLVM_UnknownOS;
+    target->environ = ZigLLVM_UnknownEnvironment;
+    target->oformat = ZigLLVM_UnknownObjectFormat;
+}
+
+int parse_target_arch(const char *str, ArchType *out_arch) {
+    for (int i = 0; i < array_length(arch_list); i += 1) {
+        const ArchType *arch = &arch_list[i];
+        char arch_name[50];
+        const char *sub_str = (arch->sub_arch == ZigLLVM_NoSubArch) ?
+            "" : ZigLLVMGetSubArchTypeName(arch->sub_arch);
+        sprintf(arch_name, "%s%s", ZigLLVMGetArchTypeName(arch->arch), sub_str);
+        if (strcmp(arch_name, str) == 0) {
+            *out_arch = *arch;
+            return 0;
+        }
+    }
+    return ErrorFileNotFound;
+}
+
+int parse_target_os(const char *str, ZigLLVM_OSType *out_os) {
+    for (int i = 0; i < array_length(os_list); i += 1) {
+        ZigLLVM_OSType os = os_list[i];
+        const char *os_name = get_target_os_name(os);
+        if (strcmp(os_name, str) == 0) {
+            *out_os = os;
+            return 0;
+        }
+    }
+    return ErrorFileNotFound;
+}
+
+int parse_target_environ(const char *str, ZigLLVM_EnvironmentType *out_environ) {
+    for (int i = 0; i < array_length(environ_list); i += 1) {
+        ZigLLVM_EnvironmentType environ = environ_list[i];
+        const char *environ_name = ZigLLVMGetEnvironmentTypeName(environ);
+        if (strcmp(environ_name, str) == 0) {
+            *out_environ = environ;
+            return 0;
+        }
+    }
+    return ErrorFileNotFound;
+}
+
+void init_all_targets(void) {
+    LLVMInitializeAllTargets();
+    LLVMInitializeAllTargetInfos();
+    LLVMInitializeAllTargetMCs();
+    LLVMInitializeAllAsmPrinters();
+    LLVMInitializeAllAsmParsers();
+}
+
+void get_target_triple(Buf *triple, const ZigTarget *target) {
+    ZigLLVMGetTargetTriple(triple, target->arch.arch, target->arch.sub_arch,
+            target->vendor, target->os, target->environ, target->oformat);
+}
+
+static bool is_os_darwin(ZigTarget *target) {
+    switch (target->os) {
+        case ZigLLVM_Darwin:
+        case ZigLLVM_IOS:
+        case ZigLLVM_MacOSX:
+            return true;
+        default:
+            return false;
+    }
+}
+
+void resolve_target_object_format(ZigTarget *target) {
+    if (target->oformat != ZigLLVM_UnknownObjectFormat) {
+        return;
+    }
+    switch (target->arch.arch) {
+    default:
+        break;
+    case ZigLLVM_hexagon:
+    case ZigLLVM_mips:
+    case ZigLLVM_mipsel:
+    case ZigLLVM_mips64:
+    case ZigLLVM_mips64el:
+    case ZigLLVM_r600:
+    case ZigLLVM_amdgcn:
+    case ZigLLVM_sparc:
+    case ZigLLVM_sparcv9:
+    case ZigLLVM_systemz:
+    case ZigLLVM_xcore:
+    case ZigLLVM_ppc64le:
+        target->oformat = ZigLLVM_ELF;
+        return;
+
+    case ZigLLVM_ppc:
+    case ZigLLVM_ppc64:
+        if (is_os_darwin(target)) {
+            target->oformat = ZigLLVM_MachO;
+            return;
+        }
+        target->oformat = ZigLLVM_ELF;
+        return;
+    }
+
+    if (is_os_darwin(target)) {
+        target->oformat = ZigLLVM_MachO;
+        return;
+    } else if (target->os == ZigLLVM_Win32) {
+        target->oformat = ZigLLVM_COFF;
+        return;
+    }
+    target->oformat = ZigLLVM_ELF;
+}
src/target.hpp
@@ -10,11 +10,21 @@
 
 #include <zig_llvm.hpp>
 
+struct Buf;
+
 struct ArchType {
     ZigLLVM_ArchType arch;
     ZigLLVM_SubArchType sub_arch;
 };
 
+struct ZigTarget {
+    ArchType arch;
+    ZigLLVM_VendorType vendor;
+    ZigLLVM_OSType os;
+    ZigLLVM_EnvironmentType environ;
+    ZigLLVM_ObjectFormatType oformat;
+};
+
 int target_arch_count(void);
 const ArchType *get_target_arch(int index);
 
@@ -28,4 +38,18 @@ const char *get_target_os_name(ZigLLVM_OSType os_type);
 int target_environ_count(void);
 ZigLLVM_EnvironmentType get_target_environ(int index);
 
