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Re: Why can't I LD_PRELOAD __assert_fail ?
On Fri, Feb 18, 2011 at 4:14 AM, Jonathan Wakely <jwakely.gcc@gmail.com> wrote:
> On 18 February 2011 04:25, Jeffrey Walton wrote:
>> I could never understand
>> why POSIX specified that a program should abort after an assert
>> (http://pubs.opengroup.org/onlinepubs/009695399/functions/assert.html).
>
> POSIX probably says that because C says that, and every implementation
> does that, and standardising anything different would have been
> incompatible with actual implementations.
>
> That's what assert does, it aborts the program if the assertion fails.
>
> If you want a different behaviour, don't use assert.
Negative. Asserts are programmer diagnostics. They are a tool to aide
in debugging.
When debugging a program, it is useless behavior since there are a
number of ways to deal with the condition which caused the assert to
fire (including terminating the program). Other ways to deal with a
failed assert would include changing a value which was unexpected.
When a release build is created for the distribution of a program,
NDEBUG is defined asserts are removed from the program.
Those who don't define DEBUG nor NDEBUG should probably learn the make
system - and take control of their preprocessor macros - rather than
depending on automake and friends. Consider: I'm a dumb Windows guy,
and I know debug builds use '-g3 -ggdb -O0 -DDEBUG', and release
builds use '-g -O{2|3} -DNDEBUG'.
Jeff