From 23a92ca9bd8780101b7bb42a567bb54a2892815e Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Sun, 20 May 2018 16:45:43 -0400
Subject: [PATCH] pull in getopt; add -o argument to specify output file name

---
 src/main.cc | 55 +++++++++++++++++++++++++++++++++++++++++++++++++----
 wscript     |  1 +
 2 files changed, 52 insertions(+), 4 deletions(-)

diff --git a/src/main.cc b/src/main.cc
index 2863ef8..358ab68 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -6,6 +6,7 @@
 #include <sys/wait.h>
 #include <stdbool.h>
 #include <string.h>
+#include <getopt.h>
 
 static char preprocessed_fname[] = "/tmp/cxlppXXXXXX";
 static char c_fname[] = "/tmp/cxlcXXXXXX.c";
@@ -88,7 +89,7 @@ bool emit_c(Node * node)
     return true;
 }
 
-bool compile()
+bool compile(const char * output_fname)
 {
     pid_t pid = fork();
     if (pid < 0)
@@ -98,7 +99,7 @@ bool compile()
     }
     else if (pid == 0)
     {
-        execlp("gcc", "gcc", "-c", c_fname, "-o", "out.o", NULL);
+        execlp("gcc", "gcc", "-c", c_fname, "-o", output_fname, NULL);
     }
     else
     {
@@ -107,9 +108,55 @@ bool compile()
     return true;
 }
 
+std::string g_output_fname;
+const char * build_output_fname(const char * input_fname)
+{
+    g_output_fname = input_fname;
+    size_t pos = g_output_fname.rfind(".");
+    if (pos != std::string::npos)
+    {
+        g_output_fname.replace(pos, g_output_fname.size() - pos, ".o");
+    }
+    else
+    {
+        g_output_fname += ".o";
+    }
+    return g_output_fname.c_str();
+}
+
 int main(int argc, char * argv[])
 {
-    bool preprocess_successful = preprocess(argv[1]);
+    int opt;
+    int option_index;
+    const char * output_fname = nullptr;
+
+    static const struct option long_options[] = {
+        { NULL, 0, NULL, 0 },
+    };
+
+    while ((opt = getopt_long(argc, argv, "o:", long_options, &option_index)) != -1)
+    {
+        switch (opt)
+        {
+        case 'o':
+            output_fname = optarg;
+            break;
+        }
+    }
+
+    if (optind >= argc)
+    {
+        return -2;
+    }
+
+    const char * input_fname = argv[optind];
+
+    if (output_fname == nullptr)
+    {
+        output_fname = build_output_fname(input_fname);
+    }
+
+    bool preprocess_successful = preprocess(input_fname);
     if (preprocess_successful)
     {
         Node * node = parse(preprocessed_fname);
@@ -117,7 +164,7 @@ int main(int argc, char * argv[])
         {
             if (emit_c(node))
             {
-                compile();
+                compile(output_fname);
             }
         }
     }
diff --git a/wscript b/wscript
index 142a301..610e0a7 100644
--- a/wscript
+++ b/wscript
@@ -7,6 +7,7 @@ def options(opt):
 
 def configure(conf):
     conf.load("compiler_c compiler_cxx flex bison");
+    conf.check(header_name = "getopt.h", global_define = False)
 
 def build(bld):
     bld.load("compiler_c compiler_cxx flex bison");