From fe2d5f848764dff8f9ba734a5e2438ca1535890e Mon Sep 17 00:00:00 2001 From: Jim Grosbach Date: Tue, 25 Sep 2012 18:07:17 +0000 Subject: ARM: Darwin BL/BLX relocations to out-of-range symbols. When a BL/BLX references a symbol in the same translation unit that is out of range, use an external relocation. The linker will use this to generate a branch island rather than a direct reference, allowing the relocation to resolve correctly. rdar://12359919 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164615 91177308-0d34-0410-b5e6-96231b3b80d8 --- .../ARM/MCTargetDesc/ARMMachObjectWriter.cpp | 49 +++++++++++++++++++++- 1 file changed, 48 insertions(+), 1 deletion(-) (limited to 'lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp') diff --git a/lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp b/lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp index 95640f7..2154c93 100644 --- a/lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp +++ b/lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp @@ -41,6 +41,12 @@ class ARMMachObjectWriter : public MCMachObjectTargetWriter { const MCFixup &Fixup, MCValue Target, uint64_t &FixedValue); + bool requiresExternRelocation(MachObjectWriter *Writer, + const MCAssembler &Asm, + const MCFragment &Fragment, + unsigned RelocType, const MCSymbolData *SD, + uint64_t FixedValue); + public: ARMMachObjectWriter(bool Is64Bit, uint32_t CPUType, uint32_t CPUSubtype) @@ -305,6 +311,46 @@ void ARMMachObjectWriter::RecordARMScatteredRelocation(MachObjectWriter *Writer, Writer->addRelocation(Fragment->getParent(), MRE); } +bool ARMMachObjectWriter::requiresExternRelocation(MachObjectWriter *Writer, + const MCAssembler &Asm, + const MCFragment &Fragment, + unsigned RelocType, + const MCSymbolData *SD, + uint64_t FixedValue) { + // Most cases can be identified purely from the symbol. + if (Writer->doesSymbolRequireExternRelocation(SD)) + return true; + int64_t Value = (int64_t)FixedValue; // The displacement is signed. + int64_t Range; + switch (RelocType) { + default: + return false; + case macho::RIT_ARM_Branch24Bit: + // PC pre-adjustment of 8 for these instructions. + Value -= 8; + // ARM BL/BLX has a 25-bit offset. + Range = 0x1ffffff; + break; + case macho::RIT_ARM_ThumbBranch22Bit: + // PC pre-adjustment of 4 for these instructions. + Value -= 4; + // Thumb BL/BLX has a 24-bit offset. + Range = 0xffffff; + } + // BL/BLX also use external relocations when an internal relocation + // would result in the target being out of range. This gives the linker + // enough information to generate a branch island. + const MCSectionData &SymSD = Asm.getSectionData( + SD->getSymbol().getSection()); + Value += Writer->getSectionAddress(&SymSD); + Value -= Writer->getSectionAddress(Fragment.getParent()); + // If the resultant value would be out of range for an internal relocation, + // use an external instead. + if (Value > Range || Value < -(Range + 1)) + return true; + return false; +} + void ARMMachObjectWriter::RecordRelocation(MachObjectWriter *Writer, const MCAssembler &Asm, const MCAsmLayout &Layout, @@ -373,7 +419,8 @@ void ARMMachObjectWriter::RecordRelocation(MachObjectWriter *Writer, } // Check whether we need an external or internal relocation. - if (Writer->doesSymbolRequireExternRelocation(SD)) { + if (requiresExternRelocation(Writer, Asm, *Fragment, RelocType, SD, + FixedValue)) { IsExtern = 1; Index = SD->getIndex(); -- cgit v1.1 From d04a8d4b33ff316ca4cf961e06c9e312eff8e64f Mon Sep 17 00:00:00 2001 From: Chandler Carruth Date: Mon, 3 Dec 2012 16:50:05 +0000 Subject: Use the new script to sort the includes of every file under lib. Sooooo many of these had incorrect or strange main module includes. I have manually inspected all of these, and fixed the main module include to be the nearest plausible thing I could find. If you own or care about any of these source files, I encourage you to take some time and check that these edits were sensible. I can't have broken anything (I strictly added headers, and reordered them, never removed), but they may not be the headers you'd really like to identify as containing the API being implemented. Many forward declarations and missing includes were added to a header files to allow them to parse cleanly when included first. The main module rule does in fact have its merits. =] git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169131 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp') diff --git a/lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp b/lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp index 2154c93..b9efe74 100644 --- a/lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp +++ b/lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp @@ -7,17 +7,18 @@ // //===----------------------------------------------------------------------===// +#include "MCTargetDesc/ARMMCTargetDesc.h" #include "MCTargetDesc/ARMBaseInfo.h" #include "MCTargetDesc/ARMFixupKinds.h" #include "llvm/ADT/Twine.h" -#include "llvm/MC/MCAssembler.h" #include "llvm/MC/MCAsmLayout.h" -#include "llvm/MC/MCMachObjectWriter.h" +#include "llvm/MC/MCAssembler.h" #include "llvm/MC/MCContext.h" #include "llvm/MC/MCExpr.h" #include "llvm/MC/MCFixup.h" #include "llvm/MC/MCFixupKindInfo.h" #include "llvm/MC/MCMachOSymbolFlags.h" +#include "llvm/MC/MCMachObjectWriter.h" #include "llvm/MC/MCValue.h" #include "llvm/Object/MachOFormat.h" #include "llvm/Support/ErrorHandling.h" -- cgit v1.1