Avoid assuming maximum string length is constant [PR102960].

Resolves:
PR tree-optimization/102960 - ICE: in sign_mask, at wide-int.h:855 in GCC 10.3.0

gcc/ChangeLog:

	PR tree-optimization/102960
	* gimple-fold.c (get_range_strlen): Take bitmap as an argument rather
	than a pointer to it.
	(get_range_strlen_tree): Same.  Remove bitmap allocation.  Use
	an auto_bitmap.
	(get_maxval_strlen): Use an auto_bitmap.
	* tree-ssa-strlen.c (get_range_strlen_dynamic): Factor out PHI
	handling...
	(get_range_strlen_phi): ...into this function.
	Avoid assuming maximum string length is constant
	(printf_strlen_execute): Dump pointer query cache contents when
	details are requisted.

gcc/testsuite/ChangeLog:

	PR tree-optimization/102960
	* gcc.dg/Wstringop-overflow-84.c: New test.

1 files changed, 8 insertions, 16 deletions

diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c
index 765726c..ad9703e 100644
--- a/gcc/gimple-fold.c
+++ b/gcc/gimple-fold.c
@@ -86,7 +86,7 @@ enum strlen_range_kind {
 };
 
 static bool
-get_range_strlen (tree, bitmap *, strlen_range_kind, c_strlen_data *, unsigned);
+get_range_strlen (tree, bitmap, strlen_range_kind, c_strlen_data *, unsigned);
 
 /* Return true when DECL can be referenced from current unit.
    FROM_DECL (if non-null) specify constructor of variable DECL was taken from.
@@ -1525,7 +1525,7 @@ gimple_fold_builtin_memset (gimple_stmt_iterator *gsi, tree c, tree len)
 /* Helper of get_range_strlen for ARG that is not an SSA_NAME.  */
 
 static bool
-get_range_strlen_tree (tree arg, bitmap *visited, strlen_range_kind rkind,
+get_range_strlen_tree (tree arg, bitmap visited, strlen_range_kind rkind,
 		       c_strlen_data *pdata, unsigned eltsize)
 {
   gcc_assert (TREE_CODE (arg) != SSA_NAME);
@@ -1849,7 +1849,7 @@ get_range_strlen_tree (tree arg, bitmap *visited, strlen_range_kind rkind,
    Return true if *PDATA was successfully populated and false otherwise.  */
 
 static bool
-get_range_strlen (tree arg, bitmap *visited,
+get_range_strlen (tree arg, bitmap visited,
 		  strlen_range_kind rkind,
 		  c_strlen_data *pdata, unsigned eltsize)
 {
@@ -1863,9 +1863,7 @@ get_range_strlen (tree arg, bitmap *visited,
     return false;
 
   /* If we were already here, break the infinite cycle.  */
-  if (!*visited)
-    *visited = BITMAP_ALLOC (NULL);
-  if (!bitmap_set_bit (*visited, SSA_NAME_VERSION (arg)))
+  if (!bitmap_set_bit (visited, SSA_NAME_VERSION (arg)))
     return true;
 
   tree var = arg;
@@ -1962,10 +1960,10 @@ get_range_strlen (tree arg, bitmap *visited,
 bool
 get_range_strlen (tree arg, c_strlen_data *pdata, unsigned eltsize)
 {
-  bitmap visited = NULL;
+  auto_bitmap visited;
   tree maxbound = pdata->maxbound;
 
-  if (!get_range_strlen (arg, &visited, SRK_LENRANGE, pdata, eltsize))
+  if (!get_range_strlen (arg, visited, SRK_LENRANGE, pdata, eltsize))
     {
       /* On failure extend the length range to an impossible maximum
 	 (a valid MAXLEN must be less than PTRDIFF_MAX - 1).  Other
@@ -1981,9 +1979,6 @@ get_range_strlen (tree arg, c_strlen_data *pdata, unsigned eltsize)
   if (maxbound && pdata->maxbound == maxbound)
     pdata->maxbound = build_all_ones_cst (size_type_node);
 
-  if (visited)
-    BITMAP_FREE (visited);
-
   return !integer_all_onesp (pdata->maxlen);
 }
 
@@ -2005,19 +2000,16 @@ get_maxval_strlen (tree arg, strlen_range_kind rkind, tree *nonstr = NULL)
   /* ARG must have an integral type when RKIND says so.  */
   gcc_assert (rkind != SRK_INT_VALUE || INTEGRAL_TYPE_P (TREE_TYPE (arg)));
 
-  bitmap visited = NULL;
+  auto_bitmap visited;
 
   /* Reset DATA.MAXLEN if the call fails or when DATA.MAXLEN
      is unbounded.  */
   c_strlen_data lendata = { };
-  if (!get_range_strlen (arg, &visited, rkind, &lendata, /* eltsize = */1))
+  if (!get_range_strlen (arg, visited, rkind, &lendata, /* eltsize = */1))
     lendata.maxlen = NULL_TREE;
   else if (lendata.maxlen && integer_all_onesp (lendata.maxlen))
     lendata.maxlen = NULL_TREE;
 
-  if (visited)
-    BITMAP_FREE (visited);
-
   if (nonstr)
     {
       /* For callers prepared to handle unterminated arrays set