llvm-project/lldb/source/Core/Value.cpp

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//===-- Value.cpp -----------------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "lldb/Core/Value.h"
// C Includes
// C++ Includes
// Other libraries and framework includes
// Project includes
#include "lldb/Core/DataExtractor.h"
#include "lldb/Core/DataBufferHeap.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/Stream.h"
#include "lldb/Symbol/ClangASTType.h"
#include "lldb/Symbol/ClangASTContext.h"
#include "lldb/Symbol/ObjectFile.h"
#include "lldb/Symbol/SymbolContext.h"
#include "lldb/Symbol/Type.h"
#include "lldb/Symbol/Variable.h"
#include "lldb/Target/ExecutionContext.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/Target.h"
using namespace lldb;
using namespace lldb_private;
Value::Value() :
m_value (),
m_value_type (eValueTypeScalar),
m_context (NULL),
m_context_type (eContextTypeInvalid),
m_data_buffer ()
{
}
Value::Value(const Scalar& scalar) :
m_value (scalar),
m_value_type (eValueTypeScalar),
m_context (NULL),
m_context_type (eContextTypeInvalid),
m_data_buffer ()
{
}
Value::Value(const uint8_t *bytes, int len) :
m_value (),
m_value_type (eValueTypeHostAddress),
m_context (NULL),
m_context_type (eContextTypeInvalid),
m_data_buffer ()
{
m_data_buffer.CopyData(bytes, len);
m_value = (uintptr_t)m_data_buffer.GetBytes();
}
Value::Value(const Value &v) :
m_value(v.m_value),
m_value_type(v.m_value_type),
m_context(v.m_context),
m_context_type(v.m_context_type)
{
if ((uintptr_t)v.m_value.ULongLong(LLDB_INVALID_ADDRESS) == (uintptr_t)v.m_data_buffer.GetBytes())
{
m_data_buffer.CopyData(v.m_data_buffer.GetBytes(),
v.m_data_buffer.GetByteSize());
m_value = (uintptr_t)m_data_buffer.GetBytes();
}
}
Value &
Value::operator=(const Value &rhs)
{
if (this != &rhs)
{
m_value = rhs.m_value;
m_value_type = rhs.m_value_type;
m_context = rhs.m_context;
m_context_type = rhs.m_context_type;
if ((uintptr_t)rhs.m_value.ULongLong(LLDB_INVALID_ADDRESS) == (uintptr_t)rhs.m_data_buffer.GetBytes())
{
m_data_buffer.CopyData(rhs.m_data_buffer.GetBytes(),
rhs.m_data_buffer.GetByteSize());
m_value = (uintptr_t)m_data_buffer.GetBytes();
}
}
return *this;
}
void
Value::Dump (Stream* strm)
{
m_value.GetValue (strm, true);
strm->Printf(", value_type = %s, context = %p, context_type = %s",
Value::GetValueTypeAsCString(m_value_type),
m_context,
Value::GetContextTypeAsCString(m_context_type));
}
Value::ValueType
Value::GetValueType() const
{
return m_value_type;
}
AddressType
Value::GetValueAddressType () const
{
switch (m_value_type)
{
default:
case eValueTypeScalar:
break;
case eValueTypeLoadAddress: return eAddressTypeLoad;
case eValueTypeFileAddress: return eAddressTypeFile;
case eValueTypeHostAddress: return eAddressTypeHost;
}
return eAddressTypeInvalid;
}
RegisterInfo *
Value::GetRegisterInfo()
{
if (m_context_type == eContextTypeRegisterInfo)
return static_cast<RegisterInfo *> (m_context);
return NULL;
}
Type *
Value::GetType()
{
if (m_context_type == eContextTypeLLDBType)
return static_cast<Type *> (m_context);
return NULL;
}
void
Value::ResizeData(int len)
{
m_value_type = eValueTypeHostAddress;
m_data_buffer.SetByteSize(len);
m_value = (uintptr_t)m_data_buffer.GetBytes();
}
bool
Value::ValueOf(ExecutionContext *exe_ctx, clang::ASTContext *ast_context)
{
switch (m_context_type)
{
default:
case eContextTypeInvalid:
case eContextTypeClangType: // clang::Type *
case eContextTypeRegisterInfo: // RegisterInfo *
case eContextTypeLLDBType: // Type *
