From b1c3ae33eacb55a54a7ce28c5a5d6aa8903fbac2 Mon Sep 17 00:00:00 2001 From: Stephen Kelly Date: Wed, 9 Apr 2014 00:05:36 +0200 Subject: cmTarget: Short-circuit language computation if context independent. Computing the language involves computing the source files, which is an expensive operation. It requires calling cmMakefile::GetOrCreateSource many times, which involves creating and matching on many cmSourceFileLocation objects. Source files of a target may depend on the head-target and the config as of commit e6971df6 (cmTarget: Make the source files depend on the config., 2014-02-13). The results are cached for each context as of commit c5b26f3b (cmTarget: Cache the cmSourceFiles in GetSourceFiles., 2014-04-05). Each target in the build graph causes language computation of all of its dependents with itself as the head-target. This means that for 'core' libraries on which everything depends, the source files are computed once for every transitive target-level-dependee and the result is not cached because the head-target is different. This was observed in the VTK buildsystem. Short circuit the computation for targets which have a source-list that is independent of the head-target. If the source-list has already been computed and the generator expression evaluation reports that it was context-independent, return the only source-list already cached for the target. Reset the short-circuit logic when sources are added and when the link libraries are re-computed. --- Source/cmTarget.cxx | 36 ++++++++++++++++++++++++++++++------ Source/cmTarget.h | 2 ++ 2 files changed, 32 insertions(+), 6 deletions(-) diff --git a/Source/cmTarget.cxx b/Source/cmTarget.cxx index d28ac3f..4903f8b 100644 --- a/Source/cmTarget.cxx +++ b/Source/cmTarget.cxx @@ -229,6 +229,7 @@ cmTarget::cmTarget() this->DebugCompileOptionsDone = false; this->DebugCompileDefinitionsDone = false; this->DebugSourcesDone = false; + this->LinkImplementationLanguageIsContextDependent = true; } //---------------------------------------------------------------------------- @@ -461,6 +462,7 @@ void cmTarget::FinishConfigure() //---------------------------------------------------------------------------- void cmTarget::ClearLinkMaps() { + this->LinkImplementationLanguageIsContextDependent = true; this->Internal->LinkImplMap.clear(); this->Internal->LinkInterfaceMap.clear(); this->Internal->LinkClosureMap.clear(); @@ -552,7 +554,7 @@ bool cmTarget::IsBundleOnApple() const } //---------------------------------------------------------------------------- -static void processSources(cmTarget const* tgt, +static bool processSources(cmTarget const* tgt, const std::vector &entries, std::vector &srcs, std::set &uniqueSrcs, @@ -562,6 +564,8 @@ static void processSources(cmTarget const* tgt, { cmMakefile *mf = tgt->GetMakefile(); + bool contextDependent = false; + for (std::vector::const_iterator it = entries.begin(), end = entries.end(); it != end; ++it) { @@ -576,8 +580,12 @@ static void processSources(cmTarget const* tgt, tgt, dagChecker), entrySources); - if (mf->IsGeneratingBuildSystem() - && !(*it)->ge->GetHadContextSensitiveCondition()) + + if ((*it)->ge->GetHadContextSensitiveCondition()) + { + contextDependent = true; + } + else if (mf->IsGeneratingBuildSystem()) { cacheSources = true; } @@ -598,7 +606,7 @@ static void processSources(cmTarget const* tgt, cm->IssueMessage(cmake::FATAL_ERROR, e, tgt->GetBacktrace()); } - return; + return contextDependent; } } if (cacheSources) @@ -629,6 +637,7 @@ static void processSources(cmTarget const* tgt, + usedSources, (*it)->ge->GetBacktrace()); } } + return contextDependent; } //---------------------------------------------------------------------------- @@ -664,7 +673,7 @@ void cmTarget::GetSourceFiles(std::vector &files, "SOURCES", 0, 0); std::set uniqueSrcs; - processSources(this, + bool contextDependentDirectSources = processSources(this, this->Internal->SourceEntries, files, uniqueSrcs, @@ -716,7 +725,8 @@ void cmTarget::GetSourceFiles(std::vector &files, } } - processSources(this, + std::vector::size_type numFilesBefore = files.size(); + bool contextDependentInterfaceSources = processSources(this, this->Internal->CachedLinkInterfaceSourcesEntries[config], files, uniqueSrcs, @@ -725,6 +735,12 @@ void cmTarget::GetSourceFiles(std::vector &files, config, debugSources); + if (!contextDependentDirectSources + && !(contextDependentInterfaceSources && numFilesBefore < files.size())) + { + this->LinkImplementationLanguageIsContextDependent = false; + } + if (!this->Makefile->IsGeneratingBuildSystem()) { deleteAndClear(this->Internal->CachedLinkInterfaceSourcesEntries); @@ -801,6 +817,12 @@ void cmTarget::GetSourceFiles(std::vector &files, // Lookup any existing link implementation for this configuration. TargetConfigPair key(head, cmSystemTools::UpperCase(config)); + if(!this->LinkImplementationLanguageIsContextDependent) + { + files = this->Internal->SourceFilesMap.begin()->second; + return; + } + cmTargetInternals::SourceFilesMapType::iterator it = this->Internal->SourceFilesMap.find(key); if(it != this->Internal->SourceFilesMap.end()) @@ -854,6 +876,7 @@ void cmTarget::AddSources(std::vector const& srcs) if (!srcFiles.empty()) { this->Internal->SourceFilesMap.clear(); + this->LinkImplementationLanguageIsContextDependent = true; cmListFileBacktrace lfbt; this->Makefile->GetBacktrace(lfbt); cmGeneratorExpression ge(lfbt); @@ -989,6 +1012,7 @@ cmSourceFile* cmTarget::AddSource(const std::string& src) == this->Internal->SourceEntries.end()) { this->Internal->SourceFilesMap.clear(); + this->LinkImplementationLanguageIsContextDependent = true; cmListFileBacktrace lfbt; this->Makefile->GetBacktrace(lfbt); cmGeneratorExpression ge(lfbt); diff --git a/Source/cmTarget.h b/Source/cmTarget.h index da9d0a1..868e260 100644 --- a/Source/cmTarget.h +++ b/Source/cmTarget.h @@ -784,6 +784,8 @@ private: std::string const& suffix, std::string const& name, const char* version) const; + + mutable bool LinkImplementationLanguageIsContextDependent; }; typedef std::map cmTargets; -- cgit v0.12