clang-1/Driver/ASTConsumers.cpp

700 строки
22 KiB
C++

//===--- ASTConsumers.cpp - ASTConsumer implementations -------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// AST Consumer Implementations.
//
//===----------------------------------------------------------------------===//
#include "ASTConsumers.h"
#include "clang/Driver/PathDiagnosticClients.h"
#include "clang/AST/TranslationUnit.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/FileManager.h"
#include "clang/AST/AST.h"
#include "clang/AST/ASTConsumer.h"
#include "clang/CodeGen/ModuleBuilder.h"
#include "llvm/Module.h"
#include "llvm/Support/Streams.h"
#include "llvm/Support/Timer.h"
#include "llvm/Support/raw_ostream.h"
using namespace clang;
//===----------------------------------------------------------------------===//
/// DeclPrinter - Utility class for printing top-level decls.
namespace {
class DeclPrinter {
public:
llvm::raw_ostream& Out;
DeclPrinter(llvm::raw_ostream* out) : Out(out ? *out : llvm::errs()) {}
DeclPrinter() : Out(llvm::errs()) {}
virtual ~DeclPrinter();
void PrintDecl(Decl *D);
void PrintFunctionDeclStart(FunctionDecl *FD);
void PrintTypeDefDecl(TypedefDecl *TD);
void PrintLinkageSpec(LinkageSpecDecl *LS);
void PrintObjCMethodDecl(ObjCMethodDecl *OMD);
void PrintObjCImplementationDecl(ObjCImplementationDecl *OID);
void PrintObjCInterfaceDecl(ObjCInterfaceDecl *OID);
void PrintObjCProtocolDecl(ObjCProtocolDecl *PID);
void PrintObjCCategoryImplDecl(ObjCCategoryImplDecl *PID);
void PrintObjCCategoryDecl(ObjCCategoryDecl *PID);
void PrintObjCCompatibleAliasDecl(ObjCCompatibleAliasDecl *AID);
void PrintObjCPropertyDecl(ObjCPropertyDecl *PD);
void PrintObjCPropertyImplDecl(ObjCPropertyImplDecl *PID);
};
} // end anonymous namespace
DeclPrinter::~DeclPrinter() {
Out.flush();
}
void DeclPrinter:: PrintDecl(Decl *D) {
if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
PrintFunctionDeclStart(FD);
if (FD->getBody()) {
Out << ' ';
FD->getBody()->printPretty(Out);
Out << '\n';
}
} else if (isa<ObjCMethodDecl>(D)) {
// Do nothing, methods definitions are printed in
// PrintObjCImplementationDecl.
} else if (TypedefDecl *TD = dyn_cast<TypedefDecl>(D)) {
PrintTypeDefDecl(TD);
} else if (ObjCInterfaceDecl *OID = dyn_cast<ObjCInterfaceDecl>(D)) {
PrintObjCInterfaceDecl(OID);
} else if (ObjCProtocolDecl *PID = dyn_cast<ObjCProtocolDecl>(D)) {
PrintObjCProtocolDecl(PID);
} else if (ObjCForwardProtocolDecl *OFPD =
dyn_cast<ObjCForwardProtocolDecl>(D)) {
Out << "@protocol ";
for (unsigned i = 0, e = OFPD->getNumForwardDecls(); i != e; ++i) {
const ObjCProtocolDecl *D = OFPD->getForwardProtocolDecl(i);
if (i) Out << ", ";
Out << D->getNameAsString();
}
Out << ";\n";
} else if (ObjCImplementationDecl *OID =
dyn_cast<ObjCImplementationDecl>(D)) {
PrintObjCImplementationDecl(OID);
} else if (ObjCCategoryImplDecl *OID =
dyn_cast<ObjCCategoryImplDecl>(D)) {
PrintObjCCategoryImplDecl(OID);
} else if (ObjCCategoryDecl *OID =
dyn_cast<ObjCCategoryDecl>(D)) {
PrintObjCCategoryDecl(OID);
} else if (ObjCCompatibleAliasDecl *OID =
dyn_cast<ObjCCompatibleAliasDecl>(D)) {
PrintObjCCompatibleAliasDecl(OID);
} else if (ObjCClassDecl *OFCD = dyn_cast<ObjCClassDecl>(D)) {
Out << "@class ";
ObjCInterfaceDecl **ForwardDecls = OFCD->getForwardDecls();
