Implement a solution for PR middle-end/10138 and PR middle-end/95136.

PR middle-end/10138 - warn for uninitialized arrays passed as const arguments
PR middle-end/95136 - missing -Wuninitialized on an array access with a variable offset

gcc/c-family/ChangeLog:

	PR middle-end/10138
	PR middle-end/95136
	* c-attribs.c (append_access_attrs): Handle attr_access::none.
	(handle_access_attribute): Same.

gcc/ChangeLog:

	PR middle-end/10138
	PR middle-end/95136
	* attribs.c (init_attr_rdwr_indices): Move function here.
	* attribs.h (rdwr_access_hash, rdwr_map): Define.
	(attr_access): Add 'none'.
	(init_attr_rdwr_indices): Declared function.
	* builtins.c (warn_for_access)): New function.
	(check_access): Call it.
	* builtins.h (checK-access): Add an optional argument.
	* calls.c (rdwr_access_hash, rdwr_map): Move to attribs.h.
	(init_attr_rdwr_indices): Declare extern.
	(append_attrname): Handle attr_access::none.
	(maybe_warn_rdwr_sizes): Same.
	(initialize_argument_information): Update comments.
	* doc/extend.texi (attribute access): Document 'none'.
	* tree-ssa-uninit.c (struct wlimits): New.
	(maybe_warn_operand): New function.
	(maybe_warn_pass_by_reference): Same.
	(warn_uninitialized_vars): Refactor code into maybe_warn_operand.
	Also call for function calls.
	(pass_late_warn_uninitialized::execute): Adjust comments.
	(execute_early_warn_uninitialized): Same.

gcc/testsuite/ChangeLog:

	PR middle-end/10138
	PR middle-end/95136
	* c-c++-common/Wsizeof-pointer-memaccess1.c: Prune out valid
	Wuninitialized.
	* c-c++-common/uninit-pr51010.c: Adjust expected warning format.
	* c-c++-common/goacc/uninit-dim-clause.c: Same.
	* c-c++-common/goacc/uninit-firstprivate-clause.c: Same.
	* c-c++-common/goacc/uninit-if-clause.c: Same.
	* c-c++-common/gomp/pr70550-1.c: Same.
	* c-c++-common/gomp/pr70550-2.c: Adjust.
	* g++.dg/20090107-1.C: Same.
	* g++.dg/20090121-1.C: Same.
	* g++.dg/ext/attr-access.C: Avoid -Wuninitialized.
	* gcc.dg/tree-ssa/forwprop-6.c: Prune out -Wuninitialized.
	* gcc.dg/Warray-bounds-52.c: Prune out valid -Wuninitialized.
	* gcc.dg/Warray-bounds-53.c: Same.
	* gcc.dg/Warray-bounds-54.c: Same.
	* gcc.dg/Wstringop-overflow-33.c: New test.
	* gcc.dg/attr-access-none.c: New test.
	* gcc.dg/attr-access-read-only.c: Adjust.
	* gcc.dg/attr-access-read-write.c: Same.
	* gcc.dg/attr-access-write-only.c: Same.
	* gcc.dg/pr71581.c: Adjust text of expected warning.
	* gcc.dg/uninit-15.c: Same.
	* gcc.dg/uninit-32.c: New test.
	* gcc.dg/uninit-33.c: New test.
	* gcc.dg/uninit-34.c: New test.
	* gcc.dg/uninit-36.c: New test.
	* gcc.dg/uninit-B-O0.c: Adjust text of expected warning.
	* gcc.dg/uninit-I-O0.c: Same.
	* gcc.dg/uninit-pr19430-O0.c: Same.
	* gcc.dg/uninit-pr19430.c: Same.
	* gcc.dg/uninit-pr95136.c: New test.
	* gfortran.dg/assignment_4.f90: Expect -Wuninitialized.
	* gfortran.dg/goacc/uninit-dim-clause.f95: Adjust text of expected
	warning.
	* gfortran.dg/goacc/uninit-firstprivate-clause.f95
	* gfortran.dg/goacc/uninit-if-clause.f95
	* gfortran.dg/pr66545_2.f90

1 files changed, 59 insertions, 0 deletions

diff --git a/gcc/attribs.c b/gcc/attribs.c
index 7d0f4b5..71dae12 100644
--- a/gcc/attribs.c
+++ b/gcc/attribs.c
@@ -2017,6 +2017,65 @@ maybe_diag_alias_attributes (tree alias, tree target)
     }
 }
 
+/* Initialize a mapping for a call to function FNDECL declared with
+   attribute access.  Each attribute positional operand inserts one
+   entry into the mapping with the operand number as the key.  */
+
+void
+init_attr_rdwr_indices (rdwr_map *rwm, tree fntype)
+{
+  if (!fntype)
+    return;
+
+  for (tree access = TYPE_ATTRIBUTES (fntype);
+       (access = lookup_attribute ("access", access));
+       access = TREE_CHAIN (access))
+    {
+      /* The TREE_VALUE of an attribute is a TREE_LIST whose TREE_VALUE
+	 is the attribute argument's value.  */
+      tree mode = TREE_VALUE (access);
+      gcc_assert (TREE_CODE (mode) == TREE_LIST);
+      mode = TREE_VALUE (mode);
+      gcc_assert (TREE_CODE (mode) == STRING_CST);
+
+      const char *modestr = TREE_STRING_POINTER (mode);
+      for (const char *m = modestr; *m; )
+	{
+	  attr_access acc = { };
+
+	  switch (*m)
+	    {
+	    case 'r': acc.mode = acc.read_only; break;
+	    case 'w': acc.mode = acc.write_only; break;
+	    case 'x': acc.mode = acc.read_write; break;
+	    case '-': acc.mode = acc.none; break;
+	    default: gcc_unreachable ();
+	    }
+
+	  char *end;
+	  acc.ptrarg = strtoul (++m, &end, 10);
+	  m = end;
+	  if (*m == ',')
+	    {
+	      acc.sizarg = strtoul (++m, &end, 10);
+	      m = end;
+	    }
+	  else
+	    acc.sizarg = UINT_MAX;
+
+	  acc.ptr = NULL_TREE;
+	  acc.size = NULL_TREE;
+
+	  /* Unconditionally add an entry for the required pointer
+	     operand of the attribute, and one for the optional size
+	     operand when it's specified.  */
+	  rwm->put (acc.ptrarg, acc);
+	  if (acc.sizarg != UINT_MAX)
+	    rwm->put (acc.sizarg, acc);
+	}
+    }
+}
+
 
 #if CHECKING_P