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.

examples/cosh.c

@@ -93,10 +93,8 @@ static void CompleteFilename(const char *p, const char *q, const char *b,
 }
 
 static void ShellCompletion(const char *p, linenoiseCompletions *c) {
-  bool slashed;
   const char *q, *b;
-  for (slashed = false, b = p, q = (p += strlen(p)); p > b; --p) {
-    if (p[-1] == '/' && p[-1] == '\\') slashed = true;
+  for (b = p, q = (p += strlen(p)); p > b; --p) {
     if (!isalnum(p[-1]) &&
         (p[-1] != '.' && p[-1] != '_' && p[-1] != '-' && p[-1] != '+' &&
          p[-1] != '[' && p[-1] != '/' && p[-1] != '\\')) {
@@ -143,8 +141,8 @@ int main(int argc, char *argv[]) {
   char *prog, path[PATH_MAX];
   sigset_t chldmask, savemask;
   int stdoutflags, stderrflags;
+  int n, rc, ws, child, killcount;
   const char *stdoutpath, *stderrpath;
-  int n, rc, ws, pid, child, killcount;
   struct sigaction sa, saveint, savequit;
   char *p, *line, **args, *arg, *start, *state, prompt[1024];
   linenoiseSetFreeHintsCallback(free);

examples/crashreport.c

@@ -36,6 +36,7 @@ dontubsan int main(int argc, char *argv[]) {
   volatile double a = 0;
   volatile double b = 23;
   volatile double c = exp(b) / a;
+  (void)c;
 
   volatile int64_t x;
   return 1 / (x = 0);

examples/crashreport2.c

@@ -43,7 +43,6 @@
  */
 
 int main(int argc, char *argv[]) {
-  volatile int64_t x;
   ShowCrashReports();
   printf("please press ctrl+\\ and see what happens...\n");
   sigsuspend(0);

examples/datauri.c

@@ -35,8 +35,7 @@ void PrintUsage(int rc, FILE *f) {
 
 void PrintUri(const char *path) {
   size_t n;
-  void *img, *src, *mime;
-  int opt, i;
+  void *img;
   if (!(img = gc(xslurp(path, &n)))) exit(2);
   fputs("data:", stdout);
   fputs(FindContentType(path, -1), stdout);

examples/defer-statements.c

@@ -7,15 +7,15 @@
 │   • http://creativecommons.org/publicdomain/zero/1.0/            │
 ╚─────────────────────────────────────────────────────────────────*/
 #endif
-#include "libc/mem/mem.h"
 #include "libc/mem/gc.h"
+#include "libc/mem/mem.h"
 #include "libc/stdio/stdio.h"
 
 /**
  * Cosmopolitan C is just as awesome as Go!
  * Example contributed by @Keithcat1 (#266)
  */
-main() {
+int main() {
   _defer(printf, "Done!\n");
   for (long i = 0; i < 100000; i++) {
     printf("%i ", i);

examples/forkexec.c

@@ -11,7 +11,6 @@
 #include "libc/stdio/stdio.h"
 
 int main(int argc, char *argv[]) {
-  int pid;
   if (argc < 3) {
     fputs("USAGE: FORKEXEC.COM PROG ARGV₀ [ARGV₁...]\n", stderr);
     return 1;

examples/forkexecwait.c

@@ -11,8 +11,6 @@
 #include "libc/stdio/stdio.h"
 
 int main(int argc, char *argv[]) {
-  int pid;
-  volatile void *p;
   if (argc < 3) {
     fputs("USAGE: FORKEXECWAIT.COM PROG ARGV₀ [ARGV₁...]\n", stderr);
     return 1;

examples/gettimeofday.c

@@ -21,7 +21,7 @@ int main(int argc, char *argv[]) {
   struct tm tm;
   struct timeval tv;
   rc = gettimeofday(&tv, 0);
-  assert(!rc);
+  unassert(!rc);
   t = tv.tv_sec;
   gmtime_r(&t, &tm);
   FormatHttpDateTime(p, &tm);

examples/greenbean.c

@@ -148,14 +148,13 @@ void *Worker(void *id) {
   while (!closingtime) {
     struct tm tm;
     int64_t unixts;
-    struct Url url;
     ssize_t got, sent;
     struct timespec ts;
     struct HttpMessage msg;
     uint32_t clientaddrsize;
     struct sockaddr_in clientaddr;
     char inbuf[1500], outbuf[512], *p, *q;
-    int clientip, client, inmsglen, outmsglen;
+    int client, inmsglen, outmsglen;
 
