r233172 - Revert "[Modules] When writing out the on-disk hash table for the decl context lookup tables, we need to establish a stable ordering for constructing the hash table. This is trickier than it might seem."

Justin Bogner mail at justinbogner.com
Tue Mar 24 23:35:46 PDT 2015


Rafael Espindola <rafael.espindola at gmail.com> writes:
> Author: rafael
> Date: Tue Mar 24 23:43:15 2015
> New Revision: 233172
>
> URL: http://llvm.org/viewvc/llvm-project?rev=233172&view=rev
> Log:
> Revert "[Modules] When writing out the on-disk hash table for the decl
> context lookup tables, we need to establish a stable ordering for
> constructing the hash table. This is trickier than it might seem."
>
> This reverts commit r233156. It broke the bots.

Which bots did it break? Lots of bots (and my local check-clang) went
red from the revert, because the tests in r233162 depend on it. I can't
actually find any bots that look like r233156 broke (at least that were
still broken after r233162+r233163), but I'm probably not looking in the
right place.

> Modified:
>     cfe/trunk/lib/Serialization/ASTWriter.cpp
>
> Modified: cfe/trunk/lib/Serialization/ASTWriter.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTWriter.cpp?rev=233172&r1=233171&r2=233172&view=diff
> ==============================================================================
> --- cfe/trunk/lib/Serialization/ASTWriter.cpp (original)
> +++ cfe/trunk/lib/Serialization/ASTWriter.cpp Tue Mar 24 23:43:15 2015
> @@ -3761,34 +3761,15 @@ ASTWriter::GenerateNameLookupTable(const
>           !DC->HasLazyExternalLexicalLookups &&
>           "must call buildLookups first");
>  
> -  // Create the on-disk hash table representation.
>    llvm::OnDiskChainedHashTableGenerator<ASTDeclContextNameLookupTrait>
>        Generator;
>    ASTDeclContextNameLookupTrait Trait(*this);
>  
> -  // Store the sortable lookup results -- IE, those with meaningful names. We
> -  // will sort them by the DeclarationName in order to stabilize the ordering
> -  // of the hash table. We can't do this for constructors or conversion
> -  // functions which are handled separately.
> -  SmallVector<std::pair<DeclarationName, DeclContext::lookup_result>, 16>
> -      NamedResults;
> -
> -  // We can't directly construct a nonce constructor or conversion name without
> -  // tripping asserts, so we just recall the first one we see. Only the kind
> -  // will actually be serialized.
> +  // Create the on-disk hash table representation.
>    DeclarationName ConstructorName;
>    DeclarationName ConversionName;
> -  // Retain a mapping from each actual declaration name to the results
> -  // associated with it. We use a map here because the order in which we
> -  // discover these lookup results isn't ordered. We have to re-establish
> -  // a stable ordering which we do by walking the children of the decl context,
> -  // and emitting these in the order in which their names first appeared. Note
> -  // that the names' first appearance may not be one of the results or a result
> -  // at all. We just use this to establish an ordering.
> -  llvm::SmallDenseMap<DeclarationName, DeclContext::lookup_result, 8>
> -      ConstructorResults;
> -  llvm::SmallDenseMap<DeclarationName, DeclContext::lookup_result, 4>
> -      ConversionResults;
> +  SmallVector<NamedDecl *, 8> ConstructorDecls;
> +  SmallVector<NamedDecl *, 4> ConversionDecls;
>  
>    visitLocalLookupResults(DC, [&](DeclarationName Name,
>                                    DeclContext::lookup_result Result) {
> @@ -3805,90 +3786,34 @@ ASTWriter::GenerateNameLookupTable(const
>        // has the DeclarationName of the inherited constructors.
>        if (!ConstructorName)
>          ConstructorName = Name;
> -      ConstructorResults.insert(std::make_pair(Name, Result));
> +      ConstructorDecls.append(Result.begin(), Result.end());
>        return;
>  
>      case DeclarationName::CXXConversionFunctionName:
>        if (!ConversionName)
>          ConversionName = Name;
> -      ConversionResults.insert(std::make_pair(Name, Result));
> +      ConversionDecls.append(Result.begin(), Result.end());
>        return;
>  
>      default:
> -      NamedResults.push_back(std::make_pair(Name, Result));
> +      break;
>      }
>  
> +    Generator.insert(Name, Result, Trait);
>    });
>  
> -  // Sort and emit the named results first. This is the easy case.
> -  std::sort(
> -      NamedResults.begin(), NamedResults.end(),
> -      [](const std::pair<DeclarationName, DeclContext::lookup_result> &LHS,
> -         const std::pair<DeclarationName, DeclContext::lookup_result> &RHS) {
> -        return LHS.first < RHS.first;
> -      });
> -  for (auto Results : NamedResults)
> -    Generator.insert(Results.first, Results.second, Trait);
> -
> -  // We have to specially handle the constructor and conversion function
> -  // declarations found.
> -  if (ConstructorResults.size() == 1) {
> -    // A special case that is easy is when we have just one constructor
> -    // declaration name.
> +  // Add the constructors.
> +  if (!ConstructorDecls.empty()) {
>      Generator.insert(ConstructorName,
> -                     ConstructorResults.lookup(ConstructorName), Trait);
> -    ConstructorResults.clear();
> -  }
> -  if (ConversionResults.size() == 1) {
> -    // A special case that is easy is when we have just one conversion function
> -    // declaration name.
> -    Generator.insert(ConversionName, ConversionResults.lookup(ConversionName),
> +                     DeclContext::lookup_result(ConstructorDecls),
>                       Trait);
> -    ConversionResults.clear();
>    }
> -  if (!ConstructorResults.empty() || !ConversionResults.empty()) {
> -    SmallVector<NamedDecl *, 8> ConstructorDecls;
> -    SmallVector<NamedDecl *, 8> ConversionDecls;
> -
> -    // Walk the decls in the context and collapse the results in that order. We
> -    // handle both constructors and conversion functions in a single walk as
> -    // the walk is a relative cache-hostile linked list walk.
> -    for (Decl *ChildD : DC->decls())
> -      if (auto *ChildND = dyn_cast<NamedDecl>(ChildD)) {
> -        auto ConstructorResultsIt =
> -            ConstructorResults.find(ChildND->getDeclName());
> -        if (ConstructorResultsIt != ConstructorResults.end()) {
> -          ConstructorDecls.append(ConstructorResultsIt->second.begin(),
> -                                  ConstructorResultsIt->second.end());
> -          ConstructorResults.erase(ConstructorResultsIt);
> -        }
> -
> -        auto ConversionResultsIt =
> -            ConversionResults.find(ChildND->getDeclName());
> -        if (ConversionResultsIt != ConversionResults.end()) {
> -          ConversionDecls.append(ConversionResultsIt->second.begin(),
> -                                 ConversionResultsIt->second.end());
> -          ConversionResults.erase(ConversionResultsIt);
> -        }
> -
> -        // If we handle all of the results, we're done.
> -        if (ConstructorResults.empty() && ConversionResults.empty())
> -          break;
> -      }
> -    assert(ConstructorResults.empty() && "Have constructor lookup results not "
> -                                         "associated with a declaration name "
> -                                         "within the context!");
> -    assert(ConversionResults.empty() && "Have conversion function lookup "
> -                                        "results not associated with a "
> -                                        "declaration name within the context!");
> -
> -    if (!ConstructorDecls.empty())
> -      Generator.insert(ConstructorName,
> -                       DeclContext::lookup_result(ConstructorDecls), Trait);
> -
> -    if (!ConversionDecls.empty())
> -      Generator.insert(ConversionName,
> -                       DeclContext::lookup_result(ConversionDecls), Trait);
> +
> +  // Add the conversion functions.
> +  if (!ConversionDecls.empty()) {
> +    Generator.insert(ConversionName,
> +                     DeclContext::lookup_result(ConversionDecls),
> +                     Trait);
>    }
>  
>    // Create the on-disk hash table in a buffer.
>
>
> _______________________________________________
> cfe-commits mailing list
> cfe-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits



More information about the cfe-commits mailing list