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| author | Manuel López-Ibáñez <manu@gcc.gnu.org> | 2008-08-20 22:23:45 +0000 |
|---|---|---|
| committer | Manuel López-Ibáñez <manu@gcc.gnu.org> | 2008-08-20 22:23:45 +0000 |
| commit | 87fe2bd0e02ac4b73d300854367de0f599d06ec8 (patch) | |
| tree | 660ae75a4cdf11380c42d11680fdb1c7ead51a82 /gcc/tree-ssa.c | |
| parent | 7735154d75efdab60161db87b086ee2c3572d512 (diff) | |
| download | gcc-87fe2bd0e02ac4b73d300854367de0f599d06ec8.zip gcc-87fe2bd0e02ac4b73d300854367de0f599d06ec8.tar.gz gcc-87fe2bd0e02ac4b73d300854367de0f599d06ec8.tar.bz2 | |
re PR middle-end/179 (-Wuninitialized missing warning with &var)
2008-08-21 Manuel Lopez-Ibanez <manu@gcc.gnu.org>
PR middle-end/179
* tree-ssa.c (warn_uninit): Do not warn for variables that can be
initialized outside the current module.
(warn_uninitialized_var): Ignore left-hand side when walking the
trees. Ignore address expressions. Examine VUSE operands in gimple
statements with a variable declaration on the right-hand side.
testsuite/
* gcc.dg/uninit-6.c (make_something): Remove XFAIL.
* gcc.dg/uninit-6-O0.c (make_something): Remove XFAIL.
* gcc.dg/uninit-B.c (baz): Remove XFAIL.
* gcc.dg/uninit-B-2.c: New.
* gcc.dg/uninit-B-O0-2.c: New.
* gcc.dg/uninit-pr19430-O0.c: New.
* gcc.dg/uninit-pr19430.c: New.
* gcc.dg/uninit-pr19430-2.c: New.
From-SVN: r139347
Diffstat (limited to 'gcc/tree-ssa.c')
| -rw-r--r-- | gcc/tree-ssa.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/gcc/tree-ssa.c b/gcc/tree-ssa.c index fb692f8..eed15c6 100644 --- a/gcc/tree-ssa.c +++ b/gcc/tree-ssa.c @@ -1411,6 +1411,10 @@ warn_uninit (tree t, const char *gmsgid, void *data) if (TREE_NO_WARNING (var)) return; + /* Do not warn if it can be initialized outside this module. */ + if (is_global_var (var)) + return; + location = (context != NULL && gimple_has_location (context)) ? gimple_location (context) : DECL_SOURCE_LOCATION (var); @@ -1443,8 +1447,46 @@ warn_uninitialized_var (tree *tp, int *walk_subtrees, void *data_) struct walk_data *data = (struct walk_data *) wi->info; tree t = *tp; + /* We do not care about LHS. */ + if (wi->is_lhs) + return NULL_TREE; + switch (TREE_CODE (t)) { + case ADDR_EXPR: + /* Taking the address of an uninitialized variable does not + count as using it. */ + *walk_subtrees = 0; + break; + + case VAR_DECL: + { + /* A VAR_DECL in the RHS of a gimple statement may mean that + this variable is loaded from memory. */ + use_operand_p vuse; + tree op; + + /* If there is not gimple stmt, + or alias information has not been computed, + then we cannot check VUSE ops. */ + if (data->stmt == NULL + || !gimple_aliases_computed_p (cfun)) + return NULL_TREE; + + vuse = SINGLE_SSA_USE_OPERAND (data->stmt, SSA_OP_VUSE); + if (vuse == NULL_USE_OPERAND_P) + return NULL_TREE; + + op = USE_FROM_PTR (vuse); + if (t != SSA_NAME_VAR (op) + || !SSA_NAME_IS_DEFAULT_DEF (op)) + return NULL_TREE; + /* If this is a VUSE of t and it is the default definition, + then warn about op. */ + t = op; + /* Fall through into SSA_NAME. */ + } + case SSA_NAME: /* We only do data flow with SSA_NAMEs, so that's all we can warn about. */ |