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//===-- ClangUserExpression.cpp ---------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include <stdio.h>
#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include <cstdlib>
#include <map>
#include <string>
#include "ClangUserExpression.h"
#include "ASTResultSynthesizer.h"
#include "ClangDiagnostic.h"
#include "ClangExpressionDeclMap.h"
#include "ClangExpressionParser.h"
#include "ClangModulesDeclVendor.h"
#include "ClangPersistentVariables.h"
#include "lldb/Core/Debugger.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/StreamFile.h"
#include "lldb/Core/ValueObjectConstResult.h"
#include "lldb/Expression/ExpressionSourceCode.h"
#include "lldb/Expression/IRExecutionUnit.h"
#include "lldb/Expression/IRInterpreter.h"
#include "lldb/Expression/Materializer.h"
#include "lldb/Host/HostInfo.h"
#include "lldb/Symbol/Block.h"
#include "lldb/Symbol/ClangASTContext.h"
#include "lldb/Symbol/ClangExternalASTSourceCommon.h"
#include "lldb/Symbol/Function.h"
#include "lldb/Symbol/ObjectFile.h"
#include "lldb/Symbol/SymbolVendor.h"
#include "lldb/Symbol/Type.h"
#include "lldb/Symbol/VariableList.h"
#include "lldb/Target/ExecutionContext.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/StackFrame.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/ThreadPlan.h"
#include "lldb/Target/ThreadPlanCallUserExpression.h"
#include "lldb/Utility/ConstString.h"
#include "lldb/Utility/Log.h"
#include "lldb/Utility/StreamString.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclObjC.h"
using namespace lldb_private;
ClangUserExpression::ClangUserExpression(
ExecutionContextScope &exe_scope, llvm::StringRef expr,
llvm::StringRef prefix, lldb::LanguageType language,
ResultType desired_type, const EvaluateExpressionOptions &options)
: LLVMUserExpression(exe_scope, expr, prefix, language, desired_type,
options),
m_type_system_helper(*m_target_wp.lock().get(),
options.GetExecutionPolicy() ==
eExecutionPolicyTopLevel),
m_result_delegate(exe_scope.CalculateTarget()) {
switch (m_language) {
case lldb::eLanguageTypeC_plus_plus:
m_allow_cxx = true;
break;
case lldb::eLanguageTypeObjC:
m_allow_objc = true;
break;
case lldb::eLanguageTypeObjC_plus_plus:
default:
m_allow_cxx = true;
m_allow_objc = true;
break;
}
}
ClangUserExpression::~ClangUserExpression() {}
void ClangUserExpression::ScanContext(ExecutionContext &exe_ctx, Status &err) {
Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
if (log)
log->Printf("ClangUserExpression::ScanContext()");
m_target = exe_ctx.GetTargetPtr();
if (!(m_allow_cxx || m_allow_objc)) {
if (log)
log->Printf(" [CUE::SC] Settings inhibit C++ and Objective-C");
return;
}
StackFrame *frame = exe_ctx.GetFramePtr();
if (frame == NULL) {
if (log)
log->Printf(" [CUE::SC] Null stack frame");
return;
}
SymbolContext sym_ctx = frame->GetSymbolContext(lldb::eSymbolContextFunction |
lldb::eSymbolContextBlock);
if (!sym_ctx.function) {
if (log)
log->Printf(" [CUE::SC] Null function");
return;
}
// Find the block that defines the function represented by "sym_ctx"
Block *function_block = sym_ctx.GetFunctionBlock();
if (!function_block) {
if (log)
log->Printf(" [CUE::SC] Null function block");
return;
}
CompilerDeclContext decl_context = function_block->GetDeclContext();
if (!decl_context) {
if (log)
log->Printf(" [CUE::SC] Null decl context");
return;
}
if (clang::CXXMethodDecl *method_decl =
ClangASTContext::DeclContextGetAsCXXMethodDecl(decl_context)) {
if (m_allow_cxx && method_decl->isInstance()) {
if (m_enforce_valid_object) {
lldb::VariableListSP variable_list_sp(
function_block->GetBlockVariableList(true));
const char *thisErrorString = "Stopped in a C++ method, but 'this' "
"isn't available; pretending we are in a "
"generic context";
if (!variable_list_sp) {
err.SetErrorString(thisErrorString);
return;
}
lldb::VariableSP this_var_sp(
variable_list_sp->FindVariable(ConstString("this")));
