Files
clang-p2996/lldb/source/Plugins/ExpressionParser/Clang/ClangUtilityFunction.cpp
Sean Callanan 9fda9d2177 Add PersistentVariableDelegate to handle language-specific dematerialization.
The concept here is that languages may have different ways of communicating
results.  In particular, languages may have different names for their result
variables and in fact may have multiple types of result variables (e.g.,
error results).  Materializer was tied to one specific model of result handling.

Instead, now UserExpressions can register their own handlers for the result
variables they inject.  This allows language-specific code in Materializer to
be moved into the expression parser plug-in, and it simplifies Materializer.
These delegates are subclasses of PersistentVariableDelegate.

PersistentVariableDelegate can provide the name of the result variable, and is
notified when the result variable is populated.  It can also be used to touch
persistent variables if need be, updating language-specific state.  The
UserExpression owns the delegate and can decide on its result based on
consulting all of its (potentially multiple) delegates.

The user expression itself now makes the determination of what the final result
of the expression is, rather than relying on the Materializer, and I've added a
virtual function to UserExpression to allow this.

llvm-svn: 249233
2015-10-03 09:09:01 +00:00

190 lines
5.5 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.
//
//===----------------------------------------------------------------------===//
#include "ClangExpressionDeclMap.h"
#include "ClangExpressionParser.h"
#include "ClangUtilityFunction.h"
// C Includes
#include <stdio.h>
#if HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
// C++ Includes
#include "lldb/Core/ConstString.h"
#include "lldb/Core/Log.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/Stream.h"
#include "lldb/Core/StreamFile.h"
#include "lldb/Expression/ExpressionSourceCode.h"
#include "lldb/Expression/IRExecutionUnit.h"
#include "lldb/Host/Host.h"
#include "lldb/Target/ExecutionContext.h"
#include "lldb/Target/Target.h"
using namespace lldb_private;
//------------------------------------------------------------------
/// Constructor
///
/// @param[in] text
/// The text of the function. Must be a full translation unit.
///
/// @param[in] name
/// The name of the function, as used in the text.
//------------------------------------------------------------------
ClangUtilityFunction::ClangUtilityFunction (ExecutionContextScope &exe_scope,
const char *text,
const char *name) :
UtilityFunction (exe_scope, text, name)
{
}
ClangUtilityFunction::~ClangUtilityFunction ()
{
}
//------------------------------------------------------------------
/// Install the utility function into a process
///
/// @param[in] error_stream
/// A stream to print parse errors and warnings to.
///
/// @param[in] exe_ctx
/// The execution context to install the utility function to.
///
/// @return
/// True on success (no errors); false otherwise.
//------------------------------------------------------------------
bool
ClangUtilityFunction::Install (Stream &error_stream,
ExecutionContext &exe_ctx)
{
if (m_jit_start_addr != LLDB_INVALID_ADDRESS)
{
error_stream.PutCString("error: already installed\n");
return false;
}
////////////////////////////////////
// Set up the target and compiler
//
Target *target = exe_ctx.GetTargetPtr();
if (!target)
{
error_stream.PutCString ("error: invalid target\n");
return false;
}
Process *process = exe_ctx.GetProcessPtr();
if (!process)
{
error_stream.PutCString ("error: invalid process\n");
return false;
}
//////////////////////////
// Parse the expression
//
bool keep_result_in_memory = false;
ResetDeclMap(exe_ctx, keep_result_in_memory);
if (!DeclMap()->WillParse(exe_ctx, NULL))
{
error_stream.PutCString ("error: current process state is unsuitable for expression parsing\n");
return false;
}
const bool generate_debug_info = true;
ClangExpressionParser parser(exe_ctx.GetBestExecutionContextScope(), *this, generate_debug_info);
unsigned num_errors = parser.Parse (error_stream);
if (num_errors)
{
error_stream.Printf ("error: %d errors parsing expression\n", num_errors);
ResetDeclMap();
return false;
}
//////////////////////////////////
// JIT the output of the parser
//
bool can_interpret = false; // should stay that way
Error jit_error = parser.PrepareForExecution (m_jit_start_addr,
m_jit_end_addr,
m_execution_unit_sp,
exe_ctx,
can_interpret,
eExecutionPolicyAlways);
if (m_jit_start_addr != LLDB_INVALID_ADDRESS)
{
m_jit_process_wp = process->shared_from_this();
if (parser.GetGenerateDebugInfo())
{
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 0
// jingham: look here
StreamFile logfile ("/tmp/exprs.txt", "a");
logfile.Printf ("0x%16.16" PRIx64 ": func = %s, source =\n%s\n",
m_jit_start_addr,
m_function_name.c_str(),
m_function_text.c_str());
#endif
DeclMap()->DidParse();
ResetDeclMap();
if (jit_error.Success())
{
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");
return false;
}
}
void
ClangUtilityFunction::ClangUtilityFunctionHelper::ResetDeclMap(ExecutionContext &exe_ctx, bool keep_result_in_memory)
{
m_expr_decl_map_up.reset(new ClangExpressionDeclMap(keep_result_in_memory, nullptr, exe_ctx));
}