r240350 - [modules] When building a module, if there are multiple matches for a header

[Richard Smith]

On Mon, Jun 22, 2015 at 4:55 PM, Sean Silva <chisophugis at gmail.com> wrote:

> What exactly does -emit-module do here? Is it basically like a PCH build
> step, but where the passed-in module map drives what clang does?
>

More-or-less, yes. -emit-module is what we run internally when we
implicitly build a module. The input file is the module map, -fmodule-name=
specifies which module to build, and the output goes to the module cache if
no -o option is explicitly specified.


> -- Sean Silva
>
> On Mon, Jun 22, 2015 at 3:20 PM, Richard Smith <richard-llvm at metafoo.co.uk
> > wrote:
>
>> Author: rsmith
>> Date: Mon Jun 22 17:20:47 2015
>> New Revision: 240350
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=240350&view=rev
>> Log:
>> [modules] When building a module, if there are multiple matches for a
>> header
>> file in the loaded module maps and one of them is from the current module,
>> that's the right match.
>>
>> Added:
>>     cfe/trunk/test/Modules/Inputs/explicit-build-prefer-self/
>>     cfe/trunk/test/Modules/Inputs/explicit-build-prefer-self/a.h
>>     cfe/trunk/test/Modules/Inputs/explicit-build-prefer-self/b.h
>>     cfe/trunk/test/Modules/Inputs/explicit-build-prefer-self/map
>>     cfe/trunk/test/Modules/Inputs/explicit-build-prefer-self/x.h
>>     cfe/trunk/test/Modules/explicit-build-prefer-self.cpp
>> Modified:
>>     cfe/trunk/lib/Lex/ModuleMap.cpp
>>
>> Modified: cfe/trunk/lib/Lex/ModuleMap.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Lex/ModuleMap.cpp?rev=240350&r1=240349&r2=240350&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/lib/Lex/ModuleMap.cpp (original)
>> +++ cfe/trunk/lib/Lex/ModuleMap.cpp Mon Jun 22 17:20:47 2015
>> @@ -346,6 +346,9 @@ ModuleMap::KnownHeader ModuleMap::findMo
>>      ModuleMap::KnownHeader Result;
>>      // Iterate over all modules that 'File' is part of to find the best
>> fit.
>>      for (KnownHeader &H : Known->second) {
>> +      // Prefer a header from the current module over all others.
>> +      if (H.getModule() == CompilingModule)
>> +        return MakeResult(H);
>>        // Cannot use a module if it is unavailable.
>>        if (!H.getModule()->isAvailable())
>>          continue;
>>
>> Added: cfe/trunk/test/Modules/Inputs/explicit-build-prefer-self/a.h
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/explicit-build-prefer-self/a.h?rev=240350&view=auto
>>
>> ==============================================================================
>> --- cfe/trunk/test/Modules/Inputs/explicit-build-prefer-self/a.h (added)
>> +++ cfe/trunk/test/Modules/Inputs/explicit-build-prefer-self/a.h Mon Jun
>> 22 17:20:47 2015
>> @@ -0,0 +1,2 @@
>> +// a
>> +#include "x.h"
>>
>> Added: cfe/trunk/test/Modules/Inputs/explicit-build-prefer-self/b.h
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/explicit-build-prefer-self/b.h?rev=240350&view=auto
>>
>> ==============================================================================
>> --- cfe/trunk/test/Modules/Inputs/explicit-build-prefer-self/b.h (added)
>> +++ cfe/trunk/test/Modules/Inputs/explicit-build-prefer-self/b.h Mon Jun
>> 22 17:20:47 2015
>> @@ -0,0 +1,2 @@
>> +// b
>> +#include "x.h"
>>
>> Added: cfe/trunk/test/Modules/Inputs/explicit-build-prefer-self/map
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/explicit-build-prefer-self/map?rev=240350&view=auto
>>
>> ==============================================================================
>> --- cfe/trunk/test/Modules/Inputs/explicit-build-prefer-self/map (added)
>> +++ cfe/trunk/test/Modules/Inputs/explicit-build-prefer-self/map Mon Jun
>> 22 17:20:47 2015
>> @@ -0,0 +1,2 @@
>> +module a { header "a.h" header "x.h" }
>> +module b { header "b.h" header "x.h" }
>>
>> Added: cfe/trunk/test/Modules/Inputs/explicit-build-prefer-self/x.h
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/explicit-build-prefer-self/x.h?rev=240350&view=auto
>>
>> ==============================================================================
>>     (empty)
>>
>> Added: cfe/trunk/test/Modules/explicit-build-prefer-self.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/explicit-build-prefer-self.cpp?rev=240350&view=auto
>>
>> ==============================================================================
>> --- cfe/trunk/test/Modules/explicit-build-prefer-self.cpp (added)
>> +++ cfe/trunk/test/Modules/explicit-build-prefer-self.cpp Mon Jun 22
>> 17:20:47 2015
>> @@ -0,0 +1,3 @@
>> +// RUN: rm -rf %t
>> +// RUN: %clang_cc1 -fmodules -fno-implicit-modules -emit-module
>> -fmodule-name=a %S/Inputs/explicit-build-prefer-self/map -o a.pcm
>> +// RUN: %clang_cc1 -fmodules -fno-implicit-modules -emit-module
>> -fmodule-name=b %S/Inputs/explicit-build-prefer-self/map -o b.pcm
>>
>>
>> _______________________________________________
>> cfe-commits mailing list
>> cfe-commits at cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
>>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20150623/114cd9c3/attachment.html>