r250577 - [modules] Allow the error when explicitly loading an incompatible module file
Manuel Klimek via cfe-commits
cfe-commits at lists.llvm.org
Tue Oct 20 01:38:53 PDT 2015
On Tue, Oct 20, 2015 at 5:52 AM Sean Silva <chisophugis at gmail.com> wrote:
> On Mon, Oct 19, 2015 at 2:10 AM, Manuel Klimek <klimek at google.com> wrote:
>
>> On Sat, Oct 17, 2015 at 3:41 AM Richard Smith via cfe-commits <
>> cfe-commits at lists.llvm.org> wrote:
>>
>>> On Fri, Oct 16, 2015 at 6:30 PM, Sean Silva <chisophugis at gmail.com>
>>> wrote:
>>>
>>>> On Fri, Oct 16, 2015 at 6:26 PM, Richard Smith <richard at metafoo.co.uk>
>>>> wrote:
>>>>
>>>>> On Fri, Oct 16, 2015 at 6:25 PM, Sean Silva <chisophugis at gmail.com>
>>>>> wrote:
>>>>>
>>>>>> On Fri, Oct 16, 2015 at 6:12 PM, Richard Smith <richard at metafoo.co.uk
>>>>>> > wrote:
>>>>>>
>>>>>>> On Fri, Oct 16, 2015 at 4:43 PM, Sean Silva <chisophugis at gmail.com>
>>>>>>> wrote:
>>>>>>>
>>>>>>>> On Fri, Oct 16, 2015 at 4:20 PM, Richard Smith via cfe-commits <
>>>>>>>> cfe-commits at lists.llvm.org> wrote:
>>>>>>>>
>>>>>>>>> Author: rsmith
>>>>>>>>> Date: Fri Oct 16 18:20:19 2015
>>>>>>>>> New Revision: 250577
>>>>>>>>>
>>>>>>>>> URL: http://llvm.org/viewvc/llvm-project?rev=250577&view=rev
>>>>>>>>> Log:
>>>>>>>>> [modules] Allow the error when explicitly loading an incompatible
>>>>>>>>> module file
>>>>>>>>> via -fmodule-file= to be turned off; in that case, just include
>>>>>>>>> the relevant
>>>>>>>>> files textually. This allows module files to be unconditionally
>>>>>>>>> passed to all
>>>>>>>>> compile actions via CXXFLAGS, and to be ignored for rules that
>>>>>>>>> specify custom
>>>>>>>>> incompatible flags.
>>>>>>>>>
>>>>>>>>
>>>>>>>> What direction are you trying to go with this? Are you thinking
>>>>>>>> something like having CMake build a bunch of modules up front?
>>>>>>>>
>>>>>>>
>>>>>>> That's certainly one thing you can do with this. Another is that you
>>>>>>> can make cmake automatically and explicitly build a module for each
>>>>>>> library, and then provide that for all the dependencies of that library,
>>>>>>>
>>>>>>
>>>>>> How does CMake know which headers are part of which library?
>>>>>> Strategically named top-level modules in the module map?
>>>>>>
>>>>>
>>>>> The idea would be for CMake to generate the module map itself based on
>>>>> the build rules.
>>>>>
>>>>
>>>> How would it know which headers to include? Do
>>>> our ADDITIONAL_HEADER_DIRS things in our CMakeLists.txt have enough
>>>> information for this?
>>>>
>>>
>>> Some additional information may need to be added to the CMakeLists to
>>> enable this. Some build systems already model the headers for a library,
>>> and so already have the requisite information.
>>>
>>
>> CMake supports specifying headers for libraries (mainly used for MS VS).
>> If we need this for modules, we'll probably need to update our build rules
>> (which will probably make sense anyway, for a better experience for VS
>> users ;)
>>
>
> Nice.
>
> Brad, do you have any idea how hard it would be to get cmake to generate
> clang module map files and add explicit module build steps? Basically, the
> requirements (off the top of my head) are:
> - for each library, generate a module map which is essentially just a list
> of the headers in that library (it's not just a flat list, but that's the
> gist of it).
> - for each module map, add a build step that invokes clang on it to say
> "build the module corresponding to this module map" (it's basically
> `clang++ path/to/foo.modulemap -o foo.pcm` with a little bit of fluff
> around it). There is also a dependency from foo.pcm on each of the
> libraries that library "foo" depends on.
> - for each library $Dep that library $Lib depends on, add $Dep's .pcm file
> as a dependency of the .o build steps for $Lib. $Dep's .pcm file also needs
> to be passed on the command line of the .o build steps for $Lib.
