From: George Rimar Date: Fri, 12 Aug 2016 09:07:57 +0000 (+0000) Subject: [ELF] - Linkerscript: reimplemented output sections constrains matching functionality. X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=06ae68362060928fdc391bea8061cf9d8dc622eb;p=platform%2Fupstream%2Fllvm.git [ELF] - Linkerscript: reimplemented output sections constrains matching functionality. Previously filtering that was used worked incorrectly. For example for next script it would just remove both sections completely: SECTIONS { . = 0x1000; .aaa : ONLY_IF_RW { *(.aaa.*) } . = 0x2000; .aaa : ONLY_IF_RO { *(.aaa.*) } } Patch fixes above issues and adds testcase showing the issue. Testcase is a subset of FreeBSD script which has: .eh_frame : ONLY_IF_RO { KEEP (*(.eh_frame)) } ... .eh_frame : ONLY_IF_RW { KEEP (*(.eh_frame)) } Differential revision: https://reviews.llvm.org/D23326 llvm-svn: 278486 --- diff --git a/lld/ELF/LinkerScript.cpp b/lld/ELF/LinkerScript.cpp index 64918d7..1c24614 100644 --- a/lld/ELF/LinkerScript.cpp +++ b/lld/ELF/LinkerScript.cpp @@ -216,20 +216,33 @@ void LinkerScript::discard(OutputSectionCommand &Cmd) { } template +static bool matchConstraints(ArrayRef *> Sections, + ConstraintKind Kind) { + bool RO = (Kind == ConstraintKind::ReadOnly); + bool RW = (Kind == ConstraintKind::ReadWrite); + return !llvm::any_of(Sections, [=](InputSectionBase *Sec) { + bool Writable = Sec->getSectionHdr()->sh_flags & SHF_WRITE; + return (RO && Writable) || (RW && !Writable); + }); +} + +template std::vector *> -LinkerScript::createInputSectionList(OutputSectionCommand &Cmd) { +LinkerScript::createInputSectionList(OutputSectionCommand &OutCmd) { std::vector *> Ret; - for (const std::unique_ptr &Base : Cmd.Commands) { - if (auto *Cmd = dyn_cast(Base.get())) { - if (shouldDefine(Cmd)) - addSynthetic(Cmd); - Ret.push_back(new (LAlloc.Allocate()) LayoutInputSection(Cmd)); + for (const std::unique_ptr &Base : OutCmd.Commands) { + if (auto *OutCmd = dyn_cast(Base.get())) { + if (shouldDefine(OutCmd)) + addSynthetic(OutCmd); + Ret.push_back(new (LAlloc.Allocate()) LayoutInputSection(OutCmd)); continue; } auto *Cmd = cast(Base.get()); std::vector *> V = getInputSections(Cmd); + if (!matchConstraints(V, OutCmd.Constraint)) + continue; if (Cmd->SortInner) std::stable_sort(V.begin(), V.end(), getComparator(Cmd->SortInner)); if (Cmd->SortOuter) @@ -283,38 +296,6 @@ void LinkerScript::createSections(OutputSectionFactory &Factory) { OutSec->addSection(S); } } - - // Remove from the output all the sections which did not meet - // the optional constraints. - filter(); -} - -template -static inline void removeElementsIf(R &Range, const T &Pred) { - Range.erase(std::remove_if(Range.begin(), Range.end(), Pred), Range.end()); -} - -// Process ONLY_IF_RO and ONLY_IF_RW. -template void LinkerScript::filter() { - // In this loop, we remove output sections if they don't satisfy - // requested properties. - for (const std::unique_ptr &Base : Opt.Commands) { - auto *Cmd = dyn_cast(Base.get()); - if (!Cmd || Cmd->Name == "/DISCARD/") - continue; - - if (Cmd->Constraint == ConstraintKind::NoConstraint) - continue; - - bool RO = (Cmd->Constraint == ConstraintKind::ReadOnly); - bool RW = (Cmd->Constraint == ConstraintKind::ReadWrite); - - removeElementsIf(*OutputSections, [&](OutputSectionBase *S) { - bool Writable = (S->getFlags() & SHF_WRITE); - return