From 85bbe2974ba7da886fac7852959b200fdd84a6c3 Mon Sep 17 00:00:00 2001 From: Fangrui Song Date: Wed, 2 Oct 2019 12:41:25 +0000 Subject: [PATCH] [llvm-objcopy] Add --set-section-alignment Fixes PR43181. This option was recently added to GNU objcopy (binutils PR24942). `llvm-objcopy -I binary -O elf64-x86-64 --set-section-alignment .data=8` can set the alignment of .data. Reviewed By: grimar, jhenderson, rupprecht Differential Revision: https://reviews.llvm.org/D67656 llvm-svn: 373461 --- docs/CommandGuide/llvm-objcopy.rst | 5 ++ test/tools/llvm-objcopy/ELF/binary-input.test | 8 +++ .../ELF/set-section-alignment.test | 54 +++++++++++++++++++ tools/llvm-objcopy/COFF/COFFObjcopy.cpp | 9 ++-- tools/llvm-objcopy/CopyConfig.cpp | 26 +++++++++ tools/llvm-objcopy/CopyConfig.h | 1 + tools/llvm-objcopy/ELF/ELFObjcopy.cpp | 8 +++ tools/llvm-objcopy/MachO/MachOObjcopy.cpp | 15 +++--- tools/llvm-objcopy/ObjcopyOpts.td | 4 ++ 9 files changed, 119 insertions(+), 11 deletions(-) create mode 100644 test/tools/llvm-objcopy/ELF/set-section-alignment.test diff --git a/docs/CommandGuide/llvm-objcopy.rst b/docs/CommandGuide/llvm-objcopy.rst index 35e4d421f0b..ccdcf13eb59 100644 --- a/docs/CommandGuide/llvm-objcopy.rst +++ b/docs/CommandGuide/llvm-objcopy.rst @@ -82,6 +82,11 @@ multiple file formats. Remove the specified section from the output. Can be specified multiple times to remove multiple sections simultaneously. +.. option:: --set-section-alignment
= + + Set the alignment of section ``
`` to ```. Can be specified + multiple times to update multiple sections. + .. option:: --strip-all-gnu Remove all symbols, debug sections and relocations from the output. This option diff --git a/test/tools/llvm-objcopy/ELF/binary-input.test b/test/tools/llvm-objcopy/ELF/binary-input.test index 8eef7f772f9..f232296ded8 100644 --- a/test/tools/llvm-objcopy/ELF/binary-input.test +++ b/test/tools/llvm-objcopy/ELF/binary-input.test @@ -110,3 +110,11 @@ # CHECK-NEXT: Section: Absolute # CHECK-NEXT: } # CHECK-NEXT: ] + +## The alignment can be changed by --set-section-alignment. +# RUN: llvm-objcopy -I binary -O elf64-x86-64 --set-section-alignment .data=8 %t.x-txt %t2.o +# RUN: llvm-readobj --sections %t2.o | FileCheck --check-prefix=ALIGN %s + +# ALIGN: Name: .data +# ALIGN: AddressAlignment: +# ALIGN-SAME: 8{{$}} diff --git a/test/tools/llvm-objcopy/ELF/set-section-alignment.test b/test/tools/llvm-objcopy/ELF/set-section-alignment.test new file mode 100644 index 00000000000..79c7eddffdd --- /dev/null +++ b/test/tools/llvm-objcopy/ELF/set-section-alignment.test @@ -0,0 +1,54 @@ +# RUN: yaml2obj %s -o %t + +# RUN: llvm-objcopy --set-section-alignment .foo=4 --set-section-alignment .bar=0x5 \ +# RUN: --set-section-alignment .baz=0 %t %t.2 +# RUN: llvm-readobj --sections %t.2 | FileCheck --check-prefix=CHECK %s + +# CHECK: Name: .foo +# CHECK: AddressAlignment: +# CHECK-SAME: 4{{$}} +# CHECK: Name: .bar +# CHECK: AddressAlignment: +# CHECK-SAME: 5{{$}} +# CHECK: Name: .baz +# CHECK: AddressAlignment: +# CHECK-SAME: 0{{$}} + +## If a section is specified multiple times, the last wins. +# RUN: llvm-objcopy --set-section-alignment .foo=4 --set-section-alignment=.foo=7 %t %t.3 +# RUN: llvm-readobj --sections %t.3 | FileCheck --check-prefix=MULTI %s + +# MULTI: Name: .foo +# MULTI: AddressAlignment: +# MULTI-SAME: 7{{$}} + +## Ignore the option if the section does not exist. +# RUN: llvm-objcopy --set-section-alignment .not_exist=4 %t.3 %t.4 +# RUN: cmp %t.3 %t.4 + +# RUN: not llvm-objcopy --set-section-alignment=.foo %t /dev/null 2>&1 | \ +# RUN: FileCheck --check-prefix=MISSING-EQUAL %s +# MISSING-EQUAL: error: bad format for --set-section-alignment: missing '=' + +# RUN: not llvm-objcopy --set-section-alignment==4 %t /dev/null 2>&1 | \ +# RUN: FileCheck --check-prefix=MISSING-SECTION %s +# MISSING-SECTION: error: bad format for --set-section-alignment: missing section name + +# RUN: not llvm-objcopy --set-section-alignment=.foo=bar %t /dev/null 2>&1 | \ +# RUN: FileCheck --check-prefix=INVALID-ALIGN %s +# INVALID-ALIGN: error: invalid alignment for --set-section-alignment: 'bar' + +!ELF +FileHeader: + Class: ELFCLASS64 + Data: ELFDATA2LSB + Type: ET_REL + Machine: EM_X86_64 +Sections: + - Name: .foo + Type: SHT_PROGBITS + - Name: .bar + Type: SHT_NOBITS + - Name: .baz + Type: SHT_NOTE + AddressAlign: 4 diff --git a/tools/llvm-objcopy/COFF/COFFObjcopy.cpp b/tools/llvm-objcopy/COFF/COFFObjcopy.cpp index 28de0eb6efd..60f70d71349 100644 --- a/tools/llvm-objcopy/COFF/COFFObjcopy.cpp +++ b/tools/llvm-objcopy/COFF/COFFObjcopy.cpp @@ -208,10 +208,11 @@ static Error handleArgs(const CopyConfig &Config, Object &Obj) { !Config.SymbolsToGlobalize.empty() || !Config.SymbolsToKeep.empty() || !Config.SymbolsToLocalize.empty() || !Config.SymbolsToWeaken.empty() || !Config.SymbolsToKeepGlobal.empty() || !Config.SectionsToRename.empty() || - !Config.SetSectionFlags.empty() || !Config.SymbolsToRename.empty() || - Config.ExtractDWO || Config.KeepFileSymbols || Config.LocalizeHidden || - Config.PreserveDates || Config.StripDWO || Config.StripNonAlloc || - Config.StripSections || Config.Weaken || Config.DecompressDebugSections || + !Config.SetSectionAlignment.empty() || !Config.SetSectionFlags.empty() || + !Config.SymbolsToRename.empty() || Config.ExtractDWO || + Config.KeepFileSymbols || Config.LocalizeHidden || Config.PreserveDates || + Config.StripDWO || Config.StripNonAlloc || Config.StripSections || + Config.Weaken || Config.DecompressDebugSections || Config.DiscardMode == DiscardType::Locals || !Config.SymbolsToAdd.empty() || Config.EntryExpr) { return createStringError(llvm::errc::invalid_argument, diff --git a/tools/llvm-objcopy/CopyConfig.cpp b/tools/llvm-objcopy/CopyConfig.cpp index 99291660a49..9b51b745d50 100644 --- a/tools/llvm-objcopy/CopyConfig.cpp +++ b/tools/llvm-objcopy/CopyConfig.cpp @@ -155,6 +155,25 @@ static Expected parseRenameSectionValue(StringRef FlagValue) { return SR; } +static Expected> +parseSetSectionAlignment(StringRef FlagValue) { + if (!FlagValue.contains('=')) + return createStringError( + errc::invalid_argument, + "bad format for --set-section-alignment: missing '='"); + auto Split = StringRef(FlagValue).split('='); + if (Split.first.empty()) + return createStringError( + errc::invalid_argument, + "bad format for --set-section-alignment: missing section name"); + uint64_t NewAlign; + if (Split.second.getAsInteger(0, NewAlign)) + return createStringError(errc::invalid_argument, + "invalid alignment for --set-section-alignment: '%s'", + Split.second.str().c_str()); + return std::make_pair(Split.first, NewAlign); +} + static Expected parseSetSectionFlagValue(StringRef FlagValue) { if (!StringRef(FlagValue).contains('=')) @@ -489,6 +508,13 @@ Expected parseObjcopyOptions(ArrayRef ArgsArr) { "multiple renames of section '%s'", SR->OriginalName.str().c_str()); } + for (auto Arg : InputArgs.filtered(OBJCOPY_set_section_alignment)) { + Expected> NameAndAlign = + parseSetSectionAlignment(Arg->getValue()); + if (!NameAndAlign) + return NameAndAlign.takeError(); + Config.SetSectionAlignment[NameAndAlign->first] = NameAndAlign->second; + } for (auto Arg : InputArgs.filtered(OBJCOPY_set_section_flags)) { Expected SFU = parseSetSectionFlagValue(Arg->getValue()); diff --git a/tools/llvm-objcopy/CopyConfig.h b/tools/llvm-objcopy/CopyConfig.h index 85d660407f0..745af0ce480 100644 --- a/tools/llvm-objcopy/CopyConfig.h +++ b/tools/llvm-objcopy/CopyConfig.h @@ -161,6 +161,7 @@ struct CopyConfig { // Map options StringMap SectionsToRename; + StringMap SetSectionAlignment; StringMap SetSectionFlags; StringMap SymbolsToRename; diff --git a/tools/llvm-objcopy/ELF/ELFObjcopy.cpp b/tools/llvm-objcopy/ELF/ELFObjcopy.cpp index 2f29d90f5be..dd6a7d7e14b 100644 --- a/tools/llvm-objcopy/ELF/ELFObjcopy.cpp +++ b/tools/llvm-objcopy/ELF/ELFObjcopy.cpp @@ -670,6 +670,14 @@ static Error handleArgs(const CopyConfig &Config, Object &Obj, } } + if (!Config.SetSectionAlignment.empty()) { + for (SectionBase &Sec : Obj.sections()) { + auto I = Config.SetSectionAlignment.find(Sec.Name); + if (I != Config.SetSectionAlignment.end()) + Sec.Align = I->second; + } + } + if (!Config.SetSectionFlags.empty()) { for (auto &Sec : Obj.sections()) { const auto Iter = Config.SetSectionFlags.find(Sec.Name); diff --git a/tools/llvm-objcopy/MachO/MachOObjcopy.cpp b/tools/llvm-objcopy/MachO/MachOObjcopy.cpp index a52931e469f..6d586e7d73f 100644 --- a/tools/llvm-objcopy/MachO/MachOObjcopy.cpp +++ b/tools/llvm-objcopy/MachO/MachOObjcopy.cpp @@ -31,13 +31,14 @@ static Error handleArgs(const CopyConfig &Config, Object &Obj) { !Config.SymbolsToKeepGlobal.empty() || !Config.SectionsToRename.empty() || !Config.SymbolsToRename.empty() || !Config.UnneededSymbolsToRemove.empty() || - !Config.SetSectionFlags.empty() || !Config.ToRemove.empty() || - Config.ExtractDWO || Config.KeepFileSymbols || Config.LocalizeHidden || - Config.PreserveDates || Config.StripDWO || Config.StripNonAlloc || - Config.StripSections || Config.Weaken || Config.DecompressDebugSections || - Config.StripDebug || Config.StripNonAlloc || Config.StripSections || - Config.StripUnneeded || Config.DiscardMode != DiscardType::None || - !Config.SymbolsToAdd.empty() || Config.EntryExpr) { + !Config.SetSectionAlignment.empty() || !Config.SetSectionFlags.empty() || + !Config.ToRemove.empty() || Config.ExtractDWO || Config.KeepFileSymbols || + Config.LocalizeHidden || Config.PreserveDates || Config.StripDWO || + Config.StripNonAlloc || Config.StripSections || Config.Weaken || + Config.DecompressDebugSections || Config.StripDebug || + Config.StripNonAlloc || Config.StripSections || Config.StripUnneeded || + Config.DiscardMode != DiscardType::None || !Config.SymbolsToAdd.empty() || + Config.EntryExpr) { return createStringError(llvm::errc::invalid_argument, "option not supported by llvm-objcopy for MachO"); } diff --git a/tools/llvm-objcopy/ObjcopyOpts.td b/tools/llvm-objcopy/ObjcopyOpts.td index 87b678a8b16..9e6b6f0005c 100644 --- a/tools/llvm-objcopy/ObjcopyOpts.td +++ b/tools/llvm-objcopy/ObjcopyOpts.td @@ -75,6 +75,10 @@ defm add_section "Make a section named
with the contents of .">, MetaVarName<"section=file">; +defm set_section_alignment + : Eq<"set-section-alignment", "Set alignment for a given section.">, + MetaVarName<"section=align">; + defm set_section_flags : Eq<"set-section-flags", "Set section flags for a given section. Flags supported for GNU "