From 94085e8a219c0015acc27fff99df16ee8ebe60c3 Mon Sep 17 00:00:00 2001
From: Joel Rosdahl <joel@rosdahl.net>
Date: Wed, 3 Jun 2015 21:10:46 +0200
Subject: [PATCH] Avoid calling exit() inside an exit handler

---
 NEWS.txt  |  2 ++
 ccache.c  | 14 +++++++-------
 ccache.h  |  1 +
 execute.c |  4 ++--
 exitfn.c  |  4 ++--
 util.c    | 24 ++++++++++++++++++++----
 6 files changed, 34 insertions(+), 15 deletions(-)

diff --git a/NEWS.txt b/NEWS.txt
index 22fe37836..cd622411d 100644
--- a/NEWS.txt
+++ b/NEWS.txt
@@ -10,6 +10,8 @@ Bug fixes
 
 - Support external zlib in nonstandard directory.
 
+- Avoid calling `exit()` inside an exit handler.
+
 
 ccache 3.2.2
 ------------
diff --git a/ccache.c b/ccache.c
index cb7e72eac..0b5694663 100644
--- a/ccache.c
+++ b/ccache.c
@@ -917,7 +917,7 @@ to_cache(struct args *args)
 			close(fd);
 			tmp_unlink(tmp_stderr);
 
-			exit(status);
+			x_exit(status);
 		}
 
 		tmp_unlink(tmp_stderr);
@@ -1647,7 +1647,7 @@ from_cache(enum fromcache_call_mode mode, bool put_object_in_manifest)
 	}
 
 	/* and exit with the right status code */
-	exit(0);
+	x_exit(0);
 }
 
 /* find the real compiler. We just search the PATH to find a executable of the
@@ -2864,7 +2864,7 @@ ccache(int argc, char *argv[])
 	/* run real compiler, sending output to cache */
 	to_cache(compiler_args);
 
-	exit(0);
+	x_exit(0);
 }
 
 static void
@@ -2919,7 +2919,7 @@ ccache_main_options(int argc, char *argv[])
 
 		case 'h': /* --help */
 			fputs(USAGE_TEXT, stdout);
-			exit(0);
+			x_exit(0);
 
 		case 'F': /* --max-files */
 			{
@@ -2990,7 +2990,7 @@ ccache_main_options(int argc, char *argv[])
 
 		case 'V': /* --version */
 			fprintf(stdout, VERSION_TEXT, CCACHE_VERSION);
-			exit(0);
+			x_exit(0);
 
 		case 'z': /* --zero-stats */
 			initialize();
@@ -3000,7 +3000,7 @@ ccache_main_options(int argc, char *argv[])
 
 		default:
 			fputs(USAGE_TEXT, stderr);
-			exit(1);
+			x_exit(1);
 		}
 	}
 
@@ -3015,7 +3015,7 @@ ccache_main(int argc, char *argv[])
 	if (same_executable_name(program_name, MYNAME)) {
 		if (argc < 2) {
 			fputs(USAGE_TEXT, stderr);
-			exit(1);
+			x_exit(1);
 		}
 		/* if the first argument isn't an option, then assume we are
 		   being passed a compiler name and options */
diff --git a/ccache.h b/ccache.h
index 6028f46c6..819b7a437 100644
--- a/ccache.h
+++ b/ccache.h
@@ -164,6 +164,7 @@ char *get_relative_path(const char *from, const char *to);
 bool is_absolute_path(const char *path);
 bool is_full_path(const char *path);
 void update_mtime(const char *path);
+void x_exit(int status) ATTR_NORETURN;
 int x_rename(const char *oldpath, const char *newpath);
 int tmp_unlink(const char *path);
 int x_unlink(const char *path);
diff --git a/execute.c b/execute.c
index 94d605dc6..3b57a6971 100644
--- a/execute.c
+++ b/execute.c
@@ -214,7 +214,7 @@ win32execute(char *path, char **argv, int doreturn,
 	CloseHandle(pi.hProcess);
 	CloseHandle(pi.hThread);
 	if (!doreturn)
-		exit(exitcode);
+		x_exit(exitcode);
 	return exitcode;
 }
 
@@ -242,7 +242,7 @@ execute(char **argv, int fd_out, int fd_err)
 		close(fd_out);
 		dup2(fd_err, 2);
 		close(fd_err);
-		exit(execv(argv[0], argv));
+		x_exit(execv(argv[0], argv));
 	}
 
 	close(fd_out);
diff --git a/exitfn.c b/exitfn.c
index bf98e5ec7..5d76eeead 100644
--- a/exitfn.c
+++ b/exitfn.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2010, 2012 Joel Rosdahl
+ * Copyright (C) 2010-2015 Joel Rosdahl
  *
  * 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
@@ -84,11 +84,11 @@ void
 exitfn_call(void)
 {
 	struct exit_function *p = exit_functions, *q;
+	exit_functions = NULL;
 	while (p) {
 		p->function(p->context);
 		q = p;
 		p = p->next;
 		free(q);
 	}
-	exit_functions = NULL;
 }
diff --git a/util.c b/util.c
index 658cab6a9..5cc9795cc 100644
--- a/util.c
+++ b/util.c
@@ -118,7 +118,7 @@ warn_log_fail(void)
 	/* Note: Can't call fatal() since that would lead to recursion. */
 	fprintf(stderr, "ccache: error: Failed to write to %s: %s\n",
 	        conf->log_file, strerror(errno));
-	exit(EXIT_FAILURE);
+	x_exit(EXIT_FAILURE);
 }
 
 static void
@@ -180,8 +180,9 @@ cc_log_argv(const char *prefix, char **argv)
 	fputs(prefix, logfile);
 	print_command(logfile, argv);
 	rc = fflush(logfile);
-	if (rc)
+	if (rc) {
 		warn_log_fail();
+	}
 }
 
 /* something went badly wrong! */
@@ -198,7 +199,7 @@ fatal(const char *format, ...)
 	cc_log("FATAL: %s", msg);
 	fprintf(stderr, "ccache: error: %s\n", msg);
 
-	exit(1);
+	x_exit(1);
 }
 
 /*
@@ -1425,9 +1426,24 @@ update_mtime(const char *path)
 }
 
 /*
- * Rename oldpath to newpath (deleting newpath).
+ * If exit() already has been called, call _exit(), otherwise exit(). This is
+ * used to avoid calling exit() inside an atexit handler.
  */
+void
+x_exit(int status)
+{
+	static bool first_time = true;
+	if (first_time) {
+		first_time = false;
+		exit(status);
+	} else {
+		_exit(status);
+	}
+}
 
+/*
+ * Rename oldpath to newpath (deleting newpath).
+ */
 int
 x_rename(const char *oldpath, const char *newpath)
 {
-- 
2.47.2