Patch for middle-end/PR79538

missing -Wformat-overflow with %s and non-member array arguments

-Wformat-overflow uses the routine "get_range_strlen" to decide the
maximum string length, however, currently "get_range_strlen" misses
the handling of non-member arrays.

Adding the handling of non-member array resolves the issue.
Adding test case pr79538.c into gcc.dg.

During gcc bootstrap, 2 source files (c-family/c-cppbuiltin.c,
fortran/class.c) were detected new warnings by -Wformat-overflow
due to the new handling of non-member array in "get_range_strlen".
in order to avoid these new warnings and continue with bootstrap,
updating these 2 files to avoid the warnings.

in c-family/c-cppbuiltin.c, the warning is following:

../../latest_gcc_2/gcc/c-family/c-cppbuiltin.c:1627:15: note:
‘sprintf’ output 2 or more bytes (assuming 257) into a destination
of size 256
       sprintf (buf1, "%s=%s", macro, buf2);
       ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
in the above, buf1 and buf2 are declared as:
char buf1[256], buf2[256];

i.e, buf1 and buf2 have same size. adjusting the size of buf1 and
buf2 resolves the warning.

fortran/class.c has the similar issue as above. Instead of adjusting
size of the buffers, replacing sprintf with xasprintf is a better
solution for these cases.

From-SVN: r255654

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 7473263a62c5bc8dcdf241947555663f5696c7d7..0192d672823c2814637e92c6d128c8d89ed7a631 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2017-12-14  Qing Zhao  <qing.zhao@oracle.com>
+
+       PR middle_end/79538
+       * gimple-fold.c (get_range_strlen): Add the handling of non-member 
+       array.
+
 2017-12-14  David Malcolm  <dmalcolm@redhat.com>
 
        PR tree-optimization/83312

diff --git a/gcc/c-family/ChangeLog b/gcc/c-family/ChangeLog
index 6c31dbef45e04d79e29f79677ecd64cd4d68fb90..abe53019aa669e0bfbcb1436c3d575f6df7b450b 100644 (file)
--- a/gcc/c-family/ChangeLog
+++ b/gcc/c-family/ChangeLog
@@ -1,3 +1,10 @@
+2017-12-14  Qing Zhao  <qing.zhao@oracle.com>
+
+       PR middle_end/79538 
+       * c-cppbuiltin.c (builtin_define_with_hex_fp_value):
+       Adjust the size of buf1 and buf2, add a new buf to avoid
+       format-overflow warning.
+
 2017-12-12  Alexandre Oliva <aoliva@redhat.com>
 
        * c-semantics.c (pop_stmt_list): Move begin stmt marker into

diff --git a/gcc/c-family/c-cppbuiltin.c b/gcc/c-family/c-cppbuiltin.c
index 2ac9616b72f1e48febad4b432157bf3f77769703..9e33aed9b8bc1457883398344c5ea629503b240e 100644 (file)
--- a/gcc/c-family/c-cppbuiltin.c
+++ b/gcc/c-family/c-cppbuiltin.c
@@ -1613,7 +1613,7 @@ builtin_define_with_hex_fp_value (const char *macro,
                                  const char *fp_cast)
 {
   REAL_VALUE_TYPE real;
-  char dec_str[64], buf1[256], buf2[256];
+  char dec_str[64], buf[256], buf1[128], buf2[64];
 
   /* This is very expensive, so if possible expand them lazily.  */
   if (lazy_hex_fp_value_count < 12
@@ -1656,11 +1656,11 @@ builtin_define_with_hex_fp_value (const char *macro,
 
   /* Assemble the macro in the following fashion
      macro = fp_cast [dec_str fp_suffix] */
-  sprintf (buf1, "%s%s", dec_str, fp_suffix);
-  sprintf (buf2, fp_cast, buf1);
-  sprintf (buf1, "%s=%s", macro, buf2);
+  sprintf (buf2, "%s%s", dec_str, fp_suffix);
+  sprintf (buf1, fp_cast, buf2);
+  sprintf (buf, "%s=%s", macro, buf1);
 
