From 7c2c4097a0f1b1db8f7167ea4880bada85082931 Mon Sep 17 00:00:00 2001 From: Peter Collingbourne Date: Tue, 2 May 2017 17:48:39 +0000 Subject: [PATCH] Bitcode: Simplify how we enumerate summaries in the index. NFCI. Instead of defining a custom iterator class, just use a function with a callback, which is much easier to understand and less error prone. Differential Revision: https://reviews.llvm.org/D32470 llvm-svn: 301942 --- llvm/lib/Bitcode/Writer/BitcodeWriter.cpp | 164 +++++------------------------- 1 file changed, 23 insertions(+), 141 deletions(-) diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp index 8aa7d0d..485d9b6 100644 --- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp +++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp @@ -340,146 +340,28 @@ public: // in writing out the call graph edges. Save the mapping from GUID // to the new global value id to use when writing those edges, which // are currently saved in the index in terms of GUID. - for (const auto &I : *this) + forEachSummary([&](GVInfo I) { GUIDToValueIdMap[I.first] = ++GlobalValueId; + }); } /// The below iterator returns the GUID and associated summary. typedef std::pair GVInfo; - /// Iterator over the value GUID and summaries to be written to bitcode, - /// hides the details of whether they are being pulled from the entire - /// index or just those in a provided ModuleToSummariesForIndex map. - class iterator - : public llvm::iterator_facade_base { - /// Enables access to parent class. - const IndexBitcodeWriter &Writer; - - // Iterators used when writing only those summaries in a provided - // ModuleToSummariesForIndex map: - - /// Points to the last element in outer ModuleToSummariesForIndex map. - std::map::const_iterator ModuleSummariesBack; - /// Iterator on outer ModuleToSummariesForIndex map. - std::map::const_iterator ModuleSummariesIter; - /// Iterator on an inner global variable summary map. - GVSummaryMapTy::const_iterator ModuleGVSummariesIter; - - // Iterators used when writing all summaries in the index: - - /// Points to the last element in the Index outer GlobalValueMap. - const_gvsummary_iterator IndexSummariesBack; - /// Iterator on outer GlobalValueMap. - const_gvsummary_iterator IndexSummariesIter; - /// Iterator on an inner GlobalValueSummaryList. - GlobalValueSummaryList::const_iterator IndexGVSummariesIter; - - public: - /// Construct iterator from parent \p Writer and indicate if we are - /// constructing the end iterator. - iterator(const IndexBitcodeWriter &Writer, bool IsAtEnd) : Writer(Writer) { - // Set up the appropriate set of iterators given whether we are writing - // the full index or just a subset. - // Can't setup the Back or inner iterators if the corresponding map - // is empty. This will be handled specially in operator== as well. - if (Writer.ModuleToSummariesForIndex && - !Writer.ModuleToSummariesForIndex->empty()) { - for (ModuleSummariesBack = Writer.ModuleToSummariesForIndex->begin(); - std::next(ModuleSummariesBack) != - Writer.ModuleToSummariesForIndex->end(); - ModuleSummariesBack++) - ; - ModuleSummariesIter = !IsAtEnd - ? Writer.ModuleToSummariesForIndex->begin() - : ModuleSummariesBack; - ModuleGVSummariesIter = !IsAtEnd ? ModuleSummariesIter->second.begin() - : ModuleSummariesBack->second.end(); - } else if (!Writer.ModuleToSummariesForIndex && - Writer.Index.begin() != Writer.Index.end()) { - for (IndexSummariesBack = Writer.Index.begin(); - std::next(IndexSummariesBack) != Writer.Index.end(); - IndexSummariesBack++) - ; - IndexSummariesIter = - !IsAtEnd ? Writer.Index.begin() : IndexSummariesBack; - IndexGVSummariesIter = !IsAtEnd ? IndexSummariesIter->second.begin() - : IndexSummariesBack->second.end(); - } - } - - /// Increment the appropriate set of iterators. - iterator &operator++() { - // First the inner iterator is incremented, then if it is at the end - // and there are more outer iterations to go, the inner is reset to - // the start of the next inner list. - if (Writer.ModuleToSummariesForIndex) { - ++ModuleGVSummariesIter; - if (ModuleGVSummariesIter == ModuleSummariesIter->second.end() && - ModuleSummariesIter != ModuleSummariesBack) { - ++ModuleSummariesIter; - ModuleGVSummariesIter = ModuleSummariesIter->second.begin(); - } - } else { - ++IndexGVSummariesIter; - if (IndexGVSummariesIter == IndexSummariesIter->second.end() && - IndexSummariesIter != IndexSummariesBack) { - ++IndexSummariesIter; - IndexGVSummariesIter = IndexSummariesIter->second.begin(); - } - } - return *this; - } - - /// Access the pair corresponding to the current - /// outer and inner iterator positions. - GVInfo operator*() { - if (Writer.ModuleToSummariesForIndex) - return std::make_pair(ModuleGVSummariesIter->first, - ModuleGVSummariesIter->second); - return std::make_pair(IndexSummariesIter->first, - IndexGVSummariesIter->get()); - } - - /// Checks if the iterators are equal, with special handling for empty - /// indexes. - bool operator==(const iterator &RHS) const { - if (Writer.ModuleToSummariesForIndex) { - // First ensure that both are writing the same subset. - if (Writer.ModuleToSummariesForIndex != - RHS.Writer.ModuleToSummariesForIndex) - return false; - // Already determined above that maps are the same, so if one is - // empty, they both are. - if (Writer.ModuleToSummariesForIndex->empty()) - return true; - // Ensure the ModuleGVSummariesIter are iterating over the same - // container before checking them below. - if (ModuleSummariesIter != RHS.ModuleSummariesIter) - return false; - return ModuleGVSummariesIter == RHS.ModuleGVSummariesIter; - } - // First ensure RHS also writing the full index, and that both are - // writing the same full index. - if (RHS.Writer.ModuleToSummariesForIndex || - &Writer.Index != &RHS.Writer.Index) - return false; - // Already determined above that maps are the same, so if one is - // empty, they both are. - if (Writer.Index.begin() == Writer.Index.end()) - return true; - // Ensure the IndexGVSummariesIter are iterating over the same - // container before checking them below. - if (IndexSummariesIter != RHS.IndexSummariesIter) - return false; - return IndexGVSummariesIter == RHS.IndexGVSummariesIter; + /// Calls the callback for each value GUID and summary to be written to + /// bitcode. This hides the details of whether they are being pulled from the + /// entire index or just those in a provided ModuleToSummariesForIndex map. + void forEachSummary(std::function Callback) { + if (ModuleToSummariesForIndex) { + for (auto &M : *ModuleToSummariesForIndex) + for (auto &Summary : M.second) + Callback(Summary); + } else { + for (auto &Summaries : Index) + for (auto &Summary : Summaries.second) + Callback({Summaries.first, Summary.get()}); } - }; - - /// Obtain the start iterator over the summaries to be written. - iterator begin() { return iterator(*this, /*IsAtEnd=*/false); } - /// Obtain the end iterator over the summaries to be written. - iterator end() { return iterator(*this, /*IsAtEnd=*/true); } + } /// Main entry point for writing a combined index to bitcode. void write(); @@ -3528,16 +3410,16 @@ void IndexBitcodeWriter::writeCombinedGlobalValueSummary() { Stream.EmitRecord(bitc::FS_VERSION, ArrayRef{INDEX_VERSION}); // Create value IDs for undefined references. - for (const auto &I : *this) { + forEachSummary([&](GVInfo I) { if (auto *VS = dyn_cast(I.second)) { for (auto &RI : VS->refs()) assignValueId(RI.getGUID()); - continue; + return; } auto *FS = dyn_cast(I.second); if (!FS) - continue; + return; for (auto &RI : FS->refs()) assignValueId(RI.getGUID()); @@ -3553,7 +3435,7 @@ void IndexBitcodeWriter::writeCombinedGlobalValueSummary() { } assignValueId(GUID); } - } + }); for (const auto &GVI : valueIds()) { Stream.EmitRecord(bitc::FS_VALUE_GUID, @@ -3624,7 +3506,7 @@ void IndexBitcodeWriter::writeCombinedGlobalValueSummary() { NameVals.clear(); }; - for (const auto &I : *this) { + forEachSummary([&](GVInfo I) { GlobalValueSummary *S = I.second; assert(S); @@ -3636,7 +3518,7 @@ void IndexBitcodeWriter::writeCombinedGlobalValueSummary() { // Will process aliases as a post-pass because the reader wants all // global to be loaded first. Aliases.push_back(AS); - continue; + return; } if (auto *VS = dyn_cast(S)) { @@ -3652,7 +3534,7 @@ void IndexBitcodeWriter::writeCombinedGlobalValueSummary() { FSModRefsAbbrev); NameVals.clear(); MaybeEmitOriginalName(*S); - continue; + return; } auto *FS = cast(S); @@ -3700,7 +3582,7 @@ void IndexBitcodeWriter::writeCombinedGlobalValueSummary() { Stream.EmitRecord(Code, NameVals, FSAbbrev); NameVals.clear(); MaybeEmitOriginalName(*S); - } + }); for (auto *AS : Aliases) { auto AliasValueId = SummaryToValueIdMap[AS]; -- 2.7.4