From a2d602560beb335cd443ccc03a41ecf714f337bb Mon Sep 17 00:00:00 2001 From: Nick Kledzik Date: Wed, 4 Jun 2014 00:34:27 +0000 Subject: [PATCH] [mach-o] Make anonymous atom out of section content before any symbol In sections that are broken into atoms at symbols, if the first symbol in the section is not at the start of the section, then make an anonymous atom for the section content that is before the first symbol. llvm-svn: 210142 --- .../MachO/MachONormalizedFileToAtoms.cpp | 36 ++++++++++++---------- lld/test/mach-o/parse-function.yaml | 21 +++++++++---- 2 files changed, 35 insertions(+), 22 deletions(-) diff --git a/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp b/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp index 9be4d0e..e5ce190 100644 --- a/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp +++ b/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp @@ -209,31 +209,29 @@ void appendSymbolsInSection(const std::vector &inSymbols, } void atomFromSymbol(DefinedAtom::ContentType atomType, const Section §ion, - MachOFile &file, const Symbol &symbol, + MachOFile &file, uint64_t symbolAddr, StringRef symbolName, + bool symbolWeakDef, Atom::Scope symbolScope, uint64_t nextSymbolAddr, bool copyRefs) { // Mach-O symbol table does have size in it. Instead the size is the // difference between this and the next symbol. - uint64_t size = nextSymbolAddr - symbol.value; + uint64_t size = nextSymbolAddr - symbolAddr; if (section.type == llvm::MachO::S_ZEROFILL) { - file.addZeroFillDefinedAtom(symbol.name, atomScope(symbol.scope), - size, copyRefs); + file.addZeroFillDefinedAtom(symbolName, symbolScope, size, copyRefs); } else { - uint64_t offset = symbol.value - section.address; + uint64_t offset = symbolAddr - section.address; ArrayRef atomContent = section.content.slice(offset, size); - DefinedAtom::Merge merge = DefinedAtom::mergeNo; - if (symbol.desc & N_WEAK_DEF) - merge = DefinedAtom::mergeAsWeak; + DefinedAtom::Merge merge = symbolWeakDef + ? DefinedAtom::mergeAsWeak : DefinedAtom::mergeNo; if (atomType == DefinedAtom::typeUnknown) { // Mach-O needs a segment and section name. Concatentate those two // with a / seperator (e.g. "seg/sect") to fit into the lld model // of just a section name. std::string segSectName = section.segmentName.str() + "/" + section.sectionName.str(); - file.addDefinedAtomInCustomSection(symbol.name, atomScope(symbol.scope), - atomType, merge, atomContent, - segSectName, true); + file.addDefinedAtomInCustomSection(symbolName, symbolScope, atomType, + merge, atomContent, segSectName, true); } else { - file.addDefinedAtom(symbol.name, atomScope(symbol.scope), atomType, merge, + file.addDefinedAtom(symbolName, symbolScope, atomType, merge, atomContent, copyRefs); } } @@ -270,20 +268,26 @@ error_code processSymboledSection(DefinedAtom::ContentType atomType, if (symbols.empty() && section.content.empty()) return error_code(); - if (symbols.front()->value != section.address) { + const uint64_t firstSymbolAddr = symbols.front()->value; + if (firstSymbolAddr != section.address) { // Section has anonymous content before first symbol. - // FIXME + atomFromSymbol(atomType, section, file, section.address, StringRef(), + false, Atom::scopeTranslationUnit, firstSymbolAddr, copyRefs); } const Symbol *lastSym = nullptr; + bool lastSymIsWeakDef; for (const Symbol *sym : symbols) { if (lastSym != nullptr) { - atomFromSymbol(atomType, section, file, *lastSym, sym->value, copyRefs); + atomFromSymbol(atomType, section, file, lastSym->value, lastSym->name, + lastSymIsWeakDef, atomScope(lastSym->scope), sym->value, copyRefs); } lastSym = sym; + lastSymIsWeakDef = (lastSym->desc & N_WEAK_DEF); } if (lastSym != nullptr) { - atomFromSymbol(atomType, section, file, *lastSym, + atomFromSymbol(atomType, section, file, lastSym->value, lastSym->name, + lastSymIsWeakDef, atomScope(lastSym->scope), section.address + section.content.size(), copyRefs); } return error_code(); diff --git a/lld/test/mach-o/parse-function.yaml b/lld/test/mach-o/parse-function.yaml index 5eb721d..19a935a 100644 --- a/lld/test/mach-o/parse-function.yaml +++ b/lld/test/mach-o/parse-function.yaml @@ -16,51 +16,60 @@ sections: attributes: [ S_ATTR_PURE_INSTRUCTIONS, S_ATTR_SOME_INSTRUCTIONS ] alignment: 4 address: 0x0000000000000000 - content: [ 0xC3, 0xC3, 0xC3, 0xC3, 0xC3 ] + content: [ 0xCC, 0xC3, 0x90, 0xC3, 0x90, 0x90, 0xC3, 0x90, + 0x90, 0x90, 0xC3, 0x90, 0x90, 0x90, 0x90, 0xC3 ] local-symbols: - name: _myStatic type: N_SECT sect: 1 - value: 0x0000000000000004 + value: 0x000000000000000B global-symbols: - name: _myGlobal type: N_SECT scope: [ N_EXT ] sect: 1 - value: 0x0000000000000000 + value: 0x0000000000000001 - name: _myGlobalWeak type: N_SECT scope: [ N_EXT ] sect: 1 desc: [ N_WEAK_DEF ] - value: 0x0000000000000001 + value: 0x0000000000000002 - name: _myHidden type: N_SECT scope: [ N_EXT, N_PEXT ] sect: 1 - value: 0x0000000000000002 + value: 0x0000000000000004 - name: _myHiddenWeak type: N_SECT scope: [ N_EXT, N_PEXT ] sect: 1 desc: [ N_WEAK_DEF ] - value: 0x0000000000000003 + value: 0x0000000000000007 ... +# CHECK-NOT: name: +# CHECK: content: [ CC ] + # CHECK: name: _myGlobal # CHECK: scope: global +# CHECK: content: [ C3 ] # CHECK: name: _myGlobalWeak # CHECK: scope: global +# CHECK: content: [ 90, C3 ] # CHECK: merge: as-weak # CHECK: name: _myHidden # CHECK: scope: hidden +# CHECK: content: [ 90, 90, C3 ] # CHECK: name: _myHiddenWeak # CHECK: scope: hidden +# CHECK: content: [ 90, 90, 90, C3 ] # CHECK: merge: as-weak # CHECK: name: _myStatic # CHECK-NOT: scope: global # CHECK-NOT: scope: hidden +# CHECK: content: [ 90, 90, 90, 90, C3 ] -- 2.7.4