From: Ralf Jung Date: Wed, 25 Jul 2018 14:32:38 +0000 (+0200) Subject: more academic pointers X-Git-Url: https://git.ralfj.de/web.git/commitdiff_plain/b98a2b58c57e48dbf601033e0e8e0ba6fe06720d?ds=sidebyside more academic pointers --- diff --git a/personal/_posts/2018-07-24-pointers-and-bytes.md b/personal/_posts/2018-07-24-pointers-and-bytes.md index 64ea94b..53daa57 100644 --- a/personal/_posts/2018-07-24-pointers-and-bytes.md +++ b/personal/_posts/2018-07-24-pointers-and-bytes.md @@ -19,7 +19,7 @@ I hope that by the end of this post, you will agree with me on both of these sta ## Pointers Are Complicated What is the problem with "pointers are just integers"? Let us consider the following example:
-(I am using C++ code here mostly because writing unsafe code is easier in C++, and unsafe code is where these problems really show up. C has all the same issues, as does unsafe Rust.) +(I am using C++ code here mostly because writing unsafe code is easier in C++ than in Rust, and unsafe code is where these problems really show up. C has all the same issues, as does unsafe Rust.) {% highlight c++ %} int test() { auto x = new int[8]; @@ -152,6 +152,8 @@ We mostly just ignore the problem in miri and opportunistically do as much as we A full definition of a language like C++ or Rust of course cannot take this shortcut, it has to explain what really happens here. To my knowledge, no satisfying solution exists, but academic research is [getting closer](http://sf.snu.ac.kr/publications/llvmtwin.pdf). +**Update:** This was by no means meant to be an exhaustive list of academic research on C in general. I do not know of other work that focuses directly on the interplay of integer-pointer casts and optimizations, but other noteworthy work on formalizing C includes [KCC](https://github.com/kframework/c-semantics), [Robbert Krebber's PhD thesis](https://robbertkrebbers.nl/thesis.html) and [Cerberus](https://www.cl.cam.ac.uk/~pes20/cerberus/). **/Update** + This is why pointers are not simple, either. ## From Pointers to Bytes