if (!this_var_sp || !this_var_sp->IsInScope(frame) ||
!this_var_sp->LocationIsValidForFrame(frame)) {
err.SetErrorString(thisErrorString);
return;
}
}
m_in_cplusplus_method = true;
m_needs_object_ptr = true;
}
} else if (clang::ObjCMethodDecl *method_decl =
ClangASTContext::DeclContextGetAsObjCMethodDecl(
decl_context)) {
if (m_allow_objc) {
if (m_enforce_valid_object) {
lldb::VariableListSP variable_list_sp(
function_block->GetBlockVariableList(true));
const char *selfErrorString = "Stopped in an Objective-C method, but "
"'self' isn't available; pretending we "
"are in a generic context";
if (!variable_list_sp) {
err.SetErrorString(selfErrorString);
return;
}
lldb::VariableSP self_variable_sp =
variable_list_sp->FindVariable(ConstString("self"));
if (!self_variable_sp || !self_variable_sp->IsInScope(frame) ||
!self_variable_sp->LocationIsValidForFrame(frame)) {
err.SetErrorString(selfErrorString);
return;
}
}
m_in_objectivec_method = true;
m_needs_object_ptr = true;
if (!method_decl->isInstanceMethod())
m_in_static_method = true;
}
} else if (clang::FunctionDecl *function_decl =
ClangASTContext::DeclContextGetAsFunctionDecl(decl_context)) {
// We might also have a function that said in the debug information that it
// captured an object pointer. The best way to deal with getting to the
// ivars at present is by pretending that this is a method of a class in
// whatever runtime the debug info says the object pointer belongs to. Do
// that here.
ClangASTMetadata *metadata =
ClangASTContext::DeclContextGetMetaData(decl_context, function_decl);
if (metadata && metadata->HasObjectPtr()) {
lldb::LanguageType language = metadata->GetObjectPtrLanguage();
if (language == lldb::eLanguageTypeC_plus_plus) {
if (m_enforce_valid_object) {
lldb::VariableListSP variable_list_sp(
function_block->GetBlockVariableList(true));
const char *thisErrorString = "Stopped in a context claiming to "
"capture a C++ object pointer, but "
"'this' isn't available; pretending we "
"are in a generic context";
if (!variable_list_sp) {
err.SetErrorString(thisErrorString);
return;
}
lldb::VariableSP this_var_sp(
variable_list_sp->FindVariable(ConstString("this")));
if (!this_var_sp || !this_var_sp->IsInScope(frame) ||
!this_var_sp->LocationIsValidForFrame(frame)) {
err.SetErrorString(thisErrorString);
return;
}
}
m_in_cplusplus_method = true;
m_needs_object_ptr = true;
} else if (language == lldb::eLanguageTypeObjC) {
if (m_enforce_valid_object) {
lldb::VariableListSP variable_list_sp(
function_block->GetBlockVariableList(true));
const char *selfErrorString =
"Stopped in a context claiming to capture an Objective-C object "
"pointer, but 'self' isn't available; pretending we are in a "
"generic context";
if (!variable_list_sp) {
err.SetErrorString(selfErrorString);
return;
}
lldb::VariableSP self_variable_sp =
variable_list_sp->FindVariable(ConstString("self"));
if (!self_variable_sp || !self_variable_sp->IsInScope(frame) ||
!self_variable_sp->LocationIsValidForFrame(frame)) {
err.SetErrorString(selfErrorString);
return;
}
Type *self_type = self_variable_sp->GetType();
if (!self_type) {
err.SetErrorString(selfErrorString);
return;
}
CompilerType self_clang_type = self_type->GetForwardCompilerType();
if (!self_clang_type) {
err.SetErrorString(selfErrorString);
return;
}
if (ClangASTContext::IsObjCClassType(self_clang_type)) {
return;
} else if (ClangASTContext::IsObjCObjectPointerType(
self_clang_type)) {
m_in_objectivec_method = true;
m_needs_object_ptr = true;
} else {
err.SetErrorString(selfErrorString);
return;
}
} else {
m_in_objectivec_method = true;
m_needs_object_ptr = true;
}
}
}
}
}
// This is a really nasty hack, meant to fix Objective-C expressions of the
// form (int)[myArray count]. Right now, because the type information for
// count is not available, [myArray count] returns id, which can't be directly
// cast to int without causing a clang error.
