Fix warnings

This change fixes Cosmopolitan so it has fewer opinions about compiler
warnings. The whole repository had to be cleaned up to be buildable in
-Werror -Wall mode. This lets us benefit from things like strict const
checking. Some actual bugs might have been caught too.

libc/thread/makecontext.c

@@ -94,7 +94,6 @@ void makecontext(ucontext_t *uc, void func(), int argc, ...) {
   va_list va;
   long sp, sb;
   struct Gadget *call;
-  struct StackFrame *sf;
 
   // allocate call
   sp = sb = (long)uc->uc_stack.ss_sp;

libc/thread/mktls.c

@@ -86,8 +86,8 @@ static char *_mktls_below(struct CosmoTib **out_tib) {
 
 static char *_mktls_above(struct CosmoTib **out_tib) {
   size_t hiz, siz;
+  struct CosmoTib *tib;
   char *mem, *dtv, *tls;
-  struct CosmoTib *tib, *old;
 
   // allocate memory for tdata, tbss, and tib
   hiz = ROUNDUP(sizeof(*tib) + 2 * sizeof(void *), I(_tls_align));

libc/thread/pthread_atfork.c

@@ -47,7 +47,6 @@ static void _pthread_purge(void) {
 
 static void _pthread_onfork(int i) {
   struct AtFork *a;
-  struct PosixThread *pt;
   unassert(0 <= i && i <= 2);
   if (!i) pthread_spin_lock(&_atforks.lock);
   for (a = _atforks.list; a; a = a->p[!i]) {
@@ -91,7 +90,7 @@ void _pthread_onfork_child(void) {
   pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
   pthread_mutex_init(&__mmi_lock_obj, &attr);
   pthread_mutex_init(&__fds_lock_obj, &attr);
-  pthread_spin_init(&_pthread_lock, 0);
+  (void)pthread_spin_init(&_pthread_lock, 0);
 
   // call user-supplied forked child callbacks
   _pthread_onfork(2);

libc/thread/pthread_cancel.c

@@ -343,7 +343,6 @@ void pthread_testcancel(void) {
  *     in masked mode when the calling thread has been cancelled
  */
 errno_t pthread_testcancel_np(void) {
-  int rc;
   struct PosixThread *pt;
   if (!__tls_enabled) return 0;
   if (!(pt = (struct PosixThread *)__get_tls()->tib_pthread)) return 0;

libc/thread/pthread_create.c

@@ -74,14 +74,12 @@ void _pthread_free(struct PosixThread *pt) {
 void pthread_kill_siblings_np(void) {
   struct Dll *e, *e2;
   struct PosixThread *pt, *self;
-  enum PosixThreadStatus status;
   self = (struct PosixThread *)__get_tls()->tib_pthread;
   pthread_spin_lock(&_pthread_lock);
   for (e = dll_first(_pthread_list); e; e = e2) {
     e2 = dll_next(_pthread_list, e);
     pt = POSIXTHREAD_CONTAINER(e);
     if (pt != self) {
-      status = atomic_load_explicit(&pt->status, memory_order_acquire);
       pthread_kill((pthread_t)pt, SIGKILL);
       dll_remove(&_pthread_list, e);
       pthread_spin_unlock(&_pthread_lock);
@@ -95,7 +93,6 @@ static int PosixThread(void *arg, int tid) {
   void *rc;
   struct sigaltstack ss;
   struct PosixThread *pt = arg;
-  enum PosixThreadStatus status;
   unassert(__get_tls()->tib_tid > 0);
   if (pt->altstack) {
     ss.ss_flags = 0;

libc/thread/pthread_ungarbage.c

@@ -21,7 +21,6 @@
 #include "libc/thread/tls.h"
 
 void _pthread_ungarbage(void) {
-  int i;
   struct Garbages *g;
   struct CosmoTib *tib;
   tib = __get_tls();

libc/thread/sem_open.c

@@ -136,7 +136,7 @@ static struct Semaphore *sem_open_reopen(const char *path) {
 
 static struct Semaphore *sem_open_get(const sem_t *sem,
                                       struct Semaphore ***out_prev) {
-  struct Semaphore *s, *t, **p;
+  struct Semaphore *s, **p;
   for (p = &g_semaphores.list, s = *p; s; p = &s->next, s = s->next) {
     if (s && sem == s->sem) {
       *out_prev = p;
@@ -176,9 +176,10 @@ static struct Semaphore *sem_open_get(const sem_t *sem,
 sem_t *sem_open(const char *name, int oflag, ...) {
   sem_t *sem;
   va_list va;
+  const char *path;
   struct Semaphore *s;
+  char pathbuf[PATH_MAX];
   unsigned mode = 0, value = 0;
-  char *path, pathbuf[PATH_MAX];
   if (oflag & ~(O_CREAT | O_EXCL)) {
     einval();
     return SEM_FAILED;
@@ -300,9 +301,10 @@ int sem_close(sem_t *sem) {
  * @raise ENAMETOOLONG if too long
  */
 int sem_unlink(const char *name) {
+  const char *path;
   int rc, e = errno;
   struct Semaphore *s;
-  char *path, pathbuf[PATH_MAX];
+  char pathbuf[PATH_MAX];
   if (!(path = sem_path_np(name, pathbuf, sizeof(pathbuf)))) return -1;
   if ((rc = unlink(path)) == -1 && IsWindows() && errno == EACCES) {
     sem_open_init();

libc/thread/sem_timedwait.c

@@ -53,7 +53,6 @@ static void sem_timedwait_cleanup(void *arg) {
  */
 int sem_timedwait(sem_t *sem, const struct timespec *abstime) {
   int e, i, v, rc;
-  struct timespec ts;
 
   e = errno;
   for (i = 0; i < 7; ++i) {

libc/thread/thread.h

@@ -218,11 +218,12 @@ void pthread_testcancel(void);
 #if (__GNUC__ + 0) * 100 + (__GNUC_MINOR__ + 0) >= 407 && \
     !defined(__STRICT_ANSI__) && !defined(MODE_DBG)
 extern const errno_t EBUSY;
-#define pthread_spin_lock(pSpin)                                           \
-  ({                                                                       \
-    pthread_spinlock_t *_s = pSpin;                                        \
-    while (__atomic_test_and_set(&_s->_lock, __ATOMIC_ACQUIRE)) donothing; \
-    0;                                                                     \
+#define pthread_spin_lock(pSpin)                                  \
+  ({                                                              \
+    pthread_spinlock_t *_s = pSpin;                               \
+    while (__atomic_test_and_set(&_s->_lock, __ATOMIC_ACQUIRE)) { \
+    }                                                             \
+    0;                                                            \
   })
 #define pthread_spin_unlock(pSpin)                     \
   ({                                                   \

libc/thread/tls2.internal.h

@@ -12,7 +12,7 @@ COSMOPOLITAN_C_START_
  * This should be favored over __get_tls() for .privileged code that
  * can't be self-modified by __enable_tls().
  */
-privileged static inline struct CosmoTib *__get_tls_privileged(void) {
+__funline struct CosmoTib *__get_tls_privileged(void) {
   char *tib, *lin = (char *)0x30;
   if (IsLinux() || IsFreebsd() || IsNetbsd() || IsOpenbsd() || IsMetal()) {
     asm("mov\t%%fs:(%1),%0" : "=a"(tib) : "r"(lin) : "memory");

libc/thread/wait0.c

@@ -41,7 +41,7 @@
  * @raise EBUSY if `abstime` was specified and deadline expired
  * @cancellationpoint
  */
-errno_t _wait0(const atomic_int *ctid, struct timespec *abstime) {
+errno_t _wait0(atomic_int *ctid, struct timespec *abstime) {
   int x, e, rc = 0;
   // "The behavior is undefined if the value specified by the thread
   //  argument to pthread_join() refers to the calling thread."

libc/thread/wait0.internal.h

@@ -1,11 +1,10 @@
 #ifndef COSMOPOLITAN_LIBC_INTRIN_WAIT0_H_
 #define COSMOPOLITAN_LIBC_INTRIN_WAIT0_H_
-#include "libc/atomic.h"
 #include "libc/calls/struct/timespec.h"
 #if !(__ASSEMBLER__ + __LINKER__ + 0)
 COSMOPOLITAN_C_START_
 
-errno_t _wait0(const atomic_int *, struct timespec *);
+errno_t _wait0(_Atomic(int) *, struct timespec *);
 
 COSMOPOLITAN_C_END_
 #endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */