r237782 - Allow skipping imports in the module visitor.
Manuel Klimek
klimek at google.com
Wed May 20 03:29:24 PDT 2015
Author: klimek
Date: Wed May 20 05:29:23 2015
New Revision: 237782
URL: http://llvm.org/viewvc/llvm-project?rev=237782&view=rev
Log:
Allow skipping imports in the module visitor.
Skip imports when we know that we do not need to visit any imports
because we've already deserialized the redecls from a module.
Modified:
cfe/trunk/include/clang/Serialization/ModuleManager.h
cfe/trunk/lib/Serialization/ASTReader.cpp
cfe/trunk/lib/Serialization/ASTReaderDecl.cpp
cfe/trunk/lib/Serialization/ModuleManager.cpp
Modified: cfe/trunk/include/clang/Serialization/ModuleManager.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Serialization/ModuleManager.h?rev=237782&r1=237781&r2=237782&view=diff
==============================================================================
--- cfe/trunk/include/clang/Serialization/ModuleManager.h (original)
+++ cfe/trunk/include/clang/Serialization/ModuleManager.h Wed May 20 05:29:23 2015
@@ -32,6 +32,10 @@ class ModuleManager {
/// \brief The chain of AST files. The first entry is the one named by the
/// user, the last one is the one that doesn't depend on anything further.
SmallVector<ModuleFile *, 2> Chain;
+
+ // \brief The roots of the dependency DAG of AST files. This is used
+ // to implement short-circuiting logic when running DFS over the dependencies.
+ SmallVector<ModuleFile *, 2> Roots;
/// \brief All loaded modules, indexed by name.
llvm::DenseMap<const FileEntry *, ModuleFile *> Modules;
@@ -264,25 +268,35 @@ public:
/// manager that is *not* in this set can be skipped.
void visit(bool (*Visitor)(ModuleFile &M, void *UserData), void *UserData,
llvm::SmallPtrSetImpl<ModuleFile *> *ModuleFilesHit = nullptr);
-
+
+ /// \brief Control DFS behavior during preorder visitation.
+ enum DFSPreorderControl {
+ Continue, /// Continue visiting all nodes.
+ Abort, /// Stop the visitation immediately.
+ SkipImports, /// Do not visit imports of the current node.
+ };
+
/// \brief Visit each of the modules with a depth-first traversal.
///
/// This routine visits each of the modules known to the module
/// manager using a depth-first search, starting with the first
- /// loaded module. The traversal invokes the callback both before
- /// traversing the children (preorder traversal) and after
- /// traversing the children (postorder traversal).
- ///
- /// \param Visitor A visitor function that will be invoked with each
- /// module and given a \c Preorder flag that indicates whether we're
- /// visiting the module before or after visiting its children. The
- /// visitor may return true at any time to abort the depth-first
- /// visitation.
+ /// loaded module. The traversal invokes one callback before
+ /// traversing the imports (preorder traversal) and one after
+ /// traversing the imports (postorder traversal).
+ ///
+ /// \param PreorderVisitor A visitor function that will be invoked with each
+ /// module before visiting its imports. The visitor can control how to
+ /// continue the visitation through its return value.
+ ///
+ /// \param PostorderVisitor A visitor function taht will be invoked with each
+ /// module after visiting its imports. The visitor may return true at any time
+ /// to abort the depth-first visitation.
///
/// \param UserData User data ssociated with the visitor object,
/// which will be passed along to the user.
- void visitDepthFirst(bool (*Visitor)(ModuleFile &M, bool Preorder,
- void *UserData),
+ void visitDepthFirst(DFSPreorderControl (*PreorderVisitor)(ModuleFile &M,
+ void *UserData),
+ bool (*PostorderVisitor)(ModuleFile &M, void *UserData),
void *UserData);
/// \brief Attempt to resolve the given module file name to a file entry.
Modified: cfe/trunk/lib/Serialization/ASTReader.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTReader.cpp?rev=237782&r1=237781&r2=237782&view=diff
==============================================================================
--- cfe/trunk/lib/Serialization/ASTReader.cpp (original)
+++ cfe/trunk/lib/Serialization/ASTReader.cpp Wed May 20 05:29:23 2015
@@ -6157,10 +6157,7 @@ namespace {
PredefsVisited[I] = false;
}
- static bool visit(ModuleFile &M, bool Preorder, void *UserData) {
- if (Preorder)
- return false;
-
+ static bool visitPostorder(ModuleFile &M, void *UserData) {
FindExternalLexicalDeclsVisitor *This
= static_cast<FindExternalLexicalDeclsVisitor *>(UserData);
@@ -6202,7 +6199,8 @@ ExternalLoadResult ASTReader::FindExtern
// There might be lexical decls in multiple modules, for the TU at
// least. Walk all of the modules in the order they were loaded.
