re PR middle-end/87099 (internal compiler error: segmentation fault)

	PR middle-end/87099
	* calls.c (maybe_warn_nonstring_arg): Punt early if
	warn_stringop_overflow is zero.  Don't call get_range_strlen
	on 3rd argument, keep iterating until lenrng[1] is INTEGER_CST.
	Swap comparison operands to have constants on rhs.  Only use
	lenrng[1] if non-NULL and INTEGER_CST.  Don't uselessly
	increment lenrng[0].

	* gcc.dg/pr87099.c: New test.

From-SVN: r263915

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 0e2f9d013c34861479c76c677f597e1d3f581b54..66396a0a4d3a594877c127ab2b975a9d4e8620db 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,13 @@
+2018-08-28  Jakub Jelinek  <jakub@redhat.com>
+
+       PR middle-end/87099
+       * calls.c (maybe_warn_nonstring_arg): Punt early if
+       warn_stringop_overflow is zero.  Don't call get_range_strlen
+       on 3rd argument, keep iterating until lenrng[1] is INTEGER_CST.
+       Swap comparison operands to have constants on rhs.  Only use
+       lenrng[1] if non-NULL and INTEGER_CST.  Don't uselessly
+       increment lenrng[0].
+
 2018-08-28  Richard Sandiford  <richard.sandiford@arm.com>
 
        * tree-ssa-sccvn.c (fully_constant_vn_reference_p): Fix unguarded

diff --git a/gcc/calls.c b/gcc/calls.c
index f57ecf916365f3b7958e391b05474319c178b01d..87e3f000eff9108d374326caeb4d876b6ea07166 100644 (file)
--- a/gcc/calls.c
+++ b/gcc/calls.c
@@ -1545,7 +1545,7 @@ maybe_warn_nonstring_arg (tree fndecl, tree exp)
   if (!fndecl || !fndecl_built_in_p (fndecl, BUILT_IN_NORMAL))
     return;
 
-  if (TREE_NO_WARNING (exp))
+  if (TREE_NO_WARNING (exp) || !warn_stringop_overflow)
     return;
 
   unsigned nargs = call_expr_nargs (exp);
@@ -1573,7 +1573,9 @@ maybe_warn_nonstring_arg (tree fndecl, tree exp)
           the range of their known or possible lengths and use it
           conservatively as the bound for the unbounded function,
           and to adjust the range of the bound of the bounded ones.  */
-       for (unsigned argno = 0; argno < nargs && !*lenrng; argno ++)
+       for (unsigned argno = 0;
+            argno < MIN (nargs, 2)
+            && !(lenrng[1] && TREE_CODE (lenrng[1]) == INTEGER_CST); argno++)
          {
            tree arg = CALL_EXPR_ARG (exp, argno);
            if (!get_attr_nonstring_decl (arg))
@@ -1585,12 +1587,12 @@ maybe_warn_nonstring_arg (tree fndecl, tree exp)
     case BUILT_IN_STRNCAT:
     case BUILT_IN_STPNCPY:
     case BUILT_IN_STRNCPY:
-      if (2 < nargs)
+      if (nargs > 2)
        bound = CALL_EXPR_ARG (exp, 2);
       break;
 
     case BUILT_IN_STRNDUP:
-      if (1 < nargs)
+      if (nargs > 1)
        bound = CALL_EXPR_ARG (exp, 1);
       break;
 
@@ -1600,7 +1602,7 @@ maybe_warn_nonstring_arg (tree fndecl, tree exp)
        if (!get_attr_nonstring_decl (arg))
          get_range_strlen (arg, lenrng);
 
-       if (1 < nargs)
+       if (nargs > 1)
          bound = CALL_EXPR_ARG (exp, 1);
        break;
       }
@@ -1640,11 +1642,9 @@ maybe_warn_nonstring_arg (tree fndecl, tree exp)
        }
     }
 
-  if (*lenrng)
+  if (lenrng[1] && TREE_CODE (lenrng[1]) == INTEGER_CST)
     {
       /* Add one for the nul.  */
-      lenrng[0] = const_binop (PLUS_EXPR, TREE_TYPE (lenrng[0]),
-                              lenrng[0], size_one_node);
       lenrng[1] = const_binop (PLUS_EXPR, TREE_TYPE (lenrng[1]),
                               lenrng[1], size_one_node);
 

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 5dea5f7e994dcb09b5175746c7b6da0dd938c629..c62104902f5b8fae7b452ae8bdcc67e5590b522e 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2018-08-28  Jakub Jelinek  <jakub@redhat.com>
+
+       PR middle-end/87099
+       * gcc.dg/pr87099.c: New test.
+
 2018-08-28  Richard Sandiford  <richard.sandiford@arm.com>
 
        PR testsuite/87078

diff --git a/gcc/testsuite/gcc.dg/pr87099.c b/gcc/testsuite/gcc.dg/pr87099.c
new file mode 100644 (file)
index 0000000..599d721
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr87099.c
@@ -0,0 +1,21 @@
+/* PR middle-end/87099 */
+/* { dg-do compile } */
+/* { dg-options "-Wstringop-overflow" } */
+
+void bar (char *);
+
+int
+foo (int n)
+{
+  char v[n];
+  bar (v);
+  return __builtin_strncmp (&v[1], "aaa", 3);
+}
+
+int
+baz (int n, char *s)
+{
+  char v[n];
+  bar (v);
+  return __builtin_strncmp (&v[1], s, 3);
+}