[PATCH] D16193: [ELF][MIPS] Ignore 'hint' relocations like R_MIPS_JALR in the `scanRelocs` method

[Simon Atanasyan via llvm-commits]

This revision was automatically updated to reflect the committed changes.
Closed by commit rL257798: [ELF][MIPS] Ignore 'hint' relocations like R_MIPS_JALR in the `scanRelocs`… (authored by atanasyan).

Changed prior to commit:
  http://reviews.llvm.org/D16193?vs=44892&id=44916#toc

Repository:
  rL LLVM

http://reviews.llvm.org/D16193

Files:
  lld/trunk/ELF/Target.cpp
  lld/trunk/ELF/Target.h
  lld/trunk/ELF/Writer.cpp
  lld/trunk/test/ELF/mips-jalr.test

Index: lld/trunk/ELF/Target.h
===================================================================
--- lld/trunk/ELF/Target.h
+++ lld/trunk/ELF/Target.h
@@ -57,6 +57,11 @@
                              uint64_t GotEntryAddr, uint64_t PltEntryAddr,
                              int32_t Index, unsigned RelOff) const = 0;
 
+  // Returns true if a relocation is just a hint for linker to make for example
+  // some code optimization. Such relocations should not be handled as a regular
+  // ones and lead to dynamic relocation creation etc.
+  virtual bool isHintReloc(uint32_t Type) const;
+
   // Returns true if a relocation is relative to the place being relocated,
   // such as relocations used for PC-relative instructions. Such relocations
   // need not be fixed up if an image is loaded to a different address than
Index: lld/trunk/ELF/Target.cpp
===================================================================
--- lld/trunk/ELF/Target.cpp
+++ lld/trunk/ELF/Target.cpp
@@ -239,6 +239,7 @@
   void relocateOne(uint8_t *Loc, uint8_t *BufEnd, uint32_t Type, uint64_t P,
                    uint64_t SA, uint64_t ZA = 0,
                    uint8_t *PairedLoc = nullptr) const override;
+  bool isHintReloc(uint32_t Type) const override;
   bool isRelRelative(uint32_t Type) const override;
 };
 } // anonymous namespace
@@ -284,6 +285,8 @@
 
 bool TargetInfo::isGotRelative(uint32_t Type) const { return false; }
 
+bool TargetInfo::isHintReloc(uint32_t Type) const { return false; }
+
 bool TargetInfo::isRelRelative(uint32_t Type) const { return true; }
 
 bool TargetInfo::isSizeReloc(uint32_t Type) const { return false; }
@@ -1581,6 +1584,11 @@
 }
 
 template <class ELFT>
+bool MipsTargetInfo<ELFT>::isHintReloc(uint32_t Type) const {
+  return Type == R_MIPS_JALR;
+}
+
+template <class ELFT>
 bool MipsTargetInfo<ELFT>::isRelRelative(uint32_t Type) const {
   switch (Type) {
   default:
Index: lld/trunk/ELF/Writer.cpp
===================================================================
--- lld/trunk/ELF/Writer.cpp
+++ lld/trunk/ELF/Writer.cpp
@@ -210,6 +210,10 @@
     SymbolBody *Body = File.getSymbolBody(SymIndex);
     uint32_t Type = RI.getType(Config->Mips64EL);
 
+    // Ignore "hint" relocation because it is for optional code optimization.
+    if (Target->isHintReloc(Type))
+      continue;
+
     if (Target->isGotRelative(Type))
       HasGotOffRel = true;
 
Index: lld/trunk/test/ELF/mips-jalr.test
===================================================================
--- lld/trunk/test/ELF/mips-jalr.test
+++ lld/trunk/test/ELF/mips-jalr.test
@@ -3,11 +3,15 @@
 # RUN: yaml2obj -format elf %s -o %t.o
 # RUN: ld.lld %t.o -o %t.so -shared
 # RUN: llvm-objdump -d %t.so | FileCheck %s
+# RUN: llvm-readobj -relocations %t.so | FileCheck -check-prefix=REL %s
 
 # REQUIRES: mips
 
 # CHECK: 10000:   09 f8 20 03   jalr    $25
 
+# REL:      Relocations [
+# REL-NEXT: ]
+
 FileHeader:
   Class:    ELFCLASS32
   Data:     ELFDATA2LSB


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D16193.44916.patch
Type: text/x-patch
Size: 2968 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20160114/8c789d9e/attachment.bin>