+void get_native_target(ZigTarget *target);
+void get_unknown_target(ZigTarget *target);
+
+int parse_target_arch(const char *str, ArchType *arch);
+int parse_target_os(const char *str, ZigLLVM_OSType *os);
+int parse_target_environ(const char *str, ZigLLVM_EnvironmentType *environ);
+
+void init_all_targets(void);
+
+void get_target_triple(Buf *triple, const ZigTarget *target);
+
+void resolve_target_object_format(ZigTarget *target);
+
+
 #endif
src/zig_llvm.cpp
@@ -14,6 +14,7 @@
 
 #include "zig_llvm.hpp"
 
+
 /*
  * The point of this file is to contain all the LLVM C++ API interaction so that:
  * 1. The compile time of other files is kept under control.
@@ -520,6 +521,11 @@ static_assert((Triple::VendorType)ZigLLVM_LastVendorType == Triple::LastVendorTy
 static_assert((Triple::OSType)ZigLLVM_LastOSType == Triple::LastOSType, "");
 static_assert((Triple::EnvironmentType)ZigLLVM_LastEnvironmentType == Triple::LastEnvironmentType, "");
 
+static_assert((Triple::ObjectFormatType)ZigLLVM_UnknownObjectFormat == Triple::UnknownObjectFormat, "");
+static_assert((Triple::ObjectFormatType)ZigLLVM_COFF == Triple::COFF, "");
+static_assert((Triple::ObjectFormatType)ZigLLVM_ELF == Triple::ELF, "");
+static_assert((Triple::ObjectFormatType)ZigLLVM_MachO == Triple::MachO, "");
+
 const char *ZigLLVMGetArchTypeName(ZigLLVM_ArchType arch) {
     return Triple::getArchTypeName((Triple::ArchType)arch);
 }
@@ -537,7 +543,8 @@ const char *ZigLLVMGetEnvironmentTypeName(ZigLLVM_EnvironmentType environ) {
 }
 
 void ZigLLVMGetNativeTarget(ZigLLVM_ArchType *arch_type, ZigLLVM_SubArchType *sub_arch_type,
-        ZigLLVM_VendorType *vendor_type, ZigLLVM_OSType *os_type, ZigLLVM_EnvironmentType *environ_type)
+        ZigLLVM_VendorType *vendor_type, ZigLLVM_OSType *os_type, ZigLLVM_EnvironmentType *environ_type,
+        ZigLLVM_ObjectFormatType *oformat)
 {
     char *native_triple = LLVMGetDefaultTargetTriple();
     Triple triple(native_triple);
@@ -547,6 +554,7 @@ void ZigLLVMGetNativeTarget(ZigLLVM_ArchType *arch_type, ZigLLVM_SubArchType *su
     *vendor_type = (ZigLLVM_VendorType)triple.getVendor();
     *os_type = (ZigLLVM_OSType)triple.getOS();
     *environ_type = (ZigLLVM_EnvironmentType)triple.getEnvironment();
+    *oformat = (ZigLLVM_ObjectFormatType)triple.getObjectFormat();
 
     free(native_triple);
 }
@@ -594,6 +602,23 @@ const char *ZigLLVMGetSubArchTypeName(ZigLLVM_SubArchType sub_arch) {
 
 #include "buffer.hpp"
 
+void ZigLLVMGetTargetTriple(Buf *out_buf, ZigLLVM_ArchType arch_type, ZigLLVM_SubArchType sub_arch_type,
+        ZigLLVM_VendorType vendor_type, ZigLLVM_OSType os_type, ZigLLVM_EnvironmentType environ_type,
+        ZigLLVM_ObjectFormatType oformat)
+{
+    Triple triple;
+
+    triple.setArch((Triple::ArchType)arch_type);
+    // TODO how to set the sub arch?
+    triple.setVendor((Triple::VendorType)vendor_type);
+    triple.setOS((Triple::OSType)os_type);
+    triple.setEnvironment((Triple::EnvironmentType)environ_type);
+    triple.setObjectFormat((Triple::ObjectFormatType)oformat);
+
+    const std::string &str = triple.str();
+    buf_init_from_mem(out_buf, str.c_str(), str.size());
+}
+
 enum FloatAbi {
     FloatAbiHard,
     FloatAbiSoft,
src/zig_llvm.hpp
@@ -189,6 +189,7 @@ enum ZigLLVM_ArchType {
   ZigLLVM_shave,      // SHAVE: Movidius vector VLIW processors
   ZigLLVM_wasm32,     // WebAssembly with 32-bit pointers
   ZigLLVM_wasm64,     // WebAssembly with 64-bit pointers
+
   ZigLLVM_LastArchType = ZigLLVM_wasm64
 };
 
