diff --git a/libc/include/android/dlext.h b/libc/include/android/dlext.h
index ca3bd25..c824544 100644
--- a/libc/include/android/dlext.h
+++ b/libc/include/android/dlext.h
@@ -129,7 +129,7 @@
   struct android_namespace_t* library_namespace;
 } android_dlextinfo;
 
-void* android_dlopen_ext(const char* filename, int flag, const android_dlextinfo* extinfo)
+void* android_dlopen_ext(const char* __filename, int __flags, const android_dlextinfo* __info)
   __INTRODUCED_IN(21);
 
 __END_DECLS
diff --git a/libc/include/android/legacy_signal_inlines.h b/libc/include/android/legacy_signal_inlines.h
index 09db2a6..4d474b0 100644
--- a/libc/include/android/legacy_signal_inlines.h
+++ b/libc/include/android/legacy_signal_inlines.h
@@ -39,7 +39,7 @@
 
 #if __ANDROID_API__ < __ANDROID_API_L__
 
-sighandler_t bsd_signal(int signum, sighandler_t handler) __REMOVED_IN(21);
+sighandler_t bsd_signal(int __signal, sighandler_t __handler) __REMOVED_IN(21);
 
 /* These weren't introduced until L. */
 int __libc_current_sigrtmax() __attribute__((__weak__)) __VERSIONER_NO_GUARD;
diff --git a/libc/include/android/legacy_sys_stat_inlines.h b/libc/include/android/legacy_sys_stat_inlines.h
index 23a9f07..bbf54c0 100644
--- a/libc/include/android/legacy_sys_stat_inlines.h
+++ b/libc/include/android/legacy_sys_stat_inlines.h
@@ -36,8 +36,8 @@
 
 __BEGIN_DECLS
 
-static __inline int mkfifo(const char *__p, mode_t __m) {
-  return mknod(__p, (__m & ~S_IFMT) | S_IFIFO, (dev_t)0);
+static __inline int mkfifo(const char* __path, mode_t __mode) {
+  return mknod(__path, (__mode & ~S_IFMT) | S_IFIFO, (dev_t)0);
 }
 
 __END_DECLS
diff --git a/libc/include/android/set_abort_message.h b/libc/include/android/set_abort_message.h
index 18881a3..3dde673 100644
--- a/libc/include/android/set_abort_message.h
+++ b/libc/include/android/set_abort_message.h
@@ -33,7 +33,7 @@
 
 __BEGIN_DECLS
 
-void android_set_abort_message(const char* msg) __INTRODUCED_IN(21);
+void android_set_abort_message(const char* __msg) __INTRODUCED_IN(21);
 
 __END_DECLS
 
diff --git a/libc/include/bits/fcntl.h b/libc/include/bits/fcntl.h
index 604d35a..e3b0e8c 100644
--- a/libc/include/bits/fcntl.h
+++ b/libc/include/bits/fcntl.h
@@ -33,7 +33,7 @@
 
 __BEGIN_DECLS
 
-int fcntl(int, int, ...);
+int fcntl(int __fd, int __cmd, ...);
 
 __END_DECLS
 
diff --git a/libc/include/bits/getopt.h b/libc/include/bits/getopt.h
index 7153d48..5481449 100644
--- a/libc/include/bits/getopt.h
+++ b/libc/include/bits/getopt.h
@@ -33,9 +33,9 @@
 
 __BEGIN_DECLS
 
-int	 getopt(int, char * const [], const char *);
+int getopt(int __argc, char* const __argv[], const char* __options);
 
-extern char *optarg;			/* getopt(3) external variables */
+extern char* optarg;
 extern int optind, opterr, optopt;
 
 __END_DECLS
diff --git a/libc/include/bits/ioctl.h b/libc/include/bits/ioctl.h
index 53116ca..0cf87d2 100644
--- a/libc/include/bits/ioctl.h
+++ b/libc/include/bits/ioctl.h
@@ -33,7 +33,7 @@
 
 __BEGIN_DECLS
 
-int ioctl(int, int, ...);
+int ioctl(int __fd, int __request, ...);
 
 __END_DECLS
 
diff --git a/libc/include/bits/lockf.h b/libc/include/bits/lockf.h
index a8e273e..929c68c 100644
--- a/libc/include/bits/lockf.h
+++ b/libc/include/bits/lockf.h
@@ -39,8 +39,8 @@
 
 __BEGIN_DECLS
 
-int lockf(int, int, off_t) __RENAME_IF_FILE_OFFSET64(lockf64) __INTRODUCED_IN(24);
-int lockf64(int, int, off64_t) __INTRODUCED_IN(24);
+int lockf(int __fd, int __cmd, off_t __length) __RENAME_IF_FILE_OFFSET64(lockf64) __INTRODUCED_IN(24);
+int lockf64(int __fd, int __cmd, off64_t __length) __INTRODUCED_IN(24);
 