for (unsigned i = 0, e = OFCD->getNumForwardDecls(); i != e; ++i) {
const ObjCInterfaceDecl *D = ForwardDecls[i];
if (i) Out << ", ";
Out << D->getNameAsString();
}
Out << ";\n";
} else if (EnumDecl *ED = dyn_cast<EnumDecl>(D)) {
Out << "enum " << ED->getNameAsString() << " {\n";
for (EnumDecl::enumerator_iterator E = ED->enumerator_begin(),
EEnd = ED->enumerator_end();
E != EEnd; ++E)
Out << " " << (*E)->getNameAsString() << ",\n";
Out << "};\n";
} else if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
Out << "Read top-level tag decl: '" << TD->getNameAsString() << "'\n";
} else if (ScopedDecl *SD = dyn_cast<ScopedDecl>(D)) {
Out << "Read top-level variable decl: '" << SD->getNameAsString() << "'\n";
} else if (LinkageSpecDecl *LSD = dyn_cast<LinkageSpecDecl>(D)) {
PrintLinkageSpec(LSD);
} else if (FileScopeAsmDecl *AD = dyn_cast<FileScopeAsmDecl>(D)) {
Out << "asm(";
AD->getAsmString()->printPretty(Out);
Out << ")\n";
} else {
assert(0 && "Unknown decl type!");
}
}
void DeclPrinter::PrintFunctionDeclStart(FunctionDecl *FD) {
bool HasBody = FD->getBody();
Out << '\n';
switch (FD->getStorageClass()) {
default: assert(0 && "Unknown storage class");
case FunctionDecl::None: break;
case FunctionDecl::Extern: Out << "extern "; break;
case FunctionDecl::Static: Out << "static "; break;
case FunctionDecl::PrivateExtern: Out << "__private_extern__ "; break;
}
if (FD->isInline())
Out << "inline ";
std::string Proto = FD->getNameAsString();
const FunctionType *AFT = FD->getType()->getAsFunctionType();
if (const FunctionTypeProto *FT = dyn_cast<FunctionTypeProto>(AFT)) {
Proto += "(";
for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i) {
if (i) Proto += ", ";
std::string ParamStr;
if (HasBody) ParamStr = FD->getParamDecl(i)->getNameAsString();
FT->getArgType(i).getAsStringInternal(ParamStr);
Proto += ParamStr;
}
if (FT->isVariadic()) {
if (FD->getNumParams()) Proto += ", ";
Proto += "...";
}
Proto += ")";
} else {
assert(isa<FunctionTypeNoProto>(AFT));
Proto += "()";
}
AFT->getResultType().getAsStringInternal(Proto);
Out << Proto;
if (!FD->getBody())
Out << ";\n";
// Doesn't print the body.
}
void DeclPrinter::PrintTypeDefDecl(TypedefDecl *TD) {
std::string S = TD->getNameAsString();
TD->getUnderlyingType().getAsStringInternal(S);
Out << "typedef " << S << ";\n";
}
void DeclPrinter::PrintLinkageSpec(LinkageSpecDecl *LS) {
const char *l;
if (LS->getLanguage() == LinkageSpecDecl::lang_c)
l = "C";
else {
assert(LS->getLanguage() == LinkageSpecDecl::lang_cxx &&
"unknown language in linkage specification");
l = "C++";
}
Out << "extern \"" << l << "\" ";
if (LS->hasBraces())
Out << "{\n";
for (LinkageSpecDecl::decl_const_iterator D = LS->decls_begin(),
DEnd = LS->decls_end();
D != DEnd; ++D)
PrintDecl(*D);
if (LS->hasBraces())
Out << "}";
Out << "\n";
}
void DeclPrinter::PrintObjCMethodDecl(ObjCMethodDecl *OMD) {
if (OMD->isInstance())
Out << "\n- ";
else
Out << "\n+ ";
if (!OMD->getResultType().isNull())
Out << '(' << OMD->getResultType().getAsString() << ")";
std::string name = OMD->getSelector().getAsString();
std::string::size_type pos, lastPos = 0;
for (unsigned i = 0, e = OMD->getNumParams(); i != e; ++i) {
ParmVarDecl *PDecl = OMD->getParamDecl(i);
// FIXME: selector is missing here!