FindExternalLexicalDeclsVisitor Visitor(*this, DC, isKindWeWant, Decls);
- ModuleMgr.visitDepthFirst(&FindExternalLexicalDeclsVisitor::visit, &Visitor);
+ ModuleMgr.visitDepthFirst(
+ nullptr, &FindExternalLexicalDeclsVisitor::visitPostorder, &Visitor);
++NumLexicalDeclContextsRead;
return ELR_Success;
}
Modified: cfe/trunk/lib/Serialization/ASTReaderDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTReaderDecl.cpp?rev=237782&r1=237781&r2=237782&view=diff
==============================================================================
--- cfe/trunk/lib/Serialization/ASTReaderDecl.cpp (original)
+++ cfe/trunk/lib/Serialization/ASTReaderDecl.cpp Wed May 20 05:29:23 2015
@@ -3311,11 +3311,13 @@ namespace {
addToChain(Reader.GetDecl(CanonID));
}
- static bool visit(ModuleFile &M, bool Preorder, void *UserData) {
- if (Preorder)
- return false;
+ static ModuleManager::DFSPreorderControl
+ visitPreorder(ModuleFile &M, void *UserData) {
+ return static_cast<RedeclChainVisitor *>(UserData)->visitPreorder(M);
+ }
- return static_cast<RedeclChainVisitor *>(UserData)->visit(M);
+ static bool visitPostorder(ModuleFile &M, void *UserData) {
+ return static_cast<RedeclChainVisitor *>(UserData)->visitPostorder(M);
}
void addToChain(Decl *D) {
@@ -3368,8 +3370,36 @@ namespace {
for (unsigned I = 0; I != N; ++I)
addToChain(Reader.GetLocalDecl(M, M.RedeclarationChains[Offset++]));
}
-
- bool visit(ModuleFile &M) {
+
+ bool needsToVisitImports(ModuleFile &M, GlobalDeclID GlobalID) {
+ DeclID ID = Reader.mapGlobalIDToModuleFileGlobalID(M, GlobalID);
+ if (!ID)
+ return false;
+
+ const LocalRedeclarationsInfo Compare = {ID, 0};
+ const LocalRedeclarationsInfo *Result = std::lower_bound(
+ M.RedeclarationsMap,
+ M.RedeclarationsMap + M.LocalNumRedeclarationsInMap, Compare);
+ if (Result == M.RedeclarationsMap + M.LocalNumRedeclarationsInMap ||
+ Result->FirstID != ID) {
+ return true;
+ }
+ unsigned Offset = Result->Offset;
+ unsigned N = M.RedeclarationChains[Offset];
+ // We don't need to visit a module or any of its imports if we've already
+ // deserialized the redecls from this module.
+ return N != 0;
+ }
+
+ ModuleManager::DFSPreorderControl visitPreorder(ModuleFile &M) {
+ for (unsigned I = 0, N = SearchDecls.size(); I != N; ++I) {
+ if (needsToVisitImports(M, SearchDecls[I]))
+ return ModuleManager::Continue;
+ }
+ return ModuleManager::SkipImports;
+ }
+
+ bool visitPostorder(ModuleFile &M) {
// Visit each of the declarations.
for (unsigned I = 0, N = SearchDecls.size(); I != N; ++I)
searchForID(M, SearchDecls[I]);
@@ -3401,11 +3431,12 @@ void ASTReader::loadPendingDeclChain(Dec
// Build up the list of redeclarations.
RedeclChainVisitor Visitor(*this, SearchDecls, RedeclsDeserialized, CanonID);
- ModuleMgr.visitDepthFirst(&RedeclChainVisitor::visit, &Visitor);
+ ModuleMgr.visitDepthFirst(&RedeclChainVisitor::visitPreorder,
+ &RedeclChainVisitor::visitPostorder, &Visitor);
// Retrieve the chains.
ArrayRef<Decl *> Chain = Visitor.getChain();
- if (Chain.empty())
+ if (Chain.empty() || (Chain.size() == 1 && Chain[0] == CanonDecl))
return;
// Hook up the chains.
Modified: cfe/trunk/lib/Serialization/ModuleManager.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ModuleManager.cpp?rev=237782&r1=237781&r2=237782&view=diff
==============================================================================
--- cfe/trunk/lib/Serialization/ModuleManager.cpp (original)
+++ cfe/trunk/lib/Serialization/ModuleManager.cpp Wed May 20 05:29:23 2015
@@ -94,6 +94,8 @@ ModuleManager::addModule(StringRef FileN
New->File = Entry;
New->ImportLoc = ImportLoc;
Chain.push_back(New);
+ if (!ImportedBy)
+ Roots.push_back(New);
NewModule = true;
ModuleEntry = New;
@@ -155,7 +157,12 @@ ModuleManager::addModule(StringRef FileN
// invalidate the file cache for Entry, and that is not safe if this
// module is *itself* up to date, but has an out-of-date importer.
