r232159 - Make a module "use" also count as use of all its submodules

[David Blaikie]

On Fri, Mar 13, 2015 at 7:32 AM, Daniel Jasper <djasper at google.com> wrote:

> Yeah, right. I think it is generally nice, but it is actually more code in
> this case as you need to access begin and end iterator instead of the
> range-based for loop.
>

Yep, pity we don't have range-based algorithms.


> Also not sure which is better.
>

Perf wise, they'll be essentially the same. It's possible that the
range-based-for formulation would be a little slower in debug builds using
MSVC's standard library. The MSVC standard library has iterator range
checks which come at some cost - raw iterator code incurs many of those
checks (because it has to check on each operation) whereas algorithms can
conspire with the range checks, performing a single range-check up-front
before using unchecked operations to perform the actual work.

- David


>
> On Fri, Mar 13, 2015 at 3:27 PM, David Blaikie <dblaikie at gmail.com> wrote:
>
>>
>> On Mar 13, 2015 4:31 AM, "Daniel Jasper" <djasper at google.com> wrote:
>> >
>> > Author: djasper
>> > Date: Fri Mar 13 06:26:16 2015
>> > New Revision: 232159
>> >
>> > URL: http://llvm.org/viewvc/llvm-project?rev=232159&view=rev
>> > Log:
>> > Make a module "use" also count as use of all its submodules
>> >
>> > Added:
>> >     cfe/trunk/test/Modules/Inputs/declare-use/sub.h
>> > Modified:
>> >     cfe/trunk/lib/Lex/ModuleMap.cpp
>> >     cfe/trunk/test/Modules/Inputs/declare-use/module.map
>> >     cfe/trunk/test/Modules/declare-use1.cpp
>> >
>> > Modified: cfe/trunk/lib/Lex/ModuleMap.cpp
>> > URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Lex/ModuleMap.cpp?rev=232159&r1=232158&r2=232159&view=diff
>> >
>> ==============================================================================
>> > --- cfe/trunk/lib/Lex/ModuleMap.cpp (original)
>> > +++ cfe/trunk/lib/Lex/ModuleMap.cpp Fri Mar 13 06:26:16 2015
>> > @@ -208,9 +208,11 @@ ModuleMap::findHeaderInUmbrellaDirs(cons
>> >  // Returns true if RequestingModule directly uses RequestedModule.
>> >  static bool directlyUses(const Module *RequestingModule,
>> >                           const Module *RequestedModule) {
>> > -  return std::find(RequestingModule->DirectUses.begin(),
>> > -                   RequestingModule->DirectUses.end(),
>> > -                   RequestedModule) !=
>> RequestingModule->DirectUses.end();
>> > +  for (const Module* DirectUse : RequestingModule->DirectUses) {
>>
>> This could be written using std::any_of - just a thought, not necessarily
>> better, but might be.
>>
>> > +    if (RequestedModule->isSubModuleOf(DirectUse))
>> > +      return true;
>> > +  }
>> > +  return false;
>> >  }
>> >
>> >  static bool violatesPrivateInclude(Module *RequestingModule,
>> >
>> > Modified: cfe/trunk/test/Modules/Inputs/declare-use/module.map
>> > URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/declare-use/module.map?rev=232159&r1=232158&r2=232159&view=diff
>> >
>> ==============================================================================
>> > --- cfe/trunk/test/Modules/Inputs/declare-use/module.map (original)
>> > +++ cfe/trunk/test/Modules/Inputs/declare-use/module.map Fri Mar 13
>> 06:26:16 2015
>> > @@ -39,6 +39,7 @@ module XG {
>> >    use XE
>> >    use XJ
>> >    use XK
>> > +  use XN
>> >  }
>> >
>> >  module XH {
>> > @@ -66,5 +67,11 @@ module XM {
>> >    textual header "m2.h"
>> >  }
>> >
>> > +module XN {
>> > +  module sub {
>> > +    header "sub.h"
>> > +  }
>> > +}
>> > +
>> >  module XS {
>> >  }
>> >
>> > Added: cfe/trunk/test/Modules/Inputs/declare-use/sub.h
>> > URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/declare-use/sub.h?rev=232159&view=auto
>> >
>> ==============================================================================
>> > --- cfe/trunk/test/Modules/Inputs/declare-use/sub.h (added)
>> > +++ cfe/trunk/test/Modules/Inputs/declare-use/sub.h Fri Mar 13 06:26:16
>> 2015
>> > @@ -0,0 +1,4 @@
>> > +#ifndef SUB_H
>> > +#define SUB_H
>> > +const int sub = 42;
>> > +#endif
>> >
>> > Modified: cfe/trunk/test/Modules/declare-use1.cpp
>> > URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/declare-use1.cpp?rev=232159&r1=232158&r2=232159&view=diff
>> >
>> ==============================================================================
>> > --- cfe/trunk/test/Modules/declare-use1.cpp (original)
>> > +++ cfe/trunk/test/Modules/declare-use1.cpp Fri Mar 13 06:26:16 2015
>> > @@ -5,4 +5,5 @@
>> >  #include "e.h"
>> >  #include "f.h" // expected-error {{module XG does not depend on a
>> module exporting 'f.h'}}
>> >  #include "i.h"
>> > -const int g2 = g1 + e + f + aux_i;
>> > +#include "sub.h"
>> > +const int g2 = g1 + e + f + aux_i + sub;
>> >
>> >
>> > _______________________________________________
>> > cfe-commits mailing list
>> > cfe-commits at cs.uiuc.edu
>> > http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
>>
>
>
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