 __END_DECLS
 
diff --git a/libc/include/bits/strcasecmp.h b/libc/include/bits/strcasecmp.h
index df1a6b8..594046a 100644
--- a/libc/include/bits/strcasecmp.h
+++ b/libc/include/bits/strcasecmp.h
@@ -35,10 +35,10 @@
 
 __BEGIN_DECLS
 
-int strcasecmp(const char*, const char*) __attribute_pure__;
-int strcasecmp_l(const char*, const char*, locale_t) __attribute_pure__ __INTRODUCED_IN(23);
-int strncasecmp(const char*, const char*, size_t) __attribute_pure__;
-int strncasecmp_l(const char*, const char*, size_t, locale_t) __attribute_pure__ __INTRODUCED_IN(23);
+int strcasecmp(const char* __s1, const char* __s2) __attribute_pure__;
+int strcasecmp_l(const char* __s1, const char* __s2, locale_t __l) __attribute_pure__ __INTRODUCED_IN(23);
+int strncasecmp(const char* __s1, const char* __s2, size_t __n) __attribute_pure__;
+int strncasecmp_l(const char* __s1, const char* __s2, size_t __n, locale_t __l) __attribute_pure__ __INTRODUCED_IN(23);
 
 __END_DECLS
 
diff --git a/libc/include/bits/wctype.h b/libc/include/bits/wctype.h
index f21d46e..a51eca2 100644
--- a/libc/include/bits/wctype.h
+++ b/libc/include/bits/wctype.h
@@ -37,29 +37,29 @@
 
 #define WEOF __BIONIC_CAST(static_cast, wint_t, -1)
 
-int iswalnum(wint_t);
-int iswalpha(wint_t);
-int iswblank(wint_t) __INTRODUCED_IN(21);
-int iswcntrl(wint_t);
-int iswdigit(wint_t);
-int iswgraph(wint_t);
-int iswlower(wint_t);
-int iswprint(wint_t);
-int iswpunct(wint_t);
-int iswspace(wint_t);
-int iswupper(wint_t);
-int iswxdigit(wint_t);
+int iswalnum(wint_t __wc);
+int iswalpha(wint_t __wc);
+int iswblank(wint_t __wc) __INTRODUCED_IN(21);
+int iswcntrl(wint_t __wc);
+int iswdigit(wint_t __wc);
+int iswgraph(wint_t __wc);
+int iswlower(wint_t __wc);
+int iswprint(wint_t __wc);
+int iswpunct(wint_t __wc);
+int iswspace(wint_t __wc);
+int iswupper(wint_t __wc);
+int iswxdigit(wint_t __wc);
 
-wint_t towlower(wint_t);
-wint_t towupper(wint_t);
+wint_t towlower(wint_t __wc);
+wint_t towupper(wint_t __wc);
 
 typedef long wctype_t;
-wctype_t wctype(const char*);
-int iswctype(wint_t, wctype_t);
+wctype_t wctype(const char* __name);
+int iswctype(wint_t __wc, wctype_t __type);
 
 typedef const void* wctrans_t;
-wint_t towctrans(wint_t, wctrans_t) __INTRODUCED_IN(26) __VERSIONER_NO_GUARD;
-wctrans_t wctrans(const char*) __INTRODUCED_IN(26) __VERSIONER_NO_GUARD;
+wint_t towctrans(wint_t __wc, wctrans_t __transform) __INTRODUCED_IN(26) __VERSIONER_NO_GUARD;
+wctrans_t wctrans(const char* __name) __INTRODUCED_IN(26) __VERSIONER_NO_GUARD;
 
 __END_DECLS
 
diff --git a/libc/include/fts.h b/libc/include/fts.h
index b46c19c..3649d3a 100644
--- a/libc/include/fts.h
+++ b/libc/include/fts.h
@@ -115,12 +115,13 @@
 } FTSENT;
 
 __BEGIN_DECLS
-FTSENT	*fts_children(FTS *, int);
-int	 fts_close(FTS *);
-FTS	*fts_open(char * const *, int,
-	    int (*)(const FTSENT **, const FTSENT **));
-FTSENT	*fts_read(FTS *);
-int	 fts_set(FTS *, FTSENT *, int);
+
+FTSENT* fts_children(FTS* __fts, int __options);
+int fts_close(FTS* __fts);
+FTS* fts_open(char* const* __path, int __options, int (*__comparator)(const FTSENT** __lhs, const FTSENT** __rhs));
+FTSENT* fts_read(FTS* __fts);
+int fts_set(FTS* __fts, FTSENT* __entry, int __options);
+
 __END_DECLS
 
