llvm-project/lldb/source/Expression/ASTResultSynthesizer.cpp

513 lines
15 KiB
C++

//===-- ASTResultSynthesizer.cpp --------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "stdlib.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclGroup.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/Expr.h"
#include "clang/AST/Stmt.h"
#include "clang/Parse/Parser.h"
#include "clang/Sema/SemaDiagnostic.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/raw_ostream.h"
#include "lldb/Core/Log.h"
#include "lldb/Expression/ClangPersistentVariables.h"
#include "lldb/Expression/ASTResultSynthesizer.h"
#include "lldb/Symbol/ClangASTContext.h"
#include "lldb/Symbol/ClangASTImporter.h"
#include "lldb/Target/Target.h"
using namespace llvm;
using namespace clang;
using namespace lldb_private;
ASTResultSynthesizer::ASTResultSynthesizer(ASTConsumer *passthrough,
Target &target) :
m_ast_context (NULL),
m_passthrough (passthrough),
m_passthrough_sema (NULL),
m_target (target),
m_sema (NULL)
{
if (!m_passthrough)
return;
m_passthrough_sema = dyn_cast<SemaConsumer>(passthrough);
}
ASTResultSynthesizer::~ASTResultSynthesizer()
{
}
void
ASTResultSynthesizer::Initialize(ASTContext &Context)
{
m_ast_context = &Context;
if (m_passthrough)
m_passthrough->Initialize(Context);
}
void
ASTResultSynthesizer::TransformTopLevelDecl(Decl* D)
{
Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
if (NamedDecl *named_decl = dyn_cast<NamedDecl>(D))
{
if (log && log->GetVerbose())
{
if (named_decl->getIdentifier())
log->Printf("TransformTopLevelDecl(%s)", named_decl->getIdentifier()->getNameStart());
else if (ObjCMethodDecl *method_decl = dyn_cast<ObjCMethodDecl>(D))
log->Printf("TransformTopLevelDecl(%s)", method_decl->getSelector().getAsString().c_str());
else
log->Printf("TransformTopLevelDecl(<complex>)");
}
}
if (LinkageSpecDecl *linkage_spec_decl = dyn_cast<LinkageSpecDecl>(D))
{
RecordDecl::decl_iterator decl_iterator;
for (decl_iterator = linkage_spec_decl->decls_begin();
decl_iterator != linkage_spec_decl->decls_end();
++decl_iterator)
{
TransformTopLevelDecl(*decl_iterator);
}
}
else if (ObjCMethodDecl *method_decl = dyn_cast<ObjCMethodDecl>(D))
{
if (m_ast_context &&
!method_decl->getSelector().getAsString().compare("$__lldb_expr:"))
{
RecordPersistentTypes(method_decl);
SynthesizeObjCMethodResult(method_decl);
}
}
else if (FunctionDecl *function_decl = dyn_cast<FunctionDecl>(D))
{
if (m_ast_context &&
!function_decl->getNameInfo().getAsString().compare("$__lldb_expr"))
{
RecordPersistentTypes(function_decl);
SynthesizeFunctionResult(function_decl);
}
}
}
bool
ASTResultSynthesizer::HandleTopLevelDecl(DeclGroupRef D)
{
DeclGroupRef::iterator decl_iterator;
for (decl_iterator = D.begin();
decl_iterator != D.end();
++decl_iterator)
{
Decl *decl = *decl_iterator;
TransformTopLevelDecl(decl);
}
if (m_passthrough)
return m_passthrough->HandleTopLevelDecl(D);
return true;
}
bool
ASTResultSynthesizer::SynthesizeFunctionResult (FunctionDecl *FunDecl)
{
Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
if (!m_sema)
return false;
FunctionDecl *function_decl = FunDecl;
if (!function_decl)
return false;
if (log && log->GetVerbose())
{
std::string s;
raw_string_ostream os(s);
function_decl->print(os);
os.flush();
log->Printf ("Untransformed function AST:\n%s", s.c_str());
}
Stmt *function_body = function_decl->getBody();
CompoundStmt *compound_stmt = dyn_cast<CompoundStmt>(function_body);
bool ret = SynthesizeBodyResult (compound_stmt,
function_decl);
if (log && log->GetVerbose())
{
std::string s;
