Commit 03ef00bc authored by Brad King's avatar Brad King
Browse files

ENH: Make cmELF parser more general and powerful

  - Add support to get RPATH and RUNPATH entries.
  - Add support to get file offsets to strings.
  - Add more DT_* tags to byte swapping.
parent 44f696f8
......@@ -65,6 +65,7 @@ void cmELFByteSwap(T& x)
class cmELFInternal
{
public:
typedef cmELF::StringEntry StringEntry;
enum ByteOrderType { ByteOrderMSB, ByteOrderLSB };
// Construct and take ownership of the file stream object.
......@@ -95,9 +96,31 @@ public:
// Forward to the per-class implementation.
virtual unsigned int GetNumberOfSections() const = 0;
virtual bool GetSOName(std::string& soname) = 0;
virtual StringEntry const* GetDynamicSectionString(int tag) = 0;
virtual void PrintInfo(std::ostream& os) const = 0;
// Lookup the SONAME in the DYNAMIC section.
StringEntry const* GetSOName()
{
return this->GetDynamicSectionString(DT_SONAME);
}
// Lookup the RPATH in the DYNAMIC section.
StringEntry const* GetRPath()
{
return this->GetDynamicSectionString(DT_RPATH);
}
// Lookup the RUNPATH in the DYNAMIC section.
StringEntry const* GetRunPath()
{
#if defined(DT_RUNPATH)
return this->GetDynamicSectionString(DT_RUNPATH);
#else
return 0;
#endif
}
// Return the recorded ELF type.
cmELF::FileType GetFileType() const { return this->ELFType; }
protected:
......@@ -127,6 +150,9 @@ protected:
this->External->ErrorMessage = msg;
this->ELFType = cmELF::FileTypeInvalid;
}
// Store string table entry states.
std::map<int, StringEntry> DynamicSectionStrings;
};
//----------------------------------------------------------------------------
......@@ -173,8 +199,8 @@ public:
return static_cast<unsigned int>(this->ELFHeader.e_shnum);
}
// Lookup the SONAME in the DYNAMIC section.
virtual bool GetSOName(std::string& soname);
// Lookup a string from the dynamic section with the given tag.
virtual StringEntry const* GetDynamicSectionString(int tag);
// Print information about the ELF file.
virtual void PrintInfo(std::ostream& os) const
......@@ -270,6 +296,33 @@ private:
case DT_DEBUG: cmELFByteSwap(dyn.d_un.d_ptr); break;
case DT_TEXTREL: /* dyn.d_un ignored */ break;
case DT_JMPREL: cmELFByteSwap(dyn.d_un.d_ptr); break;
#ifdef T_BIND_NOW
case T_BIND_NOW: /* dyn.d_un ignored */ break;
#endif
#ifdef DT_INIT_ARRAY
case DT_INIT_ARRAY: cmELFByteSwap(dyn.d_un.d_ptr); break;
#endif
#ifdef DT_FINI_ARRAY
case DT_FINI_ARRAY: cmELFByteSwap(dyn.d_un.d_ptr); break;
#endif
#ifdef DT_INIT_ARRAYSZ
case DT_INIT_ARRAYSZ: cmELFByteSwap(dyn.d_un.d_val); break;
#endif
#ifdef DT_FINI_ARRAYSZ
case DT_FINI_ARRAYSZ: cmELFByteSwap(dyn.d_un.d_val); break;
#endif
#ifdef DT_RUNPATH
case DT_RUNPATH: cmELFByteSwap(dyn.d_un.d_val); break;
#endif
#ifdef DT_FLAGS
case DT_FLAGS: cmELFByteSwap(dyn.d_un.d_val); break;
#endif
#ifdef DT_PREINIT_ARRAY
case DT_PREINIT_ARRAY: cmELFByteSwap(dyn.d_un.d_ptr); break;
#endif
#ifdef DT_PREINIT_ARRAYSZ
case DT_PREINIT_ARRAYSZ: cmELFByteSwap(dyn.d_un.d_val); break;
#endif
}
}
......@@ -329,10 +382,6 @@ private:
// Store all entries of the DYNAMIC section.
std::vector<ELF_Dyn> DynamicSectionEntries;
// Store the SOName if it has been loaded.
std::string SOName;
bool SONameChecked;
};
//----------------------------------------------------------------------------
......@@ -343,9 +392,6 @@ cmELFInternalImpl<Types>
ByteOrderType order):
cmELFInternal(external, fin, order)
{
// Initialize state.
this->SONameChecked = false;
// Read the main header.
