[llvm] r298901 - Dont emit Mapping symbols for sections that contain only data.
Weiming Zhao via llvm-commits
llvm-commits at lists.llvm.org
Mon Mar 27 22:40:37 PDT 2017
Author: weimingz
Date: Tue Mar 28 00:40:36 2017
New Revision: 298901
URL: http://llvm.org/viewvc/llvm-project?rev=298901&view=rev
Log:
Dont emit Mapping symbols for sections that contain only data.
Summary:
Dont emit mapping symbols for sections that contain only data.
Patched by Shankar Easwaran <shankare at codeaurora.org>
Reviewers: rengolin, peter.smith, weimingz, kparzysz, t.p.northover
Reviewed By: t.p.northover
Subscribers: t.p.northover, llvm-commits
Differential Revision: https://reviews.llvm.org/D30724
Added:
llvm/trunk/test/MC/ARM/Inputs/
llvm/trunk/test/MC/ARM/Inputs/1.s
llvm/trunk/test/MC/ARM/Inputs/2.s
llvm/trunk/test/MC/ARM/Inputs/3.s
llvm/trunk/test/MC/ARM/Inputs/4.s
llvm/trunk/test/MC/ARM/Inputs/5.s
llvm/trunk/test/MC/ARM/Inputs/6.s
llvm/trunk/test/MC/ARM/Inputs/7.s
llvm/trunk/test/MC/ARM/Inputs/attr.s
llvm/trunk/test/MC/ARM/Inputs/ident.s
llvm/trunk/test/MC/ARM/mappingsymbols.s
Modified:
llvm/trunk/include/llvm/MC/MCELFStreamer.h
llvm/trunk/include/llvm/MC/MCObjectStreamer.h
llvm/trunk/lib/MC/MCELFStreamer.cpp
llvm/trunk/lib/MC/MCObjectStreamer.cpp
llvm/trunk/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
llvm/trunk/test/MC/ARM/data-in-code.ll
llvm/trunk/test/MC/ARM/multi-section-mapping.s
llvm/trunk/test/Object/ARM/nm-mapping-symbol.s
Modified: llvm/trunk/include/llvm/MC/MCELFStreamer.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCELFStreamer.h?rev=298901&r1=298900&r2=298901&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCELFStreamer.h (original)
+++ llvm/trunk/include/llvm/MC/MCELFStreamer.h Tue Mar 28 00:40:36 2017
@@ -42,6 +42,7 @@ public:
void InitSections(bool NoExecStack) override;
void ChangeSection(MCSection *Section, const MCExpr *Subsection) override;
void EmitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override;
+ void EmitLabel(MCSymbol *Symbol, SMLoc Loc, MCFragment *F) override;
void EmitAssemblerFlag(MCAssemblerFlag Flag) override;
void EmitThumbFunc(MCSymbol *Func) override;
void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) override;
Modified: llvm/trunk/include/llvm/MC/MCObjectStreamer.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCObjectStreamer.h?rev=298901&r1=298900&r2=298901&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCObjectStreamer.h (original)
+++ llvm/trunk/include/llvm/MC/MCObjectStreamer.h Tue Mar 28 00:40:36 2017
@@ -90,6 +90,7 @@ public:
/// @{
void EmitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override;
+ virtual void EmitLabel(MCSymbol *Symbol, SMLoc Loc, MCFragment *F);
void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) override;
void EmitValueImpl(const MCExpr *Value, unsigned Size,
SMLoc Loc = SMLoc()) override;
Modified: llvm/trunk/lib/MC/MCELFStreamer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCELFStreamer.cpp?rev=298901&r1=298900&r2=298901&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCELFStreamer.cpp (original)
+++ llvm/trunk/lib/MC/MCELFStreamer.cpp Tue Mar 28 00:40:36 2017
@@ -103,6 +103,16 @@ void MCELFStreamer::EmitLabel(MCSymbol *
Symbol->setType(ELF::STT_TLS);
}
+void MCELFStreamer::EmitLabel(MCSymbol *S, SMLoc Loc, MCFragment *F) {
+ auto *Symbol = cast<MCSymbolELF>(S);
+ MCObjectStreamer::EmitLabel(Symbol, Loc, F);
+
+ const MCSectionELF &Section =
+ static_cast<const MCSectionELF &>(*getCurrentSectionOnly());
+ if (Section.getFlags() & ELF::SHF_TLS)
+ Symbol->setType(ELF::STT_TLS);
+}
+
void MCELFStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
// Let the target do whatever target specific stuff it needs to do.
