Move some error handling down to MCStreamer.

This makes sure we get the same redefinition rules regardless of who
is printing (asm parser, codegen) and to what (asm, obj).

This fixes an unintentional regression in r293936.

llvm-svn: 294752

llvm/include/llvm/MC/MCELFStreamer.h

@@ -41,7 +41,7 @@ public:
 
   void InitSections(bool NoExecStack) override;
   void ChangeSection(MCSection *Section, const MCExpr *Subsection) override;
-  void EmitLabel(MCSymbol *Symbol) override;
+  void EmitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override;
   void EmitAssemblerFlag(MCAssemblerFlag Flag) override;
   void EmitThumbFunc(MCSymbol *Func) override;
   void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) override;

llvm/include/llvm/MC/MCObjectStreamer.h

@@ -89,7 +89,7 @@ public:
   /// \name MCStreamer Interface
   /// @{
 
-  void EmitLabel(MCSymbol *Symbol) override;
+  void EmitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override;
   void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) override;
   void EmitValueImpl(const MCExpr *Value, unsigned Size,
                      SMLoc Loc = SMLoc()) override;

llvm/include/llvm/MC/MCStreamer.h

@@ -398,7 +398,7 @@ public:
   /// used in an assignment.
   // FIXME: These emission are non-const because we mutate the symbol to
   // add the section we're emitting it to later.
-  virtual void EmitLabel(MCSymbol *Symbol);
+  virtual void EmitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc());
 
   virtual void EmitEHSymAttributes(const MCSymbol *Symbol, MCSymbol *EHSymbol);
 

llvm/include/llvm/MC/MCWinCOFFStreamer.h

@@ -40,7 +40,7 @@ public:
   /// \{
 
   void InitSections(bool NoExecStack) override;
-  void EmitLabel(MCSymbol *Symbol) override;
+  void EmitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override;
   void EmitAssemblerFlag(MCAssemblerFlag Flag) override;
   void EmitThumbFunc(MCSymbol *Func) override;
   bool EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) override;

llvm/lib/MC/MCAsmStreamer.cpp

@@ -130,7 +130,7 @@ public:
   void ChangeSection(MCSection *Section, const MCExpr *Subsection) override;
 
   void EmitLOHDirective(MCLOHType Kind, const MCLOHArgs &Args) override;
-  void EmitLabel(MCSymbol *Symbol) override;
+  void EmitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override;
 
   void EmitAssemblerFlag(MCAssemblerFlag Flag) override;
   void EmitLinkerOptions(ArrayRef<std::string> Options) override;
@@ -397,9 +397,8 @@ void MCAsmStreamer::ChangeSection(MCSection *Section,
       Subsection);
 }
 
-void MCAsmStreamer::EmitLabel(MCSymbol *Symbol) {
+void MCAsmStreamer::EmitLabel(MCSymbol *Symbol, SMLoc Loc) {
-  assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
+  MCStreamer::EmitLabel(Symbol, Loc);
-  MCStreamer::EmitLabel(Symbol);
 
   Symbol->print(OS, MAI);
   OS << MAI->getLabelSuffix();

llvm/lib/MC/MCELFStreamer.cpp

@@ -93,11 +93,9 @@ void MCELFStreamer::InitSections(bool NoExecStack) {
     SwitchSection(Ctx.getAsmInfo()->getNonexecutableStackSection(Ctx));
 }
 
-void MCELFStreamer::EmitLabel(MCSymbol *S) {
+void MCELFStreamer::EmitLabel(MCSymbol *S, SMLoc Loc) {
   auto *Symbol = cast<MCSymbolELF>(S);
-  assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
+  MCObjectStreamer::EmitLabel(Symbol, Loc);
-
-  MCObjectStreamer::EmitLabel(Symbol);
 
   const MCSectionELF &Section =
       static_cast<const MCSectionELF &>(*getCurrentSectionOnly());

llvm/lib/MC/MCMachOStreamer.cpp

@@ -78,7 +78,7 @@ public:
   /// @{
 
   void ChangeSection(MCSection *Sect, const MCExpr *Subsect) override;
-  void EmitLabel(MCSymbol *Symbol) override;
+  void EmitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override;
   void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) override;
   void EmitEHSymAttributes(const MCSymbol *Symbol, MCSymbol *EHSymbol) override;
   void EmitAssemblerFlag(MCAssemblerFlag Flag) override;
@@ -194,15 +194,13 @@ void MCMachOStreamer::EmitEHSymAttributes(const MCSymbol *Symbol,
     EmitSymbolAttribute(EHSymbol, MCSA_PrivateExtern);
 }
 
-void MCMachOStreamer::EmitLabel(MCSymbol *Symbol) {
+void MCMachOStreamer::EmitLabel(MCSymbol *Symbol, SMLoc Loc) {
-  assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
-
   // We have to create a new fragment if this is an atom defining symbol,
   // fragments cannot span atoms.
   if (getAssembler().isSymbolLinkerVisible(*Symbol))
     insert(new MCDataFragment());
 
-  MCObjectStreamer::EmitLabel(Symbol);
+  MCObjectStreamer::EmitLabel(Symbol, Loc);
 
   // This causes the reference type flag to be cleared. Darwin 'as' was "trying"
   // to clear the weak reference and weak definition bits too, but the

llvm/lib/MC/MCObjectStreamer.cpp

@@ -153,8 +153,8 @@ void MCObjectStreamer::EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) {
   EmitLabel(Frame.End);
 }
 
