[lld] r278486 - [ELF] - Linkerscript: reimplemented output sections constrains matching functionality.
George Rimar via llvm-commits
llvm-commits at lists.llvm.org
Fri Aug 12 02:07:58 PDT 2016
Author: grimar
Date: Fri Aug 12 04:07:57 2016
New Revision: 278486
URL: http://llvm.org/viewvc/llvm-project?rev=278486&view=rev
Log:
[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
Added:
lld/trunk/test/ELF/linkerscript/linkerscript-multi-sections-constraint.s
Modified:
lld/trunk/ELF/LinkerScript.cpp
lld/trunk/ELF/LinkerScript.h
lld/trunk/test/ELF/linkerscript/linkerscript-sections-constraint.s
Modified: lld/trunk/ELF/LinkerScript.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/LinkerScript.cpp?rev=278486&r1=278485&r2=278486&view=diff
==============================================================================
--- lld/trunk/ELF/LinkerScript.cpp (original)
+++ lld/trunk/ELF/LinkerScript.cpp Fri Aug 12 04:07:57 2016
@@ -216,20 +216,33 @@ void LinkerScript<ELFT>::discard(OutputS
}
template <class ELFT>
+static bool matchConstraints(ArrayRef<InputSectionBase<ELFT> *> Sections,
+ ConstraintKind Kind) {
+ bool RO = (Kind == ConstraintKind::ReadOnly);
+ bool RW = (Kind == ConstraintKind::ReadWrite);
+ return !llvm::any_of(Sections, [=](InputSectionBase<ELFT> *Sec) {
+ bool Writable = Sec->getSectionHdr()->sh_flags & SHF_WRITE;
+ return (RO && Writable) || (RW && !Writable);
+ });
+}
+
+template <class ELFT>
std::vector<InputSectionBase<ELFT> *>
-LinkerScript<ELFT>::createInputSectionList(OutputSectionCommand &Cmd) {
+LinkerScript<ELFT>::createInputSectionList(OutputSectionCommand &OutCmd) {
std::vector<InputSectionBase<ELFT> *> Ret;
- for (const std::unique_ptr<BaseCommand> &Base : Cmd.Commands) {
- if (auto *Cmd = dyn_cast<SymbolAssignment>(Base.get())) {
- if (shouldDefine<ELFT>(Cmd))
- addSynthetic<ELFT>(Cmd);
- Ret.push_back(new (LAlloc.Allocate()) LayoutInputSection<ELFT>(Cmd));
+ for (const std::unique_ptr<BaseCommand> &Base : OutCmd.Commands) {
+ if (auto *OutCmd = dyn_cast<SymbolAssignment>(Base.get())) {
+ if (shouldDefine<ELFT>(OutCmd))
+ addSynthetic<ELFT>(OutCmd);
+ Ret.push_back(new (LAlloc.Allocate()) LayoutInputSection<ELFT>(OutCmd));
continue;
}
auto *Cmd = cast<InputSectionDescription>(Base.get());
std::vector<InputSectionBase<ELFT> *> V = getInputSections(Cmd);
+ if (!matchConstraints<ELFT>(V, OutCmd.Constraint))
+ continue;
if (Cmd->SortInner)
std::stable_sort(V.begin(), V.end(), getComparator<ELFT>(Cmd->SortInner));
if (Cmd->SortOuter)
@@ -283,38 +296,6 @@ void LinkerScript<ELFT>::createSections(
OutSec->addSection(S);
}
}
-
- // Remove from the output all the sections which did not meet
- // the optional constraints.
- filter();
-}
-
-template <class R, class T>
-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 <class ELFT> void LinkerScript<ELFT>::filter() {
- // In this loop, we remove output sections if they don't satisfy
- // requested properties.
- for (const std::unique_ptr<BaseCommand> &Base : Opt.Commands) {
- auto *Cmd = dyn_cast<OutputSectionCommand>(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<ELFT> *S) {
- bool Writable = (S->getFlags() & SHF_WRITE);
- return S->getName() == Cmd->Name &&
- ((RO && Writable) || (RW && !Writable));
- });
- }
}
template <class ELFT> void assignOffsets(OutputSectionBase<ELFT> *Sec) {
Modified: lld/trunk/ELF/LinkerScript.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/LinkerScript.h?rev=278486&r1=278485&r2=278486&view=diff
==============================================================================
--- lld/trunk/ELF/LinkerScript.h (original)
+++ lld/trunk/ELF/LinkerScript.h Fri Aug 12 04:07:57 2016
@@ -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<size_t> getPhdrIndices(StringRef SectionName);
size_t getPhdrIndex(StringRef PhdrName);
Added: lld/trunk/test/ELF/linkerscript/linkerscript-multi-sections-constraint.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/linkerscript/linkerscript-multi-sections-constraint.s?rev=278486&view=auto
==============================================================================
--- lld/trunk/test/ELF/linkerscript/linkerscript-multi-sections-constraint.s (added)
+++ lld/trunk/test/ELF/linkerscript/linkerscript-multi-sections-constraint.s Fri Aug 12 04:07:57 2016
@@ -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
Modified: lld/trunk/test/ELF/linkerscript/linkerscript-sections-constraint.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/linkerscript/linkerscript-sections-constraint.s?rev=278486&r1=278485&r2=278486&view=diff
==============================================================================
--- lld/trunk/test/ELF/linkerscript/linkerscript-sections-constraint.s (original)
+++ lld/trunk/test/ELF/linkerscript/linkerscript-sections-constraint.s Fri Aug 12 04:07:57 2016
@@ -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:
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