[cfe-dev] argv[0] in libclang

[Milian Wolff via cfe-dev]

On Thursday, October 15, 2015 10:30:54 AM CEST Benjamin Kramer via cfe-dev 
wrote:
> Hi,
> 
> currently all libclang APIs that get passed a command line expect that
> there is no argv[0] in the list, i. e. no binary name at the beginning
> of the command line. We later fake one
> (clang::createInvocationFromCommandLine) as the invocation gets passed
> down into the proper clang machinery.
> 
> This is nasty because it changes the behavior if the original clang
> invocation would've used a relative path to the standard library:
> 
> cmdline: /foo/bar/bin/clang -c test.cc
> std lib in: /foo/bar/include/c++
> libclang sees: -c test.cc
> 
> and the stdlib is lost. This comes up if we're using a compile
> database, for example ycm is using it like this.
> 
> The only sane solution I see at the moment is to add a new libclang
> API that expects a full argv. Any other ideas?

In KDevelop, we parse the output of

	clang++ --std=c++11 -xc++ -E -v /dev/null

and pass those in to liblcang as explicit include paths. It works fine for our 
use case. But for a simpler tool it might be far too much overhead of course 
to get up and running. Couldn't the code path in clang use the path to the 
clang library as a fallback when no binary is given? That way, nothing needs 
to be changed.

Bye
-- 
Milian Wolff
mail at milianw.de
http://milianw.de