Add a new Section::SetFileAddress method to change a Section's file

address.

When loading a dSYM, and the file addresses of the dSYM Sections are
different than the executable binary Sections' file addresses, the
debug info won't be remapped to the actual load addresses correctly.
This only happens with binaries on the in-memory shared cache binaries
where their File addresses have been set to their actual load address
(outside an offset value) whereas the original executable and dSYM
have 0-based File addresses.

I think this patch will not be activated for other cases -- this is
the only case we know of where the dSYM and the executable's File
addresses differ -- but if this causes other problems we can restrict
it more carefully.

<rdar://problem/12335086> 

llvm-svn: 188532

3 files changed, 45 insertions, 10 deletions

diff --git a/lldb/include/lldb/Core/Section.h b/lldb/include/lldb/Core/Section.h
index e42071b9a5c..437eaf59b9c 100644
--- a/lldb/include/lldb/Core/Section.h
+++ b/lldb/include/lldb/Core/Section.h
@@ -193,6 +193,9 @@ public:
     lldb::addr_t
     GetFileAddress () const;
 
+    bool
+    SetFileAddress (lldb::addr_t file_addr);
+
     lldb::addr_t
     GetOffset () const;
 
diff --git a/lldb/source/Core/Section.cpp b/lldb/source/Core/Section.cpp
index 492abec357b..e2a084ceb2f 100644
--- a/lldb/source/Core/Section.cpp
+++ b/lldb/source/Core/Section.cpp
@@ -98,6 +98,24 @@ Section::GetFileAddress () const
     return m_file_addr;
 }
 
+bool
+Section::SetFileAddress (lldb::addr_t file_addr)
+{
+    SectionSP parent_sp (GetParent ());
+    if (parent_sp)
+    {
+        if (m_file_addr >= file_addr)
+            return parent_sp->SetFileAddress (m_file_addr - file_addr);
+        return false;
+    }
+    else
+    {
+        // This section has no parent, so m_file_addr is the file base address
+        m_file_addr = file_addr;
+        return true;
+    }
+}
+
 lldb::addr_t
 Section::GetOffset () const
 {
diff --git a/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp b/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
index e8d31181bd6..5b4695ede05 100644
--- a/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
+++ b/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
@@ -1035,11 +1035,11 @@ ObjectFileMachO::CreateSections (SectionList &unified_section_list)
                             // is null out the SectionList vector and if a process has been set up, dump a message
                             // to stdout.  The most common case here is core file debugging with a truncated file.
                             const char *lc_segment_name = load_cmd.cmd == LoadCommandSegment64 ? "LC_SEGMENT_64" : "LC_SEGMENT";
-                            GetModule()->ReportError("is a corrupt mach-o file: load command %u %s has a fileoff (0x%" PRIx64 ") that extends beyond the end of the file (0x%" PRIx64 ")",
-                                                     i,
-                                                     lc_segment_name,
-                                                     load_cmd.fileoff,
-                                                     m_length);
+                            module_sp->ReportError("is a corrupt mach-o file: load command %u %s has a fileoff (0x%" PRIx64 ") that extends beyond the end of the file (0x%" PRIx64 ")",
+                                                   i,
+                                                   lc_segment_name,
+                                                   load_cmd.fileoff,
+                                                   m_length);
                             
                             load_cmd.fileoff = 0;
                             load_cmd.filesize = 0;
@@ -1053,11 +1053,11 @@ ObjectFileMachO::CreateSections (SectionList &unified_section_list)
                             // is null out the SectionList vector and if a process has been set up, dump a message
                             // to stdout.  The most common case here is core file debugging with a truncated file.
                             const char *lc_segment_name = load_cmd.cmd == LoadCommandSegment64 ? "LC_SEGMENT_64" : "LC_SEGMENT";
-                            GetModule()->ReportError("is a corrupt mach-o file: load command %u %s has a fileoff + filesize (0x%" PRIx64 ") that extends beyond the end of the file (0x%" PRIx64 "), the segment will be truncated",
-                                                     i,
-                                                     lc_segment_name,
-                                                     load_cmd.fileoff + load_cmd.filesize,
-                                                     m_length);
+                            module_sp->ReportError("is a corrupt mach-o file: load command %u %s has a fileoff + filesize (0x%" PRIx64 ") that extends beyond the end of the file (0x%" PRIx64 "), the segment will be truncated",
+                                                   i,
+                                                   lc_segment_name,
+                                                   load_cmd.fileoff + load_cmd.filesize,
+                                                   m_length);
                             
                             // Tuncase the length
                             load_cmd.filesize = m_length - load_cmd.fileoff;
@@ -1095,6 +1095,20 @@ ObjectFileMachO::CreateSections (SectionList &unified_section_list)
                         }
                         else if (unified_section_sp)
                         {
+                            if (is_dsym && unified_section_sp->GetFileAddress() != load_cmd.vmaddr)
+                            {
+                                // Check to see if the module was read from memory?
+                                if (module_sp->GetObjectFile()->GetHeaderAddress().IsValid())
+                                {
+                                    // We have a module that is in memory and needs to have its
+                                    // file address adjusted. We need to do this because when we
+                                    // load a file from memory, its addresses will be slid already,
+                                    // yet the addresses in the new symbol file will still be unslid.
+                                    // Since everything is stored as section offset, this shouldn't
+                                    // cause any problems.
+                                    unified_section_sp->SetFileAddress(load_cmd.vmaddr);
+                                }
+                            }
                             m_sections_ap->AddSection(unified_section_sp);
                         }