pos = name.find_first_of(":", lastPos);
Out << " " << name.substr(lastPos, pos - lastPos);
Out << ":(" << PDecl->getType().getAsString() << ")"
<< PDecl->getNameAsString();
lastPos = pos + 1;
}
if (OMD->getNumParams() == 0)
Out << " " << name;
if (OMD->isVariadic())
Out << ", ...";
Out << ";";
}
void DeclPrinter::PrintObjCImplementationDecl(ObjCImplementationDecl *OID) {
std::string I = OID->getNameAsString();
ObjCInterfaceDecl *SID = OID->getSuperClass();
if (SID)
Out << "@implementation " << I << " : " << SID->getNameAsString();
else
Out << "@implementation " << I;
for (ObjCImplementationDecl::instmeth_iterator I = OID->instmeth_begin(),
E = OID->instmeth_end(); I != E; ++I) {
ObjCMethodDecl *OMD = *I;
PrintObjCMethodDecl(OMD);
if (OMD->getBody()) {
Out << ' ';
OMD->getBody()->printPretty(Out);
Out << '\n';
}
}
for (ObjCImplementationDecl::classmeth_iterator I = OID->classmeth_begin(),
E = OID->classmeth_end(); I != E; ++I) {
ObjCMethodDecl *OMD = *I;
PrintObjCMethodDecl(OMD);
if (OMD->getBody()) {
Out << ' ';
OMD->getBody()->printPretty(Out);
Out << '\n';
}
}
for (ObjCImplementationDecl::propimpl_iterator I = OID->propimpl_begin(),
E = OID->propimpl_end(); I != E; ++I)
PrintObjCPropertyImplDecl(*I);
Out << "@end\n";
}
void DeclPrinter::PrintObjCInterfaceDecl(ObjCInterfaceDecl *OID) {
std::string I = OID->getNameAsString();
ObjCInterfaceDecl *SID = OID->getSuperClass();
if (SID)
Out << "@interface " << I << " : " << SID->getNameAsString();
else
Out << "@interface " << I;
// Protocols?
const ObjCList<ObjCProtocolDecl> &Protocols = OID->getReferencedProtocols();
if (!Protocols.empty()) {
for (ObjCList<ObjCProtocolDecl>::iterator I = Protocols.begin(),
E = Protocols.end(); I != E; ++I)
Out << (I == Protocols.begin() ? '<' : ',') << (*I)->getNameAsString();
}
if (!Protocols.empty())
Out << ">";
Out << '\n';
if (OID->ivar_size() > 0) {
Out << '{';
for (ObjCInterfaceDecl::ivar_iterator I = OID->ivar_begin(),
E = OID->ivar_end(); I != E; ++I) {
Out << '\t' << (*I)->getType().getAsString()
<< ' ' << (*I)->getNameAsString() << ";\n";
}
Out << "}\n";
}
for (ObjCInterfaceDecl::classprop_iterator I = OID->classprop_begin(),
E = OID->classprop_end(); I != E; ++I)
PrintObjCPropertyDecl(*I);
bool eol_needed = false;
for (ObjCInterfaceDecl::classmeth_iterator I = OID->classmeth_begin(),
E = OID->classmeth_end(); I != E; ++I)
eol_needed = true, PrintObjCMethodDecl(*I);
for (ObjCInterfaceDecl::instmeth_iterator I = OID->instmeth_begin(),
E = OID->instmeth_end(); I != E; ++I)
eol_needed = true, PrintObjCMethodDecl(*I);
Out << (eol_needed ? "\n@end\n" : "@end\n");
// FIXME: implement the rest...
