[RISCV] Create mapping symbols with non-unique names

Summary:
Similar to #99836 for AArch64.

Non-unique names save .strtab space and match GNU assembler.

Pull Request: #99903

Test Plan: 

Reviewers: 

Subscribers: 

Tasks: 

Tags: 


Differential Revision: https://phabricator.intern.facebook.com/D60251462

Author: MaskRay

llvm/lib/Target/RISCV/MCTargetDesc/RISCVELFStreamer.cpp

@@ -132,7 +132,6 @@ void RISCVTargetELFStreamer::emitDirectiveVariantCC(MCSymbol &Symbol) {
 void RISCVELFStreamer::reset() {
   static_cast<RISCVTargetStreamer *>(getTargetStreamer())->reset();
   MCELFStreamer::reset();
-  MappingSymbolCounter = 0;
   LastMappingSymbols.clear();
   LastEMS = EMS_None;
 }
@@ -152,8 +151,7 @@ void RISCVELFStreamer::emitInstructionsMappingSymbol() {
 }
 
 void RISCVELFStreamer::emitMappingSymbol(StringRef Name) {
-  auto *Symbol = cast<MCSymbolELF>(getContext().getOrCreateSymbol(
-      Name + "." + Twine(MappingSymbolCounter++)));
+  auto *Symbol = cast<MCSymbolELF>(getContext().createLocalSymbol(Name));
   emitLabel(Symbol);
   Symbol->setType(ELF::STT_NOTYPE);
   Symbol->setBinding(ELF::STB_LOCAL);

llvm/lib/Target/RISCV/MCTargetDesc/RISCVELFStreamer.h

@@ -22,7 +22,6 @@ class RISCVELFStreamer : public MCELFStreamer {
 
   enum ElfMappingSymbol { EMS_None, EMS_Instructions, EMS_Data };
 
-  int64_t MappingSymbolCounter = 0;
   DenseMap<const MCSection *, ElfMappingSymbol> LastMappingSymbols;
   ElfMappingSymbol LastEMS = EMS_None;
 

llvm/test/MC/RISCV/mapping-across-sections.s

@@ -1,5 +1,5 @@
-# RUN: llvm-mc -triple=riscv32 -filetype=obj < %s | llvm-readelf -Ss - | FileCheck %s
-# RUN: llvm-mc -triple=riscv64 -filetype=obj < %s | llvm-readelf -Ss - | FileCheck %s
+# RUN: llvm-mc -triple=riscv32 -filetype=obj %s | llvm-readelf -Ss - | FileCheck %s
+# RUN: llvm-mc -triple=riscv64 -filetype=obj %s | llvm-readelf -Ss - | FileCheck %s
 
         .text
         nop
@@ -28,6 +28,6 @@
 # CHECK: [[#STARTS_DATA:]]] .starts_data
 
 # CHECK:    Value  Size Type    Bind   Vis     Ndx              Name
-# CHECK: 00000000     0 NOTYPE  LOCAL  DEFAULT [[#TEXT]]        $x
-# CHECK: 00000000     0 NOTYPE  LOCAL  DEFAULT [[#WIBBLE]]      $x
-# CHECK: 00000000     0 NOTYPE  LOCAL  DEFAULT [[#STARTS_DATA]] $d
+# CHECK: 00000000     0 NOTYPE  LOCAL  DEFAULT [[#TEXT]]        $x{{$}}
+# CHECK: 00000000     0 NOTYPE  LOCAL  DEFAULT [[#WIBBLE]]      $x{{$}}
+# CHECK: 00000000     0 NOTYPE  LOCAL  DEFAULT [[#STARTS_DATA]] $d{{$}}