     // this slows the server down a lot but is needed on non-Linux to
     // react to keyboard ctrl-c

examples/hangman.c

@@ -38,8 +38,8 @@
  */
 #include "libc/calls/calls.h"
 #include "libc/calls/struct/stat.h"
-#include "libc/stdio/rand.h"
 #include "libc/runtime/runtime.h"
+#include "libc/stdio/rand.h"
 #include "libc/stdio/stdio.h"
 #include "libc/str/str.h"
 #include "libc/time/time.h"
@@ -178,8 +178,7 @@ void youwon()
 	printf("you win, the word is %s\n",realword);
 }
 
-main(argc,argv)
-	char **argv;
+int main(int argc,char **argv)
 {
 	if(argc==1) dictfile=DICT;
 	else dictfile=argv[1];

examples/hellolua.c

@@ -24,7 +24,7 @@ int main(int argc, char *argv[]) {
   luaL_openlibs(L);
   lua_pushcfunction(L, NativeAdd);
   lua_setglobal(L, "NativeAdd");
-  luaL_dofile(L, "/zip/examples/hellolua.lua");
+  (void)luaL_dofile(L, "/zip/examples/hellolua.lua");
   lua_close(L);
   return 0;
 }

examples/img.c

@@ -44,14 +44,14 @@ void PrintUsage(int rc, FILE *f) {
 
 void PrintImg(const char *path) {
   size_t n;
-  int opt, i, yn, xn, cn, w, h;
-  void *img, *pix, *src, *mime;
+  int yn, xn, cn, w, h;
+  void *img, *pix, *src;
   if (!(img = _gc(xslurp(path, &n)))) exit(2);
   if (!(pix = _gc(stbi_load_from_memory(img, n, &xn, &yn, &cn, 0)))) exit(3);
   if (linktag) {
     printf("<a href=\"%s\"\n  >", path);
   }
-  src = path;
+  src = (void *)path;
   if (datauri) {
     src = xasprintf("data:%s;base64,%s", FindContentType(path, -1),
                     _gc(EncodeBase64(img, n, &n)));

examples/kilo.c

@@ -413,9 +413,9 @@ void editorUpdateSyntax(erow *row) {
   int i, prev_sep, in_string, in_comment;
   char *p;
   const char *const *keywords = E.syntax->keywords;
-  char *scs = E.syntax->singleline_comment_start;
-  char *mcs = E.syntax->multiline_comment_start;
-  char *mce = E.syntax->multiline_comment_end;
+  const char *scs = E.syntax->singleline_comment_start;
+  const char *mcs = E.syntax->multiline_comment_start;
+  const char *mce = E.syntax->multiline_comment_end;
 
   /* Point to the first non-space char. */
   p = row->render;
@@ -575,7 +575,7 @@ int editorSyntaxToColor(int hl) {
  * setting it in the global state E.syntax. */
 void editorSelectSyntaxHighlight(char *filename) {
   for (unsigned j = 0; j < HLDB_ENTRIES; j++) {
-    struct editorSyntax *s = HLDB + j;
+    const struct editorSyntax *s = HLDB + j;
     unsigned i = 0;
     while (s->filematch[i]) {
       char *p;
@@ -898,7 +898,7 @@ struct abuf {
 };
 
 static void abAppend(struct abuf *ab, const char *s, int len) {
-  CONCAT(&ab->p, &ab->i, &ab->n, s, len);
+  CONCAT(&ab->p, &ab->i, &ab->n, (void *)s, len);
 }
 
 /* This function writes the whole screen using VT100 escape characters

examples/nanosleep_test.c

@@ -18,7 +18,7 @@
 
 int main(int argc, char *argv[]) {
   long i, ns;
-  struct timespec x, y, w;
+  struct timespec x, y;
   timespec_sleep(timespec_fromnanos(0));  // warmup
 
   printf("\nrelative sleep\n");

examples/nc.c

@@ -45,10 +45,10 @@
 int main(int argc, char *argv[]) {
   ssize_t rc;
   size_t i, got;
+  int opt, sock;
   char buf[1500];
   bool halfclose = true;
   const char *host, *port;
-  int opt, err, toto, sock;
   struct addrinfo *ai = NULL;
   struct linger linger = {true, 1};
   struct pollfd fds[2] = {{-1, POLLIN}, {-1, POLLIN}};

examples/nesemu1.cc

@@ -164,7 +164,6 @@ static struct TtyRgb* ttyrgb_;
 static unsigned char *R, *G, *B;
 static struct ZipGames zipgames_;
 static struct Action arrow_, button_;
-static struct SamplingSolution* asx_;
 static struct SamplingSolution* ssy_;
 static struct SamplingSolution* ssx_;
 static unsigned char pixels_[3][DYN][DXN];
@@ -585,7 +584,6 @@ void Raster(void) {
     f->p = stpcpy(f->p, "\e[0m\e[H");
     f->p = stpcpy(f->p, status_.text);
   }
-  CHECK_LT(f->p - f->mem, vtsize_);
   PollAndSynchronize();
 }
 
