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* [Bug c++/32786] New: Incorrect code compiles and runs well @ 2007-07-17 2:23 bachmann dot matt at gmail dot com 2007-07-17 3:17 ` [Bug c++/32786] " pinskia at gcc dot gnu dot org ` (3 more replies) 0 siblings, 4 replies; 5+ messages in thread From: bachmann dot matt at gmail dot com @ 2007-07-17 2:23 UTC (permalink / raw) To: gcc-bugs This is my first bug report... I am not quite sure what you mean by host/target/build triplet so ill give you what I can complied on an 686 architecture in linux. #include<iostream> #include<cstdlib> using namespace std; /** * Matt Bachmann * CS 331 * HW1 Due: July 9th 2007 * Main method shows different ways of traversing strings */ int main() { char mary[25] = "Mary had a little lamb."; char* moby = "Thar she blows!"; cout << strlen(mary) << endl << endl; for(unsigned int i = 0; i < strlen(mary); i++) { for(unsigned int a = i; a < strlen(mary); a++) { cout << mary[a]; } cout << endl; } cout << endl; cout << strlen(moby) << endl << endl; while(moby != '\0') { cout << moby << endl; moby++; } system("PAUSE"); return EXIT_SUCCESS; } the condition in the while loop should cause an infinite loop and should be moby* -- Summary: Incorrect code compiles and runs well Product: gcc Version: 4.1.2 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: bachmann dot matt at gmail dot com http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32786 ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/32786] Incorrect code compiles and runs well 2007-07-17 2:23 [Bug c++/32786] New: Incorrect code compiles and runs well bachmann dot matt at gmail dot com @ 2007-07-17 3:17 ` pinskia at gcc dot gnu dot org 2007-07-17 3:39 ` bachmann dot matt at gmail dot com ` (2 subsequent siblings) 3 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu dot org @ 2007-07-17 3:17 UTC (permalink / raw) To: gcc-bugs ------- Comment #1 from pinskia at gcc dot gnu dot org 2007-07-17 03:17 ------- > the condition in the while loop should cause an infinite loop and should be > moby* I think you mean *moby. Anyways it is just undefined that you go past the array bounds when incrementing a pointer so we know it will not be an infinite loop and has a finite length. Anyways the program crashes for me which is a valid behavior. while(moby != '\0') { This is valid as '\0' can be considered the NULL pointer. -- pinskia at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution| |INVALID http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32786 ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/32786] Incorrect code compiles and runs well 2007-07-17 2:23 [Bug c++/32786] New: Incorrect code compiles and runs well bachmann dot matt at gmail dot com 2007-07-17 3:17 ` [Bug c++/32786] " pinskia at gcc dot gnu dot org @ 2007-07-17 3:39 ` bachmann dot matt at gmail dot com 2007-07-17 3:58 ` pinskia at gcc dot gnu dot org 2007-07-17 4:04 ` bachmann dot matt at gmail dot com 3 siblings, 0 replies; 5+ messages in thread From: bachmann dot matt at gmail dot com @ 2007-07-17 3:39 UTC (permalink / raw) To: gcc-bugs ------- Comment #2 from bachmann dot matt at gmail dot com 2007-07-17 03:39 ------- but thats just it! alright it does not infinite loop but for me it does not crash, it runs perfectly. Here is my output: $ g++ HW1.cpp $ ./a.out 23 Mary had a little lamb. ary had a little lamb. ry had a little lamb. y had a little lamb. had a little lamb. had a little lamb. ad a little lamb. d a little lamb. a little lamb. a little lamb. little lamb. little lamb. ittle lamb. ttle lamb. tle lamb. le lamb. e lamb. lamb. lamb. amb. mb. b. . 15 Thar she blows! har she blows! ar she blows! r she blows! she blows! she blows! he blows! e blows! blows! blows! lows! ows! ws! s! ! Is there any reason that anyone can think of why this would be? I showed my professor and he is the one who suggested I submit a bug. It does this under linux, but in windows using devC++(using a windows port of g++) it breaks as its supposed to. -- bachmann dot matt at gmail dot com changed: What |Removed |Added ---------------------------------------------------------------------------- Status|RESOLVED |UNCONFIRMED Resolution|INVALID | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32786 ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/32786] Incorrect code compiles and runs well 2007-07-17 2:23 [Bug c++/32786] New: Incorrect code compiles and runs well bachmann dot matt at gmail dot com 2007-07-17 3:17 ` [Bug c++/32786] " pinskia at gcc dot gnu dot org 2007-07-17 3:39 ` bachmann dot matt at gmail dot com @ 2007-07-17 3:58 ` pinskia at gcc dot gnu dot org 2007-07-17 4:04 ` bachmann dot matt at gmail dot com 3 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu dot org @ 2007-07-17 3:58 UTC (permalink / raw) To: gcc-bugs ------- Comment #3 from pinskia at gcc dot gnu dot org 2007-07-17 03:58 ------- No, it is crashing. Anyways this is just undefined behavior so any behavior here is ok :). -- pinskia at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution| |INVALID http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32786 ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/32786] Incorrect code compiles and runs well 2007-07-17 2:23 [Bug c++/32786] New: Incorrect code compiles and runs well bachmann dot matt at gmail dot com ` (2 preceding siblings ...) 2007-07-17 3:58 ` pinskia at gcc dot gnu dot org @ 2007-07-17 4:04 ` bachmann dot matt at gmail dot com 3 siblings, 0 replies; 5+ messages in thread From: bachmann dot matt at gmail dot com @ 2007-07-17 4:04 UTC (permalink / raw) To: gcc-bugs ------- Comment #4 from bachmann dot matt at gmail dot com 2007-07-17 04:04 ------- alright then. ::shrugs:: thanks -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32786 ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2007-07-17 4:04 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2007-07-17 2:23 [Bug c++/32786] New: Incorrect code compiles and runs well bachmann dot matt at gmail dot com 2007-07-17 3:17 ` [Bug c++/32786] " pinskia at gcc dot gnu dot org 2007-07-17 3:39 ` bachmann dot matt at gmail dot com 2007-07-17 3:58 ` pinskia at gcc dot gnu dot org 2007-07-17 4:04 ` bachmann dot matt at gmail dot com
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