Make minor improvements

libc/fmt/conv.h

@@ -19,7 +19,6 @@ long labs(long) libcesque pureconst;
 long long llabs(long long) libcesque pureconst;
 char *ltpcpy(char *, long) paramsnonnull() libcesque nocallback;
 int llog10(unsigned long) libcesque pureconst;
-int unsleb128(const void *, size_t, int64_t *);
 int atoi(const char *) paramsnonnull() libcesque;
 long atol(const char *) paramsnonnull() libcesque;
 long long atoll(const char *) paramsnonnull() libcesque;

libc/fmt/dirname.c

@@ -22,6 +22,10 @@
 
 #define ISDELIM(c) (c == '/' || c == '\\' || c == '.')
 
+/**
+ * Returns directory portion of path.
+ * @param s is mutated
+ */
 char *dirname(char *s) {
   size_t i, n;
   if (!(n = strlen(s))) return s;

libc/fmt/leb128.h

@@ -0,0 +1,11 @@
+#ifndef COSMOPOLITAN_LIBC_FMT_LEB128_H_
+#define COSMOPOLITAN_LIBC_FMT_LEB128_H_
+#if !(__ASSEMBLER__ + __LINKER__ + 0)
+COSMOPOLITAN_C_START_
+
+int sleb128(const void *, size_t, int128_t);
+int unsleb128(const void *, size_t, int128_t *);
+
+COSMOPOLITAN_C_END_
+#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
+#endif /* COSMOPOLITAN_LIBC_FMT_LEB128_H_ */

libc/fmt/pflink.h

@@ -46,7 +46,7 @@
 #define ___PFLINK(FMT, FN, C) 1
 #else
 #define ___PFLINK(FMT, FN, C) \
-  !isconstant(FMT) || ((FMT) && __builtin_##FN(FMT, C) != NULL)
+  !__builtin_constant_p(FMT) || ((FMT) && __builtin_##FN(FMT, C) != NULL)
 #endif
 
 #if defined(__GNUC__) && __GNUC__ < 6

libc/fmt/sleb128.c

@@ -0,0 +1,39 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ This program is free software; you can redistribute it and/or modify         │
+│ it under the terms of the GNU General Public License as published by         │
+│ the Free Software Foundation; version 2 of the License.                      │
+│                                                                              │
+│ This program is distributed in the hope that it will be useful, but          │
+│ WITHOUT ANY WARRANTY; without even the implied warranty of                   │
+│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU             │
+│ General Public License for more details.                                     │
+│                                                                              │
+│ You should have received a copy of the GNU General Public License            │
+│ along with this program; if not, write to the Free Software                  │
+│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA                │
+│ 02110-1301 USA                                                               │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/fmt/leb128.h"
+
+/**
+ * Encodes sleb-128 signed integer.
+ */
+int sleb128(const void *buf, size_t size, int128_t x) {
+  int c;
+  unsigned i;
+  for (i = 0; i < size; ++i) {
+    c = x & 0x7f;
+    x >>= 7;
+    if ((x == 0 && !(c & 0x40)) || (x == -1 && (c & 0x40))) {
+      break;
+    } else {
+      c |= 0x80;
+    }
+    ((char *)buf)[i] = c;
+  }
+  return i;
+}

libc/fmt/strerror.c

@@ -24,7 +24,7 @@
  * @see strerror_r()
  */
 char *strerror(int err) {
-  alignas(1) static char buf[512];
+  _Alignas(1) static char buf[512];
   strerror_r(err, buf, sizeof(buf));
   return buf;
 }

libc/fmt/unsleb128.c

@@ -17,7 +17,7 @@
 │ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA                │
 │ 02110-1301 USA                                                               │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/fmt/conv.h"
+#include "libc/fmt/leb128.h"
 
 /**
  * Decodes a GNU-style varint from a buffer.
@@ -25,9 +25,9 @@
  * The GNU Assembler is able to encode numbers this way, since it's used
  * by the DWARF debug format.
  */
-int unsleb128(const void *buf, size_t size, int64_t *out) {
+int unsleb128(const void *buf, size_t size, int128_t *out) {
   int b;
-  int64_t r, w;
+  int128_t r, w;
   unsigned char c;
   const unsigned char *p, *pe;
   pe = (p = buf) + size;