[cfe-dev] standalone tool: best way to find built-in includes?

[Manuel Klimek]

Then I would suggest you compile the code with the same compiler you build
your tool based on...

On Fri Nov 21 2014 at 5:14:39 PM Christian Convey <
christian.convey at gmail.com> wrote:

> > The question is, why is it important to you whether it's the same AST?
>
> I'm also generating program traces, which report source locations
> based on the DWARF info.  I want to be able to reliably relate the
> trace events to the AST.  I want to minimize the risk that the two
> don't properly match.
>
> On Fri, Nov 21, 2014 at 11:00 AM, Manuel Klimek <klimek at google.com> wrote:
> > On Fri Nov 21 2014 at 4:40:44 PM Christian Convey
> > <christian.convey at gmail.com> wrote:
> >>
> >> Hi Manuel,
> >>
> >> What really matters is that when my tool analyzes the target program's
> >> source, it assumes the same standard headers that are normally used to
> >> build that target program.
> >>
> >> For example, the target program might normally be built with clang
> >> 3.4, but my analysis tool is built on clang 3.6.  When my tool
> >> analyzes the source code of the target program, I want the analysis to
> >> be as though the target program #include'd the 3.4 builtins, not the
> >> 3.6 builtins.  Because my goal is to obtain the same AST as the one
> >> created during the target program's normal (3.4) build process.
> >
> >
> > The builtin headers are implementation details of the compiler. If you
> > compile a file with a tool based on clang 3.6 and builtin headers of
> clang
> > 3.4 the probability that you *don't* get a correct AST is higher.
> >
> > If you want to get the same AST, you have to use the same version of
> clang.
> > The question is, why is it important to you whether it's the same AST?
> >
> >>
> >>
> >> If I understand your suggestion, my analysis would give me an AST
> >> based on the clang 3.6 builtins, not based on the 3.4 builtins.  Is
> >> that correct?
> >>
> >> Thanks,
> >> Christian
> >>
> >>
> >>
> >>
> >>
> >> On Fri, Nov 21, 2014 at 4:35 AM, Manuel Klimek <klimek at google.com>
> wrote:
> >> > +1 to needs some refactoring, but generally the trick is: you don't
> want
> >> > to
> >> > use the builtin includes that are used by the clang you used to
> produce
> >> > the
> >> > compilation database, but the one that is current at the version at
> >> > which
> >> > you built your *tool*.
> >> >
> >> > Thus, optimally you'll install your tool into some/bin and the builtin
> >> > headers into some/lib/clang/<version>.
> >> >
> >> > Cheers,
> >> > /Manuel
> >> >
> >> > On Fri Nov 21 2014 at 5:23:16 AM Sean Silva <chisophugis at gmail.com>
> >> > wrote:
> >> >>
> >> >> You can set CLANG_RESOURCE_DIR in CMake, or pass -resource-dir (the
> >> >> default resource dir is created by `llvm::sys::path::append(<exe-
> path>,
> >> >> "..", "lib", "clang", CLANG_VERSION_STRING)`).
> >> >>
> >> >> This logic is actually duplicated in more than one place
> unfortunately.
> >> >> e.g. in CompilerInvocation::GetResourcesPath
> >> >> (lib/Frontend/CompilerInvocation.cpp) and Driver::Driver
> >> >> (lib/Driver/Driver.cpp); there's also some nastiness in
> >> >> CIndexer::getClangResourcesPath. Needs some refactoring.
> >> >>
> >> >> -- Sean Silva
> >> >>
> >> >> On Thu, Nov 20, 2014 at 6:32 PM, Christian Convey
> >> >> <christian.convey at gmail.com> wrote:
> >> >>>
> >> >>> Hi guys,
> >> >>>
> >> >>> I'm developed a standalone tool for analyzing source code.  It uses
> >> >>> CommonOptionParser and ClangTool in what I think are the standard
> >> >>> ways.
> >> >>>
> >> >>> My tool analyzes some other code ("foo.c") we have.  We build foo.c
> >> >>> with clang the system-wide installed version of clang.  Thanks to
> >> >>> cmake, we also produce a compilation database for that build of
> foo.c.
> >> >>>
> >> >>> I'd really like to ensure that when my analysis tool runs, I'd like
> it
> >> >>> to simulate, as closely as possible, the way we normally build
> foo.c.
> >> >>> In particular, I'd like to be sure it's using the same builtin
> headers
> >> >>> and gcc-provided headers.
> >> >>>
> >> >>> Unfortunately, I can't easily copy my analysis tools executable into
> >> >>> the same directory as the clang which we use to build foo.c.
> >> >>>
> >> >>> So here's my question: Is there a good way for me to force my tool
> to
> >> >>> search the same include directories, in the same order, as our
> normal
> >> >>> copy of clang does when it's building foo.c?
> >> >>>
> >> >>> I've tried running "clang -### ..." in the build system for foo.c,
> so
> >> >>> that (I think) I get explicit information about the flags being
> passed
> >> >>> to the front-end.  However, I haven't found a way to pass those
> flags
> >> >>> to my analysis tool in a way that CommonOptionsParser and/or
> ClangTool
> >> >>> find acceptable.  For example, they reject "-cc1".
> >> >>>
> >> >>> Thanks,
> >> >>> Christian
> >> >>> _______________________________________________
> >> >>> cfe-dev mailing list
> >> >>> cfe-dev at cs.uiuc.edu
> >> >>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
> >> >>
> >> >>
> >> >> _______________________________________________
> >> >> cfe-dev mailing list
> >> >> cfe-dev at cs.uiuc.edu
> >> >> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
>
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