if(!this->Read(this->ELFHeader))
{
......@@ -424,20 +470,29 @@ bool cmELFInternalImpl<Types>::LoadDynamicSection()
//----------------------------------------------------------------------------
template <class Types>
bool cmELFInternalImpl<Types>::GetSOName(std::string& soname)
cmELF::StringEntry const*
cmELFInternalImpl<Types>::GetDynamicSectionString(int tag)
{
// Short-circuit if already checked.
if(this->SONameChecked)
std::map<int, StringEntry>::iterator dssi =
this->DynamicSectionStrings.find(tag);
if(dssi != this->DynamicSectionStrings.end())
{
soname = this->SOName;
return !soname.empty();
if(dssi->second.Position > 0)
{
return &dssi->second;
}
return 0;
}
this->SONameChecked = true;
// Create an entry for this tag. Assume it is missing until found.
StringEntry& se = this->DynamicSectionStrings[tag];
se.Position = 0;
// Try reading the dynamic section.
if(!this->LoadDynamicSection())
{
return false;
return 0;
}
// Get the string table referenced by the DYNAMIC section.
......@@ -445,35 +500,43 @@ bool cmELFInternalImpl<Types>::GetSOName(std::string& soname)
if(sec.sh_link >= this->SectionHeaders.size())
{
this->SetErrorMessage("Section DYNAMIC has invalid string table index.");
return false;
return 0;
}
ELF_Shdr const& strtab = this->SectionHeaders[sec.sh_link];
// Look for the soname entry.
// Look for the requested entry.
for(typename std::vector<ELF_Dyn>::iterator
di = this->DynamicSectionEntries.begin();
di != this->DynamicSectionEntries.end(); ++di)
{
ELF_Dyn& dyn = *di;
if(dyn.d_tag == DT_SONAME)
if(dyn.d_tag == tag)
{
// Seek to the position reported by the entry.
this->Stream.seekg(strtab.sh_offset + dyn.d_un.d_val);
// Read the string.
char c;
while(this->Stream.get(c) && c != 0)
{
this->SOName += c;
se.Value += c;
}
// Make sure the whole value was read.
if(!this->Stream)
{
this->SetErrorMessage("Dynamic section specifies unreadable SONAME.");
this->SOName = "";
return false;
this->SetErrorMessage("Dynamic section specifies unreadable RPATH.");
se.Value = "";
return 0;
}
soname = this->SOName;
return true;
// The value has been read successfully. Report it.
se.Position =
static_cast<unsigned long>(strtab.sh_offset + dyn.d_un.d_val);
return &se;
}
}
return false;
return 0;
}
//============================================================================
......@@ -592,15 +655,59 @@ unsigned int cmELF::GetNumberOfSections() const
//----------------------------------------------------------------------------
bool cmELF::GetSOName(std::string& soname)
{
if(StringEntry const* se = this->GetSOName())
{
soname = se->Value;
return true;
}
else
{
return false;
}
}
//----------------------------------------------------------------------------
cmELF::StringEntry const* cmELF::GetSOName()
{
if(this->Valid() &&
this->Internal->GetFileType() == cmELF::FileTypeSharedLibrary)
{
return this->Internal->GetSOName(soname);
return this->Internal->GetSOName();
}
else
{
return false;
return 0;
}
}
//----------------------------------------------------------------------------
cmELF::StringEntry const* cmELF::GetRPath()
{
if(this->Valid() &&
this->Internal->GetFileType() == cmELF::FileTypeExecutable ||
this->Internal->GetFileType() == cmELF::FileTypeSharedLibrary)
{
return this->Internal->GetRPath();
}
else
{
return 0;
}
}
//----------------------------------------------------------------------------
cmELF::StringEntry const* cmELF::GetRunPath()
{
if(this->Valid() &&
this->Internal->GetFileType() == cmELF::FileTypeExecutable ||
this->Internal->GetFileType() == cmELF::FileTypeSharedLibrary)
{
return this->Internal->GetRunPath();
}
else
{
return 0;
}
}
......
......@@ -54,6 +54,16 @@ public:
FileTypeCore
};
/** Represent string table entries. */
struct StringEntry
{
// The string value itself.
std::string Value;
// The position in the file at which the string appears.
unsigned long Position;
};
/** Get the type of the file opened. */
FileType GetFileType() const;
......@@ -62,6 +72,13 @@ public:
/** Get the SONAME field if any. */
bool GetSOName(std::string& soname);
StringEntry const* GetSOName();
/** Get the RPATH field if any. */
StringEntry const* GetRPath();
/** Get the RUNPATH field if any. */
StringEntry const* GetRunPath();
/** Print human-readable information about the ELF file. */
void PrintInfo(std::ostream& os) const;
......
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