[lld] r221421 - [mach-o] Add support for interposing tuples section

[Nick Kledzik]

Author: kledzik
Date: Wed Nov  5 19:09:13 2014
New Revision: 221421

URL: http://llvm.org/viewvc/llvm-project?rev=221421&view=rev
Log:
[mach-o] Add support for interposing tuples section

Darwin uses two-level-namespace lookup for symbols which means the static
linker records where each symbol must be found at runtime.  Thus defining a
symbol in a dylib loaded earlier will not effect where symbols needed by
later dylibs will be found.  Instead overriding is done through a section
of type S_INTERPOSING which contains tuples of <interposer, interposee>.

Modified:
    lld/trunk/include/lld/Core/DefinedAtom.h
    lld/trunk/lib/Core/DefinedAtom.cpp
    lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp
    lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp
    lld/trunk/lib/ReaderWriter/YAML/ReaderWriterYAML.cpp

Modified: lld/trunk/include/lld/Core/DefinedAtom.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/include/lld/Core/DefinedAtom.h?rev=221421&r1=221420&r2=221421&view=diff
==============================================================================
--- lld/trunk/include/lld/Core/DefinedAtom.h (original)
+++ lld/trunk/include/lld/Core/DefinedAtom.h Wed Nov  5 19:09:13 2014
@@ -135,6 +135,7 @@ public:
     typeObjCClassPtr,       // pointer to ObjC class [Darwin]
     typeObjC2CategoryList,  // pointers to ObjC category [Darwin]
     typeDTraceDOF,          // runtime data for Dtrace [Darwin]
+    typeInterposingTuples,  // tuples of interposing info for dyld [Darwin]
     typeTempLTO,            // temporary atom for bitcode reader
     typeCompactUnwindInfo,  // runtime data for unwinder [Darwin]
     typeProcessedUnwindInfo,// compressed compact unwind info [Darwin]

Modified: lld/trunk/lib/Core/DefinedAtom.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/Core/DefinedAtom.cpp?rev=221421&r1=221420&r2=221421&view=diff
==============================================================================
--- lld/trunk/lib/Core/DefinedAtom.cpp (original)
+++ lld/trunk/lib/Core/DefinedAtom.cpp Wed Nov  5 19:09:13 2014
@@ -64,6 +64,7 @@ DefinedAtom::ContentPermissions DefinedA
   case typeCStringPtr:
   case typeObjCClassPtr:
   case typeObjC2CategoryList:
+  case typeInterposingTuples:
   case typeTLVInitialData:
   case typeTLVInitialZeroFill:
   case typeTLVInitializerPtr:

Modified: lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp?rev=221421&r1=221420&r2=221421&view=diff
==============================================================================
--- lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp (original)
+++ lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp Wed Nov  5 19:09:13 2014
@@ -231,6 +231,7 @@ const MachOFinalSectionFromAtomType sect
   ENTRY("__DATA", "___got",           S_NON_LAZY_SYMBOL_POINTERS,
                                                           typeGOT),
   ENTRY("__DATA", "___bss",           S_ZEROFILL,         typeZeroFill),
+  ENTRY("__DATA", "__interposing",    S_INTERPOSING,      typeInterposingTuples),
 };
 #undef ENTRY
 

Modified: lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp?rev=221421&r1=221420&r2=221421&view=diff
==============================================================================
--- lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp (original)
+++ lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp Wed Nov  5 19:09:13 2014
@@ -77,6 +77,8 @@ const MachORelocatableSectionToAtomType
   ENTRY("__DATA", "___bss",           S_ZEROFILL,         typeZeroFill),
   ENTRY("",       "",                 S_NON_LAZY_SYMBOL_POINTERS,
                                                           typeGOT),
+  ENTRY("__DATA", "__interposing",    S_INTERPOSING,      typeInterposingTuples),
+  ENTRY("",       "",                 S_INTERPOSING,      typeInterposingTuples),
   ENTRY("__LD",   "__compact_unwind", S_REGULAR,
                                                          typeCompactUnwindInfo),
   ENTRY("",       "",                 S_REGULAR,          typeUnknown)

Modified: lld/trunk/lib/ReaderWriter/YAML/ReaderWriterYAML.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/YAML/ReaderWriterYAML.cpp?rev=221421&r1=221420&r2=221421&view=diff
==============================================================================
--- lld/trunk/lib/ReaderWriter/YAML/ReaderWriterYAML.cpp (original)
+++ lld/trunk/lib/ReaderWriter/YAML/ReaderWriterYAML.cpp Wed Nov  5 19:09:13 2014
@@ -437,6 +437,8 @@ template <> struct ScalarEnumerationTrai
                                           DefinedAtom::typeObjC2CategoryList);
     io.enumCase(value, "objc-class1",     DefinedAtom::typeObjC1Class);
     io.enumCase(value, "dtraceDOF",       DefinedAtom::typeDTraceDOF);
+    io.enumCase(value, "interposing-tuples",
+                                          DefinedAtom::typeInterposingTuples);
     io.enumCase(value, "lto-temp",        DefinedAtom::typeTempLTO);
     io.enumCase(value, "compact-unwind",  DefinedAtom::typeCompactUnwindInfo);
     io.enumCase(value, "unwind-info",     DefinedAtom::typeProcessedUnwindInfo);