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

707 lines
26 KiB
C++

//===-- ClangUserExpression.cpp ---------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// C Includes
#include <stdio.h>
#if HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
// C++ Includes
#include <cstdlib>
#include <string>
#include <map>
#include "lldb/Core/ConstString.h"
#include "lldb/Core/Log.h"
#include "lldb/Core/StreamFile.h"
#include "lldb/Core/StreamString.h"
#include "lldb/Core/ValueObjectConstResult.h"
#include "lldb/Expression/ASTResultSynthesizer.h"
#include "lldb/Expression/ClangExpressionDeclMap.h"
#include "lldb/Expression/ClangExpressionParser.h"
#include "lldb/Expression/ClangFunction.h"
#include "lldb/Expression/ClangUserExpression.h"
#include "lldb/Host/Host.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"
using namespace lldb_private;
ClangUserExpression::ClangUserExpression (const char *expr,
const char *expr_prefix) :
ClangExpression (),
m_expr_text (expr),
m_expr_prefix (expr_prefix ? expr_prefix : ""),
m_transformed_text (),
m_desired_type (NULL, NULL),
m_cplusplus (false),
m_objectivec (false),
m_needs_object_ptr (false),
m_const_object (false),
m_const_result ()
{
}
ClangUserExpression::~ClangUserExpression ()
{
}
clang::ASTConsumer *
ClangUserExpression::ASTTransformer (clang::ASTConsumer *passthrough)
{
return new ASTResultSynthesizer(passthrough,
m_desired_type);
}
void
ClangUserExpression::ScanContext(ExecutionContext &exe_ctx)
{
if (!exe_ctx.frame)
return;
VariableList *vars = exe_ctx.frame->GetVariableList(false);
if (!vars)
return;
lldb::VariableSP this_var(vars->FindVariable(ConstString("this")));
lldb::VariableSP self_var(vars->FindVariable(ConstString("self")));
if (this_var.get())
{
Type *this_type = this_var->GetType();
lldb::clang_type_t pointer_target_type;
if (ClangASTContext::IsPointerType(this_type->GetClangForwardType(),
&pointer_target_type))
{
TypeFromUser target_ast_type(pointer_target_type, this_type->GetClangAST());
if (ClangASTContext::IsCXXClassType(target_ast_type.GetOpaqueQualType()))
{
m_cplusplus = true;
if (target_ast_type.IsConst())
m_const_object = true;
}
}
}
else if (self_var.get())
{
m_objectivec = 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
}
// Another hack, meant to allow use of unichar despite it not being available in
// the type information. Although we could special-case it in type lookup,
// hopefully we'll figure out a way to #include the same environment as is
// present in the original source file rather than try to hack specific type
// definitions in as needed.
static void
ApplyUnicharHack(std::string &expr)
{
#define UNICHAR_HACK_FROM "unichar"
#define UNICHAR_HACK_TO "unsigned short"
size_t from_offset;
while ((from_offset = expr.find(UNICHAR_HACK_FROM)) != expr.npos)
expr.replace(from_offset, sizeof(UNICHAR_HACK_FROM) - 1, UNICHAR_HACK_TO);
#undef UNICHAR_HACK_TO
#undef UNICHAR_HACK_FROM
}
bool
ClangUserExpression::Parse (Stream &error_stream,
ExecutionContext &exe_ctx,
TypeFromUser desired_type,
bool keep_result_in_memory)
{
lldb::LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
ScanContext(exe_ctx);
StreamString m_transformed_stream;
////////////////////////////////////
// Generate the expression
//
ApplyObjcCastHack(m_expr_text);
//ApplyUnicharHack(m_expr_text);
if (m_cplusplus)
{
m_transformed_stream.Printf("%s \n"
"typedef unsigned short unichar; \n"
"void \n"
"$__lldb_class::%s(void *$__lldb_arg) %s\n"
"{ \n"
" %s; \n"
"} \n",
m_expr_prefix.c_str(),
FunctionName(),
(m_const_object ? "const" : ""),
m_expr_text.c_str());
m_needs_object_ptr = true;
}
else if(m_objectivec)
{
const char *function_name = FunctionName();
m_transformed_stream.Printf("%s \n"
"typedef unsigned short unichar; \n"
"@interface $__lldb_objc_class ($__lldb_category) \n"
"-(void)%s:(void *)$__lldb_arg; \n"
"@end \n"
"@implementation $__lldb_objc_class ($__lldb_category) \n"
"-(void)%s:(void *)$__lldb_arg \n"
"{ \n"
" %s; \n"
"} \n"
"@end \n",
m_expr_prefix.c_str(),
function_name,
function_name,
m_expr_text.c_str());
m_needs_object_ptr = true;
}
else
{
m_transformed_stream.Printf("%s \n"
"typedef unsigned short unichar;\n"
"void \n"
"%s(void *$__lldb_arg) \n"
"{ \n"
" %s; \n"
"} \n",
m_expr_prefix.c_str(),
FunctionName(),
m_expr_text.c_str());
}
m_transformed_text = m_transformed_stream.GetData();
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.target;
if (!target)
{
error_stream.PutCString ("error: invalid target\n");
return false;
}
//////////////////////////