getAssembler().getBackend().handleAssemblerFlag(Flag);
Modified: llvm/trunk/lib/MC/MCObjectStreamer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCObjectStreamer.cpp?rev=298901&r1=298900&r2=298901&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCObjectStreamer.cpp (original)
+++ llvm/trunk/lib/MC/MCObjectStreamer.cpp Tue Mar 28 00:40:36 2017
@@ -171,6 +171,16 @@ void MCObjectStreamer::EmitLabel(MCSymbo
}
}
+void MCObjectStreamer::EmitLabel(MCSymbol *Symbol, SMLoc Loc, MCFragment *F) {
+ MCStreamer::EmitLabel(Symbol, Loc);
+ getAssembler().registerSymbol(*Symbol);
+ auto *DF = dyn_cast_or_null<MCDataFragment>(F);
+ if (DF)
+ Symbol->setFragment(F);
+ else
+ PendingLabels.push_back(Symbol);
+}
+
void MCObjectStreamer::EmitULEB128Value(const MCExpr *Value) {
int64_t IntValue;
if (Value->evaluateAsAbsolute(IntValue, getAssembler())) {
@@ -491,8 +501,8 @@ void MCObjectStreamer::EmitGPRel32Value(
MCDataFragment *DF = getOrCreateDataFragment();
flushPendingLabels(DF, DF->getContents().size());
- DF->getFixups().push_back(MCFixup::create(DF->getContents().size(),
- Value, FK_GPRel_4));
+ DF->getFixups().push_back(
+ MCFixup::create(DF->getContents().size(), Value, FK_GPRel_4));
DF->getContents().resize(DF->getContents().size() + 4, 0);
}
@@ -501,8 +511,8 @@ void MCObjectStreamer::EmitGPRel64Value(
MCDataFragment *DF = getOrCreateDataFragment();
flushPendingLabels(DF, DF->getContents().size());
- DF->getFixups().push_back(MCFixup::create(DF->getContents().size(),
- Value, FK_GPRel_4));
+ DF->getFixups().push_back(
+ MCFixup::create(DF->getContents().size(), Value, FK_GPRel_4));
DF->getContents().resize(DF->getContents().size() + 8, 0);
}
Modified: llvm/trunk/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp?rev=298901&r1=298900&r2=298901&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp (original)
+++ llvm/trunk/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp Tue Mar 28 00:40:36 2017
@@ -464,13 +464,14 @@ public:
void emitUnwindRaw(int64_t Offset, const SmallVectorImpl<uint8_t> &Opcodes);
void ChangeSection(MCSection *Section, const MCExpr *Subsection) override {
- // We have to keep track of the mapping symbol state of any sections we
- // use. Each one should start off as EMS_None, which is provided as the
- // default constructor by DenseMap::lookup.
- LastMappingSymbols[getPreviousSection().first] = LastEMS;
- LastEMS = LastMappingSymbols.lookup(Section);
-
+ LastMappingSymbols[getPreviousSection().first] = std::move(LastEMSInfo);
MCELFStreamer::ChangeSection(Section, Subsection);
+ auto LastMappingSymbol = LastMappingSymbols.find(Section);
+ if (LastMappingSymbol != LastMappingSymbols.end()) {
+ LastEMSInfo = std::move(LastMappingSymbol->second);
+ return;
+ }
+ LastEMSInfo.reset(new ElfMappingSymbolInfo(SMLoc(), nullptr, 0));
}
/// This function is the one used to emit instruction data into the ELF
@@ -532,6 +533,14 @@ public:
MCELFStreamer::EmitBytes(Data);
}
+ void FlushPendingMappingSymbol() {
+ if (!LastEMSInfo->hasInfo())
+ return;
+ ElfMappingSymbolInfo *EMS = LastEMSInfo.get();
+ EmitMappingSymbol("$d", EMS->Loc, EMS->F, EMS->Offset);
+ EMS->resetInfo();
+ }
+
/// This is one of the functions used to emit data into an ELF section, so the
/// ARM streamer overrides it to add the appropriate mapping symbol ($d) if
/// necessary.
