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.

tool/viz/lib/bilinearscale.c

@@ -16,6 +16,7 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "tool/viz/lib/bilinearscale.h"
 #include "dsp/core/twixt8.h"
 #include "libc/intrin/bsr.h"
 #include "libc/log/check.h"
@@ -29,7 +30,6 @@
 #include "libc/testlib/testlib.h"
 #include "libc/tinymath/emod.h"
 #include "libc/x/x.h"
-#include "tool/viz/lib/bilinearscale.h"
 
 static void ComputeScalingSolution(long dn, long sn, double r, double o,
                                    unsigned char pct[dn + 1], int idx[dn + 1]) {
@@ -52,7 +52,7 @@ static void BilinearScaler(long dcw, long dyw, long dxw,
                            int iy[dyn + 1], unsigned char py[dyn + 1],
                            int ix[dxn + 1], unsigned char px[dxn + 1],
                            unsigned char db[dxn], unsigned char sb[2][sxn]) {
-  long c, y, x, b;
+  long c, y, x;
   ComputeScalingSolution(dxn, sxn, rx, ox, px, ix);
   ComputeScalingSolution(dyn, syn, ry, oy, py, iy);
   for (c = c0; c < cn; ++c) {

tool/viz/lib/dither.c

@@ -90,15 +90,14 @@ static void SerpentineDither(long yw, long xw, unsigned char rgb[3][yw][xw],
                              long yn, long xn, long y, long x, long r,
                              const struct Dither *d) {
   void *c;
-  long b, e, i, j, n, m;
-  e = 0;
+  long b, i, j, n, m;
   b = d->chunks[r].b;
   c = d->chunks[r].c;
   n = (yn - y) / b;
   m = (xn - x) / b;
   for (i = 0; i < n; ++i) {
     for (j = 0; j < m; ++j) {
-      e = SerpentineDitherSq2(yw, xw, rgb, y + i * b, x + j * b, b, c, 0);
+      SerpentineDitherSq2(yw, xw, rgb, y + i * b, x + j * b, b, c, 0);
     }
   }
   if (r) {

tool/viz/lib/formatmatrix-double.c

@@ -20,8 +20,8 @@
 #include "libc/fmt/conv.h"
 #include "libc/log/check.h"
 #include "libc/math.h"
-#include "libc/mem/mem.h"
 #include "libc/mem/gc.internal.h"
+#include "libc/mem/mem.h"
 #include "libc/x/x.h"
 #include "third_party/gdtoa/gdtoa.h"
 #include "tool/viz/lib/formatstringtable.h"
@@ -30,14 +30,13 @@
 void *ConvertMatrixToStringTable(long yn, long xn, char *T[yn][xn],
                                  const double M[yn][xn], double digs,
                                  double rounder(double)) {
-  double f;
   long y, x;
   assert(yn && xn && !T[0][0]);
   for (y = 0; y < yn; ++y) {
     for (x = 0; x < xn; ++x) {
       T[y][x] = xmalloc(40);
       T[y][x][0] = '\0';
-      g_dfmt_p(T[y][x], &M[y][x], digs, 40, 0);
+      g_dfmt_p(T[y][x], (void *)&M[y][x], digs, 40, 0);
     }
   }
   return T;

tool/viz/lib/ycbcr2rgb3.c

@@ -237,7 +237,7 @@ void YCbCr2Rgb(long yn, long xn, unsigned char RGB[restrict 3][yn][xn],
                const unsigned char Cr[restrict cys][cxs], const int K[8][4],
                const int L[6][4], const unsigned char T[256]) {
   long i, j;
-  short y, u, v, r, g, b, A, B, C;
+  short y, u, v, r, g, b;
   for (i = 0; i < yn; ++i) {
     for (j = 0; j < xn; ++j) {
       y = T[Y[i][j]];
@@ -280,8 +280,8 @@ void YCbCr2RgbScaler(struct YCbCr *me, long dyn, long dxn,
                      long cyn, long cxn, double syn, double sxn, double pry,
                      double prx) {
   long double ts;
-  long y, x, scyn, scxn;
-  double yry, yrx, cry, crx, yoy, yox, coy, cox, err, oy;
+  long scyn, scxn;
+  double yry, yrx, cry, crx, yoy, yox, coy, cox;
   scyn = syn * cyn / yyn;
   scxn = sxn * cxn / yxn;
   if (HALF(yxn) > dxn && HALF(scxn) > dxn) {