-void MCObjectStreamer::EmitLabel(MCSymbol *Symbol) {
+void MCObjectStreamer::EmitLabel(MCSymbol *Symbol, SMLoc Loc) {
-  MCStreamer::EmitLabel(Symbol);
+  MCStreamer::EmitLabel(Symbol, Loc);
 
   getAssembler().registerSymbol(*Symbol);
 

llvm/lib/MC/MCParser/AsmParser.cpp

@@ -1630,12 +1630,6 @@ bool AsmParser::parseStatement(ParseStatementInfo &Info,
       Sym = getContext().getOrCreateSymbol(IDVal);
     } else
       Sym = Ctx.createDirectionalLocalSymbol(LocalLabelVal);
-
-    Sym->redefineIfPossible();
-
-    if (!Sym->isUndefined() || Sym->isVariable())
-      return Error(IDLoc, "invalid symbol redefinition");
-
     // End of Labels should be treated as end of line for lexing
     // purposes but that information is not available to the Lexer who
     // does not understand Labels. This may cause us to see a Hash
@@ -1654,7 +1648,7 @@ bool AsmParser::parseStatement(ParseStatementInfo &Info,
 
     // Emit the label.
     if (!ParsingInlineAsm)
-      Out.EmitLabel(Sym);
+      Out.EmitLabel(Sym, IDLoc);
 
     // If we are generating dwarf for assembly source files then gather the
     // info to make a dwarf label entry for this label if needed.

llvm/lib/MC/MCStreamer.cpp

@@ -298,10 +298,17 @@ void MCStreamer::AssignFragment(MCSymbol *Symbol, MCFragment *Fragment) {
   SymbolOrdering[Symbol] = 1 + SymbolOrdering.size();
 }
 
-void MCStreamer::EmitLabel(MCSymbol *Symbol) {
+void MCStreamer::EmitLabel(MCSymbol *Symbol, SMLoc Loc) {
+  Symbol->redefineIfPossible();
+
+  if (!Symbol->isUndefined() || Symbol->isVariable())
+    return getContext().reportError(Loc, "invalid symbol redefinition");
+
   assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
   assert(getCurrentSectionOnly() && "Cannot emit before setting section!");
   assert(!Symbol->getFragment() && "Unexpected fragment on symbol data!");
+  assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
+
   Symbol->setFragment(&getCurrentSectionOnly()->getDummyFragment());
 
   MCTargetStreamer *TS = getTargetStreamer();

llvm/lib/MC/WinCOFFStreamer.cpp

@@ -79,10 +79,9 @@ void MCWinCOFFStreamer::InitSections(bool NoExecStack) {
   SwitchSection(getContext().getObjectFileInfo()->getTextSection());
 }
 
-void MCWinCOFFStreamer::EmitLabel(MCSymbol *S) {
+void MCWinCOFFStreamer::EmitLabel(MCSymbol *S, SMLoc Loc) {
   auto *Symbol = cast<MCSymbolCOFF>(S);
-  assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
+  MCObjectStreamer::EmitLabel(Symbol, Loc);
-  MCObjectStreamer::EmitLabel(Symbol);
 }
 
 void MCWinCOFFStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {

llvm/lib/Object/RecordStreamer.cpp

@@ -82,7 +82,7 @@ void RecordStreamer::EmitInstruction(const MCInst &Inst,
   MCStreamer::EmitInstruction(Inst, STI);
 }
 
-void RecordStreamer::EmitLabel(MCSymbol *Symbol) {
+void RecordStreamer::EmitLabel(MCSymbol *Symbol, SMLoc Loc) {
   MCStreamer::EmitLabel(Symbol);
   markDefined(*Symbol);
 }

llvm/lib/Object/RecordStreamer.h

@@ -31,7 +31,7 @@ public:
   const_iterator end();
   RecordStreamer(MCContext &Context);
   void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI) override;
-  void EmitLabel(MCSymbol *Symbol) override;
+  void EmitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override;
   void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) override;
   bool EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) override;
   void EmitZerofill(MCSection *Section, MCSymbol *Symbol, uint64_t Size,

llvm/lib/Target/Mips/MCTargetDesc/MipsELFStreamer.cpp

@@ -55,7 +55,7 @@ void MipsELFStreamer::createPendingLabelRelocs() {
   Labels.clear();
 }
 
-void MipsELFStreamer::EmitLabel(MCSymbol *Symbol) {
+void MipsELFStreamer::EmitLabel(MCSymbol *Symbol, SMLoc Loc) {
   MCELFStreamer::EmitLabel(Symbol);
   Labels.push_back(Symbol);
 }

llvm/lib/Target/Mips/MCTargetDesc/MipsELFStreamer.h

@@ -50,7 +50,7 @@ public:
   /// Overriding this function allows us to record all labels that should be
   /// marked as microMIPS. Based on this data marking is done in
   /// EmitInstruction.
-  void EmitLabel(MCSymbol *Symbol) override;
+  void EmitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override;
 
   /// Overriding this function allows us to dismiss all labels that are
   /// candidates for marking as microMIPS when .section directive is processed.

llvm/test/CodeGen/XCore/section-name.ll

@@ -0,0 +1,8 @@
+; RUN: llc < %s -march=xcore
+
+; we used to crash in this.
+@bar = internal global i32 zeroinitializer
+
+define void @".dp.bss"() {
+  ret void
+}