@@ -227,6 +228,7 @@ enum ZigLLVM_VendorType {
   ZigLLVM_MipsTechnologies,
   ZigLLVM_NVIDIA,
   ZigLLVM_CSR,
+
   ZigLLVM_LastVendorType = ZigLLVM_CSR
 };
 enum ZigLLVM_OSType {
@@ -256,6 +258,7 @@ enum ZigLLVM_OSType {
   ZigLLVM_NVCL,       // NVIDIA OpenCL
   ZigLLVM_AMDHSA,     // AMD HSA Runtime
   ZigLLVM_PS4,
+
   ZigLLVM_LastOSType = ZigLLVM_PS4
 };
 enum ZigLLVM_EnvironmentType {
@@ -273,14 +276,15 @@ enum ZigLLVM_EnvironmentType {
   ZigLLVM_MSVC,
   ZigLLVM_Itanium,
   ZigLLVM_Cygnus,
-  ZigLLVM_LastEnvironmentType = ZigLLVM_Cygnus
+
+  ZigLLVM_LastEnvironmentType = ZigLLVM_Cygnus,
 };
 enum ZigLLVM_ObjectFormatType {
-  ZigLLVM_UnknownObjectFormat,
+    ZigLLVM_UnknownObjectFormat,
 
-  ZigLLVM_COFF,
-  ZigLLVM_ELF,
-  ZigLLVM_MachO,
+    ZigLLVM_COFF,
+    ZigLLVM_ELF,
+    ZigLLVM_MachO,
 };
 
 const char *ZigLLVMGetArchTypeName(ZigLLVM_ArchType arch);
@@ -289,14 +293,18 @@ const char *ZigLLVMGetVendorTypeName(ZigLLVM_VendorType vendor);
 const char *ZigLLVMGetOSTypeName(ZigLLVM_OSType os);
 const char *ZigLLVMGetEnvironmentTypeName(ZigLLVM_EnvironmentType environ);
 
-void ZigLLVMGetNativeTarget(ZigLLVM_ArchType *arch_type, ZigLLVM_SubArchType *sub_arch_type,
-        ZigLLVM_VendorType *vendor_type, ZigLLVM_OSType *os_type, ZigLLVM_EnvironmentType *environ_type);
-
-
 /*
  * This stuff is not LLVM API but it depends on the LLVM C++ API so we put it here.
  */
 struct Buf;
+void ZigLLVMGetNativeTarget(ZigLLVM_ArchType *arch_type, ZigLLVM_SubArchType *sub_arch_type,
+        ZigLLVM_VendorType *vendor_type, ZigLLVM_OSType *os_type, ZigLLVM_EnvironmentType *environ_type,
+        ZigLLVM_ObjectFormatType *oformat);
+void ZigLLVMGetTargetTriple(Buf *out_buf, ZigLLVM_ArchType arch_type, ZigLLVM_SubArchType sub_arch_type,
+        ZigLLVM_VendorType vendor_type, ZigLLVM_OSType os_type, ZigLLVM_EnvironmentType environ_type,
+        ZigLLVM_ObjectFormatType oformat);
+
+
 Buf *get_dynamic_linker(LLVMTargetMachineRef target_machine);
 
 #endif
CMakeLists.txt
@@ -14,6 +14,14 @@ set(ZIG_VERSION_PATCH 0)
 set(ZIG_VERSION "${ZIG_VERSION_MAJOR}.${ZIG_VERSION_MINOR}.${ZIG_VERSION_PATCH}")
 message("Configuring zig version ${ZIG_VERSION}")
 
+set(ZIG_LIBC_LIB_DIR "" CACHE STRING "Default native target libc directory where crt1.o can be found")
+set(ZIG_LIBC_STATIC_LIB_DIR "" CACHE STRING "Default native target libc directory where crtbeginT.o can be found")
+set(ZIG_LIBC_INCLUDE_DIR "/usr/include" CACHE STRING "Default native target libc include directory")
+set(ZIG_LD_PATH "ld" CACHE STRING "Path to ld for the native target")
+set(ZIG_DYNAMIC_LINKER "" CACHE STRING "Override dynamic linker for native target")
+
+
+
 find_package(llvm)
 include_directories(${LLVM_INCLUDE_DIRS})
 link_directories(${LLVM_LIBDIRS})
@@ -27,6 +35,7 @@ include_directories(
 )
 
 set(ZIG_SOURCES
+    "${CMAKE_SOURCE_DIR}/src/link.cpp"
     "${CMAKE_SOURCE_DIR}/src/target.cpp"
     "${CMAKE_SOURCE_DIR}/src/ast_render.cpp"
     "${CMAKE_SOURCE_DIR}/src/bignum.cpp"