[ELF] Initial migration of AVR target

Reviewers: ruiu, rafael, grimar, atanasyan, psmith, dylanmckay

Reviewed By: ruiu, rafael, grimar, dylanmckay

Differential Revision: https://reviews.llvm.org/D32991

llvm-svn: 305444

4 files changed, 53 insertions, 0 deletions

diff --git a/lld/ELF/InputFiles.cpp b/lld/ELF/InputFiles.cpp
index 902593b63a7..3d11239bf88 100644
--- a/lld/ELF/InputFiles.cpp
+++ b/lld/ELF/InputFiles.cpp
@@ -821,6 +821,8 @@ static uint8_t getBitcodeMachineKind(StringRef Path, const Triple &T) {
   case Triple::arm:
   case Triple::thumb:
     return EM_ARM;
+  case Triple::avr:
+    return EM_AVR;
   case Triple::mips:
   case Triple::mipsel:
   case Triple::mips64:
diff --git a/lld/ELF/Target.cpp b/lld/ELF/Target.cpp
index ee5a7690fc6..ac21ef91066 100644
--- a/lld/ELF/Target.cpp
+++ b/lld/ELF/Target.cpp
@@ -230,6 +230,13 @@ public:
   void relocateOne(uint8_t *Loc, uint32_t Type, uint64_t Val) const override;
 };
 
+class AVRTargetInfo final : public TargetInfo {
+public:
+  RelExpr getRelExpr(uint32_t Type, const SymbolBody &S,
+                     const uint8_t *Loc) const override;
+  void relocateOne(uint8_t *Loc, uint32_t Type, uint64_t Val) const override;
+};
+
 template <class ELFT> class MipsTargetInfo final : public TargetInfo {
 public:
   MipsTargetInfo();
@@ -260,6 +267,8 @@ TargetInfo *createTarget() {
     return make<AMDGPUTargetInfo>();
   case EM_ARM:
     return make<ARMTargetInfo>();
+  case EM_AVR:
+    return make<AVRTargetInfo>();
   case EM_MIPS:
     switch (Config->EKind) {
     case ELF32LEKind:
@@ -2046,6 +2055,32 @@ int64_t ARMTargetInfo::getImplicitAddend(const uint8_t *Buf,
   }
 }
 
+RelExpr AVRTargetInfo::getRelExpr(uint32_t Type, const SymbolBody &S,
+                                  const uint8_t *Loc) const {
+  switch (Type) {
+  case R_AVR_CALL:
+    return R_ABS;
+  default:
+    error(toString(S.File) + ": unknown relocation type: " + toString(Type));
+    return R_HINT;
+  }
+}
+
+void AVRTargetInfo::relocateOne(uint8_t *Loc, uint32_t Type,
+                                uint64_t Val) const {
+  switch (Type) {
+  case R_AVR_CALL: {
+    uint16_t Hi = Val >> 17;
+    uint16_t Lo = Val >> 1;
+    write16le(Loc, read16le(Loc) | ((Hi >> 1) << 4) | (Hi & 1));
+    write16le(Loc + 2, Lo);
+    break;
+  }
+  default:
+    error(getErrorLocation(Loc) + "unrecognized reloc " + toString(Type));
+  }
+}
+
 template <class ELFT> MipsTargetInfo<ELFT>::MipsTargetInfo() {
   GotPltHeaderEntriesNum = 2;
   DefaultMaxPageSize = 65536;
diff --git a/lld/test/ELF/basic-avr.s b/lld/test/ELF/basic-avr.s
new file mode 100644
index 00000000000..c8a3af9536f
--- /dev/null
+++ b/lld/test/ELF/basic-avr.s
@@ -0,0 +1,14 @@
+# REQUIRES: avr
+# RUN: llvm-mc -filetype=obj -triple=avr-unknown-linux -mcpu=atmega328p %s -o %t.o
+# RUN: ld.lld %t.o -o %t.exe -Ttext=0
+# RUN: llvm-objdump -d %t.exe | FileCheck %s
+
+main:
+  call foo
+foo:
+  jmp foo
+
+# CHECK:      main:
+# CHECK-NEXT:   0: 0e 94 02 00 <unknown>
+# CHECK:      foo:
+# CHECK-NEXT:   4: 0c 94 02 00 <unknown>
diff --git a/lld/test/lit.cfg b/lld/test/lit.cfg
index 0f9e03aa386..c8471e1280a 100644
--- a/lld/test/lit.cfg
+++ b/lld/test/lit.cfg
@@ -247,6 +247,8 @@ if re.search(r'AArch64', archs):
     config.available_features.add('aarch64')
 if re.search(r'ARM', archs):
     config.available_features.add('arm')
+if re.search(r'AVR', archs):
+    config.available_features.add('avr')
 if re.search(r'Mips', archs):
     config.available_features.add('mips')
 if re.search(r'X86', archs):