raw_string_ostream os(s);
function_decl->print(os);
os.flush();
log->Printf ("Transformed function AST:\n%s", s.c_str());
}
return ret;
}
bool
ASTResultSynthesizer::SynthesizeObjCMethodResult (ObjCMethodDecl *MethodDecl)
{
Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
if (!m_sema)
return false;
if (!MethodDecl)
return false;
if (log && log->GetVerbose())
{
std::string s;
raw_string_ostream os(s);
MethodDecl->print(os);
os.flush();
log->Printf ("Untransformed method AST:\n%s", s.c_str());
}
Stmt *method_body = MethodDecl->getBody();
if (!method_body)
return false;
CompoundStmt *compound_stmt = dyn_cast<CompoundStmt>(method_body);
bool ret = SynthesizeBodyResult (compound_stmt,
MethodDecl);
if (log && log->GetVerbose())
{
std::string s;
raw_string_ostream os(s);
MethodDecl->print(os);
os.flush();
log->Printf("Transformed method AST:\n%s", s.c_str());
}
return ret;
}
bool
ASTResultSynthesizer::SynthesizeBodyResult (CompoundStmt *Body,
DeclContext *DC)
{
Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
ASTContext &Ctx(*m_ast_context);
if (!Body)
return false;
if (Body->body_empty())
return false;
Stmt **last_stmt_ptr = Body->body_end() - 1;
Stmt *last_stmt = *last_stmt_ptr;
while (dyn_cast<NullStmt>(last_stmt))
{
if (last_stmt_ptr != Body->body_begin())
{
last_stmt_ptr--;
last_stmt = *last_stmt_ptr;
}
else
{
return false;
}
}
Expr *last_expr = dyn_cast<Expr>(last_stmt);
if (!last_expr)
// No auxiliary variable necessary; expression returns void
return true;
// In C++11, last_expr can be a LValueToRvalue implicit cast. Strip that off if that's the
// case.
do {
ImplicitCastExpr *implicit_cast = dyn_cast<ImplicitCastExpr>(last_expr);
if (!implicit_cast)
break;
if (implicit_cast->getCastKind() != CK_LValueToRValue)
break;
last_expr = implicit_cast->getSubExpr();
} while (0);
// is_lvalue is used to record whether the expression returns an assignable Lvalue or an
// Rvalue. This is relevant because they are handled differently.
//
// For Lvalues
//
// - In AST result synthesis (here!) the expression E is transformed into an initialization
// T *$__lldb_expr_result_ptr = &E.
//
// - In structure allocation, a pointer-sized slot is allocated in the struct that is to be
// passed into the expression.
//
// - In IR transformations, reads and writes to $__lldb_expr_result_ptr are redirected at
// an entry in the struct ($__lldb_arg) passed into the expression. (Other persistent
// variables are treated similarly, having been materialized as references, but in those
// cases the value of the reference itself is never modified.)
//
// - During materialization, $0 (the result persistent variable) is ignored.
//
// - During dematerialization, $0 is marked up as a load address with value equal to the
// contents of the structure entry.
//
// For Rvalues
//
// - In AST result synthesis the expression E is transformed into an initialization
// static T $__lldb_expr_result = E.
//
// - In structure allocation, a pointer-sized slot is allocated in the struct that is to be
// passed into the expression.
//
// - In IR transformations, an instruction is inserted at the beginning of the function to
// dereference the pointer resident in the slot. Reads and writes to $__lldb_expr_result
// are redirected at that dereferenced version. Guard variables for the static variable
// are excised.
//
// - During materialization, $0 (the result persistent variable) is populated with the location
// of a newly-allocated area of memory.
//
// - During dematerialization, $0 is ignored.
