[MCJIT] Fix the ARM BR24 relocation in RuntimeDyldMachO.
We now (1) correctly decode the branch immediate, (2) modify the immediate to
corretly treat it as PC-rel, and (3) properly populate the stub entry.
Previously we had been doing each of these wrong.
<rdar://problem/17750739>
llvm-svn: 214285
diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOARM.h b/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOARM.h
index 1de9942..dadde76 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOARM.h
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOARM.h
@@ -18,6 +18,9 @@
class RuntimeDyldMachOARM
: public RuntimeDyldMachOCRTPBase<RuntimeDyldMachOARM> {
+private:
+ typedef RuntimeDyldMachOCRTPBase<RuntimeDyldMachOARM> ParentT;
+
public:
RuntimeDyldMachOARM(RTDyldMemoryManager *MM) : RuntimeDyldMachOCRTPBase(MM) {}
@@ -25,6 +28,21 @@
unsigned getStubAlignment() override { return 4; }
+ int64_t decodeAddend(uint8_t *LocalAddress, unsigned NumBytes,
+ MachO::RelocationInfoType RelType) const {
+ switch (RelType) {
+ default:
+ return ParentT::decodeAddend(LocalAddress, NumBytes, RelType);
+ case MachO::ARM_RELOC_BR24: {
+ uint32_t Temp;
+ memcpy(&Temp, LocalAddress, 4);
+ Temp &= 0x00ffffff; // Mask out the opcode.
+ // Now we've got the shifted immediate, shift by 2, sign extend and ret.
+ return SignExtend32<26>(Temp << 2);
+ }
+ }
+ }
+
relocation_iterator
processRelocationRef(unsigned SectionID, relocation_iterator RelI,
ObjectImage &ObjImg, ObjSectionToIDMap &ObjSectionToID,
@@ -41,9 +59,8 @@
RelocationValueRef Value(
getRelocationValueRef(ObjImg, RelI, RE, ObjSectionToID, Symbols));
- bool IsExtern = Obj.getPlainRelocationExternal(RelInfo);
- if (!IsExtern && RE.IsPCRel)
- makeValueAddendPCRel(Value, ObjImg, RelI);
+ if (RE.IsPCRel)
+ makeValueAddendPCRel(Value, ObjImg, RelI, 8);
if ((RE.RelType & 0xf) == MachO::ARM_RELOC_BR24)
processBranchRelocation(RE, Value, Stubs);
@@ -134,7 +151,8 @@
uint8_t *StubTargetAddr =
createStubFunction(Section.Address + Section.StubOffset);
RelocationEntry StubRE(RE.SectionID, StubTargetAddr - Section.Address,
- MachO::GENERIC_RELOC_VANILLA, Value.Addend);
+ MachO::GENERIC_RELOC_VANILLA, Value.Addend, false,
+ 2);
if (Value.SymbolName)
addRelocationForSymbol(StubRE, Value.SymbolName);
else
@@ -142,7 +160,7 @@
Addr = Section.Address + Section.StubOffset;
Section.StubOffset += getMaxStubSize();
}
- RelocationEntry TargetRE(Value.SectionID, RE.Offset, RE.RelType, 0,
+ RelocationEntry TargetRE(RE.SectionID, RE.Offset, RE.RelType, 0,
RE.IsPCRel, RE.Size);
resolveRelocation(TargetRE, (uint64_t)Addr);
}