From fefbee166d68d17dd0d5904fc52f72397fb51092 Mon Sep 17 00:00:00 2001
From: Andrew Kelley <superjoe30@gmail.com>
Date: Tue, 24 Nov 2015 13:51:36 -0700
Subject: [PATCH] hello world example working

---
 CMakeLists.txt  |  1 +
 src/codegen.cpp | 14 +++++++++++++-
 src/os.cpp      | 33 +++++++++++++++++++++++++++++++++
 src/os.hpp      | 16 ++++++++++++++++
 test/add.zig    |  4 ++--
 5 files changed, 65 insertions(+), 3 deletions(-)
 create mode 100644 src/os.cpp
 create mode 100644 src/os.hpp

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5310a16d7f..8c60947973 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -31,6 +31,7 @@ set(ZIG_SOURCES
     "${CMAKE_SOURCE_DIR}/src/util.cpp"
     "${CMAKE_SOURCE_DIR}/src/codegen.cpp"
     "${CMAKE_SOURCE_DIR}/src/zig_llvm.cpp"
+    "${CMAKE_SOURCE_DIR}/src/os.cpp"
 )
 
 set(CONFIGURE_OUT_FILE "${CMAKE_BINARY_DIR}/config.h")
diff --git a/src/codegen.cpp b/src/codegen.cpp
index 5669408be5..a9e7383321 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -8,6 +8,7 @@
 #include "codegen.hpp"
 #include "hash_map.hpp"
 #include "zig_llvm.hpp"
+#include "os.hpp"
 
 #include <stdio.h>
 
@@ -422,7 +423,18 @@ void code_gen_link(CodeGen *g, bool is_static, const char *out_file) {
     LLVMTargetMachineRef target_machine = LLVMCreateTargetMachine(target_ref, native_triple,
             native_cpu, native_features, opt_level, reloc_mode, LLVMCodeModelDefault);
 
-    if (LLVMTargetMachineEmitToFile(target_machine, g->mod, strdup(out_file), LLVMObjectFile, &err_msg)) {
+    Buf out_file_o = {0};
+    buf_init_from_str(&out_file_o, out_file);
+    buf_append_str(&out_file_o, ".o");
+
+    if (LLVMTargetMachineEmitToFile(target_machine, g->mod, buf_ptr(&out_file_o), LLVMObjectFile, &err_msg)) {
         zig_panic("unable to write object file: %s", err_msg);
     }
+
+    ZigList<const char *> args = {0};
+    args.append("-o");
+    args.append(out_file);
+    args.append((const char *)buf_ptr(&out_file_o));
+    args.append("-lc");
+    os_spawn_process("ld", args, false);
 }
diff --git a/src/os.cpp b/src/os.cpp
new file mode 100644
index 0000000000..25ce873772
--- /dev/null
+++ b/src/os.cpp
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2015 Andrew Kelley
+ *
+ * This file is part of zig, which is MIT licensed.
+ * See http://opensource.org/licenses/MIT
+ */
+
+#include "os.hpp"
+#include "util.hpp"
+
+#include <unistd.h>
+#include <errno.h>
+
+void os_spawn_process(const char *exe, ZigList<const char *> &args, bool detached) {
+    pid_t pid = fork();
+    if (pid == -1)
+        zig_panic("fork failed");
+    if (pid != 0)
+        return;
+    if (detached) {
+        if (setsid() == -1)
+            zig_panic("process detach failed");
+    }
+
+    const char **argv = allocate<const char *>(args.length + 2);
+    argv[0] = exe;
+    argv[args.length + 1] = nullptr;
+    for (int i = 0; i < args.length; i += 1) {
+        argv[i + 1] = args.at(i);
+    }
+    execvp(exe, const_cast<char * const *>(argv));
+    zig_panic("execvp failed: %s", strerror(errno));
+}
diff --git a/src/os.hpp b/src/os.hpp
new file mode 100644
index 0000000000..90487e043b
--- /dev/null
+++ b/src/os.hpp
@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2015 Andrew Kelley
+ *
+ * This file is part of zig, which is MIT licensed.
+ * See http://opensource.org/licenses/MIT
+ */
+
+#ifndef ZIG_OS_HPP
+#define ZIG_OS_HPP
+
+#include "list.hpp"
+#include "buffer.hpp"
+
+void os_spawn_process(const char *exe, ZigList<const char *> &args, bool detached);
+
+#endif
diff --git a/test/add.zig b/test/add.zig
index b25094575d..bb0175bff2 100644
--- a/test/add.zig
+++ b/test/add.zig
@@ -1,3 +1,3 @@
-pub fn add(a: int, b: int) -> int {
-    a + b
+export fn add(a: i32, b: i32) -> i32 {
+    return a + b;
 }