middle-end/94188 fix fold of addr expression generation

This adds a missing type conversion to build_fold_addr_expr and adjusts
fallout - build_fold_addr_expr was used as a convenience to build an
ADDR_EXPR but some callers do not expect the result to be simplified
to something else.

2020-03-18  Richard Biener  <rguenther@suse.de>

	PR middle-end/94188
	* fold-const.c (build_fold_addr_expr): Convert address to
	correct type.
	* asan.c (maybe_create_ssa_name): Strip useless type conversions.
	* gimple-fold.c (gimple_fold_stmt_to_constant_1): Use build1
	to build the ADDR_EXPR which we don't really want to simplify.
	* tree-ssa-dom.c (record_equivalences_from_stmt): Likewise.
	* tree-ssa-loop-im.c (gather_mem_refs_stmt): Likewise.
	* tree-ssa-forwprop.c (forward_propagate_addr_expr_1): Likewise.
	(simplify_builtin_call): Strip useless type conversions.
	* tree-ssa-strlen.c (new_strinfo): Likewise.

	* gcc.dg/pr94188.c: New testcase.

1 files changed, 3 insertions, 2 deletions

diff --git a/gcc/asan.c b/gcc/asan.c
index 05f8b63..00d0e67 100644
--- a/gcc/asan.c
+++ b/gcc/asan.c
@@ -62,6 +62,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "builtins.h"
 #include "fnmatch.h"
 #include "tree-inline.h"
+#include "tree-ssa.h"
 
 /* AddressSanitizer finds out-of-bounds and use-after-free bugs
    with <2x slowdown on average.
@@ -2061,10 +2062,10 @@ static tree
 maybe_create_ssa_name (location_t loc, tree base, gimple_stmt_iterator *iter,
 		       bool before_p)
 {
+  STRIP_USELESS_TYPE_CONVERSION (base);
   if (TREE_CODE (base) == SSA_NAME)
     return base;
-  gimple *g = gimple_build_assign (make_ssa_name (TREE_TYPE (base)),
-				  TREE_CODE (base), base);
+  gimple *g = gimple_build_assign (make_ssa_name (TREE_TYPE (base)), base);
   gimple_set_location (g, loc);
   if (before_p)
     gsi_insert_before (iter, g, GSI_SAME_STMT);