// Parse the expression
//
m_desired_type = desired_type;
m_expr_decl_map.reset(new ClangExpressionDeclMap(keep_result_in_memory));
m_expr_decl_map->WillParse(exe_ctx);
ClangExpressionParser parser(exe_ctx.process, *this);
unsigned num_errors = parser.Parse (error_stream);
if (num_errors)
{
error_stream.Printf ("error: %d errors parsing expression\n", num_errors);
m_expr_decl_map->DidParse();
return false;
}
///////////////////////////////////////////////
// Convert the output of the parser to DWARF
//
m_dwarf_opcodes.reset(new StreamString);
m_dwarf_opcodes->SetByteOrder (lldb::endian::InlHostByteOrder());
m_dwarf_opcodes->GetFlags ().Set (Stream::eBinary);
m_local_variables.reset(new ClangExpressionVariableList());
Error dwarf_error = parser.MakeDWARF ();
if (dwarf_error.Success())
{
if (log)
log->Printf("Code can be interpreted.");
m_expr_decl_map->DidParse();
return true;
}
//////////////////////////////////
// JIT the output of the parser
//
m_dwarf_opcodes.reset();
m_data_allocator.reset(new ProcessDataAllocator(*exe_ctx.process));
Error jit_error = parser.MakeJIT (m_jit_alloc, m_jit_start_addr, m_jit_end_addr, exe_ctx, m_data_allocator.get(), m_const_result, true);
if (log)
{
StreamString dump_string;
m_data_allocator->Dump(dump_string);
log->Printf("Data buffer contents:\n%s", dump_string.GetString().c_str());
}
m_expr_decl_map->DidParse();
if (jit_error.Success())
{
if (exe_ctx.process && m_jit_alloc != LLDB_INVALID_ADDRESS)
m_jit_process_sp = exe_ctx.process->GetSP();
return true;
}
else
{
const char *error_cstr = jit_error.AsCString();
if (error_cstr && error_cstr[0])
error_stream.Printf ("error: %s\n", error_cstr);
else
error_stream.Printf ("error: expression can't be interpreted or run\n", num_errors);
return false;
}
}
bool
ClangUserExpression::PrepareToExecuteJITExpression (Stream &error_stream,
ExecutionContext &exe_ctx,
lldb::addr_t &struct_address,
lldb::addr_t &object_ptr,
lldb::addr_t &cmd_ptr)
{
lldb::LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
if (m_jit_start_addr != LLDB_INVALID_ADDRESS)
{
Error materialize_error;
if (m_needs_object_ptr)
{
ConstString object_name;
if (m_cplusplus)
{
object_name.SetCString("this");
}
else if (m_objectivec)
{
object_name.SetCString("self");
}
else
{
error_stream.Printf("Need object pointer but don't know the language\n");
return false;
}
if (!(m_expr_decl_map->GetObjectPointer(object_ptr, object_name, exe_ctx, materialize_error)))
{
error_stream.Printf("Couldn't get required object pointer: %s\n", materialize_error.AsCString());
return false;
}
if (m_objectivec)
{
ConstString cmd_name("_cmd");
if (!(m_expr_decl_map->GetObjectPointer(cmd_ptr, cmd_name, exe_ctx, materialize_error, true)))
{
error_stream.Printf("Couldn't get required object pointer: %s\n", materialize_error.AsCString());
return false;
}
}
}
if (!m_expr_decl_map->Materialize(exe_ctx, struct_address, materialize_error))
{
error_stream.Printf("Couldn't materialize struct: %s\n", materialize_error.AsCString());
return false;
}
#if 0
// jingham: look here
StreamFile logfile ("/tmp/exprs.txt", "a");
logfile.Printf("0x%16.16llx: thread = 0x%4.4x, expr = '%s'\n", m_jit_start_addr, exe_ctx.thread ? exe_ctx.thread->GetID() : -1, m_expr_text.c_str());
#endif
if (log)
{
log->Printf("-- [ClangUserExpression::PrepareToExecuteJITExpression] Materializing for execution --");
log->Printf(" Function address : 0x%llx", (uint64_t)m_jit_start_addr);
if (m_needs_object_ptr)
log->Printf(" Object pointer : 0x%llx", (uint64_t)object_ptr);
log->Printf(" Structure address : 0x%llx", (uint64_t)struct_address);
StreamString args;
Error dump_error;
if (struct_address)
{
if (!m_expr_decl_map->DumpMaterializedStruct(exe_ctx, args, dump_error))
{
log->Printf(" Couldn't extract variable values : %s", dump_error.AsCString("unknown error"));
}
else
{
log->Printf(" Structure contents:\n%s", args.GetData());
}
}
}
}
return true;
}
ThreadPlan *
ClangUserExpression::GetThreadPlanToExecuteJITExpression (Stream &error_stream,
ExecutionContext &exe_ctx)
{
lldb::addr_t struct_address;
lldb::addr_t object_ptr = NULL;
lldb::addr_t cmd_ptr = NULL;
PrepareToExecuteJITExpression (error_stream, exe_ctx, struct_address, object_ptr, cmd_ptr);
// FIXME: This should really return a ThreadPlanCallUserExpression, in order to make sure that we don't release the
// ClangUserExpression resources before the thread plan finishes execution in the target. But because we are
// forcing unwind_on_error to be true here, in practical terms that can't happen.
