Add __attribute__((sentinel)) tags to execl and friends.
Give a compile time diagnostic when the nullptr sentinel is missing
from an execl family call, instead of just pulling arbitrary values.
Bug: http://b/30793878
Change-Id: I1c49005c58b7ad4a5b04f0435b722d4c744e8f0e
Test: Built bullhead
diff --git a/libc/include/unistd.h b/libc/include/unistd.h
index c792289..86949de 100644
--- a/libc/include/unistd.h
+++ b/libc/include/unistd.h
@@ -97,9 +97,10 @@
int execvp(const char* __file, char* const* __argv);
int execvpe(const char* __file, char* const* __argv, char* const* __envp) __INTRODUCED_IN(21);
int execve(const char* __file, char* const* __argv, char* const* __envp);
-int execl(const char* __path, const char* __arg0, ...);
-int execlp(const char* __file, const char* __arg0, ...);
-int execle(const char* __path, const char* __arg0, ...);
+int execl(const char* __path, const char* __arg0, ...) __attribute__((__sentinel__));
+int execlp(const char* __file, const char* __arg0, ...) __attribute__((__sentinel__));
+int execle(const char* __path, const char* __arg0, ... /*, char* const* __envp */)
+ __attribute__((__sentinel__(1)));
int nice(int __incr);