Don't create out-of-bounds BIT_FIELD_REF.

2013-11-27  Tom de Vries  <tom@codesourcery.com>
	    Marc Glisse  <marc.glisse@inria.fr>

	PR middle-end/59037
	* semantics.c (cxx_fold_indirect_ref): Don't create out-of-bounds
	BIT_FIELD_REF.

	* fold-const.c (fold_indirect_ref_1): Don't create out-of-bounds
	BIT_FIELD_REF.
	* gimple-fold.c (gimple_fold_indirect_ref): Same.
	* tree-cfg.c (verify_expr): Give error if BIT_FIELD_REF is
	out-of-bounds.

	* c-c++-common/pr59037.c: New testcase.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@205438 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 05a31a8..f572df4 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,13 @@
+2013-11-27  Tom de Vries  <tom@codesourcery.com>
+           Marc Glisse  <marc.glisse@inria.fr>
+
+       PR middle-end/59037
+       * fold-const.c (fold_indirect_ref_1): Don't create out-of-bounds
+       BIT_FIELD_REF.
+       * gimple-fold.c (gimple_fold_indirect_ref): Same.
+       * tree-cfg.c (verify_expr): Give error if BIT_FIELD_REF is
+       out-of-bounds.
+
 2013-11-27  Eric Botcazou  <ebotcazou@adacore.com>
 
        PR middle-end/59138

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 802e4fa..8c5ec0a 100644 (file)
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,10 @@
+2013-11-27  Tom de Vries  <tom@codesourcery.com>
+           Marc Glisse  <marc.glisse@inria.fr>
+
+       PR middle-end/59037
+       * semantics.c (cxx_fold_indirect_ref): Don't create out-of-bounds
+       BIT_FIELD_REF.
+
 2013-11-26  Jakub Jelinek  <jakub@redhat.com>
 
        PR c++/58874

diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index d871c4d..083c4f4 100644 (file)
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -9122,7 +9122,7 @@ cxx_fold_indirect_ref (location_t loc, tree type, tree op0, bool *empty_base)
              unsigned HOST_WIDE_INT indexi = offset * BITS_PER_UNIT;
              tree index = bitsize_int (indexi);
 
-             if (offset/part_widthi <= TYPE_VECTOR_SUBPARTS (op00type))
+             if (offset / part_widthi < TYPE_VECTOR_SUBPARTS (op00type))
                return fold_build3_loc (loc,
                                        BIT_FIELD_REF, type, op00,
                                        part_width, index);

diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 2289ba4..d56b355 100644 (file)
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -16720,7 +16720,7 @@ fold_indirect_ref_1 (location_t loc, tree type, tree op0)
              unsigned HOST_WIDE_INT indexi = offset * BITS_PER_UNIT;
              tree index = bitsize_int (indexi);
 
-             if (offset/part_widthi <= TYPE_VECTOR_SUBPARTS (op00type))
+             if (offset / part_widthi < TYPE_VECTOR_SUBPARTS (op00type))
                return fold_build3_loc (loc,
                                        BIT_FIELD_REF, type, op00,
                                        part_width, index);

diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c
index 2902e69..7e9ba65 100644 (file)
--- a/gcc/gimple-fold.c
+++ b/gcc/gimple-fold.c
@@ -3418,7 +3418,7 @@ gimple_fold_indirect_ref (tree t)
           unsigned HOST_WIDE_INT indexi = offset * BITS_PER_UNIT;
           tree index = bitsize_int (indexi);
           if (offset / part_widthi
-              <= TYPE_VECTOR_SUBPARTS (TREE_TYPE (addrtype)))
+             < TYPE_VECTOR_SUBPARTS (TREE_TYPE (addrtype)))
             return fold_build3 (BIT_FIELD_REF, type, TREE_OPERAND (addr, 0),
                                 part_width, index);
        }

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 74273b2..ca48472 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2013-11-27  Tom de Vries  <tom@codesourcery.com>
+           Marc Glisse  <marc.glisse@inria.fr>
+
+       PR middle-end/59037
+       * c-c++-common/pr59037.c: New testcase.
+
 2013-11-27  Eric Botcazou  <ebotcazou@adacore.com>
 
        * gcc.c-torture/execute/20131127-1.c: New test.

diff --git a/gcc/testsuite/c-c++-common/pr59037.c b/gcc/testsuite/c-c++-common/pr59037.c
new file mode 100644 (file)
index 0000000..fae13c2
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr59037.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O3" } */
+
+typedef int v4si __attribute__ ((vector_size (16)));
+
+int
+main (int argc, char** argv)
+{
+  v4si x = {0,1,2,3};
+  x = (v4si) {(x)[3], (x)[2], (x)[1], (x)[0]};
+  return x[4];
+}

diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c
index ab4bb09..f8937c6 100644 (file)
--- a/gcc/tree-cfg.c
+++ b/gcc/tree-cfg.c
@@ -2712,15 +2712,29 @@ verify_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
 
       if (TREE_CODE (t) == BIT_FIELD_REF)
        {
-         if (!tree_fits_uhwi_p (TREE_OPERAND (t, 1))
-             || !tree_fits_uhwi_p (TREE_OPERAND (t, 2)))
+         tree t0 = TREE_OPERAND (t, 0);
+         tree t1 = TREE_OPERAND (t, 1);
+         tree t2 = TREE_OPERAND (t, 2);
+         tree t0_type = TREE_TYPE (t0);
+         unsigned HOST_WIDE_INT t0_size = 0;
+
+         if (tree_fits_uhwi_p (TYPE_SIZE (t0_type)))
+           t0_size = tree_to_uhwi (TYPE_SIZE (t0_type));
+         else 
+           {
+             HOST_WIDE_INT t0_max_size = max_int_size_in_bytes (t0_type);
+             if (t0_max_size > 0)
+               t0_size = t0_max_size * BITS_PER_UNIT;
+           }
+         if (!tree_fits_uhwi_p (t1)
+             || !tree_fits_uhwi_p (t2))
            {
              error ("invalid position or size operand to BIT_FIELD_REF");
              return t;
            }
          if (INTEGRAL_TYPE_P (TREE_TYPE (t))
              && (TYPE_PRECISION (TREE_TYPE (t))
-                 != tree_to_uhwi (TREE_OPERAND (t, 1))))
+                 != tree_to_uhwi (t1)))
            {
              error ("integral result type precision does not match "
                     "field size of BIT_FIELD_REF");
@@ -2729,12 +2743,19 @@ verify_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
          else if (!INTEGRAL_TYPE_P (TREE_TYPE (t))
                   && TYPE_MODE (TREE_TYPE (t)) != BLKmode
                   && (GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (t)))
-                      != tree_to_uhwi (TREE_OPERAND (t, 1))))
+                      != tree_to_uhwi (t1)))
            {
              error ("mode precision of non-integral result does not "
                     "match field size of BIT_FIELD_REF");
              return t;
            }
+         if (t0_size != 0
+             && tree_to_uhwi (t1) + tree_to_uhwi (t2) > t0_size)
+           {
+             error ("position plus size exceeds size of referenced object in "
+                    "BIT_FIELD_REF");
+             return t;
+           }
        }
       t = TREE_OPERAND (t, 0);