return ClangFunction::GetThreadPlanToCallFunction (exe_ctx,
m_jit_start_addr,
struct_address,
error_stream,
true,
true,
(m_needs_object_ptr ? &object_ptr : NULL),
(m_needs_object_ptr && m_objectivec) ? &cmd_ptr : NULL);
}
bool
ClangUserExpression::FinalizeJITExecution (Stream &error_stream,
ExecutionContext &exe_ctx,
lldb::ClangExpressionVariableSP &result,
lldb::addr_t function_stack_pointer)
{
Error expr_error;
lldb::LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
if (log)
{
log->Printf("-- [ClangUserExpression::FinalizeJITExecution] Dematerializing after execution --");
StreamString args;
Error dump_error;
if (!m_expr_decl_map->DumpMaterializedStruct(exe_ctx, args, dump_error))
{
log->Printf(" Couldn't extract variable values : %s", dump_error.AsCString("unknown error"));
}
else
{
log->Printf(" Structure contents:\n%s", args.GetData());
}
}
lldb::addr_t function_stack_bottom = function_stack_pointer - Host::GetPageSize();
if (!m_expr_decl_map->Dematerialize(exe_ctx, result, function_stack_pointer, function_stack_bottom, expr_error))
{
error_stream.Printf ("Couldn't dematerialize struct : %s\n", expr_error.AsCString("unknown error"));
return false;
}
return true;
}
ExecutionResults
ClangUserExpression::Execute (Stream &error_stream,
ExecutionContext &exe_ctx,
bool discard_on_error,
ClangUserExpression::ClangUserExpressionSP &shared_ptr_to_me,
lldb::ClangExpressionVariableSP &result)
{
// The expression log is quite verbose, and if you're just tracking the execution of the
// expression, it's quite convenient to have these logs come out with the STEP log as well.
lldb::LogSP log(lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_EXPRESSIONS | LIBLLDB_LOG_STEP));
if (m_dwarf_opcodes.get())
{
// TODO execute the JITted opcodes
error_stream.Printf("We don't currently support executing DWARF expressions");
return eExecutionSetupError;
}
else if (m_jit_start_addr != LLDB_INVALID_ADDRESS)
{
lldb::addr_t struct_address;
lldb::addr_t object_ptr = NULL;
lldb::addr_t cmd_ptr = NULL;
if (!PrepareToExecuteJITExpression (error_stream, exe_ctx, struct_address, object_ptr, cmd_ptr))
return eExecutionSetupError;
const bool stop_others = true;
const bool try_all_threads = true;
Address wrapper_address (NULL, m_jit_start_addr);
lldb::ThreadPlanSP call_plan_sp(new ThreadPlanCallUserExpression (*(exe_ctx.thread),
wrapper_address,
struct_address,
stop_others,
discard_on_error,
(m_needs_object_ptr ? &object_ptr : NULL),
((m_needs_object_ptr && m_objectivec) ? &cmd_ptr : NULL),
shared_ptr_to_me));
if (call_plan_sp == NULL || !call_plan_sp->ValidatePlan (NULL))
return eExecutionSetupError;
lldb::addr_t function_stack_pointer = static_cast<ThreadPlanCallFunction *>(call_plan_sp.get())->GetFunctionStackPointer();
call_plan_sp->SetPrivate(true);
uint32_t single_thread_timeout_usec = 500000;
if (log)
log->Printf("-- [ClangUserExpression::Execute] Execution of expression begins --");
ExecutionResults execution_result = exe_ctx.process->RunThreadPlan (exe_ctx,
call_plan_sp,
stop_others,
try_all_threads,
discard_on_error,
single_thread_timeout_usec,
error_stream);
if (log)
log->Printf("-- [ClangUserExpression::Execute] Execution of expression completed --");
if (execution_result == eExecutionInterrupted)
{
const char *error_desc = NULL;
if (call_plan_sp)
{
lldb::StopInfoSP real_stop_info_sp = call_plan_sp->GetRealStopInfo();
if (real_stop_info_sp)
error_desc = real_stop_info_sp->GetDescription();
}
if (error_desc)
error_stream.Printf ("Execution was interrupted, reason: %s.", error_desc);
else
error_stream.Printf ("Execution was interrupted.", error_desc);
if (discard_on_error)
error_stream.Printf ("\nThe process has been returned to the state before execution.");
else
error_stream.Printf ("\nThe process has been left at the point where it was interrupted.");