 #endif /* !_FTS_H_ */
diff --git a/libc/include/malloc.h b/libc/include/malloc.h
index db5da04..80b08f6 100644
--- a/libc/include/malloc.h
+++ b/libc/include/malloc.h
@@ -30,13 +30,13 @@
 #define __BIONIC_ALLOC_SIZE(...) __attribute__((__alloc_size__(__VA_ARGS__)))
 #endif
 
-void* malloc(size_t byte_count) __mallocfunc __BIONIC_ALLOC_SIZE(1) __wur;
-void* calloc(size_t item_count, size_t item_size) __mallocfunc __BIONIC_ALLOC_SIZE(1,2) __wur;
-void* realloc(void* p, size_t byte_count) __BIONIC_ALLOC_SIZE(2) __wur;
-void free(void* p);
+void* malloc(size_t __byte_count) __mallocfunc __BIONIC_ALLOC_SIZE(1) __wur;
+void* calloc(size_t __item_count, size_t __item_size) __mallocfunc __BIONIC_ALLOC_SIZE(1,2) __wur;
+void* realloc(void* __ptr, size_t __byte_count) __BIONIC_ALLOC_SIZE(2) __wur;
+void free(void* __ptr);
 
-void* memalign(size_t alignment, size_t byte_count) __mallocfunc __BIONIC_ALLOC_SIZE(2) __wur;
-size_t malloc_usable_size(const void* p) __INTRODUCED_IN(17);
+void* memalign(size_t __alignment, size_t __byte_count) __mallocfunc __BIONIC_ALLOC_SIZE(2) __wur;
+size_t malloc_usable_size(const void* __ptr) __INTRODUCED_IN(17);
 
 #ifndef STRUCT_MALLINFO_DECLARED
 #define STRUCT_MALLINFO_DECLARED 1
@@ -75,12 +75,11 @@
  *   <!-- more heaps -->
  * </malloc>
  */
-int malloc_info(int, FILE*) __INTRODUCED_IN(23);
+int malloc_info(int __must_be_zero, FILE* __fp) __INTRODUCED_IN(23);
 
 /* mallopt options */
 #define M_DECAY_TIME -100
-
-int mallopt(int, int) __INTRODUCED_IN(26);
+int mallopt(int __option, int __value) __INTRODUCED_IN(26);
 
 __END_DECLS
 
diff --git a/libc/include/netinet/ether.h b/libc/include/netinet/ether.h
index e69cdaf..3e6a4e3 100644
--- a/libc/include/netinet/ether.h
+++ b/libc/include/netinet/ether.h
@@ -34,10 +34,10 @@
 
 __BEGIN_DECLS
 
-char* ether_ntoa(const struct ether_addr*) __INTRODUCED_IN(11);
-char* ether_ntoa_r(const struct ether_addr*, char*) __INTRODUCED_IN(11);
-struct ether_addr* ether_aton(const char*) __INTRODUCED_IN(11);
-struct ether_addr* ether_aton_r(const char*, struct ether_addr*) __INTRODUCED_IN(11);
+char* ether_ntoa(const struct ether_addr* __addr) __INTRODUCED_IN(11);
+char* ether_ntoa_r(const struct ether_addr* __addr, char* __buf) __INTRODUCED_IN(11);
+struct ether_addr* ether_aton(const char* __ascii) __INTRODUCED_IN(11);
+struct ether_addr* ether_aton_r(const char* __ascii, struct ether_addr* __addr) __INTRODUCED_IN(11);
 
 __END_DECLS
 
diff --git a/libc/include/netinet/in.h b/libc/include/netinet/in.h
index 10fbafa..0ca8c82 100644
--- a/libc/include/netinet/in.h
+++ b/libc/include/netinet/in.h
@@ -45,7 +45,7 @@
 typedef uint16_t in_port_t;
 typedef uint32_t in_addr_t;
 
-int bindresvport(int, struct sockaddr_in*);
+int bindresvport(int __fd, struct sockaddr_in* __sin);
 
 #if __ANDROID_API__ >= __ANDROID_API_N__
 extern const struct in6_addr in6addr_any __INTRODUCED_IN(24);
diff --git a/libc/include/sched.h b/libc/include/sched.h
index b8ef44b..de6969f8 100644
--- a/libc/include/sched.h
+++ b/libc/include/sched.h
@@ -42,22 +42,22 @@
   int sched_priority;
 };
 
-int sched_setscheduler(pid_t pid, int policy, const struct sched_param* param);
-int sched_getscheduler(pid_t pid);
+int sched_setscheduler(pid_t __pid, int __policy, const struct sched_param* __param);
+int sched_getscheduler(pid_t __pid);
 int sched_yield(void);
-int sched_get_priority_max(int policy);
-int sched_get_priority_min(int policy);
-int sched_setparam(pid_t pid, const struct sched_param* param);
-int sched_getparam(pid_t pid, struct sched_param* param);
-int sched_rr_get_interval(pid_t pid, struct timespec* quantum);
+int sched_get_priority_max(int __policy);
+int sched_get_priority_min(int __policy);
+int sched_setparam(pid_t __pid, const struct sched_param* __param);
+int sched_getparam(pid_t __pid, struct sched_param* __param);
+int sched_rr_get_interval(pid_t __pid, struct timespec* __quantum);
 