@@ -573,22 +582,54 @@ private:
EMS_Data
};
+ struct ElfMappingSymbolInfo {
+ explicit ElfMappingSymbolInfo(SMLoc Loc, MCFragment *F, uint64_t O)
+ : Loc(Loc), F(F), Offset(O), State(EMS_None) {}
+ void resetInfo() {
+ F = nullptr;
+ Offset = 0;
+ }
+ bool hasInfo() { return F != nullptr; }
+ SMLoc Loc;
+ MCFragment *F;
+ uint64_t Offset;
+ ElfMappingSymbol State;
+ };
+
void EmitDataMappingSymbol() {
- if (LastEMS == EMS_Data) return;
+ if (LastEMSInfo->State == EMS_Data)
+ return;
+ else if (LastEMSInfo->State == EMS_None) {
+ // This is a tentative symbol, it won't really be emitted until it's
+ // actually needed.
+ ElfMappingSymbolInfo *EMS = LastEMSInfo.get();
+ auto *DF = dyn_cast_or_null<MCDataFragment>(getCurrentFragment());
+ if (!DF)
+ return;
+ EMS->Loc = SMLoc();
+ EMS->F = getCurrentFragment();
+ EMS->Offset = DF->getContents().size();
+ LastEMSInfo->State = EMS_Data;
+ return;
+ }
EmitMappingSymbol("$d");
- LastEMS = EMS_Data;
+ LastEMSInfo->State = EMS_Data;
}
void EmitThumbMappingSymbol() {
- if (LastEMS == EMS_Thumb) return;
+ if (LastEMSInfo->State == EMS_Thumb)
+ return;
+ FlushPendingMappingSymbol();
EmitMappingSymbol("$t");
- LastEMS = EMS_Thumb;
+ LastEMSInfo->State = EMS_Thumb;
}
void EmitARMMappingSymbol() {
- if (LastEMS == EMS_ARM) return;
+ if (LastEMSInfo->State == EMS_ARM)
+ return;
+ FlushPendingMappingSymbol();
EmitMappingSymbol("$a");
- LastEMS = EMS_ARM;
+ LastEMSInfo->State = EMS_ARM;
}
void EmitMappingSymbol(StringRef Name) {
@@ -601,6 +642,17 @@ private:
Symbol->setExternal(false);
}
+ void EmitMappingSymbol(StringRef Name, SMLoc Loc, MCFragment *F,
+ uint64_t Offset) {
+ auto *Symbol = cast<MCSymbolELF>(getContext().getOrCreateSymbol(
+ Name + "." + Twine(MappingSymbolCounter++)));
+ EmitLabel(Symbol, Loc, F);
+ Symbol->setType(ELF::STT_NOTYPE);
+ Symbol->setBinding(ELF::STB_LOCAL);
+ Symbol->setExternal(false);
+ Symbol->setOffset(Offset);
+ }
+
void EmitThumbFunc(MCSymbol *Func) override {
getAssembler().setIsThumbFunc(Func);
EmitSymbolAttribute(Func, MCSA_ELF_TypeFunction);
@@ -626,8 +678,10 @@ private:
bool IsThumb;
int64_t MappingSymbolCounter = 0;
- DenseMap<const MCSection *, ElfMappingSymbol> LastMappingSymbols;
- ElfMappingSymbol LastEMS = EMS_None;
+ DenseMap<const MCSection *, std::unique_ptr<ElfMappingSymbolInfo>>
+ LastMappingSymbols;
+
+ std::unique_ptr<ElfMappingSymbolInfo> LastEMSInfo;
// ARM Exception Handling Frame Information
MCSymbol *ExTab;
Added: llvm/trunk/test/MC/ARM/Inputs/1.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/Inputs/1.s?rev=298901&view=auto
==============================================================================
--- llvm/trunk/test/MC/ARM/Inputs/1.s (added)
+++ llvm/trunk/test/MC/ARM/Inputs/1.s Tue Mar 28 00:40:36 2017
@@ -0,0 +1,3 @@
+ .section .foobar,"ax",%progbits
+ nop
+ .word 32
Added: llvm/trunk/test/MC/ARM/Inputs/2.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/Inputs/2.s?rev=298901&view=auto
==============================================================================
--- llvm/trunk/test/MC/ARM/Inputs/2.s (added)
+++ llvm/trunk/test/MC/ARM/Inputs/2.s Tue Mar 28 00:40:36 2017
@@ -0,0 +1,3 @@
+ .section .foobar,"",%progbits
+ nop
+ .word 32
Added: llvm/trunk/test/MC/ARM/Inputs/3.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/Inputs/3.s?rev=298901&view=auto
==============================================================================
--- llvm/trunk/test/MC/ARM/Inputs/3.s (added)
+++ llvm/trunk/test/MC/ARM/Inputs/3.s Tue Mar 28 00:40:36 2017
@@ -0,0 +1,3 @@
+ .section .foobar,"aw",%progbits
+ nop
+ .word 32
