Make numerous improvements

- Python static hello world now 1.8mb
- Python static fully loaded now 10mb
- Python HTTPS client now uses MbedTLS
- Python REPL now completes import stmts
- Increase stack size for Python for now
- Begin synthesizing posixpath and ntpath
- Restore Python \N{UNICODE NAME} support
- Restore Python NFKD symbol normalization
- Add optimized code path for Intel SHA-NI
- Get more Python unit tests passing faster
- Get Python help() pagination working on NT
- Python hashlib now supports MbedTLS PBKDF2
- Make memcpy/memmove/memcmp/bcmp/etc. faster
- Add Mersenne Twister and Vigna to LIBC_RAND
- Provide privileged __printf() for error code
- Fix zipos opendir() so that it reports ENOTDIR
- Add basic chmod() implementation for Windows NT
- Add Cosmo's best functions to Python cosmo module
- Pin function trace indent depth to that of caller
- Show memory diagram on invalid access in MODE=dbg
- Differentiate stack overflow on crash in MODE=dbg
- Add stb_truetype and tools for analyzing font files
- Upgrade to UNICODE 13 and reduce its binary footprint
- COMPILE.COM now logs resource usage of build commands
- Start implementing basic poll() support on bare metal
- Set getauxval(AT_EXECFN) to GetModuleFileName() on NT
- Add descriptions to strerror() in non-TINY build modes
- Add COUNTBRANCH() macro to help with micro-optimizations
- Make error / backtrace / asan / memory code more unbreakable
- Add fast perfect C implementation of μ-Law and a-Law audio codecs
- Make strtol() functions consistent with other libc implementations
- Improve Linenoise implementation (see also github.com/jart/bestline)
- COMPILE.COM now suppresses stdout/stderr of successful build commands

libc/calls/mkntcmdline.c

@@ -23,6 +23,22 @@
 #include "libc/str/utf16.h"
 #include "libc/sysv/errfuns.h"
 
+#define APPEND(c)                     \
+  do {                                \
+    cmdline[k++] = c;                 \
+    if (k == ARG_MAX) return e2big(); \
+  } while (0)
+
+static noasan bool NeedsQuotes(const char *s) {
+  if (!*s) return true;
+  do {
+    if (*s == ' ' || *s == '\t') {
+      return true;
+    }
+  } while (*s++);
+  return false;
+}
+
 /**
  * Converts System V argv to Windows-style command line.
  *
@@ -34,7 +50,6 @@
  * @param prog is used as argv[0]
  * @param argv is an a NULL-terminated array of UTF-8 strings
  * @return freshly allocated lpCommandLine or NULL w/ errno
- * @kudos Daniel Colascione for teaching how to quote
  * @see libc/runtime/dosargv.c
  */
 textwindows noasan int mkntcmdline(char16_t cmdline[ARG_MAX], const char *prog,
@@ -43,36 +58,19 @@ textwindows noasan int mkntcmdline(char16_t cmdline[ARG_MAX], const char *prog,
   uint64_t w;
   wint_t x, y;
   int slashes, n;
-  size_t i, j, k;
   bool needsquote;
   char16_t cbuf[2];
+  size_t i, j, k, s;
   for (arg = prog, k = i = 0; arg; arg = argv[++i]) {
-    if (i) {
-      cmdline[k++] = u' ';
-      if (k == ARG_MAX) return e2big();
-    }
-    needsquote = !arg[0] || arg[strcspn(arg, " \t\n\v\"")];
-    if (needsquote) {
-      cmdline[k++] = u'"';
-      if (k == ARG_MAX) return e2big();
-    }
-    for (j = 0;;) {
-      if (needsquote) {
-        slashes = 0;
-        while (arg[j] && arg[j] == '\\') slashes++, j++;
-        slashes <<= 1;
-        if (arg[j] == '"') slashes++;
-        while (slashes--) {
-          cmdline[k++] = u'\\';
-          if (k == ARG_MAX) return e2big();
-        }
-      }
-      x = arg[j++] & 0xff;
+    if (i) APPEND(u' ');
+    if ((needsquote = NeedsQuotes(arg))) APPEND(u'"');
+    for (slashes = j = 0;;) {
+      x = arg[j++] & 255;
       if (x >= 0300) {
         n = ThomPikeLen(x);
         x = ThomPikeByte(x);
         while (--n) {
-          if ((y = arg[j++] & 0xff)) {
+          if ((y = arg[j++] & 255)) {
             x = ThomPikeMerge(x, y);
           } else {
             x = 0;
@@ -81,16 +79,34 @@ textwindows noasan int mkntcmdline(char16_t cmdline[ARG_MAX], const char *prog,
         }
       }
       if (!x) break;
-      if (!i && x == '/') x = '\\';
-      w = EncodeUtf16(x);
-      do {
-        cmdline[k++] = w;
-        if (k == ARG_MAX) return e2big();
-      } while ((w >>= 16));
+      if (!i && x == '/') {
+        x = '\\';
+      }
+      if (x == '\\') {
+        ++slashes;
+      } else if (x == '"') {
+        for (s = 0; s < slashes * 2; ++s) {
+          APPEND(u'\\');
+        }
+        slashes = 0;
+        APPEND(u'\\');
+        APPEND(u'"');
+      } else {
+        for (s = 0; s < slashes; ++s) {
+          APPEND(u'\\');
+        }
+        slashes = 0;
+        w = EncodeUtf16(x);
+        do {
+          APPEND(w);
+        } while ((w >>= 16));
+      }
+    }
+    for (s = 0; s < (slashes << needsquote); ++s) {
+      APPEND(u'\\');
     }
     if (needsquote) {
-      cmdline[k++] = u'"';
-      if (k == ARG_MAX) return e2big();
+      APPEND(u'"');
     }
   }
   cmdline[k] = u'\0';