static void ApplyObjcCastHack(std::string &expr) {
#define OBJC_CAST_HACK_FROM "(int)["
#define OBJC_CAST_HACK_TO "(int)(long long)["
size_t from_offset;
while ((from_offset = expr.find(OBJC_CAST_HACK_FROM)) != expr.npos)
expr.replace(from_offset, sizeof(OBJC_CAST_HACK_FROM) - 1,
OBJC_CAST_HACK_TO);
#undef OBJC_CAST_HACK_TO
#undef OBJC_CAST_HACK_FROM
}
namespace {
// Utility guard that calls a callback when going out of scope.
class OnExit {
public:
typedef std::function<void(void)> Callback;
OnExit(Callback const &callback) : m_callback(callback) {}
~OnExit() { m_callback(); }
private:
Callback m_callback;
};
} // namespace
bool ClangUserExpression::SetupPersistentState(DiagnosticManager &diagnostic_manager,
ExecutionContext &exe_ctx) {
if (Target *target = exe_ctx.GetTargetPtr()) {
if (PersistentExpressionState *persistent_state =
target->GetPersistentExpressionStateForLanguage(
lldb::eLanguageTypeC)) {
m_result_delegate.RegisterPersistentState(persistent_state);
} else {
diagnostic_manager.PutString(
eDiagnosticSeverityError,
"couldn't start parsing (no persistent data)");
return false;
}
} else {
diagnostic_manager.PutString(eDiagnosticSeverityError,
"error: couldn't start parsing (no target)");
return false;
}
return true;
}
static void SetupDeclVendor(ExecutionContext &exe_ctx, Target *target) {
if (ClangModulesDeclVendor *decl_vendor =
target->GetClangModulesDeclVendor()) {
const ClangModulesDeclVendor::ModuleVector &hand_imported_modules =
llvm::cast<ClangPersistentVariables>(
target->GetPersistentExpressionStateForLanguage(
lldb::eLanguageTypeC))
->GetHandLoadedClangModules();
ClangModulesDeclVendor::ModuleVector modules_for_macros;
for (ClangModulesDeclVendor::ModuleID module : hand_imported_modules) {
modules_for_macros.push_back(module);
}
if (target->GetEnableAutoImportClangModules()) {
if (StackFrame *frame = exe_ctx.GetFramePtr()) {
if (Block *block = frame->GetFrameBlock()) {
SymbolContext sc;
block->CalculateSymbolContext(&sc);
if (sc.comp_unit) {
StreamString error_stream;
decl_vendor->AddModulesForCompileUnit(
*sc.comp_unit, modules_for_macros, error_stream);
}
}
}
}
}
}
llvm::Optional<lldb::LanguageType> ClangUserExpression::GetLanguageForExpr(
DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx) {
lldb::LanguageType lang_type = lldb::LanguageType::eLanguageTypeUnknown;
std::string prefix = m_expr_prefix;
if (m_options.GetExecutionPolicy() == eExecutionPolicyTopLevel) {
m_transformed_text = m_expr_text;
} else {
std::unique_ptr<ExpressionSourceCode> source_code(
ExpressionSourceCode::CreateWrapped(prefix.c_str(),
m_expr_text.c_str()));
if (m_in_cplusplus_method)
lang_type = lldb::eLanguageTypeC_plus_plus;
else if (m_in_objectivec_method)
lang_type = lldb::eLanguageTypeObjC;
else
lang_type = lldb::eLanguageTypeC;
if (!source_code->GetText(m_transformed_text, lang_type, m_in_static_method,
exe_ctx)) {
diagnostic_manager.PutString(eDiagnosticSeverityError,
"couldn't construct expression body");
return llvm::Optional<lldb::LanguageType>();
}
}
return lang_type;
}
bool ClangUserExpression::PrepareForParsing(
DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx) {
InstallContext(exe_ctx);
if (!SetupPersistentState(diagnostic_manager, exe_ctx))
return false;
Status err;
ScanContext(exe_ctx, err);
if (!err.Success()) {
diagnostic_manager.PutString(eDiagnosticSeverityWarning, err.AsCString());
}
////////////////////////////////////
// Generate the expression
//
ApplyObjcCastHack(m_expr_text);
SetupDeclVendor(exe_ctx, m_target);
return true;
}
bool ClangUserExpression::Parse(DiagnosticManager &diagnostic_manager,
ExecutionContext &exe_ctx,
lldb_private::ExecutionPolicy execution_policy,
