diff options
| -rw-r--r-- | gcc/gimple-ssa-warn-access.cc | 51 |
1 files changed, 32 insertions, 19 deletions
diff --git a/gcc/gimple-ssa-warn-access.cc b/gcc/gimple-ssa-warn-access.cc index ac07a6f..fcaff128 100644 --- a/gcc/gimple-ssa-warn-access.cc +++ b/gcc/gimple-ssa-warn-access.cc @@ -2141,7 +2141,7 @@ private: void check_dangling_uses (tree, tree, bool = false, bool = false); void check_dangling_uses (); void check_dangling_stores (); - void check_dangling_stores (basic_block, hash_set<tree> &, auto_bitmap &); + bool check_dangling_stores (basic_block, hash_set<tree> &); void warn_invalid_pointer (tree, gimple *, gimple *, tree, bool, bool = false); @@ -4524,17 +4524,13 @@ pass_waccess::check_dangling_uses (tree var, tree decl, bool maybe /* = false */ /* Diagnose stores in BB and (recursively) its predecessors of the addresses of local variables into nonlocal pointers that are left dangling after - the function returns. BBS is a bitmap of basic blocks visited. */ + the function returns. Returns true when we can continue walking + the CFG to predecessors. */ -void +bool pass_waccess::check_dangling_stores (basic_block bb, - hash_set<tree> &stores, - auto_bitmap &bbs) + hash_set<tree> &stores) { - if (!bitmap_set_bit (bbs, bb->index)) - /* Avoid cycles. */ - return; - /* Iterate backwards over the statements looking for a store of the address of a local variable into a nonlocal pointer. */ for (auto gsi = gsi_last_nondebug_bb (bb); ; gsi_prev_nondebug (&gsi)) @@ -4550,7 +4546,7 @@ pass_waccess::check_dangling_stores (basic_block bb, && !(gimple_call_flags (stmt) & (ECF_CONST | ECF_PURE))) /* Avoid looking before nonconst, nonpure calls since those might use the escaped locals. */ - return; + return false; if (!is_gimple_assign (stmt) || gimple_clobber_p (stmt) || !gimple_store_p (stmt)) @@ -4576,7 +4572,7 @@ pass_waccess::check_dangling_stores (basic_block bb, gimple *def_stmt = SSA_NAME_DEF_STMT (lhs_ref.ref); if (!gimple_nop_p (def_stmt)) /* Avoid looking at or before stores into unknown objects. */ - return; + return false; lhs_ref.ref = SSA_NAME_VAR (lhs_ref.ref); } @@ -4620,13 +4616,7 @@ pass_waccess::check_dangling_stores (basic_block bb, } } - edge e; - edge_iterator ei; - FOR_EACH_EDGE (e, ei, bb->preds) - { - basic_block pred = e->src; - check_dangling_stores (pred, stores, bbs); - } + return true; } /* Diagnose stores of the addresses of local variables into nonlocal @@ -4635,9 +4625,32 @@ pass_waccess::check_dangling_stores (basic_block bb, void pass_waccess::check_dangling_stores () { + if (EDGE_COUNT (EXIT_BLOCK_PTR_FOR_FN (m_func)->preds) == 0) + return; + auto_bitmap bbs; hash_set<tree> stores; - check_dangling_stores (EXIT_BLOCK_PTR_FOR_FN (m_func), stores, bbs); + auto_vec<edge_iterator, 8> worklist (n_basic_blocks_for_fn (cfun) + 1); + worklist.quick_push (ei_start (EXIT_BLOCK_PTR_FOR_FN (m_func)->preds)); + do + { + edge_iterator ei = worklist.last (); + basic_block src = ei_edge (ei)->src; + if (bitmap_set_bit (bbs, src->index)) + { + if (check_dangling_stores (src, stores) + && EDGE_COUNT (src->preds) > 0) + worklist.quick_push (ei_start (src->preds)); + } + else + { + if (ei_one_before_end_p (ei)) + worklist.pop (); + else + ei_next (&worklist.last ()); + } + } + while (!worklist.is_empty ()); } /* Check for and diagnose uses of dangling pointers to auto objects |