-  cpp_define (parse_in, buf1);
+  cpp_define (parse_in, buf);
 }
 
 /* Return a string constant for the suffix for a value of type TYPE

diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index f3f9d9c9300985637c132717c7d0b5d992d0073d..cc8b11879f3d62e110be2ab9548d893e22025f6f 100644 (file)
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,12 @@
+2017-12-14  Qing Zhao  <qing.zhao@oracle.com>
+
+       PR middle_end/79538
+       * class.c (gfc_build_class_symbol): Replace call to
+       sprintf with xasprintf to avoid format-overflow warning.
+       (generate_finalization_wrapper): Likewise.
+       (gfc_find_derived_vtab): Likewise.
+       (find_intrinsic_vtab): Likewise.
+
 2017-12-12  Thomas Koenig  <tkoenig@gcc.gnu.org>
 
        * intrinsic.texi (MAXLOC): Remove double description

diff --git a/gcc/fortran/class.c b/gcc/fortran/class.c
index ebbd41b0d96ef2832d6073391ef177db563018a5..a08fb8d81c5d10c177234c3c5cfdf3a1fb41695d 100644 (file)
--- a/gcc/fortran/class.c
+++ b/gcc/fortran/class.c
@@ -602,7 +602,8 @@ bool
 gfc_build_class_symbol (gfc_typespec *ts, symbol_attribute *attr,
                        gfc_array_spec **as)
 {
-  char name[GFC_MAX_SYMBOL_LEN+1], tname[GFC_MAX_SYMBOL_LEN+1];
+  char tname[GFC_MAX_SYMBOL_LEN+1];
+  char *name;
   gfc_symbol *fclass;
   gfc_symbol *vtab;
   gfc_component *c;
@@ -633,17 +634,17 @@ gfc_build_class_symbol (gfc_typespec *ts, symbol_attribute *attr,
   rank = !(*as) || (*as)->rank == -1 ? GFC_MAX_DIMENSIONS : (*as)->rank;
   get_unique_hashed_string (tname, ts->u.derived);
   if ((*as) && attr->allocatable)
-    sprintf (name, "__class_%s_%d_%da", tname, rank, (*as)->corank);
+    name = xasprintf ("__class_%s_%d_%da", tname, rank, (*as)->corank);
   else if ((*as) && attr->pointer)
-    sprintf (name, "__class_%s_%d_%dp", tname, rank, (*as)->corank);
+    name = xasprintf ("__class_%s_%d_%dp", tname, rank, (*as)->corank);
   else if ((*as))
-    sprintf (name, "__class_%s_%d_%dt", tname, rank, (*as)->corank);
+    name = xasprintf ("__class_%s_%d_%dt", tname, rank, (*as)->corank);
   else if (attr->pointer)
-    sprintf (name, "__class_%s_p", tname);
+    name = xasprintf ("__class_%s_p", tname);
   else if (attr->allocatable)
-    sprintf (name, "__class_%s_a", tname);
+    name = xasprintf ("__class_%s_a", tname);
   else
-    sprintf (name, "__class_%s_t", tname);
+    name = xasprintf ("__class_%s_t", tname);
 
   if (ts->u.derived->attr.unlimited_polymorphic)
     {
@@ -738,6 +739,7 @@ gfc_build_class_symbol (gfc_typespec *ts, symbol_attribute *attr,
   ts->u.derived = fclass;
   attr->allocatable = attr->pointer = attr->dimension = attr->codimension = 0;
   (*as) = NULL;
+  free (name);
   return true;
 }
 
@@ -1527,7 +1529,7 @@ generate_finalization_wrapper (gfc_symbol *derived, gfc_namespace *ns,
   gfc_component *comp;
   gfc_namespace *sub_ns;
   gfc_code *last_code, *block;
-  char name[GFC_MAX_SYMBOL_LEN+1];
+  char *name;
   bool finalizable_comp = false;
   bool expr_null_wrapper = false;
   gfc_expr *ancestor_wrapper = NULL, *rank;
@@ -1606,7 +1608,7 @@ generate_finalization_wrapper (gfc_symbol *derived, gfc_namespace *ns,
   sub_ns->resolved = 1;
 
