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Example: sig-handler funcs for C and C++ (throw-catch) PART 2

Posted 05-13-2012 at 11:37 PM by rainbowsally
Updated 05-14-2012 at 07:39 AM by rainbowsally (possible cpu hang if -O2 switch is used)

Note: The signal-handler files can't be compiled with the -O2 switch and it's probably best if you only trap the signals you really intend to redirect, such as SIGSEGV (11). If you compile what we have here with the -O2 switch your cpu may hang if you try to exit using Ctrl-C for example. See implementation notes added to signal-handler.c below.

See part 1 for main functions to test this in C and C++.

To throw and catch stuff like segfaults in C++ it's...
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Example: sig-handler funcs for C and C++ (throw-catch) PART 1

Posted 05-13-2012 at 11:22 PM by rainbowsally

Today's Features
  • Translating signals to C++ throw-catch parameters.

To compile the C++ example these vars are set in mc2.def and should be similar for other methods of building it.
COMPILE = g++ -m32 -c -o # COMPILE <output_file> ...
CFLAGS = -Wall -g3 --save-temps
# or CFLAGS = -Wall -O2 # optimized
INCLUDE = -I $(SRCDIR) -I$(PREFIX)/include 

LINK = g++ -m32 -o # LINK <output_file> ...
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Handle segmentation faults in try-catch block

Posted 05-06-2012 at 12:52 AM by rainbowsally
Updated 05-06-2012 at 05:19 AM by rainbowsally (updated code for 32 and also 64 bit arch)

May 6, 2012 (second edit)
Tested 64 bit code (and also 32), corrected close brace in function that got lost in the #if-#else-#endif mixup (with extern "C" close brace)... nevermind. It works now.

  • catch segmentation faults and continue normally

Don't underestimate this concept. We'll be using it in the GUI-Interactive interpreter.

This is a highly simplified version of the SEH for linux experiment posted...
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GUI-Interactive: Display a list of QT4 classes

Posted 05-05-2012 at 04:51 AM by rainbowsally
Updated 05-05-2012 at 05:00 AM by rainbowsally

Today's features:
  • A stand alone executable to list all of QT4's classes.
  • A first function for an interactive interpreter for QT funcs and classes
  • Another simple but interesting parse job.

  • the libLQ download (or your own work-alike hack)

We are delving into QT's system for reasons explained in earlier blog entries. When I tried early...
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QT4 Event preemption: mouse click to get object name

Posted 05-03-2012 at 11:30 AM by rainbowsally
Updated 08-06-2014 at 10:15 AM by rainbowsally

See also the experiment to dump properties.

Now that we have event preemption ability, let's get simple again and create ui application that can tell the name of a widget by clicking on it.

[It's simpler than you think but I have uploaded the sources and makefile in case my description of this process is too complicated or confusing.]
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