break;
case eContextTypeVariable: // Variable *
ResolveValue(exe_ctx, ast_context);
return true;
}
return false;
}
size_t
Value::GetValueByteSize (clang::ASTContext *ast_context, Error *error_ptr)
{
size_t byte_size = 0;
switch (m_context_type)
{
default:
case eContextTypeInvalid:
// If we have no context, there is no way to know how much memory to read
if (error_ptr)
error_ptr->SetErrorString ("Invalid context type, there is no way to know how much memory to read.");
break;
case eContextTypeClangType:
if (ast_context == NULL)
{
if (error_ptr)
error_ptr->SetErrorString ("Can't determine size of opaque clang type with NULL ASTContext *.");
}
else
{
uint64_t bit_width = ClangASTType::GetClangTypeBitWidth (ast_context, m_context);
byte_size = (bit_width + 7 ) / 8;
}
break;
case eContextTypeRegisterInfo: // RegisterInfo *
if (GetRegisterInfo())
byte_size = GetRegisterInfo()->byte_size;
else if (error_ptr)
error_ptr->SetErrorString ("Can't determine byte size with NULL RegisterInfo *.");
break;
case eContextTypeLLDBType: // Type *
if (GetType())
byte_size = GetType()->GetByteSize();
else if (error_ptr)
error_ptr->SetErrorString ("Can't determine byte size with NULL Type *.");
break;
case eContextTypeVariable: // Variable *
if (GetVariable())
byte_size = GetVariable()->GetType()->GetByteSize();
else if (error_ptr)
error_ptr->SetErrorString ("Can't determine byte size with NULL Variable *.");
break;
}
if (error_ptr)
{
if (byte_size == 0)
{
if (error_ptr->Success())
error_ptr->SetErrorString("Unable to determine byte size.");
}
else
{
error_ptr->Clear();
}
}
return byte_size;
}
clang_type_t
Value::GetClangType ()
{
switch (m_context_type)
{
default:
case eContextTypeInvalid:
break;
case eContextTypeClangType:
return m_context;
case eContextTypeRegisterInfo:
break; // TODO: Eventually convert into a clang type?
case eContextTypeLLDBType:
if (GetType())
return GetType()->GetClangForwardType();
break;
case eContextTypeVariable:
if (GetVariable())
return GetVariable()->GetType()->GetClangForwardType();
break;
}
return NULL;
}
lldb::Format
Value::GetValueDefaultFormat ()
{
switch (m_context_type)
{
default:
case eContextTypeInvalid:
break;
case eContextTypeClangType:
return ClangASTType::GetFormat (m_context);
case eContextTypeRegisterInfo:
if (GetRegisterInfo())
return GetRegisterInfo()->format;
break;
case eContextTypeLLDBType:
if (GetType())
return GetType()->GetFormat();
break;
case eContextTypeVariable:
if (GetVariable())
return GetVariable()->GetType()->GetFormat();
break;
}
// Return a good default in case we can't figure anything out
return eFormatHex;
}
Modified LLDB expressions to not have to JIT and run code just to see variable values or persistent expression variables. Now if an expression consists of a value that is a child of a variable, or of a persistent variable only, we will create a value object for it and make a ValueObjectConstResult from it to freeze the value (for program variables only, not persistent variables) and avoid running JITed code. For everything else we still parse up and JIT code and run it in the inferior. There was also a lot of clean up in the expression code. I made the ClangExpressionVariables be stored in collections of shared pointers instead of in collections of objects. This will help stop a lot of copy constructors on these large objects and also cleans up the code considerably. The persistent clang expression variables were moved over to the Target to ensure they persist across process executions. Added