[MC][ELF] Handle MIPS specific .sdata and .sbss directives

[atanasyan]

Summary

MIPS specific .sdata and .sbss directives create corresponding sections with proper initialized ELF flags including ELF::SHF_MIPS_GPREL.

[• rafael]

LGTM

llvm/trunk/lib/Target/Mips/AsmParser/MipsAsmParser.cpp

 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCInst.h"
 #include "llvm/MC/MCInstBuilder.h"
 #include "llvm/MC/MCParser/MCAsmLexer.h"
 #include "llvm/MC/MCParser/MCParsedAsmOperand.h"
 #include "llvm/MC/MCParser/MCTargetAsmParser.h"
+#include "llvm/MC/MCSectionELF.h"
 #include "llvm/MC/MCStreamer.h"
 #include "llvm/MC/MCSubtargetInfo.h"
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/Support/Debug.h"
+#include "llvm/Support/ELF.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/SourceMgr.h"
 #include "llvm/Support/TargetRegistry.h"
 #include "llvm/Support/raw_ostream.h"
 #include <memory>
 
 using namespace llvm;
 
#include "MipsGenAsmMatcher.inc"
   bool parseDirectiveCpLoad(SMLoc Loc);
   bool parseDirectiveCpRestore(SMLoc Loc);
   bool parseDirectiveCPSetup();
   bool parseDirectiveCPReturn();
   bool parseDirectiveNaN();
   bool parseDirectiveSet();
   bool parseDirectiveOption();
   bool parseInsnDirective();
+  bool parseSSectionDirective(StringRef Section, unsigned Type);
 
   bool parseSetAtDirective();
   bool parseSetNoAtDirective();
   bool parseSetMacroDirective();
   bool parseSetNoMacroDirective();
   bool parseSetMsaDirective();
   bool parseSetNoMsaDirective();
   bool parseSetNoDspDirective();
bool MipsAsmParser::parseInsnDirective() {
   // The actual label marking happens in
   // MipsELFStreamer::createPendingLabelRelocs().
   getTargetStreamer().emitDirectiveInsn();
 
   getParser().Lex(); // Eat EndOfStatement token.
   return false;
 }
 
+/// parseSSectionDirective
+///  ::= .sbss
+///  ::= .sdata
+bool MipsAsmParser::parseSSectionDirective(StringRef Section, unsigned Type) {
+  // If this is not the end of the statement, report an error.
+  if (getLexer().isNot(AsmToken::EndOfStatement)) {
+    reportParseError("unexpected token, expected end of statement");
+    return false;
+  }
+
+  MCSection *ELFSection = getContext().getELFSection(
+      Section, Type, ELF::SHF_WRITE | ELF::SHF_ALLOC | ELF::SHF_MIPS_GPREL);
+  getParser().getStreamer().SwitchSection(ELFSection);
+
+  getParser().Lex(); // Eat EndOfStatement token.
+  return false;
+}
+
 /// parseDirectiveModule
 ///  ::= .module oddspreg
 ///  ::= .module nooddspreg
 ///  ::= .module fp=value
 ///  ::= .module softfloat
 ///  ::= .module hardfloat
 bool MipsAsmParser::parseDirectiveModule() {
   MCAsmParser &Parser = getParser();
if (IDVal == ".module")
     return parseDirectiveModule();
 
   if (IDVal == ".llvm_internal_mips_reallow_module_directive")
     return parseInternalDirectiveReallowModule();
 
   if (IDVal == ".insn")
     return parseInsnDirective();
 
+  if (IDVal == ".sbss")
+    return parseSSectionDirective(IDVal, ELF::SHT_NOBITS);
+  if (IDVal == ".sdata")
+    return parseSSectionDirective(IDVal, ELF::SHT_PROGBITS);
+
   return true;
 }
 
 bool MipsAsmParser::parseInternalDirectiveReallowModule() {
   // If this is not the end of the statement, report an error.
   if (getLexer().isNot(AsmToken::EndOfStatement)) {
     reportParseError("unexpected token, expected end of statement");
     return false;

llvm/trunk/test/CodeGen/Mips/mips-shf-gprel.ll

-; Check that .sdata section has SHF_MIPS_GPREL flag.
-
-; RUN: llc -mips-ssection-threshold=16 -mgpopt -mattr=noabicalls \
-; RUN:     -relocation-model=static -march=mips -o - %s -filetype=obj \
-; RUN:   | llvm-readobj -s | FileCheck %s
-
-@data1 = global [4 x i32] [i32 1, i32 2, i32 3, i32 4], align 4
-@date2 = global [4 x i32] zeroinitializer, align 4
-
-; CHECK:      Name: .sdata
-; CHECK-NEXT: Type: SHT_PROGBITS
-; CHECK-NEXT: Flags [ (0x10000003)
-; CHECK-NEXT:   SHF_ALLOC
-; CHECK-NEXT:   SHF_MIPS_GPREL
-; CHECK-NEXT:   SHF_WRITE
-; CHECK-NEXT: ]
-
-; CHECK:      Name: .sbss
-; CHECK-NEXT: Type: SHT_NOBITS
-; CHECK-NEXT: Flags [ (0x10000003)
-; CHECK-NEXT:   SHF_ALLOC
-; CHECK-NEXT:   SHF_MIPS_GPREL
-; CHECK-NEXT:   SHF_WRITE
-; CHECK-NEXT: ]

llvm/trunk/test/CodeGen/Mips/mips-shf-gprel.s

+# Check that .sdata and .sbss sections have SHF_MIPS_GPREL flags
+# and proper section types.
+
+# RUN: llvm-mc -filetype=obj -triple=mips-unknown-linux %s -o - \
+# RUN:   | llvm-readobj -s | FileCheck %s
+
+  .sdata
+  .word 0
+
+  .sbss
+  .zero 4
+
+# CHECK:      Name: .sdata
+# CHECK-NEXT: Type: SHT_PROGBITS
+# CHECK-NEXT: Flags [ (0x10000003)
+# CHECK-NEXT:   SHF_ALLOC
+# CHECK-NEXT:   SHF_MIPS_GPREL
+# CHECK-NEXT:   SHF_WRITE
+# CHECK-NEXT: ]
+
+# CHECK:      Name: .sbss
+# CHECK-NEXT: Type: SHT_NOBITS
+# CHECK-NEXT: Flags [ (0x10000003)
+# CHECK-NEXT:   SHF_ALLOC
+# CHECK-NEXT:   SHF_MIPS_GPREL
+# CHECK-NEXT:   SHF_WRITE
+# CHECK-NEXT: ]