[Lldb-commits] [lldb] r172227 - /lldb/trunk/source/Core/Value.cpp

[Greg Clayton]

Author: gclayton
Date: Fri Jan 11 12:01:02 2013
New Revision: 172227

URL: http://llvm.org/viewvc/llvm-project?rev=172227&view=rev
Log:
Modified Value.cpp to share the code that gets the values as bytes (Value::GetValueAsData()) so now Value::ResolveValue() doesn't do its own thing by reading memory directly.

Also modified the Value class so that you can evaluate expressions without a process, yet with some sections loaded in the target. This allows casting pointers that are in data sections to types and being able to evaluate expressions in the data. For example:

(lldb) target create a.out
(lldb) target modules load --file a.out --slide 0
... find address of something in data ...
(lldb) script
expr_opts = lldb.SBExpressionOptions()
v = lldb.target.EvaluateExpression('(foo *)0x1230000', expr_opts)
print v
vv = lldb.value(v)
print v.pt.x

Above we were able to cast a pointer to an address which was in a.out's data
section and print out entire structures and navigate to the child ivars of the expression.


Modified:
    lldb/trunk/source/Core/Value.cpp

Modified: lldb/trunk/source/Core/Value.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Core/Value.cpp?rev=172227&r1=172226&r2=172227&view=diff
==============================================================================
--- lldb/trunk/source/Core/Value.cpp (original)
+++ lldb/trunk/source/Core/Value.cpp Fri Jan 11 12:01:02 2013
@@ -326,7 +326,7 @@
 }
 
 Error
-Value::GetValueAsData (ExecutionContext *exe_ctx, 
+Value::GetValueAsData (ExecutionContext *exe_ctx,
                        clang::ASTContext *ast_context, 
                        DataExtractor &data, 
                        uint32_t data_offset,
@@ -368,9 +368,54 @@
         else 
         {
             Process *process = exe_ctx->GetProcessPtr();
-            if (process == NULL)
+            if (process == NULL || !process->IsAlive())
             {
-                error.SetErrorString ("can't read load address (invalid process)");
+                Target *target = exe_ctx->GetTargetPtr();
+                if (target)
+                {
+                    // Allow expressions to run and evaluate things when the target
+                    // has memory sections loaded. This allows you to use "target modules load"
+                    // to load your executable and any shared libraries, then execute
+                    // commands where you can look at types in data sections.
+                    const SectionLoadList &target_sections = target->GetSectionLoadList();
+                    if (!target_sections.IsEmpty())
+                    {
+                        address = m_value.ULongLong(LLDB_INVALID_ADDRESS);
+                        if (target_sections.ResolveLoadAddress(address, file_so_addr))
+                        {
+                            address_type = eAddressTypeLoad;
+                            data.SetByteOrder(target->GetArchitecture().GetByteOrder());
+                            data.SetAddressByteSize(target->GetArchitecture().GetAddressByteSize());
+                        }
+                        else
+                            address = LLDB_INVALID_ADDRESS;
+                    }
+//                    else
+//                    {
+//                        ModuleSP exe_module_sp (target->GetExecutableModule());
+//                        if (exe_module_sp)
+//                        {
+//                            address = m_value.ULongLong(LLDB_INVALID_ADDRESS);
+//                            if (address != LLDB_INVALID_ADDRESS)
+//                            {
+//                                if (exe_module_sp->ResolveFileAddress(address, file_so_addr))
+//                                {
+//                                    data.SetByteOrder(target->GetArchitecture().GetByteOrder());
+//                                    data.SetAddressByteSize(target->GetArchitecture().GetAddressByteSize());
+//                                    address_type = eAddressTypeFile;
+//                                }
+//                                else
+//                                {
+//                                    address = LLDB_INVALID_ADDRESS;
+//                                }
+//                            }
+//                        }
+//                    }
+                }
+                else
+                {
+                    error.SetErrorString ("can't read load address (invalid process)");
+                }
             }
             else
             {
@@ -602,16 +647,13 @@
 
         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))
+                lldb::addr_t addr = m_value.ULongLong(LLDB_INVALID_ADDRESS);
+                Error error (GetValueAsData (exe_ctx, ast_context, data, 0, NULL));
+                if (error.Success())
                 {
                     Scalar scalar;
                     if (ClangASTType::GetValueAsScalar (ast_context, opaque_clang_qual_type, data, 0, data.GetByteSize(), scalar))