}
void DeclPrinter::PrintObjCProtocolDecl(ObjCProtocolDecl *PID) {
Out << "@protocol " << PID->getNameAsString() << '\n';
for (ObjCProtocolDecl::classprop_iterator I = PID->classprop_begin(),
E = PID->classprop_end(); I != E; ++I)
PrintObjCPropertyDecl(*I);
Out << "@end\n";
// FIXME: implement the rest...
}
void DeclPrinter::PrintObjCCategoryImplDecl(ObjCCategoryImplDecl *PID) {
Out << "@implementation "
<< PID->getClassInterface()->getNameAsString()
<< '(' << PID->getNameAsString() << ");\n";
for (ObjCCategoryImplDecl::propimpl_iterator I = PID->propimpl_begin(),
E = PID->propimpl_end(); I != E; ++I)
PrintObjCPropertyImplDecl(*I);
Out << "@end\n";
// FIXME: implement the rest...
}
void DeclPrinter::PrintObjCCategoryDecl(ObjCCategoryDecl *PID) {
Out << "@interface "
<< PID->getClassInterface()->getNameAsString()
<< '(' << PID->getNameAsString() << ");\n";
// Output property declarations.
for (ObjCCategoryDecl::classprop_iterator I = PID->classprop_begin(),
E = PID->classprop_end(); I != E; ++I)
PrintObjCPropertyDecl(*I);
Out << "@end\n";
// FIXME: implement the rest...
}
void DeclPrinter::PrintObjCCompatibleAliasDecl(ObjCCompatibleAliasDecl *AID) {
Out << "@compatibility_alias " << AID->getNameAsString()
<< ' ' << AID->getClassInterface()->getNameAsString() << ";\n";
}
/// PrintObjCPropertyDecl - print a property declaration.
///
void DeclPrinter::PrintObjCPropertyDecl(ObjCPropertyDecl *PDecl) {
if (PDecl->getPropertyImplementation() == ObjCPropertyDecl::Required)
Out << "@required\n";
else if (PDecl->getPropertyImplementation() == ObjCPropertyDecl::Optional)
Out << "@optional\n";
Out << "@property";
if (PDecl->getPropertyAttributes() != ObjCPropertyDecl::OBJC_PR_noattr) {
bool first = true;
Out << " (";
if (PDecl->getPropertyAttributes() &
ObjCPropertyDecl::OBJC_PR_readonly) {
Out << (first ? ' ' : ',') << "readonly";
first = false;
}
if (PDecl->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_getter) {
Out << (first ? ' ' : ',') << "getter = "
<< PDecl->getGetterName().getAsString();
first = false;
}
if (PDecl->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_setter) {
Out << (first ? ' ' : ',') << "setter = "
<< PDecl->getSetterName().getAsString();
first = false;
}
if (PDecl->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_assign) {
Out << (first ? ' ' : ',') << "assign";
first = false;
}
if (PDecl->getPropertyAttributes() &
ObjCPropertyDecl::OBJC_PR_readwrite) {
Out << (first ? ' ' : ',') << "readwrite";
first = false;
}
if (PDecl->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_retain) {
Out << (first ? ' ' : ',') << "retain";
first = false;
}
if (PDecl->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_copy) {
Out << (first ? ' ' : ',') << "copy";
first = false;
}
if (PDecl->getPropertyAttributes() &
ObjCPropertyDecl::OBJC_PR_nonatomic) {
Out << (first ? ' ' : ',') << "nonatomic";
first = false;
}
Out << " )";
}
Out << ' ' << PDecl->getType().getAsString()
<< ' ' << PDecl->getNameAsString();
Out << ";\n";
}
/// PrintObjCPropertyImplDecl - Print an objective-c property implementation
/// declaration syntax.
