[1/1] string: Add basic implementation of mempbrk

Message ID 20220613025739.23612-2-brandonfoongyankai@gmail.com
State Rejected
Headers
Series Adding mempbrk() function to glibc |

Checks

Context Check Description
dj/TryBot-apply_patch success Patch applied to master at the time it was sent
dj/TryBot-32bit success Build for i686

Commit Message

develop--- via Libc-alpha June 13, 2022, 2:57 a.m. UTC
  From: Brandon Foong <brandonfoongyankai@gmail.com>

---
 include/string.h      |   1 +
 string/Makefile       |   2 +
 string/Versions       |   1 +
 string/mempbrk.c      |  56 ++++++++++
 string/string.h       |  15 +++
 string/test-mempbrk.c | 242 ++++++++++++++++++++++++++++++++++++++++++
 6 files changed, 317 insertions(+)
 create mode 100644 string/mempbrk.c
 create mode 100644 string/test-mempbrk.c
  

Patch

diff --git a/include/string.h b/include/string.h
index 21f641a413..ff84288d65 100644
--- a/include/string.h
+++ b/include/string.h
@@ -151,6 +151,7 @@  libc_hidden_builtin_proto (strrchr)
 libc_hidden_builtin_proto (strspn)
 libc_hidden_builtin_proto (strstr)
 libc_hidden_builtin_proto (ffs)
+libc_hidden_builtin_proto (mempbrk)
 
 #if IS_IN (rtld)
 extern __typeof (__stpcpy) __stpcpy attribute_hidden;
diff --git a/string/Makefile b/string/Makefile
index 641e062bbb..3d8819d9f0 100644
--- a/string/Makefile
+++ b/string/Makefile
@@ -114,6 +114,7 @@  routines := \
   swab \
   wordcopy \
   xpg-strerror \
+  mempbrk \
 # routines
 
 tests := \
@@ -183,6 +184,7 @@  tests := \
   tst-svc \
   tst-svc2 \
   tst-xbzero-opt \
+  test-mempbrk \
 # tests
 
 # Both tests require the .mo translation files generated by msgfmt.
diff --git a/string/Versions b/string/Versions
index 864c4cf7a4..1f071a1da5 100644
--- a/string/Versions
+++ b/string/Versions
@@ -91,5 +91,6 @@  libc {
   }
   GLIBC_2.35 {
     __memcmpeq;
+    mempbrk;
   }
 }
diff --git a/string/mempbrk.c b/string/mempbrk.c
new file mode 100644
index 0000000000..575409b1a2
--- /dev/null
+++ b/string/mempbrk.c
@@ -0,0 +1,56 @@ 
+/* Copyright (C) 1991-2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <string.h>
+#include <stdint.h>
+
+#undef mempbrk
+
+#ifndef MEMPBRK
+# define MEMPBRK mempbrk
+#endif
+
+/* Find the first occurrence of any character in ACCEPT
+   in the first N bytes of S. */
+void *
+MEMPBRK (const void *s, const char *accept, size_t n)
+{
+  const unsigned char *t;
+
+  if (__glibc_unlikely (accept[0] == '\0'))
+    return NULL;
+
+  if (__glibc_unlikely (accept[1] == '\0'))
+    return memchr (s, accept[0], n);
+
+  /* Use multiple small memsets to enable inlining on most targets.  */
+  unsigned char table[256];
+  unsigned char *p = memset (table, 0, 64);
+  memset (p + 64, 0, 64);
+  memset (p + 128, 0, 64);
+  memset (p + 192, 0, 64);
+
+  for (t = (unsigned char*) accept; *t; ++t)
+    p[*t] = 1;
+
+  for (t = (unsigned char*) s; n > 0; --n, ++t)
+    if (p[*t])
+      return (void *) t;
+
+  return NULL;
+}
+libc_hidden_builtin_def (mempbrk)
diff --git a/string/string.h b/string/string.h
index 54dd8344de..24badfef50 100644
--- a/string/string.h
+++ b/string/string.h
@@ -136,6 +136,21 @@  extern void *memrchr (const void *__s, int __c, size_t __n)
 # endif
 #endif
 