Added: llvm/trunk/test/MC/ARM/Inputs/4.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/Inputs/4.s?rev=298901&view=auto
==============================================================================
--- llvm/trunk/test/MC/ARM/Inputs/4.s (added)
+++ llvm/trunk/test/MC/ARM/Inputs/4.s Tue Mar 28 00:40:36 2017
@@ -0,0 +1,2 @@
+ .section .foobar,"",%progbits
+ .word 32
Added: llvm/trunk/test/MC/ARM/Inputs/5.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/Inputs/5.s?rev=298901&view=auto
==============================================================================
--- llvm/trunk/test/MC/ARM/Inputs/5.s (added)
+++ llvm/trunk/test/MC/ARM/Inputs/5.s Tue Mar 28 00:40:36 2017
@@ -0,0 +1,2 @@
+ .section .foobar,"aw",%progbits
+ .word 32
Added: llvm/trunk/test/MC/ARM/Inputs/6.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/Inputs/6.s?rev=298901&view=auto
==============================================================================
--- llvm/trunk/test/MC/ARM/Inputs/6.s (added)
+++ llvm/trunk/test/MC/ARM/Inputs/6.s Tue Mar 28 00:40:36 2017
@@ -0,0 +1,12 @@
+ .section .foo
+ .word 30
+ .word 31
+ .word 32
+ .word 33
+ nop
+ .word 34
+ .word 35
+ .word 36
+ .word 37
+ .word 38
+ nop
Added: llvm/trunk/test/MC/ARM/Inputs/7.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/Inputs/7.s?rev=298901&view=auto
==============================================================================
--- llvm/trunk/test/MC/ARM/Inputs/7.s (added)
+++ llvm/trunk/test/MC/ARM/Inputs/7.s Tue Mar 28 00:40:36 2017
@@ -0,0 +1,3 @@
+ .section .foobar,"aw",%progbits
+ .word 32
+ nop
Added: llvm/trunk/test/MC/ARM/Inputs/attr.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/Inputs/attr.s?rev=298901&view=auto
==============================================================================
--- llvm/trunk/test/MC/ARM/Inputs/attr.s (added)
+++ llvm/trunk/test/MC/ARM/Inputs/attr.s Tue Mar 28 00:40:36 2017
@@ -0,0 +1,5 @@
+ .text
+ .syntax unified
+ .eabi_attribute 67, "2.09" @ Tag_conformance
+ .cpu arm7tdmi
+ .eabi_attribute 6, 2 @ Tag_CPU_arch
Added: llvm/trunk/test/MC/ARM/Inputs/ident.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/Inputs/ident.s?rev=298901&view=auto
==============================================================================
--- llvm/trunk/test/MC/ARM/Inputs/ident.s (added)
+++ llvm/trunk/test/MC/ARM/Inputs/ident.s Tue Mar 28 00:40:36 2017
@@ -0,0 +1 @@
+ .ident "LLVM ARM Compiler"
Modified: llvm/trunk/test/MC/ARM/data-in-code.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/data-in-code.ll?rev=298901&r1=298900&r2=298901&view=diff
==============================================================================
--- llvm/trunk/test/MC/ARM/data-in-code.ll (original)
+++ llvm/trunk/test/MC/ARM/data-in-code.ll Tue Mar 28 00:40:36 2017
@@ -60,23 +60,6 @@ exit:
;; ARM-NEXT: Other:
;; ARM-NEXT: Section: [[MIXED_SECT]]
-;; ARM: Symbol {
-;; ARM: Name: $d
-;; ARM-NEXT: Value: 0x0
-;; ARM-NEXT: Size: 0
-;; ARM-NEXT: Binding: Local (0x0)
-;; ARM-NEXT: Type: None (0x0)
-;; ARM-NEXT: Other: 0
-;; ARM-NEXT: Section: .ARM.exidx
-;; ARM-NEXT: }
-
-;; ARM: Symbol {
-;; ARM: Name: $d
-;; ARM-NEXT: Value: 0
-;; ARM-NEXT: Size: 0
-;; ARM-NEXT: Binding: Local
-;; ARM-NEXT: Type: None
-
;; ARM-NOT: ${{[atd]}}
;; TMB: Symbol {
Added: llvm/trunk/test/MC/ARM/mappingsymbols.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/mappingsymbols.s?rev=298901&view=auto
==============================================================================
--- llvm/trunk/test/MC/ARM/mappingsymbols.s (added)
+++ llvm/trunk/test/MC/ARM/mappingsymbols.s Tue Mar 28 00:40:36 2017
@@ -0,0 +1,48 @@
+# Check section containing code and data with permission executable for the section.
