From b94ad1e1d383630f45c3e3d67d8a61a01d8045ed Mon Sep 17 00:00:00 2001 From: Bruno Ricci Date: Thu, 15 Nov 2018 17:31:16 +0000 Subject: [AST] Store the string data in StringLiteral in a trailing array of chars Use the newly available space in the bit-fields of Stmt and store the string data in a trailing array of chars after the trailing array of SourceLocation. This cuts the size of StringLiteral by 2 pointers. Also refactor slightly StringLiteral::Create and StringLiteral::CreateEmpty so that StringLiteral::Create is just responsible for the allocation, and the constructor is responsible for doing all the initialization. This match what is done for the other classes in general. This patch should have no other functional changes apart from this. A concern was raised during review about the interaction between this patch and serialization abbreviations. I believe however that there is currently no abbreviation defined for StringLiteral. The only statements/expressions which have abbreviations are currently DeclRefExpr, IntegerLiteral, CharacterLiteral and ImplicitCastExpr. Differential Revision: https://reviews.llvm.org/D54166 Reviewed By: dblaikie, rjmccall llvm-svn: 346969 --- clang/lib/Serialization/ASTReaderStmt.cpp | 48 ++++++++++++++++++++----------- clang/lib/Serialization/ASTWriterStmt.cpp | 18 ++++++++---- 2 files changed, 44 insertions(+), 22 deletions(-) (limited to 'clang/lib/Serialization') diff --git a/clang/lib/Serialization/ASTReaderStmt.cpp b/clang/lib/Serialization/ASTReaderStmt.cpp index ef370260c54..15e89db2092 100644 --- a/clang/lib/Serialization/ASTReaderStmt.cpp +++ b/clang/lib/Serialization/ASTReaderStmt.cpp @@ -595,22 +595,35 @@ void ASTStmtReader::VisitImaginaryLiteral(ImaginaryLiteral *E) { void ASTStmtReader::VisitStringLiteral(StringLiteral *E) { VisitExpr(E); - unsigned Len = Record.readInt(); - assert(Record.peekInt() == E->getNumConcatenated() && - "Wrong number of concatenated tokens!"); - Record.skipInts(1); - auto kind = static_cast(Record.readInt()); - bool isPascal = Record.readInt(); - // Read string data - auto B = &Record.peekInt(); - SmallString<16> Str(B, B + Len); - E->setString(Record.getContext(), Str, kind, isPascal); - Record.skipInts(Len); - - // Read source locations - for (unsigned I = 0, N = E->getNumConcatenated(); I != N; ++I) + // NumConcatenated, Length and CharByteWidth are set by the empty + // ctor since they are needed to allocate storage for the trailing objects. + unsigned NumConcatenated = Record.readInt(); + unsigned Length = Record.readInt(); + unsigned CharByteWidth = Record.readInt(); + assert((NumConcatenated == E->getNumConcatenated()) && + "Wrong number of concatenated tokens!"); + assert((Length == E->getLength()) && "Wrong Length!"); + assert((CharByteWidth == E->getCharByteWidth()) && "Wrong character width!"); + E->StringLiteralBits.Kind = Record.readInt(); + E->StringLiteralBits.IsPascal = Record.readInt(); + + // The character width is originally computed via mapCharByteWidth. + // Check that the deserialized character width is consistant with the result + // of calling mapCharByteWidth. + assert((CharByteWidth == + StringLiteral::mapCharByteWidth(Record.getContext().getTargetInfo(), + E->getKind())) && + "Wrong character width!"); + + // Deserialize the trailing array of SourceLocation. + for (unsigned I = 0; I < NumConcatenated; ++I) E->setStrTokenLoc(I, ReadSourceLocation()); + + // Deserialize the trailing array of char holding the string data. + char *StrData = E->getStrDataAsChar(); + for (unsigned I = 0; I < Length * CharByteWidth; ++I) + StrData[I] = Record.readInt(); } void ASTStmtReader::VisitCharacterLiteral(CharacterLiteral *E) { @@ -2423,8 +2436,11 @@ Stmt *ASTReader::ReadStmtFromStream(ModuleFile &F) { break; case EXPR_STRING_LITERAL: - S = StringLiteral::CreateEmpty(Context, - Record[ASTStmtReader::NumExprFields + 1]); + S = StringLiteral::CreateEmpty( + Context, + /* NumConcatenated=*/Record[ASTStmtReader::NumExprFields + 0], + /* Length=*/Record[ASTStmtReader::NumExprFields + 1], + /* CharByteWidth=*/Record[ASTStmtReader::NumExprFields + 2]); break; case EXPR_CHARACTER_LITERAL: diff --git a/clang/lib/Serialization/ASTWriterStmt.cpp b/clang/lib/Serialization/ASTWriterStmt.cpp index f32705c2efc..9f861bef89d 100644 --- a/clang/lib/Serialization/ASTWriterStmt.cpp +++ b/clang/lib/Serialization/ASTWriterStmt.cpp @@ -518,17 +518,23 @@ void ASTStmtWriter::VisitImaginaryLiteral(ImaginaryLiteral *E) { void ASTStmtWriter::VisitStringLiteral(StringLiteral *E) { VisitExpr(E); - Record.push_back(E->getByteLength()); + + // Store the various bits of data of StringLiteral. Record.push_back(E->getNumConcatenated()); + Record.push_back(E->getLength()); + Record.push_back(E->getCharByteWidth()); Record.push_back(E->getKind()); Record.push_back(E->isPascal()); - // FIXME: String data should be stored as a blob at the end of the - // StringLiteral. However, we can't do so now because we have no - // provision for coping with abbreviations when we're jumping around - // the AST file during deserialization. - Record.append(E->getBytes().begin(), E->getBytes().end()); + + // Store the trailing array of SourceLocation. for (unsigned I = 0, N = E->getNumConcatenated(); I != N; ++I) Record.AddSourceLocation(E->getStrTokenLoc(I)); + + // Store the trailing array of char holding the string data. + StringRef StrData = E->getBytes(); + for (unsigned I = 0, N = E->getByteLength(); I != N; ++I) + Record.push_back(StrData[I]); + Code = serialization::EXPR_STRING_LITERAL; } -- cgit v1.2.3