diff --git a/lld/MachO/ICF.cpp b/lld/MachO/ICF.cpp --- a/lld/MachO/ICF.cpp +++ b/lld/MachO/ICF.cpp @@ -372,7 +372,8 @@ uint64_t icfUniqueID = inputSections.size(); for (ConcatInputSection *isec : inputSections) { // FIXME: consider non-code __text sections as hashable? - bool isHashable = (isCodeSection(isec) || isCfStringSection(isec)) && + bool isHashable = (isCodeSection(isec) || isCfStringSection(isec) || + isClassRefsSection(isec)) && !isec->shouldOmitFromOutput() && sectionType(isec->getFlags()) == MachO::S_REGULAR; if (isHashable) { @@ -390,7 +391,7 @@ // information gets recorded in our Reloc structs.) We therefore create a // mutable copy of the CFString and zero out the embedded addends before // performing any hashing / equality checks. - if (isCfStringSection(isec)) { + if (isCfStringSection(isec) || isClassRefsSection(isec)) { MutableArrayRef copy = isec->data.copy(bAlloc()); for (const Reloc &r : isec->relocs) target->relocateOne(copy.data() + r.offset, r, /*va=*/0, /*relocVA=*/0); diff --git a/lld/MachO/InputFiles.cpp b/lld/MachO/InputFiles.cpp --- a/lld/MachO/InputFiles.cpp +++ b/lld/MachO/InputFiles.cpp @@ -252,13 +252,18 @@ // Note that "record" is a term I came up with. In contrast, "literal" is a term // used by the Mach-O format. static Optional getRecordSize(StringRef segname, StringRef name) { - if (name == section_names::cfString) { - if (config->icfLevel != ICFLevel::none && segname == segment_names::data) - return target->wordSize == 8 ? 32 : 16; - } else if (name == section_names::compactUnwind) { - if (segname == segment_names::ld) - return target->wordSize == 8 ? 32 : 20; + if (name == section_names::compactUnwind) { + if (segname == segment_names::ld) + return target->wordSize == 8 ? 32 : 20; } + if (config->icfLevel == ICFLevel::none) + return {}; + + if (name == section_names::cfString && segname == segment_names::data) + return target->wordSize == 8 ? 32 : 16; + else if (name == section_names::objcClassRefs && + segname == segment_names::data) + return target->wordSize; return {}; } diff --git a/lld/MachO/InputSection.h b/lld/MachO/InputSection.h --- a/lld/MachO/InputSection.h +++ b/lld/MachO/InputSection.h @@ -268,8 +268,8 @@ } bool isCodeSection(const InputSection *); - bool isCfStringSection(const InputSection *); +bool isClassRefsSection(const InputSection *); extern std::vector inputSections; @@ -306,6 +306,7 @@ constexpr const char nonLazySymbolPtr[] = "__nl_symbol_ptr"; constexpr const char objcCatList[] = "__objc_catlist"; constexpr const char objcClassList[] = "__objc_classlist"; +constexpr const char objcClassRefs[] = "__objc_classrefs"; constexpr const char objcConst[] = "__objc_const"; constexpr const char objcImageInfo[] = "__objc_imageinfo"; constexpr const char objcNonLazyCatList[] = "__objc_nlcatlist"; diff --git a/lld/MachO/InputSection.cpp b/lld/MachO/InputSection.cpp --- a/lld/MachO/InputSection.cpp +++ b/lld/MachO/InputSection.cpp @@ -261,6 +261,11 @@ isec->getSegName() == segment_names::data; } +bool macho::isClassRefsSection(const InputSection *isec) { + return isec->getName() == section_names::objcClassRefs && + isec->getSegName() == segment_names::data; +} + std::string lld::toString(const InputSection *isec) { return (toString(isec->getFile()) + ":(" + isec->getName() + ")").str(); } diff --git a/lld/test/MachO/objc-classrefs-dedup.s b/lld/test/MachO/objc-classrefs-dedup.s new file mode 100644 --- /dev/null +++ b/lld/test/MachO/objc-classrefs-dedup.s @@ -0,0 +1,53 @@ +# REQUIRES: x86 +# RUN: rm -rf %t; split-file %s %t +# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/defs.s -o %t/defs.o +# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/refs1.s -o %t/refs1.o +# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/refs2.s -o %t/refs2.o +# RUN: %lld -lSystem -dylib %t/defs.o -o %t/libdefs.dylib +# RUN: %lld -lSystem -dylib --icf=all %t/refs1.o %t/refs2.o %t/libdefs.dylib -o %t/out +# RUN: llvm-objdump --macho --section-headers --bind %t/out | FileCheck %s \ +# RUN: --implicit-check-not __objc_classrefs + +## Check that we only have 3 (unique) entries +# CHECK: Sections: +# CHECK-NEXT: Idx Name Size +# CHECK: __objc_classrefs 00000018 + +## And only two binds +# CHECK: Bind table: +# CHECK-NEXT: segment section address type addend dylib symbol +# CHECK-DAG: __DATA __objc_classrefs {{.*}} pointer 0 libdefs _OBJC_CLASS_$_Bar +# CHECK-DAG: __DATA __objc_classrefs {{.*}} pointer 0 libdefs _OBJC_CLASS_$_Foo + +#--- defs.s +.globl _OBJC_CLASS_$_Foo, _OBJC_CLASS_$_Bar +.section __DATA,__objc_data +_OBJC_CLASS_$_Foo: + .quad 123 + +_OBJC_CLASS_$_Bar: + .quad 456 + +.subsections_via_symbols + +#--- refs1.s +.globl _OBJC_CLASS_$_Baz + +.section __DATA,__objc_data +_OBJC_CLASS_$_Baz: + .quad 789 + +.section __DATA,__objc_classrefs +.quad _OBJC_CLASS_$_Foo +.quad _OBJC_CLASS_$_Bar +.quad _OBJC_CLASS_$_Baz +.quad _OBJC_CLASS_$_Baz + +.subsections_via_symbols + +#--- refs2.s +.section __DATA,__objc_classrefs +.quad _OBJC_CLASS_$_Foo +.quad _OBJC_CLASS_$_Bar + +.subsections_via_symbols