 #if defined(__USE_GNU)
 
-int clone(int (*fn)(void*), void* child_stack, int flags, void* arg, ...)
+int clone(int (*__fn)(void*), void* __child_stack, int __flags, void* __arg, ...)
     __INTRODUCED_IN_ARM(9) __INTRODUCED_IN_MIPS(12) __INTRODUCED_IN_X86(17);
-int unshare(int flags) __INTRODUCED_IN(17);
+int unshare(int __flags) __INTRODUCED_IN(17);
 int sched_getcpu(void) __INTRODUCED_IN(12);
-int setns(int fd, int ns_type) __INTRODUCED_IN(21);
+int setns(int __fd, int __ns_type) __INTRODUCED_IN(21);
 
 #ifdef __LP64__
 #define CPU_SETSIZE 1024
@@ -74,8 +74,8 @@
   __CPU_BITTYPE  __bits[ CPU_SETSIZE / __CPU_BITS ];
 } cpu_set_t;
 
-int sched_setaffinity(pid_t pid, size_t setsize, const cpu_set_t* set) __INTRODUCED_IN(12);
-int sched_getaffinity(pid_t pid, size_t setsize, cpu_set_t* set) __INTRODUCED_IN(12);
+int sched_setaffinity(pid_t __pid, size_t __set_size, const cpu_set_t* __set) __INTRODUCED_IN(12);
+int sched_getaffinity(pid_t __pid, size_t __set_size, cpu_set_t* __set) __INTRODUCED_IN(12);
 
 #define CPU_ZERO(set)          CPU_ZERO_S(sizeof(cpu_set_t), set)
 #define CPU_SET(cpu, set)      CPU_SET_S(cpu, sizeof(cpu_set_t), set)
@@ -98,8 +98,8 @@
 #define CPU_ALLOC(count)  __sched_cpualloc((count))
 #define CPU_FREE(set)     __sched_cpufree((set))
 
-cpu_set_t* __sched_cpualloc(size_t count) __INTRODUCED_IN(12);
-void __sched_cpufree(cpu_set_t* set) __INTRODUCED_IN(12);
+cpu_set_t* __sched_cpualloc(size_t __count) __INTRODUCED_IN(12);
+void __sched_cpufree(cpu_set_t* __set) __INTRODUCED_IN(12);
 
 #define CPU_ZERO_S(setsize, set)  __builtin_memset(set, 0, setsize)
 
@@ -143,7 +143,7 @@
 
 #define CPU_COUNT_S(setsize, set)  __sched_cpucount((setsize), (set))
 
-int __sched_cpucount(size_t setsize, cpu_set_t* set) __INTRODUCED_IN(12);
+int __sched_cpucount(size_t __set_size, cpu_set_t* __set) __INTRODUCED_IN(12);
 
 #endif /* __USE_GNU */
 
diff --git a/libc/include/signal.h b/libc/include/signal.h
index 89d85fc..ece2916 100644
--- a/libc/include/signal.h
+++ b/libc/include/signal.h
@@ -109,55 +109,55 @@
 
 #endif
 
-int sigaction(int, const struct sigaction*, struct sigaction*);
+int sigaction(int __signal, const struct sigaction* __new_action, struct sigaction* __old_action);
 
-int siginterrupt(int, int);
+int siginterrupt(int __signal, int __flag);
 
 #if __ANDROID_API__ >= __ANDROID_API_L__
-sighandler_t signal(int, sighandler_t) __INTRODUCED_IN(21);
-int sigaddset(sigset_t*, int) __INTRODUCED_IN(21);
-int sigdelset(sigset_t*, int) __INTRODUCED_IN(21);
-int sigemptyset(sigset_t*) __INTRODUCED_IN(21);
-int sigfillset(sigset_t*) __INTRODUCED_IN(21);
-int sigismember(const sigset_t*, int) __INTRODUCED_IN(21);
+sighandler_t signal(int __signal, sighandler_t __handler) __INTRODUCED_IN(21);
+int sigaddset(sigset_t* __set, int __signal) __INTRODUCED_IN(21);
+int sigdelset(sigset_t* __set, int __signal) __INTRODUCED_IN(21);
+int sigemptyset(sigset_t* __set) __INTRODUCED_IN(21);
+int sigfillset(sigset_t* __set) __INTRODUCED_IN(21);
+int sigismember(const sigset_t* __set, int __signal) __INTRODUCED_IN(21);
 #else
 // Implemented as static inlines before 21.
 #endif
 