+/* Find the first occurrence of any character in ACCEPT
+   in the first N bytes of S. */
+#ifdef __CORRECT_ISO_CPP_STRING_H_PROTO
+extern "C++"
+{
+extern void *mempbrk (void *__s, const char *__accept, size_t __n)
+     __THROW __asm ("mempbrk") __attribute_pure__ __nonnull ((1, 2));
+extern const void *mempbrk (const void *__s, const char *__accept, size_t __n)
+     __THROW __asm ("mempbrk") __attribute_pure__ __nonnull ((1, 2));
+}
+#else
+extern void *mempbrk (const void *__s, const char *__accept, size_t __n)
+     __THROW __attribute_pure__ __nonnull ((1, 2));
+#endif
+
 
 /* Copy SRC to DEST.  */
 extern char *strcpy (char *__restrict __dest, const char *__restrict __src)
diff --git a/string/test-mempbrk.c b/string/test-mempbrk.c
new file mode 100644
index 0000000000..8d50039952
--- /dev/null
+++ b/string/test-mempbrk.c
@@ -0,0 +1,242 @@ 
+/* Test and measure strpbrk functions.
+   Copyright (C) 1999-2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef WIDE
+# define CHAR char
+# define UCHAR unsigned char
+# define STRLEN strlen
+# define STRCHR strchr
+# define BIG_CHAR CHAR_MAX
+# define SMALL_CHAR 127
+#else
+# include <wchar.h>
+# define CHAR wchar_t
+# define UCHAR wchar_t
+# define STRLEN wcslen
+# define STRCHR wcschr
+# define BIG_CHAR WCHAR_MAX
+# define SMALL_CHAR 1273
+#endif /* WIDE */
+
+#ifndef MEMPBRK_RESULT
+# define TEST_MAIN
+# ifndef WIDE
+#  define TEST_NAME "mempbrk"
+# else
+#  define TEST_NAME "wmempbrk"
+# endif /* WIDE */
+# include "test-string.h"
+
+# ifndef WIDE
+#  define MEMPBRK mempbrk
+#  define SIMPLE_MEMPBRK simple_mempbrk
+# else
+#  include <wchar.h>
+#  define MEMPBRK wmempbrk
+#  define SIMPLE_MEMPBRK simple_wmempbrk
+# endif /* WIDE */
+
+typedef void *(*proto_t) (const void *, const CHAR *, size_t);
+
+IMPL (MEMPBRK, 1)
+
+/* Naive implementation to verify results.  */
+
+CHAR *
+SIMPLE_MEMPBRK (const void *s, const CHAR *rej, size_t n)
+{
+  const CHAR *r;
+  CHAR c;
+
+  while (c = *(char *) s++, n--)
+    for (r = rej; *r != '\0'; ++r)
+      if (*r == c)
+       return (void *) s - 1;
+  return NULL;
+}
+
+#endif /* !MEMPBRK_RESULT */
+
+static void
+do_one_test (impl_t *impl, const void *s, const CHAR *acc, size_t n, void * exp_res)
+{
+  void * res = CALL (impl, s, acc, n);
+  if (res != exp_res)
+    {
+      error (0, 0, "Wrong result in function %s %p %p", impl->name,
+	      res, exp_res);
+      ret = 1;
+      return;
+    }
+}
+
+static void
+do_test (size_t align, size_t pos, size_t len)
+{
+  size_t i;
+  int c, byte_exists;
+  void * result;
+  CHAR *rej, *s;
+
+  align &= 7;
+  if ((align + pos + 10) * sizeof (CHAR) >= page_size || len > 240)
+    return;
+
+  rej = (CHAR *) (buf2) + (random () & 255);
+  s = (CHAR *) (buf1) + align;
+
+  for (i = 0; i < len; ++i)
+    {
+      rej[i] = random () & BIG_CHAR;
+      if (!rej[i])
+	rej[i] = random () & BIG_CHAR;
+      if (!rej[i])
+	rej[i] = 1 + (random () & SMALL_CHAR);
+    }
+  rej[len] = '\0';
+  for (c = 1; c <= BIG_CHAR; ++c)
