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| author | Dirk Mueller <dmueller@suse.com> | 2006-01-20 09:30:22 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2006-01-20 09:30:22 +0000 |
| commit | 74ac79fa800af6de648e984cc5576c20b817839d (patch) | |
| tree | bc92b7d88bae96e3177ed2217eb031fe56a30961 /gcc/c-common.c | |
| parent | 577b02d86397e9f5a09392d2ea9f722b8a250709 (diff) | |
| download | gcc-74ac79fa800af6de648e984cc5576c20b817839d.zip gcc-74ac79fa800af6de648e984cc5576c20b817839d.tar.gz gcc-74ac79fa800af6de648e984cc5576c20b817839d.tar.bz2 | |
re PR c++/5520 (Add a warning to detect empty body of if statements (like in the C frontend))
2006-01-20 Dirk Mueller <dmueller@suse.com>
PR c++/5520
* c-parser.c (c_parser_if_body): Use build_empty_stmt()
instead of a special NOP marker.
* c-typeck.c (c_finish_if_stmt): Remove obsoleted special
NOP marker handling.
* c-common.h (empty_body_warning): Add forward declaration.
* c-common.c (empty_body_warning): Add (from c_finish_if_stmt).
Now uses IS_EMPTY_STMT() instead of special NOP markers.
* semantics.c (finish_if_stmt): Call empty_body_warning.
* parser.c (cp_parser_implicitly_scoped_statement):
Mark empty statement with an empty stmt.
* g++.dg/warn/empty-body.C: New.
From-SVN: r110019
Diffstat (limited to 'gcc/c-common.c')
| -rw-r--r-- | gcc/c-common.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/gcc/c-common.c b/gcc/c-common.c index 2a7c1e7..60035ea 100644 --- a/gcc/c-common.c +++ b/gcc/c-common.c @@ -994,6 +994,36 @@ strict_aliasing_warning(tree otype, tree type, tree expr) } } + +/* Print a warning about if (); or if () .. else; constructs + via the special empty statement node that we create. INNER_THEN + and INNER_ELSE are the statement lists of the if and the else + block. */ + +void +empty_body_warning (tree inner_then, tree inner_else) +{ + if (extra_warnings) + { + if (TREE_CODE (inner_then) == STATEMENT_LIST + && STATEMENT_LIST_TAIL (inner_then)) + inner_then = STATEMENT_LIST_TAIL (inner_then)->stmt; + + if (inner_else && TREE_CODE (inner_else) == STATEMENT_LIST + && STATEMENT_LIST_TAIL (inner_else)) + inner_else = STATEMENT_LIST_TAIL (inner_else)->stmt; + + if (IS_EMPTY_STMT (inner_then) && !inner_else) + warning (OPT_Wextra, "%Hempty body in an if-statement", + EXPR_LOCUS (inner_then)); + + if (inner_else && IS_EMPTY_STMT (inner_else)) + warning (OPT_Wextra, "%Hempty body in an else-statement", + EXPR_LOCUS (inner_else)); + } +} + + /* Nonzero if constant C has a value that is permissible for type TYPE (an INTEGER_TYPE). */ |