-int sigpending(sigset_t*);
-int sigprocmask(int, const sigset_t*, sigset_t*);
-int sigsuspend(const sigset_t*);
-int sigwait(const sigset_t*, int*);
+int sigpending(sigset_t* __set);
+int sigprocmask(int __how, const sigset_t* __new_set, sigset_t* __old_set);
+int sigsuspend(const sigset_t* __mask);
+int sigwait(const sigset_t* __set, int* __signal);
 
-int sighold(int)
+int sighold(int __signal)
   __attribute__((deprecated("use sigprocmask() or pthread_sigmask() instead")))
   __INTRODUCED_IN(26);
-int sigignore(int)
+int sigignore(int __signal)
   __attribute__((deprecated("use sigaction() instead"))) __INTRODUCED_IN(26);
-int sigpause(int)
+int sigpause(int __signal)
   __attribute__((deprecated("use sigsuspend() instead"))) __INTRODUCED_IN(26);
-int sigrelse(int)
+int sigrelse(int __signal)
   __attribute__((deprecated("use sigprocmask() or pthread_sigmask() instead")))
   __INTRODUCED_IN(26);
-sighandler_t sigset(int, sighandler_t)
+sighandler_t sigset(int __signal, sighandler_t __handler)
   __attribute__((deprecated("use sigaction() instead"))) __INTRODUCED_IN(26);
 
-int raise(int);
-int kill(pid_t, int);
-int killpg(int, int);
-int tgkill(int tgid, int tid, int sig) __INTRODUCED_IN_32(16);
+int raise(int __signal);
+int kill(pid_t __pid, int __signal);
+int killpg(int __pgrp, int __signal);
+int tgkill(int __tgid, int __tid, int __signal) __INTRODUCED_IN_32(16);
 
-int sigaltstack(const stack_t*, stack_t*);
+int sigaltstack(const stack_t* __new_signal_stack, stack_t* __old_signal_stack);
 
-void psiginfo(const siginfo_t*, const char*) __INTRODUCED_IN(17);
-void psignal(int, const char*) __INTRODUCED_IN(17);
+void psiginfo(const siginfo_t* __info, const char* __msg) __INTRODUCED_IN(17);
+void psignal(int __signal, const char* __msg) __INTRODUCED_IN(17);
 
-int pthread_kill(pthread_t, int);
-int pthread_sigmask(int, const sigset_t*, sigset_t*);
+int pthread_kill(pthread_t __pthread, int __signal);
+int pthread_sigmask(int __how, const sigset_t* __new_set, sigset_t* __old_set);
 
-int sigqueue(pid_t, int, const union sigval) __INTRODUCED_IN(23);
-int sigtimedwait(const sigset_t*, siginfo_t*, const struct timespec*) __INTRODUCED_IN(23);
-int sigwaitinfo(const sigset_t*, siginfo_t*) __INTRODUCED_IN(23);
+int sigqueue(pid_t __pid, int __signal, const union sigval __value) __INTRODUCED_IN(23);
+int sigtimedwait(const sigset_t* __set, siginfo_t* __info, const struct timespec* __timeout) __INTRODUCED_IN(23);
+int sigwaitinfo(const sigset_t* __set, siginfo_t* __info) __INTRODUCED_IN(23);
 
 __END_DECLS
 
diff --git a/libc/include/stdio_ext.h b/libc/include/stdio_ext.h
index 3c5abc3..66a3ab9 100644
--- a/libc/include/stdio_ext.h
+++ b/libc/include/stdio_ext.h
@@ -32,22 +32,23 @@
 #include <sys/cdefs.h>
 #include <stdio.h>
 
-#define FSETLOCKING_QUERY 0
-#define FSETLOCKING_INTERNAL 1
-#define FSETLOCKING_BYCALLER 2
 
 __BEGIN_DECLS
 
-size_t __fbufsize(FILE*) __INTRODUCED_IN(23);
-int __freadable(FILE*) __INTRODUCED_IN(23);
-int __freading(FILE*) __INTRODUCED_IN_FUTURE;
-int __fwritable(FILE*) __INTRODUCED_IN(23);
-int __fwriting(FILE*) __INTRODUCED_IN_FUTURE;
-int __flbf(FILE*) __INTRODUCED_IN(23);
-void __fpurge(FILE*) __INTRODUCED_IN(23);
-size_t __fpending(FILE*) __INTRODUCED_IN(23);
+size_t __fbufsize(FILE* __fp) __INTRODUCED_IN(23);
+int __freadable(FILE* __fp) __INTRODUCED_IN(23);
+int __freading(FILE* __fp) __INTRODUCED_IN_FUTURE;
+int __fwritable(FILE* __fp) __INTRODUCED_IN(23);
+int __fwriting(FILE* __fp) __INTRODUCED_IN_FUTURE;
+int __flbf(FILE* __fp) __INTRODUCED_IN(23);
+void __fpurge(FILE* __fp) __INTRODUCED_IN(23);
+size_t __fpending(FILE* __fp) __INTRODUCED_IN(23);
 void _flushlbf(void) __INTRODUCED_IN(23);
-int __fsetlocking(FILE*, int) __INTRODUCED_IN(23);
+
+#define FSETLOCKING_QUERY 0
+#define FSETLOCKING_INTERNAL 1
+#define FSETLOCKING_BYCALLER 2
+int __fsetlocking(FILE* __fp, int __type) __INTRODUCED_IN(23);
 