   /* Set up the procedure symbol.  */
-  sprintf (name, "__final_%s", tname);
+  name = xasprintf ("__final_%s", tname);
   gfc_get_symbol (name, sub_ns, &final);
   sub_ns->proc_name = final;
   final->attr.flavor = FL_PROCEDURE;
@@ -2172,6 +2174,7 @@ generate_finalization_wrapper (gfc_symbol *derived, gfc_namespace *ns,
   gfc_free_expr (rank);
   vtab_final->initializer = gfc_lval_expr_from_sym (final);
   vtab_final->ts.interface = final;
+  free (name);
 }
 
 
@@ -2239,10 +2242,11 @@ gfc_find_derived_vtab (gfc_symbol *derived)
 
   if (ns)
     {
-      char name[GFC_MAX_SYMBOL_LEN+1], tname[GFC_MAX_SYMBOL_LEN+1];
+      char tname[GFC_MAX_SYMBOL_LEN+1];
+      char *name;
 
       get_unique_hashed_string (tname, derived);
-      sprintf (name, "__vtab_%s", tname);
+      name = xasprintf ("__vtab_%s", tname);
 
       /* Look for the vtab symbol in various namespaces.  */
       if (gsym && gsym->ns)
@@ -2270,7 +2274,7 @@ gfc_find_derived_vtab (gfc_symbol *derived)
          vtab->attr.vtab = 1;
          vtab->attr.access = ACCESS_PUBLIC;
          gfc_set_sym_referenced (vtab);
-         sprintf (name, "__vtype_%s", tname);
+         name = xasprintf ("__vtype_%s", tname);
 
          gfc_find_symbol (name, ns, 0, &vtype);
          if (vtype == NULL)
@@ -2373,7 +2377,7 @@ gfc_find_derived_vtab (gfc_symbol *derived)
              else
                {
                  /* Construct default initialization variable.  */
-                 sprintf (name, "__def_init_%s", tname);
+                 name = xasprintf ("__def_init_%s", tname);
                  gfc_get_symbol (name, ns, &def_init);
                  def_init->attr.target = 1;
                  def_init->attr.artificial = 1;
@@ -2406,7 +2410,7 @@ gfc_find_derived_vtab (gfc_symbol *derived)
                  ns->contained = sub_ns;
                  sub_ns->resolved = 1;
                  /* Set up procedure symbol.  */
-                 sprintf (name, "__copy_%s", tname);
+                 name = xasprintf ("__copy_%s", tname);
                  gfc_get_symbol (name, sub_ns, &copy);
                  sub_ns->proc_name = copy;
                  copy->attr.flavor = FL_PROCEDURE;
@@ -2483,7 +2487,7 @@ gfc_find_derived_vtab (gfc_symbol *derived)
                  ns->contained = sub_ns;
                  sub_ns->resolved = 1;
                  /* Set up procedure symbol.  */
-                 sprintf (name, "__deallocate_%s", tname);
+                 name = xasprintf ("__deallocate_%s", tname);
                  gfc_get_symbol (name, sub_ns, &dealloc);
                  sub_ns->proc_name = dealloc;
                  dealloc->attr.flavor = FL_PROCEDURE;
@@ -2532,6 +2536,7 @@ have_vtype:
          vtab->ts.u.derived = vtype;
          vtab->value = gfc_default_initializer (&vtab->ts);
        }
+      free (name);
     }
 
   found_sym = vtab;
@@ -2623,13 +2628,14 @@ find_intrinsic_vtab (gfc_typespec *ts)
 
   if (ns)
     {
-      char name[GFC_MAX_SYMBOL_LEN+1], tname[GFC_MAX_SYMBOL_LEN+1];
-
+      char tname[GFC_MAX_SYMBOL_LEN+1];
+      char *name;
+      
       /* Encode all types as TYPENAME_KIND_ including especially character
         arrays, whose length is now consistently stored in the _len component
         of the class-variable.  */
       sprintf (tname, "%s_%d_", gfc_basic_typename (ts->type), ts->kind);
-      sprintf (name, "__vtab_%s", tname);
+      name = xasprintf ("__vtab_%s", tname);
 