bool keep_result_in_memory,
bool generate_debug_info) {
Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
if (!PrepareForParsing(diagnostic_manager, exe_ctx))
return false;
lldb::LanguageType lang_type = lldb::LanguageType::eLanguageTypeUnknown;
if (auto new_lang = GetLanguageForExpr(diagnostic_manager, exe_ctx)) {
lang_type = new_lang.getValue();
}
if (log)
log->Printf("Parsing the following code:\n%s", m_transformed_text.c_str());
////////////////////////////////////
// Set up the target and compiler
//
Target *target = exe_ctx.GetTargetPtr();
if (!target) {
diagnostic_manager.PutString(eDiagnosticSeverityError, "invalid target");
return false;
}
//////////////////////////
// Parse the expression
//
m_materializer_ap.reset(new Materializer());
ResetDeclMap(exe_ctx, m_result_delegate, keep_result_in_memory);
OnExit on_exit([this]() { ResetDeclMap(); });
if (!DeclMap()->WillParse(exe_ctx, m_materializer_ap.get())) {
diagnostic_manager.PutString(
eDiagnosticSeverityError,
"current process state is unsuitable for expression parsing");
return false;
}
if (m_options.GetExecutionPolicy() == eExecutionPolicyTopLevel) {
DeclMap()->SetLookupsEnabled(true);
}
Process *process = exe_ctx.GetProcessPtr();
ExecutionContextScope *exe_scope = process;
if (!exe_scope)
exe_scope = exe_ctx.GetTargetPtr();
// We use a shared pointer here so we can use the original parser - if it
// succeeds or the rewrite parser we might make if it fails. But the
// parser_sp will never be empty.
ClangExpressionParser parser(exe_scope, *this, generate_debug_info);
unsigned num_errors = parser.Parse(diagnostic_manager);
// Check here for FixItHints. If there are any try to apply the fixits and
// set the fixed text in m_fixed_text before returning an error.
if (num_errors) {
if (diagnostic_manager.HasFixIts()) {
if (parser.RewriteExpression(diagnostic_manager)) {
size_t fixed_start;
size_t fixed_end;
const std::string &fixed_expression =
diagnostic_manager.GetFixedExpression();
if (ExpressionSourceCode::GetOriginalBodyBounds(
fixed_expression, lang_type, fixed_start, fixed_end))
m_fixed_text =
fixed_expression.substr(fixed_start, fixed_end - fixed_start);
}
}
return false;
}
//////////////////////////////////////////////////////////////////////////////////////////
// Prepare the output of the parser for execution, evaluating it statically
// if possible
//
{
Status jit_error = parser.PrepareForExecution(
m_jit_start_addr, m_jit_end_addr, m_execution_unit_sp, exe_ctx,
m_can_interpret, execution_policy);
if (!jit_error.Success()) {
const char *error_cstr = jit_error.AsCString();
if (error_cstr && error_cstr[0])
diagnostic_manager.PutString(eDiagnosticSeverityError, error_cstr);
else
diagnostic_manager.PutString(eDiagnosticSeverityError,
"expression can't be interpreted or run");
return false;
}
}
if (exe_ctx.GetProcessPtr() && execution_policy == eExecutionPolicyTopLevel) {
Status static_init_error =
parser.RunStaticInitializers(m_execution_unit_sp, exe_ctx);
if (!static_init_error.Success()) {
const char *error_cstr = static_init_error.AsCString();
if (error_cstr && error_cstr[0])
diagnostic_manager.Printf(eDiagnosticSeverityError,
"couldn't run static initializers: %s\n",
error_cstr);
else
diagnostic_manager.PutString(eDiagnosticSeverityError,
"couldn't run static initializers\n");
return false;
}
}
if (m_execution_unit_sp) {
bool register_execution_unit = false;
if (m_options.GetExecutionPolicy() == eExecutionPolicyTopLevel) {
register_execution_unit = true;
}
// If there is more than one external function in the execution unit, it
// needs to keep living even if it's not top level, because the result
// could refer to that function.