the ability for lldb_private::Target objects to evaluate expressions. We want to evaluate expressions at the target level in case we aren't running yet, or we have just completed running. We still want to be able to access the persistent expression variables between runs, and also evaluate constant expressions. Added extra logging to the dynamic loader plug-in for MacOSX. ModuleList objects can now dump their contents with the UUID, arch and full paths being logged with appropriate prefix values. Thread hardened the Communication class a bit by making the connection auto_ptr member into a shared pointer member and then making a local copy of the shared pointer in each method that uses it to make sure another thread can't nuke the connection object while it is being used by another thread. Added a new file to the lldb/test/load_unload test that causes the test a.out file to link to the libd.dylib file all the time. This will allow us to test using the DYLD_LIBRARY_PATH environment variable after moving libd.dylib somewhere else. llvm-svn: 121745
2010-12-14 10:59:59 +08:00
bool
Value::GetData (DataExtractor &data)
{
switch (m_value_type)
{
default:
break;
case eValueTypeScalar:
if (m_value.GetData (data))
return true;
break;
case eValueTypeLoadAddress:
case eValueTypeFileAddress:
case eValueTypeHostAddress:
if (m_data_buffer.GetByteSize())
{
data.SetData(m_data_buffer.GetBytes(), m_data_buffer.GetByteSize(), data.GetByteOrder());
return true;
}
break;
}
return false;
}
Error
Value::GetValueAsData (ExecutionContext *exe_ctx,
clang::ASTContext *ast_context,
DataExtractor &data,
uint32_t data_offset,
Module *module)
{
data.Clear();
Error error;
lldb::addr_t address = LLDB_INVALID_ADDRESS;
AddressType address_type = eAddressTypeFile;
Address file_so_addr;
switch (m_value_type)
{
default:
error.SetErrorStringWithFormat("invalid value type %i", m_value_type);
break;
case eValueTypeScalar:
data.SetByteOrder (lldb::endian::InlHostByteOrder());
if (m_context_type == eContextTypeClangType && ast_context)
{
uint32_t ptr_bit_width = ClangASTType::GetClangTypeBitWidth (ast_context,
ClangASTContext::GetVoidPtrType(ast_context, false));
uint32_t ptr_byte_size = (ptr_bit_width + 7) / 8;
data.SetAddressByteSize (ptr_byte_size);
}
else
data.SetAddressByteSize(sizeof(void *));
if (m_value.GetData (data))
return error; // Success;
error.SetErrorStringWithFormat("extracting data from value failed");
break;
case eValueTypeLoadAddress:
if (exe_ctx == NULL)
{
error.SetErrorString ("can't read load address (no execution context)");
}
else
{
Process *process = exe_ctx->GetProcessPtr();
if (process == NULL)
{
error.SetErrorString ("can't read load address (invalid process)");
}
else
{
address = m_value.ULongLong(LLDB_INVALID_ADDRESS);
address_type = eAddressTypeLoad;
data.SetByteOrder(process->GetTarget().GetArchitecture().GetByteOrder());
data.SetAddressByteSize(process->GetTarget().GetArchitecture().GetAddressByteSize());
}
}
break;
case eValueTypeFileAddress:
if (exe_ctx == NULL)
{
error.SetErrorString ("can't read file address (no execution context)");
}
else if (exe_ctx->GetTargetPtr() == NULL)
{
error.SetErrorString ("can't read file address (invalid target)");
}
else
{
address = m_value.ULongLong(LLDB_INVALID_ADDRESS);
if (address == LLDB_INVALID_ADDRESS)
{
error.SetErrorString ("invalid file address");
}
else
{
if (module == NULL)
{
// The only thing we can currently lock down to a module so that
// we can resolve a file address, is a variable.
