[Lldb-commits] [lldb] r177372 - Fixed handling of function pointers in the IR

[Sean Callanan]

Author: spyffe
Date: Mon Mar 18 20:45:02 2013
New Revision: 177372

URL: http://llvm.org/viewvc/llvm-project?rev=177372&view=rev
Log:
Fixed handling of function pointers in the IR
interpreter.  They now have correct values, even
when the process is not running.

Modified:
    lldb/trunk/source/Expression/ClangExpressionDeclMap.cpp
    lldb/trunk/source/Expression/IRInterpreter.cpp

Modified: lldb/trunk/source/Expression/ClangExpressionDeclMap.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Expression/ClangExpressionDeclMap.cpp?rev=177372&r1=177371&r2=177372&view=diff
==============================================================================
--- lldb/trunk/source/Expression/ClangExpressionDeclMap.cpp (original)
+++ lldb/trunk/source/Expression/ClangExpressionDeclMap.cpp Mon Mar 18 20:45:02 2013
@@ -1066,6 +1066,21 @@ ClangExpressionDeclMap::LookupDecl (clan
     ClangExpressionVariableSP expr_var_sp (m_found_entities.GetVariable(decl, GetParserID()));
     ClangExpressionVariableSP persistent_var_sp (m_parser_vars->m_persistent_vars->GetVariable(decl, GetParserID()));
     
+    if (isa<FunctionDecl>(decl))
+    {
+        ClangExpressionVariableSP entity_sp(m_found_entities.GetVariable(decl, GetParserID()));
+        
+        if (!entity_sp)
+            return Value();
+        
+        // We know m_parser_vars is valid since we searched for the variable by
+        // its NamedDecl
+        
+        ClangExpressionVariable::ParserVars *parser_vars = entity_sp->GetParserVars(GetParserID());
+        
+        return *parser_vars->m_lldb_value;
+    }
+    
     if (expr_var_sp)
     {
         flags = expr_var_sp->m_flags;
@@ -3690,8 +3705,21 @@ ClangExpressionDeclMap::AddOneFunction (
     Target *target = m_parser_vars->m_exe_ctx.GetTargetPtr();
 
     lldb::addr_t load_addr = fun_address->GetCallableLoadAddress(target, is_indirect_function);
-    fun_location->SetValueType(Value::eValueTypeLoadAddress);
-    fun_location->GetScalar() = load_addr;
+    
+    if (load_addr != LLDB_INVALID_ADDRESS)
+    {
+        fun_location->SetValueType(Value::eValueTypeLoadAddress);
+        fun_location->GetScalar() = load_addr;
+    }
+    else
+    {
+        // We have to try finding a file address.
+        
+        lldb::addr_t file_addr = fun_address->GetFileAddress();
+        
+        fun_location->SetValueType(Value::eValueTypeFileAddress);
+        fun_location->GetScalar() = file_addr;
+    }
     
     ClangExpressionVariableSP entity(m_found_entities.CreateVariable (m_parser_vars->m_exe_ctx.GetBestExecutionContextScope (),
                                                                       m_parser_vars->m_target_info.byte_order,

Modified: lldb/trunk/source/Expression/IRInterpreter.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Expression/IRInterpreter.cpp?rev=177372&r1=177371&r2=177372&view=diff
==============================================================================
--- lldb/trunk/source/Expression/IRInterpreter.cpp (original)
+++ lldb/trunk/source/Expression/IRInterpreter.cpp Mon Mar 18 20:45:02 2013
@@ -624,6 +624,11 @@ public:
         // "this", "self", and "_cmd" are direct.
         bool variable_is_this = false;
         
+        // If the variable is a function pointer, we do not need to
+        // build an extra layer of indirection for it because it is
+        // accessed directly.
+        bool variable_is_function_address = false;
+        
         // Attempt to resolve the value using the program's data.
         // If it is, the values to be created are:
         //
@@ -647,12 +652,7 @@ public:
                     break;
                 
                 if (isa<clang::FunctionDecl>(decl))
-                {
-                    if (log)
-                        log->Printf("The interpreter does not handle function pointers at the moment");
-                    
-                    return Memory::Region();
-                }
+                    variable_is_function_address = true;
                 
                 resolved_value = m_decl_map.LookupDecl(decl, flags);
             }
@@ -786,17 +786,19 @@ public:
                 }
                 else
                 {
+                    bool no_extra_redirect = (variable_is_this || variable_is_function_address);
+                    
                     Memory::Region data_region = m_memory.Place(value->getType(), resolved_value.GetScalar().ULongLong(), resolved_value);
                     Memory::Region ref_region = m_memory.Malloc(value->getType());
                     Memory::Region pointer_region;
                     
-                    if (!variable_is_this)
+                    if (!no_extra_redirect)
                         pointer_region = m_memory.Malloc(value->getType());
                            
                     if (ref_region.IsInvalid())
                         return Memory::Region();
                     
-                    if (pointer_region.IsInvalid() && !variable_is_this)
+                    if (pointer_region.IsInvalid() && !no_extra_redirect)
                         return Memory::Region();
                     
                     DataEncoderSP ref_encoder = m_memory.GetEncoder(ref_region);
@@ -804,7 +806,7 @@ public:
                     if (ref_encoder->PutAddress(0, data_region.m_base) == UINT32_MAX)
                         return Memory::Region();
                     
-                    if (!variable_is_this)
+                    if (!no_extra_redirect)
                     {
                         DataEncoderSP pointer_encoder = m_memory.GetEncoder(pointer_region);
                     
@@ -824,7 +826,7 @@ public:
                             log->Printf("  Pointer region : %llx", (unsigned long long)pointer_region.m_base);
                     }
                     
-                    if (variable_is_this)
+                    if (no_extra_redirect)
                         return ref_region;
                     else
                         return pointer_region;