Modules.erase(Entry);
+ assert(Chain.back() == ModuleEntry);
Chain.pop_back();
+ if (Roots.back() == ModuleEntry)
+ Roots.pop_back();
+ else
+ assert(ImportedBy);
delete ModuleEntry;
}
return OutOfDate;
@@ -186,12 +193,15 @@ void ModuleManager::removeModules(
// Collect the set of module file pointers that we'll be removing.
llvm::SmallPtrSet<ModuleFile *, 4> victimSet(first, last);
+ auto IsVictim = [&](ModuleFile *MF) {
+ return victimSet.count(MF);
+ };
// Remove any references to the now-destroyed modules.
for (unsigned i = 0, n = Chain.size(); i != n; ++i) {
- Chain[i]->ImportedBy.remove_if([&](ModuleFile *MF) {
- return victimSet.count(MF);
- });
+ Chain[i]->ImportedBy.remove_if(IsVictim);
}
+ Roots.erase(std::remove_if(Roots.begin(), Roots.end(), IsVictim),
+ Roots.end());
// Delete the modules and erase them from the various structures.
for (ModuleIterator victim = first; victim != last; ++victim) {
@@ -398,16 +408,38 @@ ModuleManager::visit(bool (*Visitor)(Mod
returnVisitState(State);
}
+static void markVisitedDepthFirst(ModuleFile &M,
+ SmallVectorImpl<bool> &Visited) {
+ for (llvm::SetVector<ModuleFile *>::iterator IM = M.Imports.begin(),
+ IMEnd = M.Imports.end();
+ IM != IMEnd; ++IM) {
+ if (Visited[(*IM)->Index])
+ continue;
+ Visited[(*IM)->Index] = true;
+ if (!M.DirectlyImported)
+ markVisitedDepthFirst(**IM, Visited);
+ }
+}
+
/// \brief Perform a depth-first visit of the current module.
-static bool visitDepthFirst(ModuleFile &M,
- bool (*Visitor)(ModuleFile &M, bool Preorder,
- void *UserData),
- void *UserData,
- SmallVectorImpl<bool> &Visited) {
- // Preorder visitation
- if (Visitor(M, /*Preorder=*/true, UserData))
- return true;
-
+static bool visitDepthFirst(
+ ModuleFile &M,
+ ModuleManager::DFSPreorderControl (*PreorderVisitor)(ModuleFile &M,
+ void *UserData),
+ bool (*PostorderVisitor)(ModuleFile &M, void *UserData), void *UserData,
+ SmallVectorImpl<bool> &Visited) {
+ if (PreorderVisitor) {
+ switch (PreorderVisitor(M, UserData)) {
+ case ModuleManager::Abort:
+ return true;
+ case ModuleManager::SkipImports:
+ markVisitedDepthFirst(M, Visited);
+ return false;
+ case ModuleManager::Continue:
+ break;
+ }
+ }
+
// Visit children
for (llvm::SetVector<ModuleFile *>::iterator IM = M.Imports.begin(),
IMEnd = M.Imports.end();
@@ -416,24 +448,27 @@ static bool visitDepthFirst(ModuleFile &
continue;
Visited[(*IM)->Index] = true;
- if (visitDepthFirst(**IM, Visitor, UserData, Visited))
+ if (visitDepthFirst(**IM, PreorderVisitor, PostorderVisitor, UserData, Visited))
return true;
}
- // Postorder visitation
- return Visitor(M, /*Preorder=*/false, UserData);
+ if (PostorderVisitor)
+ return PostorderVisitor(M, UserData);
+
+ return false;
}
-void ModuleManager::visitDepthFirst(bool (*Visitor)(ModuleFile &M, bool Preorder,
- void *UserData),
- void *UserData) {
+void ModuleManager::visitDepthFirst(
+ ModuleManager::DFSPreorderControl (*PreorderVisitor)(ModuleFile &M,
+ void *UserData),
+ bool (*PostorderVisitor)(ModuleFile &M, void *UserData), void *UserData) {
SmallVector<bool, 16> Visited(size(), false);
- for (unsigned I = 0, N = Chain.size(); I != N; ++I) {
- if (Visited[Chain[I]->Index])
+ for (unsigned I = 0, N = Roots.size(); I != N; ++I) {
+ if (Visited[Roots[I]->Index])
continue;
- Visited[Chain[I]->Index] = true;
+ Visited[Roots[I]->Index] = true;
- if (::visitDepthFirst(*Chain[I], Visitor, UserData, Visited))
+ if (::visitDepthFirst(*Roots[I], PreorderVisitor, PostorderVisitor, UserData, Visited))
return;
}
}
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