 __END_DECLS
 
diff --git a/libc/include/stdlib.h b/libc/include/stdlib.h
index 13c9d37..4182f2d 100644
--- a/libc/include/stdlib.h
+++ b/libc/include/stdlib.h
@@ -42,115 +42,114 @@
 #define EXIT_SUCCESS 0
 
 __noreturn void abort(void);
-__noreturn void exit(int);
-__noreturn void _Exit(int) __INTRODUCED_IN(21);
-int atexit(void (*)(void));
+__noreturn void exit(int __status);
+__noreturn void _Exit(int __status) __INTRODUCED_IN(21);
+int atexit(void (*__fn)(void));
 
-int at_quick_exit(void (*)(void)) __INTRODUCED_IN(21);
-void quick_exit(int) __noreturn __INTRODUCED_IN(21);
+int at_quick_exit(void (*__fn)(void)) __INTRODUCED_IN(21);
+void quick_exit(int __status) __noreturn __INTRODUCED_IN(21);
 
-char* getenv(const char*);
-int putenv(char*);
-int setenv(const char*, const char*, int);
-int unsetenv(const char*);
+char* getenv(const char* __name);
+int putenv(char* __assignment);
+int setenv(const char* __name, const char* __value, int __overwrite);
+int unsetenv(const char* __name);
 int clearenv(void);
 
-char* mkdtemp(char*);
-char* mktemp(char*) __attribute__((deprecated("mktemp is unsafe, use mkstemp or tmpfile instead")));
+char* mkdtemp(char* __template);
+char* mktemp(char* __template) __attribute__((deprecated("mktemp is unsafe, use mkstemp or tmpfile instead")));
 
-int mkostemp64(char*, int) __INTRODUCED_IN(23);
-int mkostemp(char*, int) __INTRODUCED_IN(23);
-int mkostemps64(char*, int, int) __INTRODUCED_IN(23);
-int mkostemps(char*, int, int) __INTRODUCED_IN(23);
-int mkstemp64(char*) __INTRODUCED_IN(21);
-int mkstemp(char*);
-int mkstemps64(char*, int) __INTRODUCED_IN(23);
-int mkstemps(char*, int);
+int mkostemp64(char* __template, int __flags) __INTRODUCED_IN(23);
+int mkostemp(char* __template, int __flags) __INTRODUCED_IN(23);
+int mkostemps64(char* __template, int __suffix_length, int __flags) __INTRODUCED_IN(23);
+int mkostemps(char* __template, int __suffix_length, int __flags) __INTRODUCED_IN(23);
+int mkstemp64(char* __template) __INTRODUCED_IN(21);
+int mkstemp(char* __template);
+int mkstemps64(char* __template, int __flags) __INTRODUCED_IN(23);
+int mkstemps(char* __template, int __flags);
 
-long strtol(const char *, char **, int);
-long long strtoll(const char *, char **, int);
-unsigned long strtoul(const char *, char **, int);
-unsigned long long strtoull(const char *, char **, int);
+long strtol(const char* __s, char** __end_ptr, int __base);
+long long strtoll(const char* __s, char** __end_ptr, int __base);
+unsigned long strtoul(const char* __s, char** __end_ptr, int __base);
+unsigned long long strtoull(const char* __s, char** __end_ptr, int __base);
 
-int posix_memalign(void** memptr, size_t alignment, size_t size) __INTRODUCED_IN(16);
+int posix_memalign(void** __memptr, size_t __alignment, size_t __size) __INTRODUCED_IN(16);
 
-double strtod(const char*, char**);
-long double strtold(const char*, char**) __INTRODUCED_IN(21);
+double strtod(const char* __s, char** __end_ptr);
+long double strtold(const char* __s, char** __end_ptr) __INTRODUCED_IN(21);
 
-unsigned long strtoul_l(const char*, char**, int, locale_t) __INTRODUCED_IN(26);
+unsigned long strtoul_l(const char* __s, char** __end_ptr, int __base, locale_t __l) __INTRODUCED_IN(26);
 