       /* Look for the vtab symbol in the top-level namespace only.  */
       gfc_find_symbol (name, ns, 0, &vtab);
@@ -2646,7 +2652,7 @@ find_intrinsic_vtab (gfc_typespec *ts)
          vtab->attr.vtab = 1;
          vtab->attr.access = ACCESS_PUBLIC;
          gfc_set_sym_referenced (vtab);
-         sprintf (name, "__vtype_%s", tname);
+         name = xasprintf ("__vtype_%s", tname);
 
          gfc_find_symbol (name, ns, 0, &vtype);
          if (vtype == NULL)
@@ -2722,12 +2728,12 @@ find_intrinsic_vtab (gfc_typespec *ts)
              c->tb->ppc = 1;
 
              if (ts->type != BT_CHARACTER)
-               sprintf (name, "__copy_%s", tname);
+               name = xasprintf ("__copy_%s", tname);
              else
                {
                  /* __copy is always the same for characters.
                     Check to see if copy function already exists.  */
-                 sprintf (name, "__copy_character_%d", ts->kind);
+                 name = xasprintf ("__copy_character_%d", ts->kind);
                  contained = ns->contained;
                  for (; contained; contained = contained->sibling)
                    if (contained->proc_name
@@ -2796,6 +2802,7 @@ find_intrinsic_vtab (gfc_typespec *ts)
          vtab->ts.u.derived = vtype;
          vtab->value = gfc_default_initializer (&vtab->ts);
        }
+      free (name);
     }
 
   found_sym = vtab;

diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c
index 24f7e76228b9000f6250e39365843982ba15b4c8..403fbb8c940872edc4c5ccbad526cf540ad5190e 100644 (file)
--- a/gcc/gimple-fold.c
+++ b/gcc/gimple-fold.c
@@ -1340,6 +1340,19 @@ get_range_strlen (tree arg, tree length[2], bitmap *visited, int type,
                 the array could have zero length.  */
              *minlen = ssize_int (0);
            }
+
+         if (VAR_P (arg) 
+             && TREE_CODE (TREE_TYPE (arg)) == ARRAY_TYPE)
+           {
+             val = TYPE_SIZE_UNIT (TREE_TYPE (arg));
+             if (!val || TREE_CODE (val) != INTEGER_CST || integer_zerop (val))
+               return false;
+             val = wide_int_to_tree (TREE_TYPE (val), 
+                                     wi::sub(wi::to_wide (val), 1));
+             /* Set the minimum size to zero since the string in
+                the array could have zero length.  */
+             *minlen = ssize_int (0);
+           }
        }
 
       if (!val)

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 81d28f1adb6ba35b96b4b347e4f111af92312c55..6cedc130701225f2ae0efeeae144c35af88ddd73 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2017-12-14  Qing Zhao  <qing.zhao@oracle.com>
+
+       PR middle_end/79538
+       * gcc.dg/pr79538.c: New test.
+
 2017-12-14  David Malcolm  <dmalcolm@redhat.com>
 
        PR tree-optimization/83312

diff --git a/gcc/testsuite/gcc.dg/pr79538.c b/gcc/testsuite/gcc.dg/pr79538.c
new file mode 100644 (file)
index 0000000..6cdab45
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr79538.c
@@ -0,0 +1,22 @@
+/* PR middle-end/79538 - missing -Wformat-overflow with %s and non-member array arguments
+   { dg-do compile }
+   { dg-options "-O2 -Wformat-overflow" } */
+
+char a3[3];
+char a4[4];
+char d[3];
+
+void g (int i)
+{
+  const char *s = i < 0 ? a3 : a4;
+  __builtin_sprintf (d, "%s", s);      /* { dg-warning ".__builtin_sprintf. may write a terminating nul past the end of the destination" } */
+  return;
+}
+
+void f ()
+{
+  char des[3];
+  char src[] = "abcd";
+  __builtin_sprintf (des, "%s", src); /* { dg-warning "directive writing up to 4 bytes into a region of size 3" } */
+  return;
+}