///
void DeclPrinter::PrintObjCPropertyImplDecl(ObjCPropertyImplDecl *PID) {
if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize)
Out << "\n@synthesize ";
else
Out << "\n@dynamic ";
Out << PID->getPropertyDecl()->getNameAsString();
if (PID->getPropertyIvarDecl())
Out << "=" << PID->getPropertyIvarDecl()->getNameAsString();
Out << ";\n";
}
//===----------------------------------------------------------------------===//
/// ASTPrinter - Pretty-printer of ASTs
namespace {
class ASTPrinter : public ASTConsumer, public DeclPrinter {
public:
ASTPrinter(llvm::raw_ostream* o = NULL) : DeclPrinter(o) {}
virtual void HandleTopLevelDecl(Decl *D) {
PrintDecl(D);
}
};
}
ASTConsumer *clang::CreateASTPrinter(llvm::raw_ostream* out) {
return new ASTPrinter(out);
}
//===----------------------------------------------------------------------===//
/// ASTDumper - Low-level dumper of ASTs
namespace {
class ASTDumper : public ASTConsumer, public DeclPrinter {
SourceManager *SM;
public:
ASTDumper() : DeclPrinter() {}
void Initialize(ASTContext &Context) {
SM = &Context.getSourceManager();
}
virtual void HandleTopLevelDecl(Decl *D) {
if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
PrintFunctionDeclStart(FD);
if (FD->getBody()) {
Out << '\n';
// FIXME: convert dumper to use std::ostream?
FD->getBody()->dumpAll(*SM);
Out << '\n';
}
} else if (TypedefDecl *TD = dyn_cast<TypedefDecl>(D)) {
PrintTypeDefDecl(TD);
} else if (ScopedDecl *SD = dyn_cast<ScopedDecl>(D)) {
Out << "Read top-level variable decl: '" << SD->getNameAsString()
<< "'\n";
} else if (ObjCInterfaceDecl *OID = dyn_cast<ObjCInterfaceDecl>(D)) {
Out << "Read objc interface '" << OID->getNameAsString() << "'\n";
} else if (ObjCProtocolDecl *OPD = dyn_cast<ObjCProtocolDecl>(D)) {
Out << "Read objc protocol '" << OPD->getNameAsString() << "'\n";
} else if (ObjCCategoryDecl *OCD = dyn_cast<ObjCCategoryDecl>(D)) {
Out << "Read objc category '" << OCD->getNameAsString() << "'\n";
} else if (isa<ObjCForwardProtocolDecl>(D)) {
Out << "Read objc fwd protocol decl\n";
} else if (isa<ObjCClassDecl>(D)) {
Out << "Read objc fwd class decl\n";
} else if (isa<FileScopeAsmDecl>(D)) {
Out << "Read file scope asm decl\n";
} else if (ObjCMethodDecl* MD = dyn_cast<ObjCMethodDecl>(D)) {
Out << "Read objc method decl: '" << MD->getSelector().getAsString()
<< "'\n";
if (MD->getBody()) {
// FIXME: convert dumper to use std::ostream?
MD->getBody()->dumpAll(*SM);
Out << '\n';
}
} else if (isa<ObjCImplementationDecl>(D)) {
Out << "Read objc implementation decl\n";
} else if (isa<ObjCCategoryImplDecl>(D)) {
Out << "Read objc category implementation decl\n";
} else if (isa<LinkageSpecDecl>(D)) {
Out << "Read linkage spec decl\n";
} else {
assert(0 && "Unknown decl type!");
}
}
};
}
ASTConsumer *clang::CreateASTDumper() { return new ASTDumper(); }
//===----------------------------------------------------------------------===//
/// ASTViewer - AST Visualization
namespace {
class ASTViewer : public ASTConsumer {
SourceManager *SM;
public:
void Initialize(ASTContext &Context) {
SM = &Context.getSourceManager();
}
virtual void HandleTopLevelDecl(Decl *D) {
if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
DeclPrinter().PrintFunctionDeclStart(FD);
if (FD->getBody()) {
llvm::cerr << '\n';
FD->getBody()->viewAST();
llvm::cerr << '\n';
}
}
else if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) {
DeclPrinter().PrintObjCMethodDecl(MD);
if (MD->getBody()) {
llvm::cerr << '\n';
MD->getBody()->viewAST();
llvm::cerr << '\n';
}
}
}
};
}
ASTConsumer *clang::CreateASTViewer() { return new ASTViewer(); }
//===----------------------------------------------------------------------===//
/// InheritanceViewer - C++ Inheritance Visualization
namespace {
class InheritanceViewer : public ASTConsumer {
const std::string clsname;
public:
InheritanceViewer(const std::string& cname) : clsname(cname) {}
void HandleTranslationUnit(TranslationUnit& TU) {
ASTContext& C = TU.getContext();
for (ASTContext::type_iterator I=C.types_begin(),E=C.types_end(); I!=E; ++I)
if (CXXRecordType *T = dyn_cast<CXXRecordType>(*I)) {
CXXRecordDecl* D = T->getDecl();
// FIXME: This lookup needs to be generalized to handle namespaces and
// (when we support them) templates.
