[llvm] r298932 - Revert "Dont emit Mapping symbols for sections that contain only data."

Weiming Zhao via llvm-commits llvm-commits at lists.llvm.org
Tue Mar 28 10:15:12 PDT 2017


Author: weimingz
Date: Tue Mar 28 12:15:11 2017
New Revision: 298932

URL: http://llvm.org/viewvc/llvm-project?rev=298932&view=rev
Log:
Revert "Dont emit Mapping symbols for sections that contain only data."

It breaks some lld tests.

This reverts commit 3a50eea6d9732ab40e9a7aebe6be777b53a8b35c.

Removed:
    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=298932&r1=298931&r2=298932&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCELFStreamer.h (original)
+++ llvm/trunk/include/llvm/MC/MCELFStreamer.h Tue Mar 28 12:15:11 2017
@@ -42,7 +42,6 @@ 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=298932&r1=298931&r2=298932&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCObjectStreamer.h (original)
+++ llvm/trunk/include/llvm/MC/MCObjectStreamer.h Tue Mar 28 12:15:11 2017
@@ -90,7 +90,6 @@ 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=298932&r1=298931&r2=298932&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCELFStreamer.cpp (original)
+++ llvm/trunk/lib/MC/MCELFStreamer.cpp Tue Mar 28 12:15:11 2017
@@ -103,16 +103,6 @@ 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=298932&r1=298931&r2=298932&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCObjectStreamer.cpp (original)
+++ llvm/trunk/lib/MC/MCObjectStreamer.cpp Tue Mar 28 12:15:11 2017
@@ -171,16 +171,6 @@ 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())) {
@@ -501,8 +491,8 @@ 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);
 }
 
@@ -511,8 +501,8 @@ 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=298932&r1=298931&r2=298932&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp (original)
+++ llvm/trunk/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp Tue Mar 28 12:15:11 2017
@@ -464,14 +464,13 @@ public:
   void emitUnwindRaw(int64_t Offset, const SmallVectorImpl<uint8_t> &Opcodes);
 
   void ChangeSection(MCSection *Section, const MCExpr *Subsection) override {
-    LastMappingSymbols[getPreviousSection().first] = std::move(LastEMSInfo);
+    // 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);
+
     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
@@ -533,14 +532,6 @@ 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.
@@ -582,54 +573,22 @@ 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 (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;
-    }
+    if (LastEMS == EMS_Data) return;
     EmitMappingSymbol("$d");
-    LastEMSInfo->State = EMS_Data;
+    LastEMS = EMS_Data;
   }
 
   void EmitThumbMappingSymbol() {
-    if (LastEMSInfo->State == EMS_Thumb)
-      return;
-    FlushPendingMappingSymbol();
+    if (LastEMS == EMS_Thumb) return;
     EmitMappingSymbol("$t");
-    LastEMSInfo->State = EMS_Thumb;
+    LastEMS = EMS_Thumb;
   }
 
   void EmitARMMappingSymbol() {
-    if (LastEMSInfo->State == EMS_ARM)
-      return;
-    FlushPendingMappingSymbol();
+    if (LastEMS == EMS_ARM) return;
     EmitMappingSymbol("$a");
-    LastEMSInfo->State = EMS_ARM;
+    LastEMS = EMS_ARM;
   }
 
   void EmitMappingSymbol(StringRef Name) {
@@ -642,17 +601,6 @@ 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);
@@ -678,10 +626,8 @@ private:
   bool IsThumb;
   int64_t MappingSymbolCounter = 0;
 
-  DenseMap<const MCSection *, std::unique_ptr<ElfMappingSymbolInfo>>
-      LastMappingSymbols;
-
-  std::unique_ptr<ElfMappingSymbolInfo> LastEMSInfo;
+  DenseMap<const MCSection *, ElfMappingSymbol> LastMappingSymbols;
+  ElfMappingSymbol LastEMS = EMS_None;
 
   // ARM Exception Handling Frame Information
   MCSymbol *ExTab;

Removed: llvm/trunk/test/MC/ARM/Inputs/1.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/Inputs/1.s?rev=298931&view=auto
==============================================================================
--- llvm/trunk/test/MC/ARM/Inputs/1.s (original)
+++ llvm/trunk/test/MC/ARM/Inputs/1.s (removed)
@@ -1,3 +0,0 @@
-        .section        .foobar,"ax",%progbits
-         nop
-        .word 32

Removed: llvm/trunk/test/MC/ARM/Inputs/2.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/Inputs/2.s?rev=298931&view=auto
==============================================================================
--- llvm/trunk/test/MC/ARM/Inputs/2.s (original)
+++ llvm/trunk/test/MC/ARM/Inputs/2.s (removed)
@@ -1,3 +0,0 @@
-        .section        .foobar,"",%progbits
-         nop
-        .word 32

