* builtins.def (BUILT_IN_STPNCPY_CHK): New definition.

	* builtins.c (expand_builtin, fold_builtin_4, maybe_emit_chk_warning):
	Add BUILT_IN_STPNCPY_CHK case.
	* gimple-fold.c (gimple_fold_builtin): Likewise.
	* tree-object-size.c (pass_through_call): Likewise.
	* tree-ssa-alias.c (ref_maybe_used_by_call_p_1,
	call_may_clobber_ref_p_1): Likewise.
	* tree-ssa-structalias.c (find_func_aliases_for_builtin_call,
	find_func_clobbers): Likewise.
	* tree.h (fold_builtin_strncpy_chk): Rename to fold_builtin_stxncpy_chk
	* builtins.c (fold_builtin_strncpy_chk): Likewise.
	Rewrite stpncpy_chk calls to strncpy_chk calls if returned value is
	ignored.

	* gcc.c-torture/execute/builtins/chk.h (stpncpy, stpncpy_disallowed):
	New definitions.
	* gcc.c-torture/execute/builtins/lib/chk.c (stpncpy_disallowed):
	Likewise.
	(stpncpy, __stpncpy_chk): New functions.
	* gcc.c-torture/execute/builtins/stpncpy-chk-lib.c: New file.
	* gcc.c-torture/execute/builtins/stpncpy-chk.c: Likewise.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@182378 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 261 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.c-torture/execute/builtins/stpncpy-chk.c b/gcc/testsuite/gcc.c-torture/execute/builtins/stpncpy-chk.c
new file mode 100644
index 00000000000..772f19c4e22
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/builtins/stpncpy-chk.c
@@ -0,0 +1,261 @@
+/* Copyright (C) 2004, 2005, 2011  Free Software Foundation.
+
+   Ensure builtin __stpncpy_chk performs correctly.  */
+
+extern void abort (void);
+typedef __SIZE_TYPE__ size_t;
+extern size_t strlen(const char *);
+extern void *memcpy (void *, const void *, size_t);
+extern char *stpncpy (char *, const char *, size_t);
+extern int memcmp (const void *, const void *, size_t);
+extern int strcmp (const char *, const char *);
+extern int strncmp (const char *, const char *, size_t);
+extern void *memset (void *, int, size_t);
+
+#include "chk.h"
+
+const char s1[] = "123";
+char p[32] = "";
+char * volatile s2 = "defg";  /* prevent constant propagation to happen when whole program assumptions are made.  */
+char * volatile s3 = "FGH";  /* prevent constant propagation to happen when whole program assumptions are made.  */
+char *s4;
+volatile size_t l1 = 1;  /* prevent constant propagation to happen when whole program assumptions are made.  */
+int i;
+
+void
+__attribute__((noinline))
+test1 (void)
+{
+  const char *const src = "hello world";
+  const char *src2;
+  char dst[64], *dst2;
+
+  chk_calls = 0;
+
+  memset (dst, 0, sizeof (dst));
+  if (stpncpy (dst, src, 4) != dst+4 || strncmp (dst, src, 4))
+    abort();
+
+  memset (dst, 0, sizeof (dst));
+  if (stpncpy (dst+16, src, 4) != dst+20 || strncmp (dst+16, src, 4))
+    abort();
+
+  memset (dst, 0, sizeof (dst));
+  if (stpncpy (dst+32, src+5, 4) != dst+36 || strncmp (dst+32, src+5, 4))
+    abort();
+
+  memset (dst, 0, sizeof (dst));
+  dst2 = dst;
+  if (stpncpy (++dst2, src+5, 4) != dst+5 || strncmp (dst2, src+5, 4)
+      || dst2 != dst+1)
+    abort();
+
+  memset (dst, 0, sizeof (dst));
+  if (stpncpy (dst, src, 0) != dst || strcmp (dst, ""))
+    abort();
+  
+  memset (dst, 0, sizeof (dst));
+  dst2 = dst; src2 = src;
+  if (stpncpy (++dst2, ++src2, 0) != dst+1 || strcmp (dst2, "")
+      || dst2 != dst+1 || src2 != src+1)
+    abort();
+
+  memset (dst, 0, sizeof (dst));
+  dst2 = dst; src2 = src;
+  if (stpncpy (++dst2+5, ++src2+5, 0) != dst+6 || strcmp (dst2+5, "")
+      || dst2 != dst+1 || src2 != src+1)
+    abort();
+
+  memset (dst, 0, sizeof (dst));
+  if (stpncpy (dst, src, 12) != dst+11 || strcmp (dst, src))
+    abort();
+
+  /* Test at least one instance of the __builtin_ style.  We do this
+     to ensure that it works and that the prototype is correct.  */
+  memset (dst, 0, sizeof (dst));
+  if (__builtin_stpncpy (dst, src, 4) != dst+4 || strncmp (dst, src, 4))
+    abort();
+
+  memset (dst, 0, sizeof (dst));
+  if (stpncpy (dst, i++ ? "xfoo" + 1 : "bar", 4) != dst+3
+      || strcmp (dst, "bar")
+      || i != 1)
+    abort ();
+
+  /* If return value of stpncpy is ignored, it should be optimized into
+     stpncpy call.  */
+  stpncpy_disallowed = 1;
+  stpncpy (dst + 1, src, 4);
+  stpncpy_disallowed = 0;
+  if (strncmp (dst + 1, src, 4))
+    abort ();
+
+  if (chk_calls)
+    abort ();
+}
+
+void
+__attribute__((noinline))
+test2 (void)
+{
+  chk_calls = 0;
+
+  /* No runtime checking should be done here, both destination
+     and length are unknown.  */
+  size_t cpy_length = l1 < 4 ? l1 + 1 : 4;
+  if (stpncpy (s4, "abcd", l1 + 1) != s4 + cpy_length || strncmp (s4, "abcd", cpy_length))
+    abort ();
+
+  if (chk_calls)
+    abort ();
+}
+
+/* Test whether compile time checking is done where it should
+   and so is runtime object size checking.  */
+void
+__attribute__((noinline))
+test3 (void)
+{
+  struct A { char buf1[10]; char buf2[10]; } a;
+  char *r = l1 == 1 ? &a.buf1[5] : &a.buf2[4];
+  char buf3[20];
+  int i;
+  const char *l;
+  size_t l2;
+
+  /* The following calls should do runtime checking
+     - source length is not known, but destination is.  