Variable *variable = GetVariable();
if (variable)
{
SymbolContext var_sc;
variable->CalculateSymbolContext(&var_sc);
module = var_sc.module_sp.get();
}
}
if (module)
{
bool resolved = false;
ObjectFile *objfile = module->GetObjectFile();
if (objfile)
{
Address so_addr(address, objfile->GetSectionList());
addr_t load_address = so_addr.GetLoadAddress (exe_ctx->GetTargetPtr());
if (load_address != LLDB_INVALID_ADDRESS)
{
resolved = true;
address = load_address;
address_type = eAddressTypeLoad;
data.SetByteOrder(exe_ctx->GetTargetRef().GetArchitecture().GetByteOrder());
data.SetAddressByteSize(exe_ctx->GetTargetRef().GetArchitecture().GetAddressByteSize());
}
else
{
if (so_addr.IsSectionOffset())
{
resolved = true;
file_so_addr = so_addr;
data.SetByteOrder(objfile->GetByteOrder());
data.SetAddressByteSize(objfile->GetAddressByteSize());
}
}
}
if (!resolved)
{
Variable *variable = GetVariable();
if (module)
{
if (variable)
error.SetErrorStringWithFormat ("unable to resolve the module for file address 0x%llx for variable '%s' in %s%s%s",
address,
variable->GetName().AsCString(""),
module->GetFileSpec().GetDirectory().GetCString(),
module->GetFileSpec().GetDirectory() ? "/" : "",
module->GetFileSpec().GetFilename().GetCString());
else
error.SetErrorStringWithFormat ("unable to resolve the module for file address 0x%llx in %s%s%s",
address,
module->GetFileSpec().GetDirectory().GetCString(),
module->GetFileSpec().GetDirectory() ? "/" : "",
module->GetFileSpec().GetFilename().GetCString());
}
else
{
if (variable)
error.SetErrorStringWithFormat ("unable to resolve the module for file address 0x%llx for variable '%s'",
address,
variable->GetName().AsCString(""));
else
error.SetErrorStringWithFormat ("unable to resolve the module for file address 0x%llx", address);
}
}
}
else
{
// Can't convert a file address to anything valid without more
// context (which Module it came from)
error.SetErrorString ("can't read memory from file address without more context");
}
}
}
break;
case eValueTypeHostAddress:
address = m_value.ULongLong(LLDB_INVALID_ADDRESS);
data.SetByteOrder(lldb::endian::InlHostByteOrder());
data.SetAddressByteSize(sizeof(void *));
address_type = eAddressTypeHost;
break;
}
// Bail if we encountered any errors
if (error.Fail())
return error;
if (address == LLDB_INVALID_ADDRESS)
{
error.SetErrorStringWithFormat ("invalid %s address", address_type == eAddressTypeHost ? "host" : "load");
return error;
}
// If we got here, we need to read the value from memory
uint32_t byte_size = GetValueByteSize (ast_context, &error);
// Bail if we encountered any errors getting the byte size
if (error.Fail())
return error;
// Make sure we have enough room within "data", and if we don't make
// something large enough that does
if (!data.ValidOffsetForDataOfSize (data_offset, byte_size))
{
DataBufferSP data_sp(new DataBufferHeap (data_offset + byte_size, '\0'));
data.SetData(data_sp);
}
uint8_t* dst = const_cast<uint8_t*>(data.PeekData (data_offset, byte_size));
if (dst != NULL)
{
if (address_type == eAddressTypeHost)
{
// The address is an address in this process, so just copy it
memcpy (dst, (uint8_t*)NULL + address, byte_size);
}
else if ((address_type == eAddressTypeLoad) || (address_type == eAddressTypeFile))
{
if (file_so_addr.IsValid())
{
// We have a file address that we were able to translate into a
// section offset address so we might be able to read this from
// the object files if we don't have a live process. Lets always
// try and read from the process if we have one though since we
// want to read the actual value by setting "prefer_file_cache"
// to false.
const bool prefer_file_cache = false;
if (exe_ctx->GetTargetRef().ReadMemory(file_so_addr, prefer_file_cache, dst, byte_size, error) != byte_size)
{
error.SetErrorStringWithFormat("read memory from 0x%llx failed", (uint64_t)address);
}
}
else
{
// The execution context might have a NULL process, but it
// might have a valid process in the exe_ctx->target, so use
// the ExecutionContext::GetProcess accessor to ensure we
// get the process if there is one.