+    if (STRCHR (rej, c) == NULL)
+      break;
+
+  for (i = 0; i < pos + 10; ++i)
+    {
+      s[i] = random () & BIG_CHAR;
+      if (STRCHR (rej, s[i]))
+	{
+	  s[i] = random () & BIG_CHAR;
+	  if (STRCHR (rej, s[i]))
+	    s[i] = c;
+	}
+    }
+  byte_exists = (random() & 1) && len;
+  s[pos] = byte_exists ? rej[random () % len] : s[pos];
+  result = byte_exists ? s + pos : NULL;
+
+  FOR_EACH_IMPL (impl, 0)
+    do_one_test (impl, s, rej, pos + 10, result);
+}
+
+static void
+do_random_tests (void)
+{
+  size_t i, j, n, align, pos, len, rlen;
+  void * result;
+  int c, byte_exists;
+  UCHAR *p = (UCHAR *) (buf1 + page_size) - 512;
+  UCHAR *rej;
+
+  for (n = 0; n < ITERATIONS; n++)
+    {
+      align = random () & 15;
+      pos = random () & 511;
+      if (pos + align >= 511)
+	pos = 510 - align - (random () & 7);
+      len = random () & 511;
+      if (pos >= len && (random () & 1))
+	len = pos + 1 + (random () & 7);
+      if (len + align >= 512)
+	len = 511 - align - (random () & 7);
+      if (random () & 1)
+	rlen = random () & 63;
+      else
+	rlen = random () & 15;
+      rej = (UCHAR *) (buf2 + page_size) - rlen - 1 - (random () & 7);
+      for (i = 0; i < rlen; ++i)
+	{
+	  rej[i] = random () & BIG_CHAR;
+	  if (!rej[i])
+	    rej[i] = random () & BIG_CHAR;
+	  if (!rej[i])
+	    rej[i] = 1 + (random () & SMALL_CHAR);
+	}
+      rej[i] = '\0';
+      for (c = 1; c <= BIG_CHAR; ++c)
+	if (STRCHR ((CHAR *) rej, c) == NULL)
+	  break;
+      j = (pos > len ? pos : len) + align + 64;
+      if (j > 512)
+	j = 512;
+
+      byte_exists = (random() & 1) && rlen;
+      for (i = 0; i < j; i++)
+	{
+	  if (i == pos + align)
+	    p[i] = byte_exists ? rej[random () % rlen] : '\0';
+	  else if (i < align || i > len + align)
+	    p[i] = random () & BIG_CHAR;
+	  else
+	    {
+	      p[i] = random () & BIG_CHAR;
+	      if (STRCHR ((CHAR *) rej, p[i]))
+		{
+		  p[i] = random () & BIG_CHAR;
+		  if (STRCHR ((CHAR *) rej, p[i]))
+		    p[i] = c;
+		}
+	    }
+	}
+
+      result = pos < len && byte_exists ? (CHAR *) p + align + pos : NULL;
+
+      FOR_EACH_IMPL (impl, 1)
+	if (CALL (impl, (CHAR *) p + align, (CHAR *) rej, len) != result)
+	  {
+	    error (0, 0, "Iteration %zd - wrong result in function %s (%zd, %p, %zd, %zd, %zd) %p != %p",
+		   n, impl->name, align, rej, rlen, pos, len,
+		   (void *) CALL (impl, (CHAR *) (p + align), (CHAR *) rej, len),
+		   (void *) result);
+	    ret = 1;
+	  }
+    }
+}
+
+int
+test_main (void)
+{
+  size_t i;
+
+  test_init ();
+
+  printf ("%32s", "");
+  FOR_EACH_IMPL (impl, 0)
+    printf ("\t%s", impl->name);
+  putchar ('\n');
+
+  for (i = 0; i < 32; ++i)
+    {
+      do_test (0, 512, i);
+      do_test (i, 512, i);
+    }
+
+  for (i = 1; i < 8; ++i)
+    {
+      do_test (0, 16 << i, 4);
+      do_test (i, 16 << i, 4);
+    }
+
+  for (i = 1; i < 8; ++i)
+    do_test (i, 64, 10);
+
+  for (i = 0; i < 64; ++i)
+    do_test (0, i, 6);
+
+  do_random_tests ();
+  return ret;
+}
+
+#include <support/test-driver.c>