if (m_execution_unit_sp->GetJittedFunctions().size() > 1) {
register_execution_unit = true;
}
if (register_execution_unit) {
llvm::cast<PersistentExpressionState>(
exe_ctx.GetTargetPtr()->GetPersistentExpressionStateForLanguage(
m_language))
->RegisterExecutionUnit(m_execution_unit_sp);
}
}
if (generate_debug_info) {
lldb::ModuleSP jit_module_sp(m_execution_unit_sp->GetJITModule());
if (jit_module_sp) {
ConstString const_func_name(FunctionName());
FileSpec jit_file;
jit_file.GetFilename() = const_func_name;
jit_module_sp->SetFileSpecAndObjectName(jit_file, ConstString());
m_jit_module_wp = jit_module_sp;
target->GetImages().Append(jit_module_sp);
}
}
if (process && m_jit_start_addr != LLDB_INVALID_ADDRESS)
m_jit_process_wp = lldb::ProcessWP(process->shared_from_this());
return true;
}
bool ClangUserExpression::AddArguments(ExecutionContext &exe_ctx,
std::vector<lldb::addr_t> &args,
lldb::addr_t struct_address,
DiagnosticManager &diagnostic_manager) {
lldb::addr_t object_ptr = LLDB_INVALID_ADDRESS;
lldb::addr_t cmd_ptr = LLDB_INVALID_ADDRESS;
if (m_needs_object_ptr) {
lldb::StackFrameSP frame_sp = exe_ctx.GetFrameSP();
if (!frame_sp)
return true;
ConstString object_name;
if (m_in_cplusplus_method) {
object_name.SetCString("this");
} else if (m_in_objectivec_method) {
object_name.SetCString("self");
} else {
diagnostic_manager.PutString(
eDiagnosticSeverityError,
"need object pointer but don't know the language");
return false;
}
Status object_ptr_error;
object_ptr = GetObjectPointer(frame_sp, object_name, object_ptr_error);
if (!object_ptr_error.Success()) {
exe_ctx.GetTargetRef().GetDebugger().GetAsyncOutputStream()->Printf(
"warning: `%s' is not accessible (substituting 0)\n",
object_name.AsCString());
object_ptr = 0;
}
if (m_in_objectivec_method) {
ConstString cmd_name("_cmd");
cmd_ptr = GetObjectPointer(frame_sp, cmd_name, object_ptr_error);
if (!object_ptr_error.Success()) {
diagnostic_manager.Printf(
eDiagnosticSeverityWarning,
"couldn't get cmd pointer (substituting NULL): %s",
object_ptr_error.AsCString());
cmd_ptr = 0;
}
}
args.push_back(object_ptr);
if (m_in_objectivec_method)
args.push_back(cmd_ptr);
args.push_back(struct_address);
} else {
args.push_back(struct_address);
}
return true;
}
lldb::ExpressionVariableSP ClangUserExpression::GetResultAfterDematerialization(
ExecutionContextScope *exe_scope) {
return m_result_delegate.GetVariable();
}
void ClangUserExpression::ClangUserExpressionHelper::ResetDeclMap(
ExecutionContext &exe_ctx,
Materializer::PersistentVariableDelegate &delegate,
bool keep_result_in_memory) {
m_expr_decl_map_up.reset(
new ClangExpressionDeclMap(keep_result_in_memory, &delegate, exe_ctx));
}
clang::ASTConsumer *
ClangUserExpression::ClangUserExpressionHelper::ASTTransformer(
clang::ASTConsumer *passthrough) {
m_result_synthesizer_up.reset(
new ASTResultSynthesizer(passthrough, m_top_level, m_target));
return m_result_synthesizer_up.get();
}
void ClangUserExpression::ClangUserExpressionHelper::CommitPersistentDecls() {
if (m_result_synthesizer_up.get()) {
m_result_synthesizer_up->CommitPersistentDecls();
}
}
ConstString ClangUserExpression::ResultDelegate::GetName() {
auto prefix = m_persistent_state->GetPersistentVariablePrefix();
return m_persistent_state->GetNextPersistentVariableName(*m_target_sp,
prefix);
}
void ClangUserExpression::ResultDelegate::DidDematerialize(
lldb::ExpressionVariableSP &variable) {
m_variable = variable;
}
void ClangUserExpression::ResultDelegate::RegisterPersistentState(
PersistentExpressionState *persistent_state) {
m_persistent_state = persistent_state;
}
lldb::ExpressionVariableSP &ClangUserExpression::ResultDelegate::GetVariable() {
return m_variable;
}