S->getName() == Cmd->Name && - ((RO && Writable) || (RW && !Writable)); - }); - } } template void assignOffsets(OutputSectionBase *Sec) { diff --git a/lld/ELF/LinkerScript.h b/lld/ELF/LinkerScript.h index ecf9f5c..53a6db5 100644 --- a/lld/ELF/LinkerScript.h +++ b/lld/ELF/LinkerScript.h @@ -167,8 +167,6 @@ private: // "ScriptConfig" is a bit too long, so define a short name for it. ScriptConfiguration &Opt = *ScriptConfig; - void filter(); - int getSectionIndex(StringRef Name); std::vector getPhdrIndices(StringRef SectionName); size_t getPhdrIndex(StringRef PhdrName); diff --git a/lld/test/ELF/linkerscript/linkerscript-multi-sections-constraint.s b/lld/test/ELF/linkerscript/linkerscript-multi-sections-constraint.s new file mode 100644 index 0000000..c9d0943 --- /dev/null +++ b/lld/test/ELF/linkerscript/linkerscript-multi-sections-constraint.s @@ -0,0 +1,26 @@ +# REQUIRES: x86 +# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t +# RUN: echo "SECTIONS { \ +# RUN: . = 0x1000; .aaa : ONLY_IF_RO { *(.aaa.*) } \ +# RUN: . = 0x2000; .aaa : ONLY_IF_RW { *(.aaa.*) } } " > %t.script +# RUN: ld.lld -o %t1 --script %t.script %t +# RUN: llvm-objdump -section-headers %t1 | FileCheck %s + +# CHECK: Sections: +# CHECK-NEXT: Idx Name Size Address Type +# CHECK-NEXT: 0 00000000 0000000000000000 +# CHECK-NEXT: 1 .aaa 00000010 0000000000002000 DATA +# CHECK-NEXT: 2 .text 00000001 0000000000002010 TEXT DATA +# CHECK-NEXT: 3 .symtab 00000030 0000000000000000 +# CHECK-NEXT: 4 .shstrtab 00000026 0000000000000000 +# CHECK-NEXT: 5 .strtab 00000008 0000000000000000 + +.global _start +_start: + nop + +.section .aaa.1, "aw" +.quad 1 + +.section .aaa.2, "aw" +.quad 1 diff --git a/lld/test/ELF/linkerscript/linkerscript-sections-constraint.s b/lld/test/ELF/linkerscript/linkerscript-sections-constraint.s index cceba92..75c192c 100644 --- a/lld/test/ELF/linkerscript/linkerscript-sections-constraint.s +++ b/lld/test/ELF/linkerscript/linkerscript-sections-constraint.s @@ -13,22 +13,20 @@ # BASE-NEXT: 2 .readable 00000004 0000000000000204 DATA # RUN: echo "SECTIONS { \ -# RUN: .writable : ONLY_IF_RO { *(.writable) } \ -# RUN: .readable : ONLY_IF_RW { *(.readable) }}" > %t.script -# RUN: ld.lld -o %t1 --script %t.script %t -# RUN: llvm-objdump -section-headers %t1 | \ -# RUN: FileCheck -check-prefix=NOSECTIONS %s -# NOSECTIONS: Sections: -# NOSECTIONS-NOT: .writable -# NOSECTIONS-NOT: .readable - -# RUN: echo "SECTIONS { \ -# RUN: .foo : ONLY_IF_RO { *(.foo.*) }}" > %t.script -# RUN: ld.lld -o %t1 --script %t.script %t -# RUN: llvm-objdump -section-headers %t1 | \ -# RUN: FileCheck -check-prefix=NOSECTIONS2 %s -# NOSECTIONS2: Sections: -# NOSECTIONS2-NOT: .foo +# RUN: .foo : ONLY_IF_RO { *(.foo.*) } \ +# RUN: .writable : ONLY_IF_RW { *(.writable) } \ +# RUN: .readable : ONLY_IF_RO { *(.readable) }}" > %t2.script +# RUN: ld.lld -o %t2 --script %t2.script %t +# RUN: llvm-objdump -section-headers %t2 | \ +# RUN: FileCheck -check-prefix=NO1 %s +# NO1: Sections: +# NO1-NEXT: Idx Name Size Address Type +# NO1-NEXT: 0 00000000 0000000000000000 +# NO1-NEXT: 1 .writable 00000004 0000000000000200 DATA +# NO1-NEXT: 2 .readable 00000004 0000000000000204 DATA +# NO1-NEXT: 3 .text 00000001 0000000000000208 TEXT DATA +# NO1-NEXT: 4 .foo.2 00000004 0000000000000209 DATA +# NO1-NEXT: 5 .foo.1 00000004 000000000000020d TEXT DATA .global _start _start: