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| author | Richard Biener <rguenther@suse.de> | 2017-04-24 07:34:51 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2017-04-24 07:34:51 +0000 |
| commit | d21a8e3bc6325a94da178050181a4bcb7e017dfa (patch) | |
| tree | 12b9e6a87f27dca7b5f2a5244498407cbf486b95 /gcc/tree-ssa-uninit.c | |
| parent | 3c5b0ca4c5d8aa8a0f13a4e57b4f9cf4a9de48cb (diff) | |
| download | gcc-d21a8e3bc6325a94da178050181a4bcb7e017dfa.zip gcc-d21a8e3bc6325a94da178050181a4bcb7e017dfa.tar.gz gcc-d21a8e3bc6325a94da178050181a4bcb7e017dfa.tar.bz2 | |
re PR c++/2972 (-Wuninitialized could warn about uninitialized member variable usage in constructors)
2017-04-24 Richard Biener <rguenther@suse.de>
PR c++/2972
* tree-ssa-uninit.c (warn_uninitialized_vars): Handle some
pointer-based references.
* g++.dg/warn/Wuninitialized-10.C: New testcase.
From-SVN: r247090
Diffstat (limited to 'gcc/tree-ssa-uninit.c')
| -rw-r--r-- | gcc/tree-ssa-uninit.c | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/gcc/tree-ssa-uninit.c b/gcc/tree-ssa-uninit.c index e019ecc..60731b2 100644 --- a/gcc/tree-ssa-uninit.c +++ b/gcc/tree-ssa-uninit.c @@ -279,20 +279,22 @@ warn_uninitialized_vars (bool warn_possibly_uninitialized) ao_ref ref; ao_ref_init (&ref, rhs); - /* Do not warn if it can be initialized outside this function. */ + /* Do not warn if the base was marked so or this is a + hard register var. */ tree base = ao_ref_base (&ref); - if (!VAR_P (base) - || DECL_HARD_REGISTER (base) - || is_global_var (base) + if ((VAR_P (base) + && DECL_HARD_REGISTER (base)) || TREE_NO_WARNING (base)) continue; /* Do not warn if the access is fully outside of the variable. */ - if (ref.size != -1 + if (DECL_P (base) + && ref.size != -1 && ref.max_size == ref.size && (ref.offset + ref.size <= 0 || (ref.offset >= 0 + && DECL_SIZE (base) && TREE_CODE (DECL_SIZE (base)) == INTEGER_CST && compare_tree_int (DECL_SIZE (base), ref.offset) <= 0))) @@ -305,11 +307,12 @@ warn_uninitialized_vars (bool warn_possibly_uninitialized) && oracle_cnt > vdef_cnt * 2) limit = 32; check_defs_data data; + bool fentry_reached = false; data.found_may_defs = false; use = gimple_vuse (stmt); int res = walk_aliased_vdefs (&ref, use, check_defs, &data, NULL, - NULL, limit); + &fentry_reached, limit); if (res == -1) { oracle_cnt += limit; @@ -318,6 +321,16 @@ warn_uninitialized_vars (bool warn_possibly_uninitialized) oracle_cnt += res; if (data.found_may_defs) continue; + /* 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 (fentry_reached + /* ??? We'd like to use ref_may_alias_global_p but that + excludes global readonly memory and thus we get bougs + warnings from p = cond ? "a" : "b" for example. */ + && (!VAR_P (base) + || is_global_var (base))) + continue; /* We didn't find any may-defs so on all paths either reached function entry or a killing clobber. */ |