>
> It seems like similar requirements are going to be common in the
> standardized modules feature (except for the module map I think? Richard?).
> Basically, in order to avoid redundantly parsing textual headers, you need
> to run a build step on headers that turns them into some form that can be
> processed more efficiently than just parsing it. E.g. the build step on
> slide 36 of this cppcon presentation about the Microsoft experimental
> modules implementation https://www.youtube.com/watch?v=RwdQA0pGWa4
> (slides: https://goo.gl/t4Eg89 ).
>
> Let me know if there is anything I can do to help (up to and including
> patches, but I'll need pointers and possibly some hand-holding as I'm
> unfamiliar with the CMake language and CMake codebase).
>
> There's also some issues of detecting if the host clang is new enough that
> we want to use its modules feature and also the issue of detecting
> modularized system headers if available, but we can hammer those things out
> as we run into them.
>
> Manuel, I heard through the grape vine that you were the one that
> implemented the explicit modules stuff for bazel? Did I miss anything in my
> list above?
>
I think that's about right. We also embed the module maps into the modules,
but most of these things only matter for distributed builds at scale.
Also, I have some experience hacking on cmake, and from my experience I
think this shouldn't be too hard to get working (mainly work ;)
> Richard, are there any blockers to exposing a driver flag for explicit
> modules?
>
Which flag are you missing?
>
> -- Sean Silva
>
>
>>
>>
>>>
>>>
>>>> -- Sean Silva
>>>>
>>>>
>>>>>
>>>>>
>>>>>> -- Sean Silva
>>>>>>
>>>>>>
>>>>>>> with an (error-by-default) warning in the case where the downstream
>>>>>>> library specifies incompatible compilation flags. You can use this warning
>>>>>>> flag to turn off the error so you can make progress before you get around
>>>>>>> to fixing all the incompatible flags.
>>>>>>>
>>>>>>>
>>>>>>>> If that's the case, it would be nice to explain what caused the
>>>>>>>> mismatch, so that the user can look into rectifying it. Otherwise this
>>>>>>>> warning is not directly actionable. The existing diagnostics seemed
>>>>>>>> alright. Demoting them to "error: {{.*}} configuration mismatch" seems like
>>>>>>>> a regression.
>>>>>>>>
>>>>>>>
>>>>>>> I agree, it is a regression, and fixing it is high on my list of
>>>>>>> priorities (sorry for not mentioning that in the commit message).
>>>>>>>
>>>>>>> -- Sean Silva
>>>>>>>>
>>>>>>>>
>>>>>>>>>
>>>>>>>>> Modified:
>>>>>>>>> cfe/trunk/include/clang/Basic/DiagnosticFrontendKinds.td
>>>>>>>>> cfe/trunk/lib/Frontend/CompilerInstance.cpp
>>>>>>>>> cfe/trunk/test/Modules/merge-target-features.cpp
>>>>>>>>>
>>>>>>>>> Modified: cfe/trunk/include/clang/Basic/DiagnosticFrontendKinds.td
>>>>>>>>> URL:
>>>>>>>>> http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticFrontendKinds.td?rev=250577&r1=250576&r2=250577&view=diff
>>>>>>>>>
>>>>>>>>> ==============================================================================
>>>>>>>>> --- cfe/trunk/include/clang/Basic/DiagnosticFrontendKinds.td
>>>>>>>>> (original)
>>>>>>>>> +++ cfe/trunk/include/clang/Basic/DiagnosticFrontendKinds.td Fri
>>>>>>>>> Oct 16 18:20:19 2015
>>>>>>>>> @@ -172,6 +172,9 @@ def warn_incompatible_analyzer_plugin_ap
>>>>>>>>> def note_incompatible_analyzer_plugin_api : Note<
>>>>>>>>> "current API version is '%0', but plugin was compiled with
>>>>>>>>> version '%1'">;
>>>>>>>>>
>>>>>>>>> +def warn_module_config_mismatch : Warning<
>>>>>>>>> + "module file %0 cannot be loaded due to a configuration
>>>>>>>>> mismatch with the current "
>>>>>>>>> + "compilation">,
>>>>>>>>> InGroup<DiagGroup<"module-file-config-mismatch">>, DefaultError;
>>>>>>>>> def err_module_map_not_found : Error<"module map file '%0' not
>>>>>>>>> found">,
>>>>>>>>> DefaultFatal;
>>>>>>>>> def err_missing_module_name : Error<
>>>>>>>>>
>>>>>>>>> Modified: cfe/trunk/lib/Frontend/CompilerInstance.cpp
>>>>>>>>> URL:
>>>>>>>>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Frontend/CompilerInstance.cpp?rev=250577&r1=250576&r2=250577&view=diff
>>>>>>>>>
>>>>>>>>> ==============================================================================
>>>>>>>>> --- cfe/trunk/lib/Frontend/CompilerInstance.cpp (original)
>>>>>>>>> +++ cfe/trunk/lib/Frontend/CompilerInstance.cpp Fri Oct 16
>>>>>>>>> 18:20:19 2015
>>>>>>>>> @@ -1335,15 +1335,24 @@ bool CompilerInstance::loadModuleFile(St
>>>>>>>>>
>>>>>>>>> std::move(Listener));
>>>>>>>>>
>>>>>>>>> // Try to load the module file.