-int atoi(const char*) __attribute_pure__;
-long atol(const char*) __attribute_pure__;
-long long atoll(const char*) __attribute_pure__;
+int atoi(const char* __s) __attribute_pure__;
+long atol(const char* __s) __attribute_pure__;
+long long atoll(const char* __s) __attribute_pure__;
 
-char* realpath(const char* path, char* resolved);
-int system(const char *string);
+char* realpath(const char* __path, char* __resolved);
+int system(const char* __command);
 
-void* bsearch(const void* key, const void* base0, size_t nmemb, size_t size,
-              int (*compar)(const void*, const void*));
+void* bsearch(const void* __key, const void* __base, size_t __nmemb, size_t __size, int (*__comparator)(const void* __lhs, const void* __rhs));
 
-void qsort(void*, size_t, size_t, int (*)(const void*, const void*));
+void qsort(void* __base, size_t __nmemb, size_t __size, int (*__comparator)(const void* __lhs, const void* __rhs));
 
 uint32_t arc4random(void);
-uint32_t arc4random_uniform(uint32_t);
-void arc4random_buf(void*, size_t);
+uint32_t arc4random_uniform(uint32_t __upper_bound);
+void arc4random_buf(void* __buf, size_t __n);
 
 #define RAND_MAX 0x7fffffff
 
-int rand_r(unsigned int*) __INTRODUCED_IN(21);
+int rand_r(unsigned int* __seed_ptr) __INTRODUCED_IN(21);
 
 double drand48(void);
-double erand48(unsigned short[3]);
-long jrand48(unsigned short[3]);
-void lcong48(unsigned short[7]) __INTRODUCED_IN(23);
+double erand48(unsigned short __xsubi[3]);
+long jrand48(unsigned short __xsubi[3]);
+void lcong48(unsigned short __param[7]) __INTRODUCED_IN(23);
 long lrand48(void);
 long mrand48(void);
-long nrand48(unsigned short[3]);
-unsigned short* seed48(unsigned short[3]);
-void srand48(long);
+long nrand48(unsigned short __xsubi[3]);
+unsigned short* seed48(unsigned short __seed16v[3]);
+void srand48(long __seed);
 
-char* initstate(unsigned int, char*, size_t) __INTRODUCED_IN(21);
-char* setstate(char*) __INTRODUCED_IN(21);
+char* initstate(unsigned int __seed, char* __state, size_t __n) __INTRODUCED_IN(21);
+char* setstate(char* __state) __INTRODUCED_IN(21);
 
 int getpt(void);
-int posix_openpt(int) __INTRODUCED_IN(21);
-char* ptsname(int);
-int ptsname_r(int, char*, size_t);
-int unlockpt(int);
+int posix_openpt(int __flags) __INTRODUCED_IN(21);
+char* ptsname(int __fd);
+int ptsname_r(int __fd, char* __buf, size_t __n);
+int unlockpt(int __fd);
 
-int getsubopt(char**, char* const*, char**) __INTRODUCED_IN(26);
+int getsubopt(char** __option, char* const* __tokens, char** __value_ptr) __INTRODUCED_IN(26);
 
 typedef struct {
-    int  quot;
-    int  rem;
+  int quot;
+  int rem;
 } div_t;
 
-div_t div(int, int) __attribute_const__;
+div_t div(int __numerator, int __denominator) __attribute_const__;
 
 typedef struct {
-    long int  quot;
-    long int  rem;
+  long int quot;
+  long int rem;
 } ldiv_t;
 
-ldiv_t ldiv(long, long) __attribute_const__;
+ldiv_t ldiv(long __numerator, long __denominator) __attribute_const__;
 
 typedef struct {
-    long long int  quot;
-    long long int  rem;
+  long long int quot;
+  long long int rem;
 } lldiv_t;
 
-lldiv_t lldiv(long long, long long) __attribute_const__;
+lldiv_t lldiv(long long __numerator, long long __denominator) __attribute_const__;
 
 /* BSD compatibility. */
 const char* getprogname(void) __INTRODUCED_IN(21);
-void setprogname(const char*) __INTRODUCED_IN(21);
+void setprogname(const char* __name) __INTRODUCED_IN(21);
 
-int mblen(const char*, size_t) __INTRODUCED_IN(26) __VERSIONER_NO_GUARD;
-size_t mbstowcs(wchar_t*, const char*, size_t);
-int mbtowc(wchar_t*, const char*, size_t) __INTRODUCED_IN(21) __VERSIONER_NO_GUARD;
-int wctomb(char*, wchar_t) __INTRODUCED_IN(21) __VERSIONER_NO_GUARD;
+int mblen(const char* __s, size_t __n) __INTRODUCED_IN(26) __VERSIONER_NO_GUARD;
+size_t mbstowcs(wchar_t* __dst, const char* __src, size_t __n);
+int mbtowc(wchar_t* __wc_ptr, const char* __s, size_t __n) __INTRODUCED_IN(21) __VERSIONER_NO_GUARD;
+int wctomb(char* __dst, wchar_t __wc) __INTRODUCED_IN(21) __VERSIONER_NO_GUARD;
 
