[mips] Replace custom parsing logic for data directives by the addAliasForDirective

The target independent AsmParser doesn't recognise .hword, .word, .dword
which are required for Mips. Currently MipsAsmParser recognises these
through dispatch to MipsAsmParser::parseDataDirective. This contains
equivalent logic to AsmParser::parseDirectiveValue. This patch allows
reuse of AsmParser::parseDirectiveValue by making use of
addAliasForDirective to support .hword, .word and .dword.

Original patch provided by Alex Bradbury at D47001 was modified to fix
handling of microMIPS symbols. The `AsmParser::parseDirectiveValue`
calls either `EmitIntValue` or `EmitValue`. In this patch we override
`EmitIntValue` in the `MipsELFStreamer` to clear a pending set of
microMIPS symbols.

Differential revision: https://reviews.llvm.org/D49539

llvm-svn: 337893

lib/Target/Mips/AsmParser/MipsAsmParser.cpp

@@ -355,7 +355,6 @@ class MipsAsmParser : public MCTargetAsmParser {
 
   bool parseSetAssignment();
 
-  bool parseDataDirective(unsigned Size, SMLoc L);
   bool parseDirectiveGpWord();
   bool parseDirectiveGpDWord();
   bool parseDirectiveDtpRelWord();
@@ -487,6 +486,9 @@ public:
     MCAsmParserExtension::Initialize(parser);
 
     parser.addAliasForDirective(".asciiz", ".asciz");
+    parser.addAliasForDirective(".hword", ".2byte");
+    parser.addAliasForDirective(".word", ".4byte");
+    parser.addAliasForDirective(".dword", ".8byte");
 
     // Initialize the set of available features.
     setAvailableFeatures(ComputeAvailableFeatures(getSTI().getFeatureBits()));
@@ -7357,31 +7359,6 @@ bool MipsAsmParser::parseDirectiveSet() {
   return parseSetAssignment();
 }
 
-/// parseDataDirective
-///  ::= .word [ expression (, expression)* ]
-bool MipsAsmParser::parseDataDirective(unsigned Size, SMLoc L) {
-  MCAsmParser &Parser = getParser();
-  if (getLexer().isNot(AsmToken::EndOfStatement)) {
-    while (true) {
-      const MCExpr *Value;
-      if (getParser().parseExpression(Value))
-        return true;
-
-      getParser().getStreamer().EmitValue(Value, Size);
-
-      if (getLexer().is(AsmToken::EndOfStatement))
-        break;
-
-      if (getLexer().isNot(AsmToken::Comma))
-        return Error(L, "unexpected token, expected comma");
-      Parser.Lex();
-    }
-  }
-
-  Parser.Lex();
-  return false;
-}
-
 /// parseDirectiveGpWord
 ///  ::= .gpword local_sym
 bool MipsAsmParser::parseDirectiveGpWord() {
@@ -7961,10 +7938,6 @@ bool MipsAsmParser::ParseDirective(AsmToken DirectiveID) {
     parseDirectiveCpRestore(DirectiveID.getLoc());
     return false;
   }
-  if (IDVal == ".dword") {
-    parseDataDirective(8, DirectiveID.getLoc());
-    return false;
-  }
   if (IDVal == ".ent") {
     StringRef SymbolName;
 
@@ -8212,16 +8185,6 @@ bool MipsAsmParser::ParseDirective(AsmToken DirectiveID) {
     return false;
   }
 
-  if (IDVal == ".word") {
-    parseDataDirective(4, DirectiveID.getLoc());
-    return false;
-  }
-
-  if (IDVal == ".hword") {
-    parseDataDirective(2, DirectiveID.getLoc());
-    return false;
-  }
-
   if (IDVal == ".option") {
     parseDirectiveOption();
     return false;

lib/Target/Mips/MCTargetDesc/MipsELFStreamer.cpp

@@ -86,6 +86,11 @@ void MipsELFStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size,
   Labels.clear();
 }
 
+void MipsELFStreamer::EmitIntValue(uint64_t Value, unsigned Size) {
+  MCELFStreamer::EmitIntValue(Value, Size);
+  Labels.clear();
+}
+
 void MipsELFStreamer::EmitMipsOptionRecords() {
   for (const auto &I : MipsOptionRecords)
     I->EmitMipsOptionRecord();

lib/Target/Mips/MCTargetDesc/MipsELFStreamer.h

@@ -54,9 +54,11 @@ public:
   void SwitchSection(MCSection *Section,
                      const MCExpr *Subsection = nullptr) override;
 
-  /// Overriding this function allows us to dismiss all labels that are
+  /// Overriding these functions allows us to dismiss all labels that are
-  /// candidates for marking as microMIPS when .word directive is emitted.
+  /// candidates for marking as microMIPS when .word/.long/.4byte etc
+  /// directives are emitted.
   void EmitValueImpl(const MCExpr *Value, unsigned Size, SMLoc Loc) override;
+  void EmitIntValue(uint64_t Value, unsigned Size) override;
 
   /// Emits all the option records stored up until the point it's called.
   void EmitMipsOptionRecords();

test/MC/Mips/micromips-label-test.s

@@ -9,6 +9,16 @@ g:
   nop
 h:
   .word 0
+k:
+  .long 0
+l:
+  .hword 0
+m:
+  .2byte 0
+n:
+  .4byte 0
+o:
+  .8byte 0
 i:
   nop
 j:
@@ -54,5 +64,39 @@ j:
 # CHECK:     Other: 0
 # CHECK:     Section: .text
 # CHECK:   }
+# CHECK:   Symbol {
+# CHECK:     Name: k
+# CHECK:     Binding: Local
+# CHECK:     Type: None
+# CHECK:     Other: 0
+# CHECK:     Section: .text
+# CHECK:   }
+# CHECK:   Symbol {
+# CHECK:     Name: l
+# CHECK:     Binding: Local
+# CHECK:     Type: None
+# CHECK:     Other: 0
+# CHECK:     Section: .text
+# CHECK:   }
+# CHECK:   Symbol {
+# CHECK:     Name: m
+# CHECK:     Binding: Local
+# CHECK:     Type: None
+# CHECK:     Other: 0
+# CHECK:     Section: .text
+# CHECK:   }
+# CHECK:   Symbol {
+# CHECK:     Name: n
+# CHECK:     Binding: Local
+# CHECK:     Type: None
+# CHECK:     Other: 0
+# CHECK:     Section: .text
+# CHECK:   }
+# CHECK:   Symbol {
+# CHECK:     Name: o
+# CHECK:     Binding: Local
+# CHECK:     Type: None
+# CHECK:     Other: 0
+# CHECK:     Section: .text
+# CHECK:   }
 # CHECK: ]
-