+     The returned value is checked so that stpncpy calls
+     are not rewritten to strncpy calls. */
+  chk_calls = 0;
+  if (!stpncpy (a.buf1 + 2, s3 + 3, l1))
+    abort();
+  if (!stpncpy (r, s3 + 2, l1 + 2))
+    abort();
+  r = l1 == 1 ? __builtin_alloca (4) : &a.buf2[7];
+  if (!stpncpy (r, s2 + 2, l1 + 2))
+    abort();
+  if (!stpncpy (r + 2, s3 + 3, l1))
+    abort();
+  r = buf3;
+  for (i = 0; i < 4; ++i)
+    {
+      if (i == l1 - 1)
+	r = &a.buf1[1];
+      else if (i == l1)
+	r = &a.buf2[7];
+      else if (i == l1 + 1)
+	r = &buf3[5];
+      else if (i == l1 + 2)
+	r = &a.buf1[9];
+    }
+  if (!stpncpy (r, s2 + 4, l1))
+    abort();
+  if (chk_calls != 5)
+    abort ();
+
+  /* Following have known destination and known length,
+     so if optimizing certainly shouldn't result in the checking
+     variants.  */
+  chk_calls = 0;
+  if (!stpncpy (a.buf1 + 2, "", 3))
+    abort ();
+  if (!stpncpy (a.buf1 + 2, "", 0))
+    abort ();
+  if (!stpncpy (r, "a", 1))
+    abort ();
+  if (!stpncpy (r, "a", 3))
+    abort ();
+  r = l1 == 1 ? __builtin_alloca (4) : &a.buf2[7];
+  if (!stpncpy (r, s1 + 1, 3))
+    abort ();
+  if (!stpncpy (r, s1 + 1, 2))
+    abort ();
+  r = buf3;
+  l = "abc";
+  l2 = 4;
+  for (i = 0; i < 4; ++i)
+    {
+      if (i == l1 - 1)
+	r = &a.buf1[1], l = "e", l2 = 2;
+      else if (i == l1)
+	r = &a.buf2[7], l = "gh", l2 = 3;
+      else if (i == l1 + 1)
+	r = &buf3[5], l = "jkl", l2 = 4;
+      else if (i == l1 + 2)
+	r = &a.buf1[9], l = "", l2 = 1;
+    }
+  if (!stpncpy (r, "", 1))
+    abort ();
+  /* Here, strlen (l) + 1 is known to be at most 4 and
+     __builtin_object_size (&buf3[16], 0) is 4, so this doesn't need
+     runtime checking.  */
+  if (!stpncpy (&buf3[16], l, l2))
+    abort ();
+  if (!stpncpy (&buf3[15], "abc", l2))
+    abort ();
+  if (!stpncpy (&buf3[10], "fghij", l2))
+    abort ();
+  if (chk_calls)
+    abort ();
+  chk_calls = 0;
+}
+
+/* Test whether runtime and/or compile time checking catches
+   buffer overflows.  */
+void
+__attribute__((noinline))
+test4 (void)
+{
+  struct A { char buf1[10]; char buf2[10]; } a;
+  char buf3[20];
+
+  chk_fail_allowed = 1;
+  /* Runtime checks.  */
+  if (__builtin_setjmp (chk_fail_buf) == 0)
+    {
+      if (stpncpy (&a.buf2[9], s2 + 4, l1 + 1))
+        // returned value used to prevent stpncpy calls
+        // to be rewritten in strncpy calls
+        i++;
+      abort ();
+    }
+  if (__builtin_setjmp (chk_fail_buf) == 0)
+    {
+      if (stpncpy (&a.buf2[7], s3, l1 + 4))
+        i++;
+      abort ();
+    }
+  /* This should be detectable at compile time already.  */
+  if (__builtin_setjmp (chk_fail_buf) == 0)
+    {
+      if (stpncpy (&buf3[19], "abc", 2))
+        i++;
+      abort ();
+    }
+  if (__builtin_setjmp (chk_fail_buf) == 0)
+    {
+      if (stpncpy (&buf3[18], "", 3))
+        i++;
+      abort ();
+    }
+  chk_fail_allowed = 0;
+}
+
+void
+main_test (void)
+{
+#ifndef __OPTIMIZE__
+  /* Object size checking is only intended for -O[s123].  */
+  return;
+#endif
+  __asm ("" : "=r" (s2) : "0" (s2));
+  __asm ("" : "=r" (s3) : "0" (s3));
+  __asm ("" : "=r" (l1) : "0" (l1));
+  test1 ();
+  
+  s4 = p;
+  test2 ();
+  test3 ();
+  test4 ();
+}