5 ms·

Isn't it very similar to something Clang has had for years?

legends2k 6y ago
Tangential: I think many platforms that GCC supports and the kind of optimisation GCC provides might make it a superior choice for projects. For those developers its exciting. Also if an existing project is using it for a long-time and has not intentions of switching to Clang, for them too this would be interesting.
- CoolGuySteve 6y ago
  My project uses g++ but I’ve been using a clang static-analysis step in my CI pipeline for a while now. Compiling with clang is much, much slower but it finds interesting errors sometimes. I only had to ifdef out one code section that it couldn’t understand (something about indexing an array with a constexpr function returning an enum class from a template parameter). It depends on the project, but this one and another project I made work are both 100k lines of C++ and took half a day to setup. It was worth it imo.
  - tele_ski 6y ago
    Interesting that your build times are slower with clang. I've found on most of my projects clang is roughly 30% faster to compile in debug, but release I haven't seen a huge difference between the two.
    - petters 6y ago
      Perhaps they are slower because Clang is doing static analysis in this case.
      - CoolGuySteve 6y ago
        Static analysis is a lot slower but regular clang++ is also significantly slower than g++, like a 4-5 minute build time vs 2:30 on g++. It might have something to do with a heavy usage of templates in a few files, I don't know. Clang's autovectorization is better in a few functions I disassembled but otherwise the generated code doesn't benchmark any faster, it's better in some places, worse in others.
    - cheez 6y ago
      Nope, also slower for me.
    - moonchild 6y ago
      My build times are identical between GCC and Clang (debug and release). But TCC is 10x faster than both of them.
TeaDude 6y ago
Clang has it although I've personally never tried it due to the horrible rigamarole of setting it up. In GCC it's a compiler flag. In LLVM it's a convoluted process automated by either an irritating perl/python script (The python one isn't included by default for some reason despite being far more common these days) or AN ENTIRE WEB SERVER TO OUTPUT TEXT (Which thankfully isn't included by default). I'm sure you could set it up in make but since my projects aren't large scale enough to really need it I can't be bothered, even if it's one of those things you'll probably only need to write once and can just copy and paste ad-infinitum.
- ndesaulniers 6y ago
  Lest other people get the wrong impression from someone who's admitted not even trying it, running Clang's static analyzer is as simple as switching cc with scan-build. You can even drive it from clang-tidy. No Perl or Python setup in my experience.
  - TeaDude 6y ago
    You appear to have it installed somewhere. Open up scan-build in your favorite text editor if you don't believe me.
- Freaky 6y ago
  > Clang has it although I've personally never tried it due to the horrible rigamarole of setting it up. -% scan-build10 make scan-build: Using '/usr/local/llvm10/bin/clang-10' for static analysis ... scan-build: No bugs found. What could ever have driven them to such a long and convoluted setup process?
  - TeaDude 6y ago
    Yep! Thanks for pointing out the perl script I mentioned. You appear to have completely ignored the rest of my post on them leaving important functionality to third party scripting languages.

Tangential: I think many platforms that GCC supports and the kind of optimisation GCC provides might make it a superior choice for projects. For those developers its exciting. Also if an existing project is using it for a long-time and has not intentions of switching to Clang, for them too this would be interesting.

CoolGuySteve 6y ago
My project uses g++ but I’ve been using a clang static-analysis step in my CI pipeline for a while now. Compiling with clang is much, much slower but it finds interesting errors sometimes. I only had to ifdef out one code section that it couldn’t understand (something about indexing an array with a constexpr function returning an enum class from a template parameter). It depends on the project, but this one and another project I made work are both 100k lines of C++ and took half a day to setup. It was worth it imo.
- tele_ski 6y ago
  Interesting that your build times are slower with clang. I've found on most of my projects clang is roughly 30% faster to compile in debug, but release I haven't seen a huge difference between the two.
  - petters 6y ago
    Perhaps they are slower because Clang is doing static analysis in this case.
    - CoolGuySteve 6y ago
      Static analysis is a lot slower but regular clang++ is also significantly slower than g++, like a 4-5 minute build time vs 2:30 on g++. It might have something to do with a heavy usage of templates in a few files, I don't know. Clang's autovectorization is better in a few functions I disassembled but otherwise the generated code doesn't benchmark any faster, it's better in some places, worse in others.
  - cheez 6y ago
    Nope, also slower for me.
  - moonchild 6y ago
    My build times are identical between GCC and Clang (debug and release). But TCC is 10x faster than both of them.

TeaDude 6y ago

Clang has it although I've personally never tried it due to the horrible rigamarole of setting it up. In GCC it's a compiler flag. In LLVM it's a convoluted process automated by either an irritating perl/python script (The python one isn't included by default for some reason despite being far more common these days) or AN ENTIRE WEB SERVER TO OUTPUT TEXT (Which thankfully isn't included by default). I'm sure you could set it up in make but since my projects aren't large scale enough to really need it I can't be bothered, even if it's one of those things you'll probably only need to write once and can just copy and paste ad-infinitum.

ndesaulniers 6y ago
Lest other people get the wrong impression from someone who's admitted not even trying it, running Clang's static analyzer is as simple as switching cc with scan-build. You can even drive it from clang-tidy. No Perl or Python setup in my experience.
- TeaDude 6y ago
  You appear to have it installed somewhere. Open up scan-build in your favorite text editor if you don't believe me.
Freaky 6y ago
> Clang has it although I've personally never tried it due to the horrible rigamarole of setting it up. -% scan-build10 make scan-build: Using '/usr/local/llvm10/bin/clang-10' for static analysis ... scan-build: No bugs found. What could ever have driven them to such a long and convoluted setup process?
- TeaDude 6y ago
  Yep! Thanks for pointing out the perl script I mentioned. You appear to have completely ignored the rest of my post on them leaving important functionality to third party scripting languages.