Process *process = exe_ctx->GetProcessPtr();
if (process)
{
const size_t bytes_read = process->ReadMemory(address, dst, byte_size, error);
if (bytes_read != byte_size)
error.SetErrorStringWithFormat("read memory from 0x%llx failed (%u of %u bytes read)",
(uint64_t)address,
(uint32_t)bytes_read,
(uint32_t)byte_size);
}
else
{
error.SetErrorStringWithFormat("read memory from 0x%llx failed (invalid process)", (uint64_t)address);
}
}
}
else
{
error.SetErrorStringWithFormat ("unsupported AddressType value (%i)", address_type);
}
}
else
{
error.SetErrorStringWithFormat ("out of memory");
}
return error;
}
Scalar &
Value::ResolveValue(ExecutionContext *exe_ctx, clang::ASTContext *ast_context)
{
void *opaque_clang_qual_type = GetClangType();
if (opaque_clang_qual_type)
{
switch (m_value_type)
{
case eValueTypeScalar: // raw scalar value
break;
default:
case eValueTypeFileAddress:
m_value.Clear();
break;
case eValueTypeLoadAddress: // load address value
case eValueTypeHostAddress: // host address value (for memory in the process that is using liblldb)
{
AddressType address_type = m_value_type == eValueTypeLoadAddress ? eAddressTypeLoad : eAddressTypeHost;
lldb::addr_t addr = m_value.ULongLong(LLDB_INVALID_ADDRESS);
DataExtractor data;
if (ClangASTType::ReadFromMemory (ast_context, opaque_clang_qual_type, exe_ctx, addr, address_type, data))
{
Scalar scalar;
if (ClangASTType::GetValueAsScalar (ast_context, opaque_clang_qual_type, data, 0, data.GetByteSize(), scalar))
{
m_value = scalar;
m_value_type = eValueTypeScalar;
}
else
{
if ((uintptr_t)addr != (uintptr_t)m_data_buffer.GetBytes())
{
m_value.Clear();
m_value_type = eValueTypeScalar;
}
}
}
else
{
if ((uintptr_t)addr != (uintptr_t)m_data_buffer.GetBytes())
{
m_value.Clear();
m_value_type = eValueTypeScalar;
}
}
}
break;
}
}
return m_value;
}
Variable *
Value::GetVariable()
{
if (m_context_type == eContextTypeVariable)
return static_cast<Variable *> (m_context);
return NULL;
}
const char *
Value::GetValueTypeAsCString (ValueType value_type)
{
switch (value_type)
{
case eValueTypeScalar: return "scalar";
case eValueTypeFileAddress: return "file address";
case eValueTypeLoadAddress: return "load address";
case eValueTypeHostAddress: return "host address";
};
return "???";
}
const char *
Value::GetContextTypeAsCString (ContextType context_type)
{
switch (context_type)
{
case eContextTypeInvalid: return "invalid";
case eContextTypeClangType: return "clang::Type *";
case eContextTypeRegisterInfo: return "RegisterInfo *";
case eContextTypeLLDBType: return "Type *";
case eContextTypeVariable: return "Variable *";
};
return "???";
}
ValueList::ValueList (const ValueList &rhs)
{
m_values = rhs.m_values;
}
const ValueList &
ValueList::operator= (const ValueList &rhs)
{
m_values = rhs.m_values;
return *this;
}
void
ValueList::PushValue (const Value &value)
{
m_values.push_back (value);
}
size_t
ValueList::GetSize()
{
return m_values.size();
}
Value *
ValueList::GetValueAtIndex (size_t idx)
{
if (idx < GetSize())
{
return &(m_values[idx]);
}
else
return NULL;
}
void
ValueList::Clear ()
{
m_values.clear();
}