/* -*- c-file-style: "java"; indent-tabs-mode: nil; fill-column: 78; -*- * * distcc -- A simple distributed compiler system * * Copyright (C) 2002 by Martin Pool <mbp@samba.org> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of the * License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 * USA */ /* "I do not trouble myself to be understood. I see * that the elementary laws never apologize." * -- Whitman, "Song of Myself". */ #include "config.h" #include <stdio.h> #include <stdlib.h> #include <string.h> #include <errno.h> #include <sys/types.h> #include "distcc.h" #include "trace.h" #include "exitcode.h" #include "util.h" #include "implicit.h" /** * @file * * Handle invocations where the compiler name is implied rather than * specified. * * This is used on the client only. The compiler name is always passed (as * argv[0]) to the server. * * The current implementation determines that no compiler name has been * specified by checking whether the first argument is either an option, or a * source file name. If not, it is assumed to be the name of the compiler to * use. * * At the moment the compiler name is always "cc", but this could change to * come from an environment variable. * * This would also allow installing distcc under the name "cc", and then * pointing DISTCC_CC=gcc.real or some such. When this is done, we perhaps * ought to set an environment variable to prevent inadvertent infinite * recursion. * * The main shortcoming of that approach is that it would means all * invocations of distcc from the same Makefile probably have to end * up calling the same compiler. For example, if both $(CC) and * $(CXX) are set to "distcc", then they can't be different remotely. * On the other hand, since "gcc" is our main target and it can handle * both C and C++ this is not important. Using several different * compilers would be a bit strange. * * An alternative approach would be to examine our argv[0], and if * it's not "distcc" then conclude we are being implicitly invoked. * This would allow argv[0] to be used as the real compiler name. * There are a few disadvantages, though: * * <ol><li>Examining argv[1] is apparently unambiguous and simpler. * * <li>argv[0] tricks can be confusing and are deprecated by the GNU * Standards. * * <li>Requiring distcc to appear under this name on the correct PATH * may make installation more complex: people will need to get their * PATH set correctly, etc. * * </ol> **/ /* * FIXME: Handle "distcc hello.o -o hello". How are we meant to work * this one out? By seeing that the first argument is a .o file? * Mozilla does this. * * FIXME: Some people depend on calling the compiler "c++" or "g++", * because they have c++ source called foo.c. */ /** * If we're invoked with no compiler name, insert one. Either use an * environment variable, or "cc" by default. You can tell there's no * compiler name because argv[1] will be either a source filename or * an option. I don't think anything else is possible. **/ int dcc_find_compiler(char **argv, char ***out_argv) { if (argv[1][0] == '-' || dcc_is_source(argv[1])) { dcc_shallowcopy_argv(argv, out_argv, 0); /* FIXME: Allow the command name to be specified by a * client-side environment variable */ /* change "distcc -c foo.c" -> "cc -c foo.c" */ (*out_argv)[0] = strdup("cc"); return 0; } else { /* skip "distcc", point to "gcc -c foo.c" */ *out_argv = argv+1; return 0; } }