+@ RUN: llvm-mc -triple armv7-none-linux -filetype=obj -o %t.o %p/Inputs/1.s
+@ RUN: llvm-readobj -elf-output-style=GNU -symbols %t.o | FileCheck %s
+
+# Check section containing code and data with no permissions for the section.
+@ RUN: llvm-mc -triple armv7-none-linux -filetype=obj -o %t.o %p/Inputs/2.s
+@ RUN: llvm-readobj -elf-output-style=GNU -symbols %t.o | FileCheck %s
+
+# Check section containing code and data with read/write permissions for the section.
+@ RUN: llvm-mc -triple armv7-none-linux -filetype=obj -o %t.o %p/Inputs/3.s
+@ RUN: llvm-readobj -elf-output-style=GNU -symbols %t.o | FileCheck %s
+
+# Check section containing data with no permissions for the section.
+@ RUN: llvm-mc -triple armv7-none-linux -filetype=obj -o %t.o %p/Inputs/4.s
+@ RUN: llvm-readobj -elf-output-style=GNU -symbols %t.o | FileCheck %s -check-prefix=MAPPINGSYMBOLS
+
+# Check section containing only data with read/write permissions for the section.
+@ RUN: llvm-mc -triple armv7-none-linux -filetype=obj -o %t.o %p/Inputs/5.s
+@ RUN: llvm-readobj -elf-output-style=GNU -symbols %t.o | FileCheck %s -check-prefix=MAPPINGSYMBOLS
+
+# Check section containing the ident string with no permissions for the section.
+@ RUN: llvm-mc -triple armv7-none-linux -filetype=obj -o %t.o %p/Inputs/ident.s
+@ RUN: llvm-readobj -elf-output-style=GNU -symbols %t.o | FileCheck %s -check-prefix=MAPPINGSYMBOLS
+
+# Check section containing the attributes with no permissions for the section.
+@ RUN: llvm-mc -triple armv7-none-linux -filetype=obj -o %t.o %p/Inputs/attr.s
+@ RUN: llvm-readobj -elf-output-style=GNU -symbols %t.o | FileCheck %s -check-prefix=MAPPINGSYMBOLS
+
+# Check section containing code and data with no permissions for the section.
+# data comes before code.
+@ RUN: llvm-mc -triple armv7-none-linux -filetype=obj -o %t.o %p/Inputs/6.s
+@ RUN: llvm-readobj -elf-output-style=GNU -symbols %t.o | FileCheck %s -check-prefix=MIX
+
+# Check section containing code and data with no permissions for the section.
+# data comes before code.
+@ RUN: llvm-mc -triple armv7-none-linux -filetype=obj -o %t.o %p/Inputs/7.s
+@ RUN: llvm-readobj -elf-output-style=GNU -symbols %t.o | FileCheck %s
+
+#CHECK: $a
+#CHECK: $d
+
+#MIX: $a
+#MIX: $a
+#MIX: $d
+#MIX: $d
+
+#MAPPINGSYMBOLS-NOT: $a
+#MAPPINGSYMBOLS-NOT: $d
Modified: llvm/trunk/test/MC/ARM/multi-section-mapping.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/multi-section-mapping.s?rev=298901&r1=298900&r2=298901&view=diff
==============================================================================
--- llvm/trunk/test/MC/ARM/multi-section-mapping.s (original)
+++ llvm/trunk/test/MC/ARM/multi-section-mapping.s Tue Mar 28 00:40:36 2017
@@ -29,7 +29,6 @@
@ CHECK: 00000000 .text 00000000 $a
@ CHECK-NEXT: 00000000 .wibble 00000000 $a
-@ CHECK-NEXT: 00000000 .starts_data 00000000 $d
@ CHECK-NEXT: 00000000 .starts_thumb 00000000 $t
@ CHECK-NOT: ${{[adt]}}
Modified: llvm/trunk/test/Object/ARM/nm-mapping-symbol.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Object/ARM/nm-mapping-symbol.s?rev=298901&r1=298900&r2=298901&view=diff
==============================================================================
--- llvm/trunk/test/Object/ARM/nm-mapping-symbol.s (original)
+++ llvm/trunk/test/Object/ARM/nm-mapping-symbol.s Tue Mar 28 00:40:36 2017
@@ -9,3 +9,4 @@
.section .foobar,"",%progbits
.asciz "foo"
+ nop
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