From 287ff291e34dd93f1e75868242f1a54289fb3027 Mon Sep 17 00:00:00 2001 From: Daniel Dunbar Date: Fri, 19 Mar 2010 09:29:03 +0000 Subject: [PATCH] MC: Add TargetAsmBackend::isVirtualSection hook. llvm-svn: 98950 --- include/llvm/Target/TargetAsmBackend.h | 4 ++++ lib/MC/MCAssembler.cpp | 22 +++++++--------------- lib/Target/X86/X86AsmBackend.cpp | 25 +++++++++++++++++++++++-- 3 files changed, 34 insertions(+), 17 deletions(-) diff --git a/include/llvm/Target/TargetAsmBackend.h b/include/llvm/Target/TargetAsmBackend.h index cada3e4479f..97b1d6024e1 100644 --- a/include/llvm/Target/TargetAsmBackend.h +++ b/include/llvm/Target/TargetAsmBackend.h @@ -80,6 +80,10 @@ public: return false; } + /// isVirtualSection - Check whether the given section is "virtual", that is + /// has no actual object file contents. + virtual bool isVirtualSection(const MCSection &Section) const = 0; + /// ApplyFixup - Apply the \arg Value for given \arg Fixup into the provided /// data fragment, at the offset specified by the fixup and following the /// fixup kind as appropriate. diff --git a/lib/MC/MCAssembler.cpp b/lib/MC/MCAssembler.cpp index ae8ca4bf7ee..f1847df2f14 100644 --- a/lib/MC/MCAssembler.cpp +++ b/lib/MC/MCAssembler.cpp @@ -43,14 +43,6 @@ STATISTIC(EmittedFragments, "Number of emitted assembler fragments"); // object file, which may truncate it. We should detect that truncation where // invalid and report errors back. -/// isVirtualSection - Check if this is a section which does not actually exist -/// in the object file. -static bool isVirtualSection(const MCSection &Section) { - // FIXME: Lame. - const MCSectionMachO &SMO = static_cast(Section); - return (SMO.getType() == MCSectionMachO::S_ZEROFILL); -} - static unsigned getFixupKindLog2Size(unsigned Kind) { switch (Kind) { default: llvm_unreachable("invalid fixup kind!"); @@ -264,7 +256,7 @@ public: uint64_t FileOffset, uint64_t RelocationsStart, unsigned NumRelocations) { // The offset is unused for virtual sections. - if (isVirtualSection(SD.getSection())) { + if (Asm.getBackend().isVirtualSection(SD.getSection())) { assert(SD.getFileSize() == 0 && "Invalid file size!"); FileOffset = 0; } @@ -748,7 +740,7 @@ public: VMSize = std::max(VMSize, SD.getAddress() + SD.getSize()); - if (isVirtualSection(SD.getSection())) + if (Asm.getBackend().isVirtualSection(SD.getSection())) continue; SectionDataSize = std::max(SectionDataSize, @@ -776,7 +768,7 @@ public: std::vector &Relocs = Relocations[it]; unsigned NumRelocs = Relocs.size(); uint64_t SectionStart = SectionDataStart + it->getAddress(); - WriteSection(*it, SectionStart, RelocTableEnd, NumRelocs); + WriteSection(Asm, *it, SectionStart, RelocTableEnd, NumRelocs); RelocTableEnd += NumRelocs * RelocationInfoSize; } @@ -1194,7 +1186,7 @@ void MCAssembler::LayoutSection(MCSectionData &SD) { // Set the section sizes. SD.setSize(Address - SD.getAddress()); - if (isVirtualSection(SD.getSection())) + if (getBackend().isVirtualSection(SD.getSection())) SD.setFileSize(0); else SD.setFileSize(Address - SD.getAddress()); @@ -1342,7 +1334,7 @@ static void WriteFragmentData(const MCFragment &F, MCObjectWriter *OW) { void MCAssembler::WriteSectionData(const MCSectionData *SD, MCObjectWriter *OW) const { // Ignore virtual sections. - if (isVirtualSection(SD->getSection())) { + if (getBackend().isVirtualSection(SD->getSection())) { assert(SD->getFileSize() == 0); return; } @@ -1444,7 +1436,7 @@ bool MCAssembler::LayoutOnce() { MCSectionData &SD = *it; // Skip virtual sections. - if (isVirtualSection(SD.getSection())) + if (getBackend().isVirtualSection(SD.getSection())) continue; // Align this section if necessary by adding padding bytes to the previous @@ -1467,7 +1459,7 @@ bool MCAssembler::LayoutOnce() { for (iterator it = begin(), ie = end(); it != ie; ++it) { MCSectionData &SD = *it; - if (!isVirtualSection(SD.getSection())) + if (!getBackend().isVirtualSection(SD.getSection())) continue; // Align this section if necessary by adding padding bytes to the previous diff --git a/lib/Target/X86/X86AsmBackend.cpp b/lib/Target/X86/X86AsmBackend.cpp index fec563817e6..1d66b841523 100644 --- a/lib/Target/X86/X86AsmBackend.cpp +++ b/lib/Target/X86/X86AsmBackend.cpp @@ -11,6 +11,7 @@ #include "X86.h" #include "X86FixupKinds.h" #include "llvm/MC/MCAssembler.h" +#include "llvm/MC/MCSectionELF.h" #include "llvm/MC/MCSectionMachO.h" #include "llvm/Target/TargetRegistry.h" #include "llvm/Target/TargetAsmBackend.h" @@ -48,6 +49,20 @@ public: } }; +class ELFX86AsmBackend : public X86AsmBackend { +public: + ELFX86AsmBackend(const Target &T) + : X86AsmBackend(T) { + HasAbsolutizedSet = true; + HasScatteredSymbols = true; + } + + bool isVirtualSection(const MCSection &Section) const { + const MCSectionELF &SE = static_cast(Section); + return SE.getType() == MCSectionELF::SHT_NOBITS;; + } +}; + class DarwinX86AsmBackend : public X86AsmBackend { public: DarwinX86AsmBackend(const Target &T) @@ -55,6 +70,12 @@ public: HasAbsolutizedSet = true; HasScatteredSymbols = true; } + + bool isVirtualSection(const MCSection &Section) const { + const MCSectionMachO &SMO = static_cast(Section); + return (SMO.getType() == MCSectionMachO::S_ZEROFILL || + SMO.getType() == MCSectionMachO::S_GB_ZEROFILL); + } }; class DarwinX86_32AsmBackend : public DarwinX86AsmBackend { @@ -92,7 +113,7 @@ TargetAsmBackend *llvm::createX86_32AsmBackend(const Target &T, case Triple::Darwin: return new DarwinX86_32AsmBackend(T); default: - return new X86AsmBackend(T); + return new ELFX86AsmBackend(T); } } @@ -102,6 +123,6 @@ TargetAsmBackend *llvm::createX86_64AsmBackend(const Target &T, case Triple::Darwin: return new DarwinX86_64AsmBackend(T); default: - return new X86AsmBackend(T); + return new ELFX86AsmBackend(T); } }