@@ -599,7 +597,6 @@ void FlushScanline(unsigned py) {
 }
 
 static void PutPixel(unsigned px, unsigned py, unsigned pixel, int offset) {
-  unsigned rgb;
   static unsigned prev;
   pixels_[0][py][px] = palette_[offset][prev % 64][pixel][2];
   pixels_[1][py][px] = palette_[offset][prev % 64][pixel][1];
@@ -1811,8 +1808,8 @@ void GetOpts(int argc, char* argv[]) {
 
 size_t FindZipGames(void) {
   char* name;
+  size_t i, cf;
   struct Zipos* zipos;
-  size_t i, cf, namesize;
   if ((zipos = __zipos_get())) {
     for (i = 0, cf = ZIP_CDIR_OFFSET(zipos->cdir);
          i < ZIP_CDIR_RECORDS(zipos->cdir);
@@ -1834,14 +1831,14 @@ int SelectGameFromZip(void) {
   int i, rc;
   char *line, *uri;
   fputs("\nCOSMOPOLITAN NESEMU1\n\n", stdout);
-  for (i = 0; i < zipgames_.i; ++i) {
+  for (i = 0; i < (int)zipgames_.i; ++i) {
     printf("  [%d] %s\n", i, zipgames_.p[i]);
   }
   fputs("\nPlease choose a game (or CTRL-C to quit) [default 0]: ", stdout);
   fflush(stdout);
   rc = 0;
   if ((line = GetLine())) {
-    i = MAX(0, MIN(zipgames_.i - 1, atoi(line)));
+    i = MAX(0, MIN((int)zipgames_.i - 1, atoi(line)));
     uri = zipgames_.p[i];
     rc = PlayGame(uri, NULL);
     free(uri);

examples/panels.c

@@ -122,7 +122,7 @@ void Clear(void) {
 }
 
 void Layout(void) {
-  long i, j;
+  long i;
   i = txn >> 1;
   pan.left.top = 0;
   pan.left.left = 0;

examples/script.c

@@ -113,9 +113,9 @@ main(int argc, char *argv[])
 	static char obuf[BUFSIZ];
 	static char ibuf[BUFSIZ];
 	fd_set rfd;
+	int fm_fd;
 	int aflg, Fflg, kflg, pflg, ch, k, n;
 	int flushtime, readstdin;
-	int fm_fd, fm_log;
 
 	aflg = Fflg = kflg = pflg = 0;
 	usesleep = 1;
@@ -125,6 +125,8 @@ main(int argc, char *argv[])
 			   warning. (not needed w/clang) */
 	showexit = 0;
 
+	(void)fm_fd;
+
 	while ((ch = getopt(argc, argv, "adeFfkpqrt:")) != -1)
 		switch(ch) {
 		case 'a':

examples/unbourne.c

@@ -1026,7 +1026,6 @@ struct t_op {
 │ cosmopolitan § the unbourne shell » bss                                  ─╬─│┼
 ╚────────────────────────────────────────────────────────────────────────────│*/
 
-static int inter;
 static char **argptr; /* argument list for builtin commands */
 static char **gargv;
 static char **t_wp;
@@ -5747,7 +5746,7 @@ static void CompleteCommand(const char *p, const char *q, const char *b,
         }
         closedir(d);
       }
-      free(path);
+      free((void *)path);
     }
   }
 }
@@ -5784,7 +5783,6 @@ static void CompleteFilename(const char *p, const char *q, const char *b,
 static void ShellCompletion(const char *p, linenoiseCompletions *c) {
   bool slashed;
   const char *q, *b;
-  struct tblentry **pp, *cmdp;
   for (slashed = false, b = p, q = (p += strlen(p)); p > b; --p) {
     if (p[-1] == '/' && p[-1] == '\\') slashed = true;
     if (!isalnum(p[-1]) &&

examples/wall.c

@@ -75,7 +75,6 @@ char *GetHost(void) {
 }
 
 char *GetTime(void) {
-  int64_t t;
   struct tm tm;
   struct timespec ts;
   clock_gettime(0, &ts);