[cfe-commits] r119285 - in /cfe/trunk: lib/Frontend/ASTUnit.cpp tools/c-index-test/c-index-test.c

[Manuel Klimek via cfe-commits]

+Val FYI

On Wed, Nov 18, 2015 at 6:59 PM Douglas Gregor <dgregor at apple.com> wrote:

> On Nov 18, 2015, at 9:36 AM, Manuel Klimek <klimek at google.com> wrote:
>
>
>
> On Wed, Nov 18, 2015 at 6:19 PM Douglas Gregor <dgregor at apple.com> wrote:
>
>>
>>
>> Sent from my iPhone
>>
>> On Nov 18, 2015, at 8:19 AM, Manuel Klimek <klimek at google.com> wrote:
>>
>> (now with the right list)
>>
>> On Tue, Nov 16, 2010 at 12:03 AM Douglas Gregor <dgregor at apple.com>
>> wrote:
>>
>>> Author: dgregor
>>> Date: Mon Nov 15 17:00:34 2010
>>> New Revision: 119285
>>>
>>> URL: http://llvm.org/viewvc/llvm-project?rev=119285&view=rev
>>> Log:
>>> Tweak libclang's heuristics for building precompiled preambles and
>>> caching global code-completion results. In particular, don't perform
>>> either operation the first time we parse, but do both after the first
>>> reparse.
>>>
>>
>> Do you remember the reason behind not building the preamble on the first
>> parse? For really large TUs having to parse 2 times before we get a
>> preamble is rather painful.
>>
>>
>> We wanted to get the first set of results quickly, especially for syntax
>> coloring when a file is first opened.
>>
>
> Do you remember how much storing the preamble would make this slower
> (without the preamble many of our parses are >> 20 seconds, so 2x that is
> rather unfortunate). Perhaps we can add a flag?
>
>
> I don’t remember the numbers from… 5 years ago. I do remember that it was
> a noticeable lag in the UI when opening a new file, primarily because the
> AST serialization step needed to produce the preamble file is fairly
> expensive. You can turn on the timers by setting the LIBCLANG_TIMING
> environment variable to see how long things are taking without having to
> recompile, since it’s probably worth re-measuring now.
>
> - Doug
>
>
>
>>
>>
>> Cheers,
>> /Manuel
>>
>>
>>> Modified:
>>>     cfe/trunk/lib/Frontend/ASTUnit.cpp
>>>     cfe/trunk/tools/c-index-test/c-index-test.c
>>>
>>> Modified: cfe/trunk/lib/Frontend/ASTUnit.cpp
>>> URL:
>>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Frontend/ASTUnit.cpp?rev=119285&r1=119284&r2=119285&view=diff
>>>
>>> ==============================================================================
>>> --- cfe/trunk/lib/Frontend/ASTUnit.cpp (original)
>>> +++ cfe/trunk/lib/Frontend/ASTUnit.cpp Mon Nov 15 17:00:34 2010
>>> @@ -326,7 +326,6 @@
>>>
>>>    // Make a note of the state when we performed this caching.
>>>    NumTopLevelDeclsAtLastCompletionCache = top_level_size();
>>> -  CacheCodeCompletionCoolDown = 15;
>>>  }
>>>
>>>  void ASTUnit::ClearCachedCompletionResults() {
>>> @@ -824,12 +823,6 @@
>>>    }
>>>
>>>    Invocation.reset(Clang.takeInvocation());
>>> -
>>> -  // If we were asked to cache code-completion results and don't have
>>> any
>>> -  // results yet, do so now.
>>> -  if (ShouldCacheCodeCompletionResults &&
>>> CachedCompletionResults.empty())
>>> -    CacheCodeCompletionResults();
>>> -
>>>    return false;
>>>
>>>  error:
>>> @@ -1350,7 +1343,7 @@
>>>
>>>    llvm::MemoryBuffer *OverrideMainBuffer = 0;
>>>    if (PrecompilePreamble) {
>>> -    PreambleRebuildCounter = 1;
>>> +    PreambleRebuildCounter = 2;
>>>      OverrideMainBuffer
>>>        = getMainBufferWithPrecompiledPreamble(*Invocation);
>>>    }
>>> @@ -1377,6 +1370,7 @@
>>>    AST->CaptureDiagnostics = CaptureDiagnostics;
>>>    AST->CompleteTranslationUnit = CompleteTranslationUnit;
>>>    AST->ShouldCacheCodeCompletionResults = CacheCodeCompletionResults;
>>> +  AST->CacheCodeCompletionCoolDown = 1;
>>>    AST->Invocation.reset(CI);
>>>
>>>    return AST->LoadFromCompilerInvocation(PrecompilePreamble)? 0 :
>>> AST.take();
>>> @@ -1481,6 +1475,7 @@
>>>    AST->CaptureDiagnostics = CaptureDiagnostics;
>>>    AST->CompleteTranslationUnit = CompleteTranslationUnit;
>>>    AST->ShouldCacheCodeCompletionResults = CacheCodeCompletionResults;
>>> +  AST->CacheCodeCompletionCoolDown = 1;
>>>    AST->NumStoredDiagnosticsFromDriver = StoredDiagnostics.size();
>>>    AST->NumStoredDiagnosticsInPreamble = StoredDiagnostics.size();
>>>    AST->StoredDiagnostics.swap(StoredDiagnostics);
>>>
>>> Modified: cfe/trunk/tools/c-index-test/c-index-test.c
>>> URL:
>>> http://llvm.org/viewvc/llvm-project/cfe/trunk/tools/c-index-test/c-index-test.c?rev=119285&r1=119284&r2=119285&view=diff
>>>
>>> ==============================================================================
>>> --- cfe/trunk/tools/c-index-test/c-index-test.c (original)
>>> +++ cfe/trunk/tools/c-index-test/c-index-test.c Mon Nov 15 17:00:34 2010
>>> @@ -1040,6 +1040,11 @@
>>>      fprintf(stderr, "Unable to load translation unit!\n");
>>>      return 1;
>>>    }
>>> +
>>> +  if (clang_reparseTranslationUnit(TU, 0, 0,
>>> clang_defaultReparseOptions(TU))) {
>>> +    fprintf(stderr, "Unable to reparse translation init!\n");
>>> +    return 1;
>>> +  }
>>>
>>>    for (I = 0; I != Repeats; ++I) {
>>>      results = clang_codeCompleteAt(TU, filename, line, column,
>>>
>>>
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>>>
>>
>
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