diff options
Diffstat (limited to 'gcc/tree-ssa-uninit.cc')
| -rw-r--r-- | gcc/tree-ssa-uninit.cc | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/gcc/tree-ssa-uninit.cc b/gcc/tree-ssa-uninit.cc index cb82001..45e789c 100644 --- a/gcc/tree-ssa-uninit.cc +++ b/gcc/tree-ssa-uninit.cc @@ -641,6 +641,7 @@ maybe_warn_operand (ao_ref &ref, gimple *stmt, tree lhs, tree rhs, return NULL_TREE; bool found_alloc = false; + bool found_clobber_deref_this = false; if (fentry_reached) { @@ -662,12 +663,30 @@ maybe_warn_operand (ao_ref &ref, gimple *stmt, tree lhs, tree rhs, tree fndecl = gimple_call_fndecl (def_stmt); const built_in_function fncode = DECL_FUNCTION_CODE (fndecl); if (fncode == BUILT_IN_ALLOCA - || fncode == BUILT_IN_ALLOCA_WITH_ALIGN - || fncode == BUILT_IN_MALLOC) + || fncode == BUILT_IN_ALLOCA_WITH_ALIGN + || fncode == BUILT_IN_MALLOC) found_alloc = true; break; } + /* The C++ FE for -flifetime-dse=2 marks this parameters + of certain constructors with "clobber *this" attribute. + Emit uninitialized warnings if we read from what this points + to. This is similar to access (write_only, 1) attribute, + except it is a -Wuninitialized warning rather than + -Wmaybe-uninitialized and doesn't talk about access + attribute. */ + if (SSA_NAME_IS_DEFAULT_DEF (base) + && POINTER_TYPE_P (TREE_TYPE (base)) + && SSA_NAME_VAR (base) + && TREE_CODE (SSA_NAME_VAR (base)) == PARM_DECL + && lookup_attribute ("clobber *this", + DECL_ATTRIBUTES (SSA_NAME_VAR (base)))) + { + found_clobber_deref_this = true; + break; + } + if (!is_gimple_assign (def_stmt)) break; @@ -702,7 +721,7 @@ maybe_warn_operand (ao_ref &ref, gimple *stmt, tree lhs, tree rhs, /* Do not warn if it can be initialized outside this function. If we did not reach function entry then we found killing clobbers on all paths to entry. */ - if (!found_alloc && fentry_reached) + if ((!found_alloc && !found_clobber_deref_this) && fentry_reached) { if (TREE_CODE (base) == SSA_NAME) { |