Files
clang-p2996/lldb/source/Plugins/ExpressionParser/Clang/ASTResultSynthesizer.cpp
Pavel Labath c34698a811 [lldb] Rename Logging.h to LLDBLog.h and clean up includes
Most of our code was including Log.h even though that is not where the
"lldb" log channel is defined (Log.h defines the generic logging
infrastructure). This worked because Log.h included Logging.h, even
though it should.

After the recent refactor, it became impossible the two files include
each other in this direction (the opposite inclusion is needed), so this
patch removes the workaround that was put in place and cleans up all
files to include the right thing. It also renames the file to LLDBLog to
better reflect its purpose.
2022-02-03 14:47:01 +01:00

512 lines
14 KiB
C++

//===-- ASTResultSynthesizer.cpp ------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "ASTResultSynthesizer.h"
#include "ClangASTImporter.h"
#include "ClangPersistentVariables.h"
#include "Plugins/TypeSystem/Clang/TypeSystemClang.h"
#include "lldb/Target/Target.h"
#include "lldb/Utility/LLDBAssert.h"
#include "lldb/Utility/LLDBLog.h"
#include "lldb/Utility/Log.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 <cstdlib>
using namespace llvm;
using namespace clang;
using namespace lldb_private;
ASTResultSynthesizer::ASTResultSynthesizer(ASTConsumer *passthrough,
bool top_level, Target &target)
: m_ast_context(nullptr), m_passthrough(passthrough),
m_passthrough_sema(nullptr), m_target(target), m_sema(nullptr),
m_top_level(top_level) {
if (!m_passthrough)
return;
m_passthrough_sema = dyn_cast<SemaConsumer>(passthrough);
}
ASTResultSynthesizer::~ASTResultSynthesizer() = default;
void ASTResultSynthesizer::Initialize(ASTContext &Context) {
m_ast_context = &Context;
if (m_passthrough)
m_passthrough->Initialize(Context);
}
void ASTResultSynthesizer::TransformTopLevelDecl(Decl *D) {
Log *log = GetLog(LLDBLog::Expressions);
if (NamedDecl *named_decl = dyn_cast<NamedDecl>(D)) {
if (log && log->GetVerbose()) {
if (named_decl->getIdentifier())
LLDB_LOGF(log, "TransformTopLevelDecl(%s)",
named_decl->getIdentifier()->getNameStart());
else if (ObjCMethodDecl *method_decl = dyn_cast<ObjCMethodDecl>(D))
LLDB_LOGF(log, "TransformTopLevelDecl(%s)",
method_decl->getSelector().getAsString().c_str());
else
LLDB_LOGF(log, "TransformTopLevelDecl(<complex>)");
}
if (m_top_level) {
RecordPersistentDecl(named_decl);
}
}
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 (!m_top_level) {
if (ObjCMethodDecl *method_decl = dyn_cast<ObjCMethodDecl>(D)) {
if (m_ast_context &&
!method_decl->getSelector().getAsString().compare("$__lldb_expr:")) {
RecordPersistentTypes(method_decl);
SynthesizeObjCMethodResult(method_decl);
}
} else if (FunctionDecl *function_decl = dyn_cast<FunctionDecl>(D)) {
// When completing user input the body of the function may be a nullptr.
if (m_ast_context && function_decl->hasBody() &&
!function_decl->getNameInfo().getAsString().compare("$__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 = GetLog(LLDBLog::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();
LLDB_LOGF(log, "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();
LLDB_LOGF(log, "Transformed function AST:\n%s", s.c_str());
}
return ret;
}
bool ASTResultSynthesizer::SynthesizeObjCMethodResult(
ObjCMethodDecl *MethodDecl) {
Log *log = GetLog(LLDBLog::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();
LLDB_LOGF(log, "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();
LLDB_LOGF(log, "Transformed method AST:\n%s", s.c_str());
}
return ret;
}
bool ASTResultSynthesizer::SynthesizeBodyResult(CompoundStmt *Body,
DeclContext *DC) {
Log *log = GetLog(LLDBLog::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 (isa<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 (false);
