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* [Bug c++/15787] New: Poor error message @ 2004-06-02 21:31 igodard at pacbell dot net 2004-06-02 21:32 ` [Bug c++/15787] " igodard at pacbell dot net ` (4 more replies) 0 siblings, 5 replies; 6+ messages in thread From: igodard at pacbell dot net @ 2004-06-02 21:31 UTC (permalink / raw) To: gcc-bugs The actual problem in the test case is a missing "}", which fact appears nowhere in the message. The message talks about a "primary-expression", which is technically correct but reflects a compiler- and formal syntax-centric view. A user will in general neither know nor care what a primary-expression is; he wants to know what's wrong in terms of his code. The education, experience and knowledge of compiler users is *not* the same as of compiler writers :-) The great bulk of syntactic arrors are bracket errors or missing semis. Now that you have a recursive descent parser, it is trivial to have the compiler suggest a plausible fix for these. For example, have the compiler keep a side stack of brackets entered and not exited. If you get a closer that matches the *second* item on the stack then your message offers the closers of the *top* item on the stack as suggestions. In the case of this code, the top item is "{" and the second is "if". When the parse error happens the cursor is on "else", which matches the "if". So you produce a message "expected primary-expression before 'else'; possibly a missing '}'?". This same stack can be used for repair. Ivan -- Summary: Poor error message Product: gcc Version: 3.4.0 Status: UNCONFIRMED Severity: normal Priority: P2 Component: c++ AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: igodard at pacbell dot net CC: gcc-bugs at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15787 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug c++/15787] Poor error message 2004-06-02 21:31 [Bug c++/15787] New: Poor error message igodard at pacbell dot net @ 2004-06-02 21:32 ` igodard at pacbell dot net 2004-06-02 21:33 ` igodard at pacbell dot net ` (3 subsequent siblings) 4 siblings, 0 replies; 6+ messages in thread From: igodard at pacbell dot net @ 2004-06-02 21:32 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From igodard at pacbell dot net 2004-06-02 21:32 ------- Created an attachment (id=6453) --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=6453&action=view) Compiler output (-v -save-temps) -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15787 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug c++/15787] Poor error message 2004-06-02 21:31 [Bug c++/15787] New: Poor error message igodard at pacbell dot net 2004-06-02 21:32 ` [Bug c++/15787] " igodard at pacbell dot net @ 2004-06-02 21:33 ` igodard at pacbell dot net 2004-06-02 21:37 ` igodard at pacbell dot net ` (2 subsequent siblings) 4 siblings, 0 replies; 6+ messages in thread From: igodard at pacbell dot net @ 2004-06-02 21:33 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From igodard at pacbell dot net 2004-06-02 21:33 ------- Created an attachment (id=6454) --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=6454&action=view) Source code (-save-temps) -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15787 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug c++/15787] Poor error message 2004-06-02 21:31 [Bug c++/15787] New: Poor error message igodard at pacbell dot net 2004-06-02 21:32 ` [Bug c++/15787] " igodard at pacbell dot net 2004-06-02 21:33 ` igodard at pacbell dot net @ 2004-06-02 21:37 ` igodard at pacbell dot net 2004-06-03 1:32 ` pinskia at gcc dot gnu dot org 2004-10-23 20:37 ` [Bug c++/15787] Poor error message with if and blocks pinskia at gcc dot gnu dot org 4 siblings, 0 replies; 6+ messages in thread From: igodard at pacbell dot net @ 2004-06-02 21:37 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From igodard at pacbell dot net 2004-06-02 21:37 ------- p.s. Also put the line number of the opener in the info on that side stack. Then you can say "expected...; possibly a missing '}' matching the '{' on line 17?". You wouldn't really need this in Algol68 or other languages with distinct opener/closer pairs, but in C with the heavy overload of "{}" and "()" it would be real helpful. And you *are* trying to be helpful, aren't you? :-) Ivan -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15787 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug c++/15787] Poor error message 2004-06-02 21:31 [Bug c++/15787] New: Poor error message igodard at pacbell dot net ` (2 preceding siblings ...) 2004-06-02 21:37 ` igodard at pacbell dot net @ 2004-06-03 1:32 ` pinskia at gcc dot gnu dot org 2004-10-23 20:37 ` [Bug c++/15787] Poor error message with if and blocks pinskia at gcc dot gnu dot org 4 siblings, 0 replies; 6+ messages in thread From: pinskia at gcc dot gnu dot org @ 2004-06-03 1:32 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From pinskia at gcc dot gnu dot org 2004-06-03 01:32 ------- Confirmed, here is much smaller example: int f() { if (1) { return 1; else { } } -- What |Removed |Added ---------------------------------------------------------------------------- Severity|normal |enhancement Status|UNCONFIRMED |NEW Ever Confirmed| |1 Keywords| |diagnostic Last reconfirmed|0000-00-00 00:00:00 |2004-06-03 01:32:18 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15787 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug c++/15787] Poor error message with if and blocks 2004-06-02 21:31 [Bug c++/15787] New: Poor error message igodard at pacbell dot net ` (3 preceding siblings ...) 2004-06-03 1:32 ` pinskia at gcc dot gnu dot org @ 2004-10-23 20:37 ` pinskia at gcc dot gnu dot org 4 siblings, 0 replies; 6+ messages in thread From: pinskia at gcc dot gnu dot org @ 2004-10-23 20:37 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From pinskia at gcc dot gnu dot org 2004-10-23 20:37 ------- *** Bug 15788 has been marked as a duplicate of this bug. *** -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15787 ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2004-10-23 20:37 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2004-06-02 21:31 [Bug c++/15787] New: Poor error message igodard at pacbell dot net 2004-06-02 21:32 ` [Bug c++/15787] " igodard at pacbell dot net 2004-06-02 21:33 ` igodard at pacbell dot net 2004-06-02 21:37 ` igodard at pacbell dot net 2004-06-03 1:32 ` pinskia at gcc dot gnu dot org 2004-10-23 20:37 ` [Bug c++/15787] Poor error message with if and blocks pinskia at gcc dot gnu dot org
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