-size_t wcstombs(char*, const wchar_t*, size_t);
+size_t wcstombs(char* __dst, const wchar_t* __src, size_t __n);
 
 #if __ANDROID_API__ >= __ANDROID_API_L__
 size_t __ctype_get_mb_cur_max(void) __INTRODUCED_IN(21);
@@ -169,28 +168,28 @@
 #endif
 
 #if __ANDROID_API__ >= __ANDROID_API_L__
-float strtof(const char*, char**) __INTRODUCED_IN(21);
-double atof(const char*) __attribute_pure__ __INTRODUCED_IN(21);
-int abs(int) __attribute_const__ __INTRODUCED_IN(21);
-long labs(long) __attribute_const__ __INTRODUCED_IN(21);
-long long llabs(long long) __attribute_const__ __INTRODUCED_IN(21);
+float strtof(const char* __s, char** __end_ptr) __INTRODUCED_IN(21);
+double atof(const char* __s) __attribute_pure__ __INTRODUCED_IN(21);
+int abs(int __x) __attribute_const__ __INTRODUCED_IN(21);
+long labs(long __x) __attribute_const__ __INTRODUCED_IN(21);
+long long llabs(long long __x) __attribute_const__ __INTRODUCED_IN(21);
 int rand(void) __INTRODUCED_IN(21);
-void srand(unsigned int) __INTRODUCED_IN(21);
+void srand(unsigned int __seed) __INTRODUCED_IN(21);
 long random(void) __INTRODUCED_IN(21);
-void srandom(unsigned int) __INTRODUCED_IN(21);
-int grantpt(int) __INTRODUCED_IN(21);
+void srandom(unsigned int __seed) __INTRODUCED_IN(21);
+int grantpt(int __fd) __INTRODUCED_IN(21);
 
-long long strtoll_l(const char*, char**, int, locale_t) __INTRODUCED_IN(21);
-unsigned long long strtoull_l(const char*, char**, int, locale_t) __INTRODUCED_IN(21);
-long double strtold_l(const char*, char**, locale_t) __INTRODUCED_IN(21);
+long long strtoll_l(const char* __s, char** __end_ptr, int __base, locale_t __l) __INTRODUCED_IN(21);
+unsigned long long strtoull_l(const char* __s, char** __end_ptr, int __base, locale_t __l) __INTRODUCED_IN(21);
+long double strtold_l(const char* __s, char** __end_ptr, locale_t __l) __INTRODUCED_IN(21);
 #else
 // Implemented as static inlines before 21.
 #endif
 
 #if __ANDROID_API__ >= __ANDROID_API_O__
-double strtod_l(const char*, char**, locale_t) __INTRODUCED_IN(26);
-float strtof_l(const char*, char**, locale_t) __INTRODUCED_IN(26);
-long strtol_l(const char*, char**, int, locale_t) __INTRODUCED_IN(26);
+double strtod_l(const char* __s, char** __end_ptr, locale_t __l) __INTRODUCED_IN(26);
+float strtof_l(const char* __s, char** __end_ptr, locale_t __l) __INTRODUCED_IN(26);
+long strtol_l(const char* __s, char** __end_ptr, int, locale_t __l) __INTRODUCED_IN(26);
 #else
 // Implemented as static inlines before 26.
 #endif
diff --git a/libc/include/syslog.h b/libc/include/syslog.h
index a320352..fff565e 100644
--- a/libc/include/syslog.h
+++ b/libc/include/syslog.h
@@ -87,10 +87,10 @@
 #define LOG_PERROR 0x20
 
 void closelog(void);
-void openlog(const char*, int, int);
-int setlogmask(int);
-void syslog(int, const char*, ...) __printflike(2, 3);
-void vsyslog(int, const char*, va_list) __printflike(2, 0);
+void openlog(const char* __prefix, int __option, int __facility);
+int setlogmask(int __mask);
+void syslog(int __priority, const char* __fmt, ...) __printflike(2, 3);
+void vsyslog(int __priority, const char* __fmt, va_list __args) __printflike(2, 0);
 
 __END_DECLS
 
diff --git a/libc/include/utmp.h b/libc/include/utmp.h
index 62e8d59..6a52511 100644
--- a/libc/include/utmp.h
+++ b/libc/include/utmp.h
@@ -96,12 +96,12 @@
 
 __BEGIN_DECLS
 
-int utmpname(const char*);
+int utmpname(const char* __path);
 void setutent(void);
 struct utmp* getutent(void);
 void endutent(void);
 
-int login_tty(int) __INTRODUCED_IN(23);
+int login_tty(int __fd) __INTRODUCED_IN(23);
 
 __END_DECLS