From 5d97c823a480f3b523fcd3f21d9e09ea601e3333 Mon Sep 17 00:00:00 2001 From: Paul Semel Date: Tue, 15 May 2018 14:09:37 +0000 Subject: [PATCH] [llvm-objcopy] Add --keep-symbol (-K) option This option permits to explicitly keep the specified symbol so that it doesn't get removed. Differential Revision: https://reviews.llvm.org/D46819 llvm-svn: 332356 --- .../llvm-objcopy/keep-symbol-remove-section.test | 36 ++++++++++++ llvm/test/tools/llvm-objcopy/keep-symbol.test | 66 ++++++++++++++++++++++ llvm/tools/llvm-objcopy/ObjcopyOpts.td | 5 ++ llvm/tools/llvm-objcopy/llvm-objcopy.cpp | 7 +++ 4 files changed, 114 insertions(+) create mode 100644 llvm/test/tools/llvm-objcopy/keep-symbol-remove-section.test create mode 100644 llvm/test/tools/llvm-objcopy/keep-symbol.test diff --git a/llvm/test/tools/llvm-objcopy/keep-symbol-remove-section.test b/llvm/test/tools/llvm-objcopy/keep-symbol-remove-section.test new file mode 100644 index 0000000..6b02caa --- /dev/null +++ b/llvm/test/tools/llvm-objcopy/keep-symbol-remove-section.test @@ -0,0 +1,36 @@ +# RUN: yaml2obj %s > %t +# RUN: llvm-objcopy --remove-section .text --keep-symbol foo %t %t2 +# RUN: llvm-readobj -symbols %t2 | FileCheck %s + +!ELF +FileHeader: + Class: ELFCLASS64 + Data: ELFDATA2LSB + Type: ET_REL + Machine: EM_X86_64 +Sections: + - Name: .text + Type: SHT_PROGBITS + Flags: [ SHF_ALLOC, SHF_EXECINSTR ] + Address: 0x1000 + AddressAlign: 0x0000000000000010 + Size: 64 +Symbols: + Local: + - Name: foo + Type: STT_FUNC + Section: .text + Value: 0x1000 + Size: 8 + +#CHECK: Symbols [ +#CHECK-NEXT: Symbol { +#CHECK-NEXT: Name: +#CHECK-NEXT: Value: 0x0 +#CHECK-NEXT: Size: 0 +#CHECK-NEXT: Binding: Local +#CHECK-NEXT: Type: None +#CHECK-NEXT: Other: 0 +#CHECK-NEXT: Section: Undefined +#CHECK-NEXT: } +#CHECK-NEXT:] diff --git a/llvm/test/tools/llvm-objcopy/keep-symbol.test b/llvm/test/tools/llvm-objcopy/keep-symbol.test new file mode 100644 index 0000000..8c6415f --- /dev/null +++ b/llvm/test/tools/llvm-objcopy/keep-symbol.test @@ -0,0 +1,66 @@ +# RUN: yaml2obj %s > %t +# RUN: llvm-objcopy --discard-all -K foo --keep-symbol bar %t %t2 +# RUN: llvm-objcopy -K foo -N foo -N bar --keep-symbol bar -N baz %t %t3 +# RUN: llvm-readobj -symbols %t2 | FileCheck %s +# RUN: llvm-readobj -symbols %t3 | FileCheck %s + +!ELF +FileHeader: + Class: ELFCLASS64 + Data: ELFDATA2LSB + Type: ET_REL + Machine: EM_X86_64 +Sections: + - Name: .text + Type: SHT_PROGBITS + Flags: [ SHF_ALLOC, SHF_EXECINSTR ] + Address: 0x1000 + AddressAlign: 0x0000000000000010 + Size: 64 +Symbols: + Local: + - Name: foo + Type: STT_FUNC + Section: .text + Value: 0x1000 + Size: 8 + - Name: bar + Type: STT_FUNC + Section: .text + Value: 0x1008 + Size: 8 + - Name: baz + Type: STT_FUNC + Section: .text + Value: 0x1010 + Size: 8 + +#CHECK: Symbols [ +#CHECK-NEXT: Symbol { +#CHECK-NEXT: Name: +#CHECK-NEXT: Value: 0x0 +#CHECK-NEXT: Size: 0 +#CHECK-NEXT: Binding: Local +#CHECK-NEXT: Type: None +#CHECK-NEXT: Other: 0 +#CHECK-NEXT: Section: Undefined +#CHECK-NEXT: } +#CHECK-NEXT: Symbol { +#CHECK-NEXT: Name: foo +#CHECK-NEXT: Value: 0x1000 +#CHECK-NEXT: Size: 8 +#CHECK-NEXT: Binding: Local +#CHECK-NEXT: Type: Function +#CHECK-NEXT: Other: 0 +#CHECK-NEXT: Section: .text +#CHECK-NEXT: } +#CHECK-NEXT: Symbol { +#CHECK-NEXT: Name: bar +#CHECK-NEXT: Value: 0x1008 +#CHECK-NEXT: Size: 8 +#CHECK-NEXT: Binding: Local +#CHECK-NEXT: Type: Function +#CHECK-NEXT: Other: 0 +#CHECK-NEXT: Section: .text +#CHECK-NEXT: } +#CHECK-NEXT:] diff --git a/llvm/tools/llvm-objcopy/ObjcopyOpts.td b/llvm/tools/llvm-objcopy/ObjcopyOpts.td index 0ab658b..92f2c74 100644 --- a/llvm/tools/llvm-objcopy/ObjcopyOpts.td +++ b/llvm/tools/llvm-objcopy/ObjcopyOpts.td @@ -83,3 +83,8 @@ defm strip_symbol : Eq<"strip-symbol">, HelpText<"Remove symbol ">; def N : JoinedOrSeparate<["-"], "N">, Alias; +defm keep_symbol : Eq<"keep-symbol">, + MetaVarName<"symbol">, + HelpText<"Do not remove symbol ">; +def K : JoinedOrSeparate<["-"], "K">, + Alias; diff --git a/llvm/tools/llvm-objcopy/llvm-objcopy.cpp b/llvm/tools/llvm-objcopy/llvm-objcopy.cpp index c71e2b9..24ec188 100644 --- a/llvm/tools/llvm-objcopy/llvm-objcopy.cpp +++ b/llvm/tools/llvm-objcopy/llvm-objcopy.cpp @@ -148,6 +148,7 @@ struct CopyConfig { std::vector SymbolsToGlobalize; std::vector SymbolsToWeaken; std::vector SymbolsToRemove; + std::vector SymbolsToKeep; StringMap SymbolsToRename; bool StripAll = false; bool StripAllGNU = false; @@ -373,6 +374,10 @@ void HandleArgs(const CopyConfig &Config, Object &Obj, const Reader &Reader, }); Obj.removeSymbols([&](const Symbol &Sym) { + if (!Config.SymbolsToKeep.empty() && + is_contained(Config.SymbolsToKeep, Sym.Name)) + return false; + if (Config.DiscardAll && Sym.Binding == STB_LOCAL && Sym.getShndx() != SHN_UNDEF && Sym.Type != STT_FILE && Sym.Type != STT_SECTION) @@ -485,6 +490,8 @@ CopyConfig ParseObjcopyOptions(ArrayRef ArgsArr) { Config.SymbolsToWeaken.push_back(Arg->getValue()); for (auto Arg : InputArgs.filtered(OBJCOPY_strip_symbol)) Config.SymbolsToRemove.push_back(Arg->getValue()); + for (auto Arg : InputArgs.filtered(OBJCOPY_keep_symbol)) + Config.SymbolsToKeep.push_back(Arg->getValue()); return Config; } -- 2.7.4