Cyclone (programming language): Difference between revisions

Revision as of 00:47, 16 August 2017

Revision as of 08:50, 7 November 2017

Line 107:

}

</source>

ThisFunction returns<code>itoa</code> allocates an objectarray thatof ischars allocated<code>buf</code> on the stack ofand returns a pointer to the functionstart of <code>itoabuf</code>,. whichHowever isthe notmemory availableused afteron the stack for <code>buf</code> is deallocated when the function returns, so the returned value cannot be used safely outside of the function. While [[GNU Compiler Collection|gcc]] and other compilers will warn about such code, the following will typically compile without warnings:

<source lang="C">

char *itoa(int i)

Line 117:

}

</source>

[[GNU Compiler Collection|gcc]] can produce warnings for such code as a side-effect of option -O2 or -O3, but there are no guarantees that all such errors will be detected.

Cyclone does regional analysis of each segment of code, preventing dangling pointers, such as the one returned from this version of <code>itoa</code>. All of the local variables in a given scope are considered to be part of the same region, separate from the heap or any other local region. Thus, when analyzing <code>itoa</code>, the Cyclone compiler would see that <code>z</code> is a pointer into the local stack, and would report an error.

==See also==