LLDB: API for Permission of object file's sections

[abhishek.aggarwal]

Summary

• Added an API to public interface that provides permissions (RWX) of individual sections of an object file
• Earlier, there was no way to find out this information through SB APIs
• A possible use case of this API is: when a user wants to know the sections that have executable machine instructions and want to write a tool on top of LLDB based on this information

Signed-off-by: Abhishek Aggarwal <[e-mail]>

[clayborg]

Just add header doc and this is good to go.

include/lldb/API/SBSection.h

74

I know not everything is documented, but we should document this new call to let users know that the uint32_t will return a mask of bits from lldb::Permissions.

[Eugene.Zelenko]

Please rebase code on trunk and run Clang-format.

[abhishek.aggarwal]

Changes based on review

• Added header doc and ran clang-format on code

[Eugene.Zelenko]

source/API/SBSection.cpp

257

You don't need to use get(), because smart pointers have http://en.cppreference.com/w/cpp/memory/shared_ptr/operator_bool. Will be good idea to remove it in other conditions in this file.

[abhishek.aggarwal]

Removed get() for shared_ptr

[abhishek.aggarwal]

Already merged it in LLDb repo. So closing this revision.

include/lldb/API/SBSection.h

public:
 
     lldb::SBData
     GetSectionData (uint64_t offset,
                     uint64_t size);
     
     SectionType
     GetSectionType ();
 
     //------------------------------------------------------------------
+    /// Gets the permissions (RWX) of the section of the object file
+    ///
+    /// Returns a mask of bits of enum lldb::Permissions for this section.
+    /// Sections for which permissions are not defined, 0 is returned for
+    /// them. The binary representation of this value corresponds to [XRW]
+    /// i.e. for a section having read and execute permissions, the value
+    /// returned is 6
+    ///
+    /// @return
+    ///     Returns an unsigned value for Permissions for the section.
+    //------------------------------------------------------------------
+    uint32_t
+    GetPermissions() const;
+
+    //------------------------------------------------------------------
     /// Return the size of a target's byte represented by this section
     /// in numbers of host bytes. Note that certain architectures have
     /// varying minimum addressable unit (i.e. byte) size for their 
     /// CODE or DATA buses.
     ///
     /// @return
     ///     The number of host (8-bit) bytes needed to hold a target byte
     //------------------------------------------------------------------

scripts/interface/SBSection.i

public:
 
     lldb::SBData
     GetSectionData (uint64_t offset,
                     uint64_t size);
 
     SectionType
     GetSectionType ();
 
+    uint32_t
+    GetPermissions() const;
+
     %feature("docstring", "
     //------------------------------------------------------------------
     /// Return the size of a target's byte represented by this section
     /// in numbers of host bytes. Note that certain architectures have
     /// varying minimum addressable unit (i.e. byte) size for their 
     /// CODE or DATA buses.
     ///
     /// @return

source/API/SBSection.cpp

 {
     SectionSP section_sp (GetSP());
     if (section_sp.get())
         return section_sp->GetType();
     return eSectionTypeInvalid;
 }
 
 uint32_t
+SBSection::GetPermissions() const
+{
+    SectionSP section_sp(GetSP());
+    if (section_sp.get())
+        return section_sp->GetPermissions();
+    return 0;
+}
+
+uint32_t
 SBSection::GetTargetByteSize ()
 {
     SectionSP section_sp (GetSP());
     if (section_sp.get())
         return section_sp->GetTargetByteSize();
     return 0;
 }