>>>>>>>>> - if (ModuleManager->ReadAST(FileName,
>>>>>>>>> serialization::MK_ExplicitModule,
>>>>>>>>> - SourceLocation(),
>>>>>>>>> ASTReader::ARR_None)
>>>>>>>>> - != ASTReader::Success)
>>>>>>>>> - return false;
>>>>>>>>> -
>>>>>>>>> + switch (ModuleManager->ReadAST(FileName,
>>>>>>>>> serialization::MK_ExplicitModule,
>>>>>>>>> + SourceLocation(),
>>>>>>>>> +
>>>>>>>>> ASTReader::ARR_ConfigurationMismatch)) {
>>>>>>>>> + case ASTReader::Success:
>>>>>>>>> // We successfully loaded the module file; remember the set of
>>>>>>>>> provided
>>>>>>>>> // modules so that we don't try to load implicit modules for
>>>>>>>>> them.
>>>>>>>>> ListenerRef.registerAll();
>>>>>>>>> return true;
>>>>>>>>> +
>>>>>>>>> + case ASTReader::ConfigurationMismatch:
>>>>>>>>> + // Ignore unusable module files.
>>>>>>>>> + getDiagnostics().Report(SourceLocation(),
>>>>>>>>> diag::warn_module_config_mismatch)
>>>>>>>>> + << FileName;
>>>>>>>>> + return true;
>>>>>>>>> +
>>>>>>>>> + default:
>>>>>>>>> + return false;
>>>>>>>>> + }
>>>>>>>>> }
>>>>>>>>>
>>>>>>>>> ModuleLoadResult
>>>>>>>>>
>>>>>>>>> Modified: cfe/trunk/test/Modules/merge-target-features.cpp
>>>>>>>>> URL:
>>>>>>>>> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/merge-target-features.cpp?rev=250577&r1=250576&r2=250577&view=diff
>>>>>>>>>
>>>>>>>>> ==============================================================================
>>>>>>>>> --- cfe/trunk/test/Modules/merge-target-features.cpp (original)
>>>>>>>>> +++ cfe/trunk/test/Modules/merge-target-features.cpp Fri Oct 16
>>>>>>>>> 18:20:19 2015
>>>>>>>>> @@ -20,7 +20,7 @@
>>>>>>>>> // RUN: -target-cpu i386 \
>>>>>>>>> // RUN: -fsyntax-only merge-target-features.cpp 2>&1 \
>>>>>>>>> // RUN: | FileCheck --check-prefix=SUBSET %s
>>>>>>>>> -// SUBSET: AST file was compiled with the target feature'+sse2'
>>>>>>>>> but the current translation unit is not
>>>>>>>>> +// SUBSET: error: {{.*}} configuration mismatch
>>>>>>>>> //
>>>>>>>>> // RUN: %clang_cc1 -fmodules -x c++ -fmodules-cache-path=%t \
>>>>>>>>> // RUN: -iquote Inputs/merge-target-features \
>>>>>>>>> @@ -56,8 +56,7 @@
>>>>>>>>> // RUN: -target-cpu i386 -target-feature +cx16 \
>>>>>>>>> // RUN: -fsyntax-only merge-target-features.cpp 2>&1 \
>>>>>>>>> // RUN: | FileCheck --check-prefix=MISMATCH %s
>>>>>>>>> -// MISMATCH: AST file was compiled with the target feature'+sse2'
>>>>>>>>> but the current translation unit is not
>>>>>>>>> -// MISMATCH: current translation unit was compiled with the
>>>>>>>>> target feature'+cx16' but the AST file was not
>>>>>>>>> +// MISMATCH: error: {{.*}} configuration mismatch
>>>>>>>>>
>>>>>>>>> #include "foo.h"
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> _______________________________________________
>>>>>>>>> cfe-commits mailing list
>>>>>>>>> cfe-commits at lists.llvm.org
>>>>>>>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
>>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>
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