1 Nov
2012
1 Nov
'12
4:21 p.m.
I noticed the following warning when building tdewebdev:
execbutton.cpp:210:55: warning: comparison with string literal results in unspecified
behaviour [-Waddress]
From what I gather the problem is trying to compare incompatible data types, usually
strings to pointers.
Somebody please review the proposed patch:
======================================
diff -urN tdewebdev/kommander/widgets/execbutton.cpp
tdewebdev.new/kommander/widgets/execbutton.cpp
--- tdewebdev/kommander/widgets/execbutton.cpp 2012-10-21 13:12:11.000000000 -0500
+++ tdewebdev.new/kommander/widgets/execbutton.cpp 2012-11-01 11:10:09.000000000 -0500
@@ -207,7 +207,7 @@
TQWidget * w;
while ( (w=it.current()) != 0 ) { // for each widget...
++it;
- if (w->name() == args[0] && w->className() ==
"PopupMenu")
+ if (strcmp(w->name(), args[0]) && w->className() ==
"PopupMenu")
{
TQPopupMenu *popup =
dynamic_cast<TQPopupMenu*>(w->child("unnamed",
"KPopupMenu"));
this->setPopup(popup);
======================================
Thanks!
Darrell
1 Nov
1 Nov
4:42 p.m.
New subject: [trinity-devel] tdewebdev: warning: comparison with string literal
On Thursday 01 November 2012 18:21:22 Darrell Anderson wrote:
I noticed the following warning when building
tdewebdev:
execbutton.cpp:210:55: warning: comparison with string literal results in
unspecified behaviour [-Waddress]
From what I gather the problem is trying to compare incompatible data
types, usually strings to pointers.
Somebody please review the proposed patch:
======================================
diff -urN tdewebdev/kommander/widgets/execbutton.cpp
tdewebdev.new/kommander/widgets/execbutton.cpp ---
tdewebdev/kommander/widgets/execbutton.cpp 2012-10-21 13:12:11.000000000
-0500 +++ tdewebdev.new/kommander/widgets/execbutton.cpp 2012-11-01
11:10:09.000000000 -0500 @@ -207,7 +207,7 @@
TQWidget * w;
while ( (w=it.current()) != 0 ) { // for each widget...
++it;
- if (w->name() == args[0] && w->className() ==
"PopupMenu")
+ if (strcmp(w->name(), args[0]) && w->className() ==
"PopupMenu")
{
TQPopupMenu *popup =
dynamic_cast<TQPopupMenu*>(w->child("unnamed",
"KPopupMenu"));
this->setPopup(popup);
======================================
Thanks!
Darrell
You reversed the sense of comparison,
strcmp(w->name(), args[0]) meaning "is not equal".
Correct:
if (0 == strcmp(w->name(), args[0]) && w->className() ==
"PopupMenu")
In any case, this seems a workaround. I guess that args[0] is TQString, so the
comparison should be valid. Try to reverse order of arguments, like:
if (args[0] == w->name() && w->className() == "PopupMenu")
--
Serghei
2 Nov
2 Nov
12:12 a.m.
New subject: [trinity-devel] tdewebdev: warning: comparison with string literal
You reversed the sense of comparison,
strcmp(w->name(), args[0]) meaning "is not equal".
Correct:
if (0 == strcmp(w->name(), args[0]) && w->className() ==
"PopupMenu")
In any case, this seems a workaround. I guess that args[0] is TQString, so the
comparison should be valid. Try to reverse order of arguments, like:
if (args[0] == w->name() && w->className() == "PopupMenu")
Thank you much for coaching. Very much! :)
My original proposed patch failed because I received the same warning message with the
patch. The problematic comparison causing the warning message is the second part of the
AND, not the first part. My original proposed patch:
- if (w->name() == args[0] && w->className() ==
"PopupMenu")
+ if (strcmp(w->name(), args[0]) && w->className() ==
"PopupMenu")
My new patch:
- if (w->name() == args[0] && w->className() ==
"PopupMenu")
+ if (w->name() == args[0] && strcmp(w->className(),
"PopupMenu"))
That revision resulted in no warning message during the build. However, after reading your
explanation I now am concerned that the patch is incorrect.
From what I have read, in C++ the strcmp function returns three possible values. If I
understand correctly, the strcmp function returns zero when the two strings are equal, a
-1 when the first string is alphabetically "less than" the first string and a
positive value when the first string is alphabetically "greater than" the second
string.
AND statements are used to produce only one true result: when both condition A and
condition B are true. In our tdewebdev code the only time condition B [ w->className()
== "PopupMenu" ] is true is when the strcmp result is compared to a value. As I
don't yet read C++ code very well, I don't know the intent of the code, but
I'm guessing the following is the intent:
- if (w->name() == args[0] && w->className() ==
"PopupMenu")
+ if (w->name() == args[0] && ( strcmp(w->className(),
"PopupMenu")) == 0 )
Does that look correct? :)
Darrell
8:29 a.m.
New subject: [trinity-devel] tdewebdev: warning: comparison with string literal
On Friday 02 November 2012 02:12:54 Darrell Anderson wrote:
Yes, it's correct.
--
Serghei
You reversed
the sense of comparison,
strcmp(w->name(), args[0]) meaning "is not equal".
Correct:
if (0 == strcmp(w->name(), args[0]) && w->className() ==
"PopupMenu")
In any case, this seems a workaround. I guess that args[0] is TQString,
so the comparison should be valid. Try to reverse order of arguments,
like:
if (args[0] == w->name() && w->className() == "PopupMenu")
Thank you much for coaching. Very much! :)
My original proposed patch failed because I received the same warning
message with the patch. The problematic comparison causing the warning
message is the second part of the AND, not the first part. My original
proposed patch:
- if (w->name() == args[0] && w->className() ==
"PopupMenu")
+ if (strcmp(w->name(), args[0]) && w->className() ==
"PopupMenu")
My new patch:
- if (w->name() == args[0] && w->className() ==
"PopupMenu")
+ if (w->name() == args[0] && strcmp(w->className(),
"PopupMenu"))
That revision resulted in no warning message during the build. However,
after reading your explanation I now am concerned that the patch is
incorrect.
From what I have read, in C++ the strcmp function returns three possible
values. If I understand correctly, the strcmp function returns zero when
the two strings are equal, a -1 when the first string is alphabetically
"less than" the first string and a positive value when the first string is
alphabetically "greater than" the second string.
AND statements are used to produce only one true result: when both
condition A and condition B are true. In our tdewebdev code the only time
condition B [ w->className() == "PopupMenu" ] is true is when the strcmp
result is compared to a value. As I don't yet read C++ code very well, I
don't know the intent of the code, but I'm guessing the following is the
intent:
- if (w->name() == args[0] && w->className() ==
"PopupMenu")
+ if (w->name() == args[0] && ( strcmp(w->className(),
"PopupMenu"))
== 0 )
Does that look correct? :)
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days inactive
4195
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3 comments
2 participants
participants (2)
-
Darrell Anderson -
Serghei Amelian