Add a method "GetEntryPoint" to the ObjectFile class, and implement it on MachO & ELF - though the ELF implementation is probably a little weak. Then use this method in place of directly looking for "start" in the ThreadPlanCallFunction constructor to find the stopping point for our function evaluation.

llvm-svn: 127194

2 files changed, 34 insertions, 0 deletions

diff --git a/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp b/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
index 8793cfac93e..546dc7840d2 100644
--- a/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
+++ b/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
@@ -16,9 +16,11 @@
 #include "lldb/Core/DataBuffer.h"
 #include "lldb/Core/Error.h"
 #include "lldb/Core/FileSpecList.h"
+#include "lldb/Core/Module.h"
 #include "lldb/Core/PluginManager.h"
 #include "lldb/Core/Section.h"
 #include "lldb/Core/Stream.h"
+#include "lldb/Symbol/SymbolContext.h"
 #include "lldb/Host/Host.h"
 
 #define CASE_AND_STREAM(s, def, width)                  \
@@ -276,6 +278,32 @@ ObjectFileELF::GetImageInfoAddress()
     return Address();
 }
 
+lldb_private::Address
+ObjectFileELF::GetEntryPointAddress () 
+{
+    // If the object file is not an executable it can't hold the entry point.  m_entry_point_address
+    // is initialized to an invalid address, so we can just return that.
+    // If m_entry_point_address is valid it means we've found it already, so return the cached value.
+    
+    if (!IsExecutable() || m_entry_point_address.IsValid())
+        return m_entry_point_address;
+    
+    // FIXME: This is just looking for the "start" symbol, but that will fail if "start" is stripped.
+    // There's probably a better way in ELF to find the start address of an executable module.
+    
+    SymbolContextList contexts;
+    SymbolContext context;
+    if (!m_module->FindSymbolsWithNameAndType(ConstString ("start"), lldb::eSymbolTypeCode, contexts))
+        return m_entry_point_address;
+    
+    contexts.GetContextAtIndex(0, context);
+    
+    m_entry_point_address = context.symbol->GetValue();
+    
+    return m_entry_point_address;
+
+}
+
 //----------------------------------------------------------------------
 // ParseDependentModules
 //----------------------------------------------------------------------
diff --git a/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.h b/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.h
index 5de0a8aa83a..2b78da5436b 100644
--- a/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.h
+++ b/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.h
@@ -115,6 +115,9 @@ public:
 
     virtual lldb_private::Address
     GetImageInfoAddress();
+    
+    virtual lldb_private::Address
+    GetEntryPointAddress ();
 
 private:
     ObjectFileELF(lldb_private::Module* module,
@@ -156,6 +159,9 @@ private:
     /// Data extractor holding the string table used to resolve section names.
     lldb_private::DataExtractor m_shstr_data;
 
+    /// Cached value of the entry point for this module.
+    lldb_private::Address  m_entry_point_address;
+    
     /// Returns a 1 based index of the given section header.
     unsigned
     SectionIndex(const SectionHeaderCollIter &I);