diff options
Diffstat (limited to 'gcc/c-decl.c')
| -rw-r--r-- | gcc/c-decl.c | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/gcc/c-decl.c b/gcc/c-decl.c index 8d66b4e..d97419d 100644 --- a/gcc/c-decl.c +++ b/gcc/c-decl.c @@ -6924,6 +6924,55 @@ c_expand_body (fndecl, nested_p) } +/* Check the declarations given in a for-loop for satisfying the C99 + constraints. */ +void +check_for_loop_decls () +{ + tree t; + + if (!flag_isoc99) + { + /* If we get here, declarations have been used in a for loop without + the C99 for loop scope. This doesn't make much sense, so don't + allow it. */ + error ("`for' loop initial declaration used outside C99 mode"); + return; + } + /* C99 subclause 6.8.5 paragraph 3: + + [#3] The declaration part of a for statement shall only + declare identifiers for objects having storage class auto or + register. + + It isn't clear whether, in this sentence, "identifiers" binds to + "shall only declare" or to "objects" - that is, whether all identifiers + declared must be identifiers for objects, or whether the restriction + only applies to those that are. (A question on this in comp.std.c + in November 2000 received no answer.) We implement the strictest + interpretation, to avoid creating an extension which later causes + problems. */ + + for (t = gettags (); t; t = TREE_CHAIN (t)) + { + if (TREE_PURPOSE (t) != 0) + error ("`%s %s' declared in `for' loop initial declaration", + (TREE_CODE (TREE_VALUE (t)) == RECORD_TYPE ? "struct" + : TREE_CODE (TREE_VALUE (t)) == UNION_TYPE ? "union" + : "enum"), + IDENTIFIER_POINTER (TREE_PURPOSE (t))); + } + for (t = getdecls (); t; t = TREE_CHAIN (t)) + { + if (TREE_CODE (t) != VAR_DECL && DECL_NAME (t)) + error_with_decl (t, "declaration of non-variable `%s' in `for' loop initial declaration"); + else if (TREE_STATIC (t)) + error_with_decl (t, "declaration of static variable `%s' in `for' loop initial declaration"); + else if (DECL_EXTERNAL (t)) + error_with_decl (t, "declaration of `extern' variable `%s' in `for' loop initial declaration"); + } +} + /* Save and restore the variables in this file and elsewhere that keep track of the progress of compilation of the current function. Used for nested functions. */ |