https://github.com/mpark updated
https://github.com/llvm/llvm-project/pull/140867
>From 1013ab2297935cc3a7eccf8a812984d9b454a27f Mon Sep 17 00:00:00 2001
From: Michael Park <mcyp...@gmail.com>
Date: Tue, 20 May 2025 17:18:36 -0700
Subject: [PATCH] Lazily, but fully load 'HeaderFileInfo' table into memory.
---
clang/include/clang/Serialization/ASTReader.h | 4 +
clang/lib/Serialization/ASTReader.cpp | 80 ++++++++++++-------
clang/lib/Serialization/ASTReaderInternals.h | 3 +-
3 files changed, 54 insertions(+), 33 deletions(-)
diff --git a/clang/include/clang/Serialization/ASTReader.h
b/clang/include/clang/Serialization/ASTReader.h
index 57b0266af26bb..9b63ad1a7cde7 100644
--- a/clang/include/clang/Serialization/ASTReader.h
+++ b/clang/include/clang/Serialization/ASTReader.h
@@ -654,6 +654,10 @@ class ASTReader
/// Map from the TU to its lexical contents from each module file.
std::vector<std::pair<ModuleFile*, LexicalContents>> TULexicalDecls;
+ unsigned HeaderFileInfoIdx = 0;
+
+ llvm::DenseMap<FileEntryRef, HeaderFileInfo> HeaderFileInfoLookup;
+
/// Map from a DeclContext to its lookup tables.
llvm::DenseMap<const DeclContext *,
serialization::reader::DeclContextLookupTable> Lookups;
diff --git a/clang/lib/Serialization/ASTReader.cpp
b/clang/lib/Serialization/ASTReader.cpp
index d068f5e163176..93766be18f775 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -4155,6 +4155,7 @@ llvm::Error ASTReader::ReadASTBlock(ModuleFile &F,
if (Record[0]) {
F.HeaderFileInfoTable = HeaderFileInfoLookupTable::Create(
(const unsigned char *)F.HeaderFileInfoTableData + Record[0],
+ (const unsigned char *)F.HeaderFileInfoTableData +
sizeof(uint32_t),
(const unsigned char *)F.HeaderFileInfoTableData,
HeaderFileInfoTrait(*this, F));
@@ -6831,43 +6832,60 @@ std::optional<bool>
ASTReader::isPreprocessedEntityInFileID(unsigned Index,
return false;
}
-namespace {
-
- /// Visitor used to search for information about a header file.
- class HeaderFileInfoVisitor {
- FileEntryRef FE;
- std::optional<HeaderFileInfo> HFI;
-
- public:
- explicit HeaderFileInfoVisitor(FileEntryRef FE) : FE(FE) {}
-
- bool operator()(ModuleFile &M) {
- HeaderFileInfoLookupTable *Table
- = static_cast<HeaderFileInfoLookupTable *>(M.HeaderFileInfoTable);
- if (!Table)
- return false;
+static void mergeHeaderFileInfoModuleBits(HeaderFileInfo &HFI,
+ bool isModuleHeader,
+ bool isTextualModuleHeader) {
+ HFI.isModuleHeader |= isModuleHeader;
+ if (HFI.isModuleHeader)
+ HFI.isTextualModuleHeader = false;
+ else
+ HFI.isTextualModuleHeader |= isTextualModuleHeader;
+}
- // Look in the on-disk hash table for an entry for this file name.
- HeaderFileInfoLookupTable::iterator Pos = Table->find(FE);
- if (Pos == Table->end())
- return false;
+/// Merge the header file info provided by \p OtherHFI into the current
+/// header file info (\p HFI)
+static void mergeHeaderFileInfo(HeaderFileInfo &HFI,
+ const HeaderFileInfo &OtherHFI) {
+ assert(OtherHFI.External && "expected to merge external HFI");
- HFI = *Pos;
- return true;
- }
+ HFI.isImport |= OtherHFI.isImport;
+ HFI.isPragmaOnce |= OtherHFI.isPragmaOnce;
+ mergeHeaderFileInfoModuleBits(HFI, OtherHFI.isModuleHeader,
+ OtherHFI.isTextualModuleHeader);
- std::optional<HeaderFileInfo> getHeaderFileInfo() const { return HFI; }
- };
+ if (!HFI.LazyControllingMacro.isValid())
+ HFI.LazyControllingMacro = OtherHFI.LazyControllingMacro;
-} // namespace
+ HFI.DirInfo = OtherHFI.DirInfo;
+ HFI.External = (!HFI.IsValid || HFI.External);
+ HFI.IsValid = true;
+}
HeaderFileInfo ASTReader::GetHeaderFileInfo(FileEntryRef FE) {
- HeaderFileInfoVisitor Visitor(FE);
- ModuleMgr.visit(Visitor);
- if (std::optional<HeaderFileInfo> HFI = Visitor.getHeaderFileInfo())
- return *HFI;
-
- return HeaderFileInfo();
+ for (auto Iter = ModuleMgr.begin() + HeaderFileInfoIdx, End =
ModuleMgr.end();
+ Iter != End; ++Iter) {
+ if (auto *Table = static_cast<HeaderFileInfoLookupTable *>(
+ Iter->HeaderFileInfoTable)) {
+ auto &Info = Table->getInfoObj();
+ for (auto Iter = Table->data_begin(), End = Table->data_end();
+ Iter != End; ++Iter) {
+ const auto *Item = Iter.getItem();
+ // Determine the length of the key and the data.
+ const auto& [KeyLen, DataLen] =
+ HeaderFileInfoTrait::ReadKeyDataLength(Item);
+ // Read the key.
+ const auto &Key = Info.ReadKey(Item, KeyLen);
+ if (auto EKey = Info.getFile(Key)) {
+ auto Data = Info.ReadData(Key, Item + KeyLen, DataLen);
+ auto [Iter, Inserted] = HeaderFileInfoLookup.try_emplace(*EKey,
Data);
+ if (!Inserted)
+ mergeHeaderFileInfo(Iter->second, Data);
+ }
+ }
+ }
+ }
+ HeaderFileInfoIdx = ModuleMgr.size();
+ return HeaderFileInfoLookup.lookup(FE);
}
void ASTReader::ReadPragmaDiagnosticMappings(DiagnosticsEngine &Diag) {
diff --git a/clang/lib/Serialization/ASTReaderInternals.h
b/clang/lib/Serialization/ASTReaderInternals.h
index 4a7794889b039..d78d9fee6042d 100644
--- a/clang/lib/Serialization/ASTReaderInternals.h
+++ b/clang/lib/Serialization/ASTReaderInternals.h
@@ -402,13 +402,12 @@ class HeaderFileInfoTrait {
data_type ReadData(internal_key_ref,const unsigned char *d, unsigned
DataLen);
-private:
OptionalFileEntryRef getFile(const internal_key_type &Key);
};
/// The on-disk hash table used for known header files.
using HeaderFileInfoLookupTable =
- llvm::OnDiskChainedHashTable<HeaderFileInfoTrait>;
+ llvm::OnDiskIterableChainedHashTable<HeaderFileInfoTrait>;
} // namespace reader
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