if (D->getNameAsString() == clsname) {
D->viewInheritance(C);
}
}
}
};
}
ASTConsumer *clang::CreateInheritanceViewer(const std::string& clsname) {
return new InheritanceViewer(clsname);
}
//===----------------------------------------------------------------------===//
// AST Serializer
namespace {
class ASTSerializer : public ASTConsumer {
protected:
Diagnostic& Diags;
public:
ASTSerializer(Diagnostic& diags) : Diags(diags) {}
};
class SingleFileSerializer : public ASTSerializer {
const llvm::sys::Path FName;
public:
SingleFileSerializer(const llvm::sys::Path& F, Diagnostic& diags)
: ASTSerializer(diags), FName(F) {}
virtual void HandleTranslationUnit(TranslationUnit& TU) {
if (Diags.hasErrorOccurred())
return;
EmitASTBitcodeFile(&TU, FName);
}
};
class BuildSerializer : public ASTSerializer {
llvm::sys::Path EmitDir;
public:
BuildSerializer(const llvm::sys::Path& dir, Diagnostic& diags)
: ASTSerializer(diags), EmitDir(dir) {}
virtual void HandleTranslationUnit(TranslationUnit& TU) {
if (Diags.hasErrorOccurred())
return;
SourceManager& SourceMgr = TU.getContext().getSourceManager();
unsigned ID = SourceMgr.getMainFileID();
assert (ID && "MainFileID not set!");
const FileEntry* FE = SourceMgr.getFileEntryForID(ID);
assert (FE && "No FileEntry for main file.");
// FIXME: This is not portable to Windows.
// FIXME: This logic should probably be moved elsewhere later.
llvm::sys::Path FName(EmitDir);
std::vector<char> buf;
buf.reserve(strlen(FE->getName())+100);
sprintf(&buf[0], "dev_%llx", (uint64_t) FE->getDevice());
FName.appendComponent(&buf[0]);
FName.createDirectoryOnDisk(true);
if (!FName.canWrite() || !FName.isDirectory()) {
assert (false && "Could not create 'device' serialization directory.");
return;
}
sprintf(&buf[0], "%s-%llX.ast", FE->getName(), (uint64_t) FE->getInode());
FName.appendComponent(&buf[0]);
EmitASTBitcodeFile(&TU, FName);
// Now emit the sources.
}
};
} // end anonymous namespace
ASTConsumer* clang::CreateASTSerializer(const std::string& InFile,
const std::string& OutputFile,
Diagnostic &Diags) {
if (OutputFile.size()) {
if (InFile == "-") {
llvm::cerr <<
"error: Cannot use --serialize with -o for source read from STDIN.\n";
return NULL;
}
// The user specified an AST-emission directory. Determine if the path
// is absolute.
llvm::sys::Path EmitDir(OutputFile);
if (!EmitDir.isAbsolute()) {
llvm::cerr <<
"error: Output directory for --serialize must be an absolute path.\n";
return NULL;
}
// Create the directory if it does not exist.
EmitDir.createDirectoryOnDisk(true);
if (!EmitDir.canWrite() || !EmitDir.isDirectory()) {
llvm::cerr <<
"error: Could not create output directory for --serialize.\n";
return NULL;
}
// FIXME: We should probably only allow using BuildSerializer when
// the ASTs come from parsed source files, and not from .ast files.
return new BuildSerializer(EmitDir, Diags);
}
// The user did not specify an output directory for serialized ASTs.
// Serialize the translation to a single file whose name is the same
// as the input file with the ".ast" extension appended.
llvm::sys::Path FName(InFile.c_str());
FName.appendSuffix("ast");
return new SingleFileSerializer(FName, Diags);
}