Removed: llvm/trunk/test/MC/ARM/Inputs/3.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/Inputs/3.s?rev=298931&view=auto
==============================================================================
--- llvm/trunk/test/MC/ARM/Inputs/3.s (original)
+++ llvm/trunk/test/MC/ARM/Inputs/3.s (removed)
@@ -1,3 +0,0 @@
-        .section        .foobar,"aw",%progbits
-         nop
-        .word 32

Removed: llvm/trunk/test/MC/ARM/Inputs/4.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/Inputs/4.s?rev=298931&view=auto
==============================================================================
--- llvm/trunk/test/MC/ARM/Inputs/4.s (original)
+++ llvm/trunk/test/MC/ARM/Inputs/4.s (removed)
@@ -1,2 +0,0 @@
-        .section        .foobar,"",%progbits
-        .word 32

Removed: llvm/trunk/test/MC/ARM/Inputs/5.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/Inputs/5.s?rev=298931&view=auto
==============================================================================
--- llvm/trunk/test/MC/ARM/Inputs/5.s (original)
+++ llvm/trunk/test/MC/ARM/Inputs/5.s (removed)
@@ -1,2 +0,0 @@
-        .section        .foobar,"aw",%progbits
-        .word 32

Removed: llvm/trunk/test/MC/ARM/Inputs/6.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/Inputs/6.s?rev=298931&view=auto
==============================================================================
--- llvm/trunk/test/MC/ARM/Inputs/6.s (original)
+++ llvm/trunk/test/MC/ARM/Inputs/6.s (removed)
@@ -1,12 +0,0 @@
-        .section        .foo
-        .word 30
-        .word 31
-        .word 32
-        .word 33
-        nop
-        .word 34
-        .word 35
-        .word 36
-        .word 37
-        .word 38
-        nop

Removed: llvm/trunk/test/MC/ARM/Inputs/7.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/Inputs/7.s?rev=298931&view=auto
==============================================================================
--- llvm/trunk/test/MC/ARM/Inputs/7.s (original)
+++ llvm/trunk/test/MC/ARM/Inputs/7.s (removed)
@@ -1,3 +0,0 @@
-        .section        .foobar,"aw",%progbits
-        .word 32
-        nop

Removed: llvm/trunk/test/MC/ARM/Inputs/attr.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/Inputs/attr.s?rev=298931&view=auto
==============================================================================
--- llvm/trunk/test/MC/ARM/Inputs/attr.s (original)
+++ llvm/trunk/test/MC/ARM/Inputs/attr.s (removed)
@@ -1,5 +0,0 @@
-	.text
-	.syntax unified
-	.eabi_attribute	67, "2.09"	@ Tag_conformance
-	.cpu	arm7tdmi
-	.eabi_attribute	6, 2	@ Tag_CPU_arch

Removed: llvm/trunk/test/MC/ARM/Inputs/ident.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/Inputs/ident.s?rev=298931&view=auto
==============================================================================
--- llvm/trunk/test/MC/ARM/Inputs/ident.s (original)
+++ llvm/trunk/test/MC/ARM/Inputs/ident.s (removed)
@@ -1 +0,0 @@
-	.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=298932&r1=298931&r2=298932&view=diff
==============================================================================
--- llvm/trunk/test/MC/ARM/data-in-code.ll (original)
+++ llvm/trunk/test/MC/ARM/data-in-code.ll Tue Mar 28 12:15:11 2017
@@ -60,6 +60,23 @@ 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 {

Removed: llvm/trunk/test/MC/ARM/mappingsymbols.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/mappingsymbols.s?rev=298931&view=auto
==============================================================================
--- llvm/trunk/test/MC/ARM/mappingsymbols.s (original)
+++ llvm/trunk/test/MC/ARM/mappingsymbols.s (removed)
@@ -1,48 +0,0 @@
-# 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=298932&r1=298931&r2=298932&view=diff
==============================================================================
--- llvm/trunk/test/MC/ARM/multi-section-mapping.s (original)
+++ llvm/trunk/test/MC/ARM/multi-section-mapping.s Tue Mar 28 12:15:11 2017
@@ -29,6 +29,7 @@
 
 @ 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=298932&r1=298931&r2=298932&view=diff
==============================================================================
--- llvm/trunk/test/Object/ARM/nm-mapping-symbol.s (original)
+++ llvm/trunk/test/Object/ARM/nm-mapping-symbol.s Tue Mar 28 12:15:11 2017
@@ -9,4 +9,3 @@
 
         .section        .foobar,"",%progbits
         .asciz  "foo"
-        nop




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