Factor out the code to find gcc, and add a command-line option to override the

default executable name.
This should help cross-compilation by allowing a cross-gcc to be specified from
the configuration file instead of only through the CC environment variable.

gen/linker.cpp

@@ -14,6 +14,7 @@
 #include "gen/logger.h"
 #include "gen/cl_options.h"
 #include "gen/optimizer.h"
+#include "gen/programs.h"
 
 //////////////////////////////////////////////////////////////////////////////
 
@@ -216,25 +217,16 @@ int linkObjToExecutable(const char* argv0)
     // error string
     std::string errstr;
 
-    const char *cc;
-#if !_WIN32
-    cc = getenv("CC");
-    if (!cc)
-#endif
-	cc = "gcc";
-
     // find gcc for linking
-    llvm::sys::Path gcc = llvm::sys::Program::FindProgramByName(cc);
-    if (gcc.isEmpty())
-    {
-        gcc.set(cc);
-    }
+    llvm::sys::Path gcc = getGcc();
+    // get a string version for argv[0]
+    std::string gccStr = gcc.toString();
 
     // build arguments
     std::vector<const char*> args;
 
     // first the program name ??
-    args.push_back(cc);
+    args.push_back(gccStr.c_str());
 
     // object files
     for (int i = 0; i < global.params.objfiles->dim; i++)