return execution_result;
}
else if (execution_result != eExecutionCompleted)
{
error_stream.Printf ("Couldn't execute function; result was %s\n", Process::ExecutionResultAsCString (execution_result));
return execution_result;
}
if (FinalizeJITExecution (error_stream, exe_ctx, result, function_stack_pointer))
return eExecutionCompleted;
else
return eExecutionSetupError;
}
else
{
error_stream.Printf("Expression can't be run; neither DWARF nor a JIT compiled function is present");
return eExecutionSetupError;
}
}
StreamString &
ClangUserExpression::DwarfOpcodeStream ()
{
if (!m_dwarf_opcodes.get())
m_dwarf_opcodes.reset(new StreamString());
return *m_dwarf_opcodes.get();
}
ExecutionResults
ClangUserExpression::Evaluate (ExecutionContext &exe_ctx,
bool discard_on_error,
const char *expr_cstr,
const char *expr_prefix,
lldb::ValueObjectSP &result_valobj_sp)
{
lldb::LogSP log(lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_EXPRESSIONS | LIBLLDB_LOG_STEP));
Error error;
ExecutionResults execution_results = eExecutionSetupError;
if (exe_ctx.process == NULL)
{
error.SetErrorString ("Must have a process to evaluate expressions.");
result_valobj_sp = ValueObjectConstResult::Create (NULL, error);
return eExecutionSetupError;
}
if (!exe_ctx.process->GetDynamicCheckers())
{
if (log)
log->Printf("== [ClangUserExpression::Evaluate] Installing dynamic checkers ==");
DynamicCheckerFunctions *dynamic_checkers = new DynamicCheckerFunctions();
StreamString install_errors;
if (!dynamic_checkers->Install(install_errors, exe_ctx))
{
if (install_errors.GetString().empty())
error.SetErrorString ("couldn't install checkers, unknown error");
else
error.SetErrorString (install_errors.GetString().c_str());
result_valobj_sp = ValueObjectConstResult::Create (NULL, error);
return eExecutionSetupError;
}
exe_ctx.process->SetDynamicCheckers(dynamic_checkers);
if (log)
log->Printf("== [ClangUserExpression::Evaluate] Finished installing dynamic checkers ==");
}
ClangUserExpressionSP user_expression_sp (new ClangUserExpression (expr_cstr, expr_prefix));
StreamString error_stream;
if (log)
log->Printf("== [ClangUserExpression::Evaluate] Parsing expression %s ==", expr_cstr);
if (!user_expression_sp->Parse (error_stream, exe_ctx, TypeFromUser(NULL, NULL), true))
{
if (error_stream.GetString().empty())
error.SetErrorString ("expression failed to parse, unknown error");
else
error.SetErrorString (error_stream.GetString().c_str());
}
else
{
lldb::ClangExpressionVariableSP expr_result;
if (user_expression_sp->m_const_result.get())
{
if (log)
log->Printf("== [ClangUserExpression::Evaluate] Expression evaluated as a constant ==");
result_valobj_sp = user_expression_sp->m_const_result->GetValueObject();
}
else
{
error_stream.GetString().clear();
if (log)
log->Printf("== [ClangUserExpression::Evaluate] Executing expression ==");
execution_results = user_expression_sp->Execute (error_stream,
exe_ctx,
discard_on_error,
user_expression_sp,
expr_result);
if (execution_results != eExecutionCompleted)
{
if (log)
log->Printf("== [ClangUserExpression::Evaluate] Execution completed abnormally ==");
if (error_stream.GetString().empty())
error.SetErrorString ("expression failed to execute, unknown error");
else
error.SetErrorString (error_stream.GetString().c_str());
}
else
{
if (expr_result)
{
result_valobj_sp = expr_result->GetValueObject();
if (log)
log->Printf("== [ClangUserExpression::Evaluate] Execution completed normally with result %s ==", result_valobj_sp->GetValueAsCString());
}
else
{
if (log)
log->Printf("== [ClangUserExpression::Evaluate] Execution completed normally with no result ==");
error.SetErrorString ("Expression did not return a result");
}
}
}
}
if (result_valobj_sp.get() == NULL)
result_valobj_sp = ValueObjectConstResult::Create (NULL, error);
return execution_results;
}