// 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, $0 is ignored.
bool is_lvalue = last_expr->getValueKind() == VK_LValue &&
last_expr->getObjectKind() == OK_Ordinary;
QualType expr_qual_type = last_expr->getType();
const clang::Type *expr_type = expr_qual_type.getTypePtr();
if (!expr_type)
return false;
if (expr_type->isVoidType())
return true;
if (log) {
std::string s = expr_qual_type.getAsString();
LLDB_LOGF(log, "Last statement is an %s with type: %s",
(is_lvalue ? "lvalue" : "rvalue"), s.c_str());
}
clang::VarDecl *result_decl = nullptr;
if (is_lvalue) {
IdentifierInfo *result_ptr_id;
if (expr_type->isFunctionType())
result_ptr_id =
&Ctx.Idents.get("$__lldb_expr_result"); // functions actually should
// be treated like function
// pointers
else
result_ptr_id = &Ctx.Idents.get("$__lldb_expr_result_ptr");
m_sema->RequireCompleteType(last_expr->getSourceRange().getBegin(),
expr_qual_type,
clang::diag::err_incomplete_type);
QualType ptr_qual_type;
if (expr_qual_type->getAs<ObjCObjectType>() != nullptr)
ptr_qual_type = Ctx.getObjCObjectPointerType(expr_qual_type);
else
ptr_qual_type = Ctx.getPointerType(expr_qual_type);
result_decl =
VarDecl::Create(Ctx, DC, SourceLocation(), SourceLocation(),
result_ptr_id, ptr_qual_type, nullptr, SC_Static);
if (!result_decl)
return false;
ExprResult address_of_expr =
m_sema->CreateBuiltinUnaryOp(SourceLocation(), UO_AddrOf, last_expr);
if (address_of_expr.get())
m_sema->AddInitializerToDecl(result_decl, address_of_expr.get(), true);
else
return false;
} else {
IdentifierInfo &result_id = Ctx.Idents.get("$__lldb_expr_result");
result_decl =
VarDecl::Create(Ctx, DC, SourceLocation(), SourceLocation(), &result_id,
expr_qual_type, nullptr, SC_Static);
if (!result_decl)
return false;
m_sema->AddInitializerToDecl(result_decl, last_expr, true);
}
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 = static_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 = GetLog(LLDBLog::Expressions);
ConstString name_cs(name.str().c_str());
LLDB_LOGF(log, "Recording persistent type %s\n", name_cs.GetCString());
m_decls.push_back(D);
}
void ASTResultSynthesizer::RecordPersistentDecl(NamedDecl *D) {
lldbassert(m_top_level);
if (!D->getIdentifier())
return;
StringRef name = D->getName();
if (name.size() == 0)
return;
Log *log = GetLog(LLDBLog::Expressions);
ConstString name_cs(name.str().c_str());
LLDB_LOGF(log, "Recording persistent decl %s\n", name_cs.GetCString());
m_decls.push_back(D);
}
void ASTResultSynthesizer::CommitPersistentDecls() {
auto *state =
m_target.GetPersistentExpressionStateForLanguage(lldb::eLanguageTypeC);
if (!state)
return;
auto *persistent_vars = llvm::cast<ClangPersistentVariables>(state);
TypeSystemClang *scratch_ctx = ScratchTypeSystemClang::GetForTarget(
m_target, m_ast_context->getLangOpts());
for (clang::NamedDecl *decl : m_decls) {
StringRef name = decl->getName();
ConstString name_cs(name.str().c_str());
Decl *D_scratch = persistent_vars->GetClangASTImporter()->DeportDecl(
&scratch_ctx->getASTContext(), decl);
if (!D_scratch) {
Log *log = GetLog(LLDBLog::Expressions);
if (log) {
std::string s;
llvm::raw_string_ostream ss(s);
decl->dump(ss);
ss.flush();
LLDB_LOGF(log, "Couldn't commit persistent decl: %s\n", s.c_str());
}
continue;
}
if (NamedDecl *NamedDecl_scratch = dyn_cast<NamedDecl>(D_scratch))
persistent_vars->RegisterPersistentDecl(name_cs, NamedDecl_scratch,
scratch_ctx);
}
}
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) {
if (m_passthrough)
m_passthrough->HandleVTable(RD);
}
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 = nullptr;
if (m_passthrough_sema)
m_passthrough_sema->ForgetSema();
}