bool is_lvalue =
(last_expr->getValueKind() == VK_LValue || last_expr->getValueKind() == VK_XValue) &&
(last_expr->getObjectKind() == OK_Ordinary);
QualType expr_qual_type = last_expr->getType();
const clang::Type *expr_type = expr_qual_type.getTypePtr();
if (!expr_type)
return false;
if (expr_type->isVoidType())
return true;
if (log)
{
std::string s = expr_qual_type.getAsString();
log->Printf("Last statement is an %s with type: %s", (is_lvalue ? "lvalue" : "rvalue"), s.c_str());
}
clang::VarDecl *result_decl = NULL;
if (is_lvalue)
{
IdentifierInfo *result_ptr_id;
if (expr_type->isFunctionType())
result_ptr_id = &Ctx.Idents.get("$__lldb_expr_result"); // functions actually should be treated like function pointers
else
result_ptr_id = &Ctx.Idents.get("$__lldb_expr_result_ptr");
m_sema->RequireCompleteType(SourceLocation(), expr_qual_type, clang::diag::err_incomplete_type);
QualType ptr_qual_type;
if (expr_qual_type->getAs<ObjCObjectType>() != NULL)
ptr_qual_type = Ctx.getObjCObjectPointerType(expr_qual_type);
else
ptr_qual_type = Ctx.getPointerType(expr_qual_type);
result_decl = VarDecl::Create(Ctx,
DC,
SourceLocation(),
SourceLocation(),
result_ptr_id,
ptr_qual_type,
NULL,
SC_Static);
if (!result_decl)
return false;
ExprResult address_of_expr = m_sema->CreateBuiltinUnaryOp(SourceLocation(), UO_AddrOf, last_expr);
m_sema->AddInitializerToDecl(result_decl, address_of_expr.get(), true, false);
}
else
{
IdentifierInfo &result_id = Ctx.Idents.get("$__lldb_expr_result");
result_decl = VarDecl::Create(Ctx,
DC,
SourceLocation(),
SourceLocation(),
&result_id,
expr_qual_type,
NULL,
SC_Static);
if (!result_decl)
return false;
m_sema->AddInitializerToDecl(result_decl, last_expr, true, false);
}
DC->addDecl(result_decl);
///////////////////////////////
// call AddInitializerToDecl
//
//m_sema->AddInitializerToDecl(result_decl, last_expr);
/////////////////////////////////
// call ConvertDeclToDeclGroup
//
Sema::DeclGroupPtrTy result_decl_group_ptr;
result_decl_group_ptr = m_sema->ConvertDeclToDeclGroup(result_decl);
////////////////////////
// call ActOnDeclStmt
//
StmtResult result_initialization_stmt_result(m_sema->ActOnDeclStmt(result_decl_group_ptr,
SourceLocation(),
SourceLocation()));
////////////////////////////////////////////////
// replace the old statement with the new one
//
*last_stmt_ptr = reinterpret_cast<Stmt*>(result_initialization_stmt_result.get());
return true;
}
void
ASTResultSynthesizer::HandleTranslationUnit(ASTContext &Ctx)
{
if (m_passthrough)
m_passthrough->HandleTranslationUnit(Ctx);
}
void
ASTResultSynthesizer::RecordPersistentTypes(DeclContext *FunDeclCtx)
{
typedef DeclContext::specific_decl_iterator<TypeDecl> TypeDeclIterator;
for (TypeDeclIterator i = TypeDeclIterator(FunDeclCtx->decls_begin()),
e = TypeDeclIterator(FunDeclCtx->decls_end());
i != e;
++i)
{
MaybeRecordPersistentType(*i);
}
}
void
ASTResultSynthesizer::MaybeRecordPersistentType(TypeDecl *D)
{
if (!D->getIdentifier())
return;
StringRef name = D->getName();
if (name.size() == 0 || name[0] != '$')
return;
Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
ConstString name_cs(name.str().c_str());
if (log)
log->Printf ("Recording persistent type %s\n", name_cs.GetCString());
Decl *D_scratch = m_target.GetClangASTImporter()->DeportDecl(m_target.GetScratchClangASTContext()->getASTContext(),
m_ast_context,
D);
if (TypeDecl *TypeDecl_scratch = dyn_cast<TypeDecl>(D_scratch))
m_target.GetPersistentVariables().RegisterPersistentType(name_cs, TypeDecl_scratch);
}
void
ASTResultSynthesizer::HandleTagDeclDefinition(TagDecl *D)
{
if (m_passthrough)
m_passthrough->HandleTagDeclDefinition(D);
}
void
ASTResultSynthesizer::CompleteTentativeDefinition(VarDecl *D)
{
if (m_passthrough)
m_passthrough->CompleteTentativeDefinition(D);
}
void
ASTResultSynthesizer::HandleVTable(CXXRecordDecl *RD, bool DefinitionRequired)
{
if (m_passthrough)
m_passthrough->HandleVTable(RD, DefinitionRequired);
}
void
ASTResultSynthesizer::PrintStats()
{
if (m_passthrough)
m_passthrough->PrintStats();
}
void
ASTResultSynthesizer::InitializeSema(Sema &S)
{
m_sema = &S;
if (m_passthrough_sema)
m_passthrough_sema->InitializeSema(S);
}
void
ASTResultSynthesizer::ForgetSema()
{
m_sema = NULL;
if (m_passthrough_sema)
m_passthrough_sema->ForgetSema();
}