From 14b7950f126f84fa585e3a057940ff10d4c5b3f8 Mon Sep 17 00:00:00 2001 From: Martin Sebor Date: Thu, 22 Aug 2019 23:09:26 +0000 Subject: PR middle-end/91490 - bogus argument missing terminating nul warning on strlen of a flexible array member gcc/c-family/ChangeLog: PR middle-end/91490 * c-common.c (braced_list_to_string): Add argument and overload. Handle flexible length arrays and unions. gcc/testsuite/ChangeLog: PR middle-end/91490 * c-c++-common/Warray-bounds-7.c: New test. * gcc.dg/Warray-bounds-39.c: Expect either -Warray-bounds or -Wstringop-overflow. * gcc.dg/strlenopt-78.c: New test. gcc/ChangeLog: PR middle-end/91490 * builtins.c (c_strlen): Rename argument and introduce new local. Set no-warning bit on original argument. * expr.c (string_constant): Pass argument type to fold_ctor_reference. Fold empty and zero constructors into empty strings. * gimple-fold.c (fold_nonarray_ctor_reference): Return a STRING_CST for missing initializers. * tree.c (build_string_literal): Handle optional argument. * tree.h (build_string_literal): Add defaulted argument. * gimple-ssa-warn-restrict.c (maybe_diag_access_bounds): Check no-warning bit on original expression. From-SVN: r274837 --- gcc/gimple-fold.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) (limited to 'gcc/gimple-fold.c') diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c index d576b08..fcffb98 100644 --- a/gcc/gimple-fold.c +++ b/gcc/gimple-fold.c @@ -759,11 +759,13 @@ gimple_fold_builtin_memory_op (gimple_stmt_iterator *gsi, dest_align = get_pointer_alignment (dest); if (tree_fits_uhwi_p (len) && compare_tree_int (len, MOVE_MAX) <= 0 - /* ??? Don't transform copies from strings with known length this - confuses the tree-ssa-strlen.c. This doesn't handle - the case in gcc.dg/strlenopt-8.c which is XFAILed for that - reason. */ - && !c_strlen (src, 2) + /* FIXME: Don't transform copies from strings with known length. + Until GCC 9 this prevented a case in gcc.dg/strlenopt-8.c + from being handled, and the case was XFAILed for that reason. + Now that it is handled and the XFAIL removed, as soon as other + strlenopt tests that rely on it for passing are adjusted, this + hack can be removed. */ + && !c_strlen (src, 1) && !((tmp_str = c_getstr (src, &tmp_len)) != NULL && memchr (tmp_str, 0, tmp_len) == NULL)) { @@ -6969,12 +6971,15 @@ fold_nonarray_ctor_reference (tree type, tree ctor, from_decl, suboff); } } - /* Memory not explicitly mentioned in constructor is 0. */ - return type ? build_zero_cst (type) : NULL_TREE; + + if (!type) + return NULL_TREE; + + return build_zero_cst (type); } /* CTOR is value initializing memory. Fold a reference of TYPE and - bit size POLY_SIZE to the memory at bit POLY_OFFSET. When SIZE + bit size POLY_SIZE to the memory at bit POLY_OFFSET. When POLY_SIZE is zero, attempt to fold a reference to the entire subobject which OFFSET refers to. This is used when folding accesses to string members of aggregates. When non-null, set *SUBOFF to -- cgit v1.1