//===-- ClangExpressionDeclMap.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/Expression/ClangExpressionDeclMap.h"

// C Includes
// C++ Includes
// Other libraries and framework includes
// Project includes
#include "lldb/lldb-private.h"
#include "lldb/Core/Address.h"
#include "lldb/Core/Module.h"
#include "lldb/Expression/ClangASTSource.h"
#include "lldb/Symbol/ClangASTContext.h"
#include "lldb/Symbol/CompileUnit.h"
#include "lldb/Symbol/Function.h"
#include "lldb/Symbol/ObjectFile.h"
#include "lldb/Symbol/SymbolContext.h"
#include "lldb/Symbol/Type.h"
#include "lldb/Symbol/TypeList.h"
#include "lldb/Symbol/Variable.h"
#include "lldb/Symbol/VariableList.h"
#include "lldb/Target/StackFrame.h"
#include "lldb/Target/ExecutionContext.h"

//#define DEBUG_CEDM
#ifdef DEBUG_CEDM
#define DEBUG_PRINTF(...) fprintf(stderr, __VA_ARGS__)
#else
#define DEBUG_PRINTF(...)
#endif

using namespace lldb_private;
using namespace clang;

ClangExpressionDeclMap::ClangExpressionDeclMap(ExecutionContext *exe_ctx) :
    m_exe_ctx(exe_ctx)
{
    if (exe_ctx && exe_ctx->frame)
        m_sym_ctx = new SymbolContext(exe_ctx->frame->GetSymbolContext(lldb::eSymbolContextEverything));
    else
        m_sym_ctx = NULL;
}

ClangExpressionDeclMap::~ClangExpressionDeclMap()
{
    uint32_t num_tuples = m_tuples.size ();
    uint32_t tuple_index;
    
    for (tuple_index = 0; tuple_index < num_tuples; ++tuple_index)
        delete m_tuples[tuple_index].m_value;
    
    if (m_sym_ctx)
        delete m_sym_ctx;
}

bool 
ClangExpressionDeclMap::GetIndexForDecl (uint32_t &index,
                                         const clang::Decl *decl)
{
    uint32_t num_tuples = m_tuples.size ();
    uint32_t tuple_index;
    
    for (tuple_index = 0; tuple_index < num_tuples; ++tuple_index)
    {
        if (m_tuples[tuple_index].m_decl == decl) 
        {
            index = tuple_index;
            return true;
        }
    }
    
    return false;
}

// Interface for DwarfExpression
Value 
*ClangExpressionDeclMap::GetValueForIndex (uint32_t index)
{
    if (index >= m_tuples.size ())
        return NULL;
    
    return m_tuples[index].m_value;
}

// Interface for ClangASTSource
void 
ClangExpressionDeclMap::GetDecls(NameSearchContext &context,
                                 const char *name)
{
    DEBUG_PRINTF("Hunting for a definition for %s\n", name);
    
    // Back out in all cases where we're not fully initialized
    if (!m_exe_ctx || !m_exe_ctx->frame || !m_sym_ctx)
        return;
    
    Function *function = m_sym_ctx->function;
    Block *block = m_sym_ctx->block;
    
    if (!function || !block)
    {
        DEBUG_PRINTF("function = %p, block = %p\n", function, block);
        return;
    }
    
    BlockList& blocks = function->GetBlocks(true);
    
    lldb::user_id_t current_block_id = block->GetID();
    
    ConstString name_cs(name);
    
    for (current_block_id = block->GetID();
         current_block_id != Block::InvalidID;
         current_block_id = blocks.GetParent(current_block_id))
    {
        Block *current_block = blocks.GetBlockByID(current_block_id);
        
        lldb::VariableListSP var_list = current_block->GetVariableList(false, true);
        
        if (!var_list)
            continue;
        
        lldb::VariableSP var = var_list->FindVariable(name_cs);
        
        if (!var)
            continue;
        
        AddOneVariable(context, var.get());
        return;
    }
    
    {
        CompileUnit *compile_unit = m_sym_ctx->comp_unit;
        
        if (!compile_unit)
        {
            DEBUG_PRINTF("compile_unit = %p\n", compile_unit);
            return;
        }
        
        lldb::VariableListSP var_list = compile_unit->GetVariableList(true);
        
        if (!var_list)
            return;
        
        lldb::VariableSP var = var_list->FindVariable(name_cs);
        
        if (!var)
            return;
        
        AddOneVariable(context, var.get());
        return;
    }
}

void
ClangExpressionDeclMap::AddOneVariable(NameSearchContext &context,
                                       Variable* var)
{
    Type *var_type = var->GetType();
    
    if (!var_type) 
    {
        DEBUG_PRINTF("Skipped a definition for %s because it has no type\n", name);
        return;
    }
    
    void *var_opaque_type = var_type->GetOpaqueClangQualType();
    
    if (!var_opaque_type)
    {
        DEBUG_PRINTF("Skipped a definition for %s because it has no Clang type\n", name);
        return;
    }
    
    DWARFExpression &var_location_expr = var->LocationExpression();
    
    TypeList *type_list = var_type->GetTypeList();
    
    if (!type_list)
    {
        DEBUG_PRINTF("Skipped a definition for %s because the type has no associated type list\n", name);
        return;
    }
    
    clang::ASTContext *exe_ast_ctx = type_list->GetClangASTContext().getASTContext();
    
    if (!exe_ast_ctx)
    {
        DEBUG_PRINTF("There is no AST context for the current execution context\n");
        return;
    }
    
    std::auto_ptr<Value> var_location(new Value);
    
    Error err;
    
    if (!var_location_expr.Evaluate(m_exe_ctx, exe_ast_ctx, NULL, *var_location.get(), &err))
    {
        DEBUG_PRINTF("Error evaluating the location of %s: %s\n", name, err.AsCString());
        return;
    }
    
    void *copied_type = ClangASTContext::CopyType(context.GetASTContext(), type_list->GetClangASTContext().getASTContext(), var_opaque_type);
    
    if (var_location.get()->GetContextType() == Value::eContextTypeInvalid)
        var_location.get()->SetContext(Value::eContextTypeOpaqueClangQualType, copied_type);
    
    if (var_location.get()->GetValueType() == Value::eValueTypeFileAddress)
    {
        SymbolContext var_sc;
        var->CalculateSymbolContext(&var_sc);
    
        if (!var_sc.module_sp)
            return;
        
        ObjectFile *object_file = var_sc.module_sp->GetObjectFile();
        
        if (!object_file)
            return;
    
        Address so_addr(var_location->GetScalar().ULongLong(), object_file->GetSectionList());
        
        lldb::addr_t load_addr = so_addr.GetLoadAddress(m_exe_ctx->process);
        
        var_location->GetScalar() = load_addr;
        var_location->SetValueType(Value::eValueTypeLoadAddress);
    }
    
    NamedDecl *var_decl = context.AddVarDecl(copied_type);
    
    Tuple tuple;
    
    tuple.m_decl  = var_decl;
    tuple.m_value = var_location.release();
    
    m_tuples.push_back(tuple);
    
    DEBUG_PRINTF("Found for a definition for %s\n", name);    
}