enable multiple-exit() detection

3 files changed, 10 insertions, 10 deletions

diff --git a/src/stdlib/_stdlib.h b/src/stdlib/_stdlib.h
index 4d456594..82b7943d 100644
--- a/src/stdlib/_stdlib.h
+++ b/src/stdlib/_stdlib.h
@@ -19,6 +19,8 @@ struct __stdlib {
         	struct atexit *next;
         	struct atexit *prev;
 	} atexit;
+	int exit_called;
+	int quick_exit_called;
 	unsigned int rand;
 	char **environ;
 	constraint_handler_t constraint_handler;
diff --git a/src/stdlib/atexit.c b/src/stdlib/atexit.c
index d48b9d0e..79b486d0 100644
--- a/src/stdlib/atexit.c
+++ b/src/stdlib/atexit.c
@@ -1,5 +1,3 @@
-#if 0
-
 #include <errno.h>
 #include <stdlib.h>
 #include "_stdlib.h"
@@ -38,6 +36,3 @@ RETURN_FAILURE(NONZERO)
 RETURN_SUCCESS(0)
 STDC(1)
 */
-
-
-#endif
diff --git a/src/stdlib/exit.c b/src/stdlib/exit.c
index 55800ace..60a933b8 100644
--- a/src/stdlib/exit.c
+++ b/src/stdlib/exit.c
@@ -1,5 +1,3 @@
-#if 0
-
 #include <stdlib.h>
 #include <stdio.h>
 #include "_stdlib.h"
@@ -11,6 +9,14 @@ _Noreturn void exit(int status)
 	long scno = __syscall_lookup(exit);
 	struct atexit *ae = &(__stdlib.atexit);
 
+	if (__stdlib.quick_exit_called) {
+		__stdlib.constraint_handler("Undefined behavior: exit() called after quick_exit()", NULL, 0);
+	}
+	if (__stdlib.exit_called) {
+		__stdlib.constraint_handler("Undefined behavior: exit() called twice", NULL, 0);
+	}
+	__stdlib.exit_called = 1;
+
 	/* execute all atexit() registered functions in reverse order */
 	while (ae) {
 		int i = ae->nfns;
@@ -47,6 +53,3 @@ IMPLEMENTATION(The unsuccessful termination value returned to the host environme
 /*
 STDC(1)
 */
-
-
-#endif