Add support for leb128 of absolute expressions.

[oota-llvm.git] / lib / MC / MCParser / AsmParser.cpp

diff --git a/lib/MC/MCParser/AsmParser.cpp b/lib/MC/MCParser/AsmParser.cpp
index 0a664fd876ac35fd77a8cb7d8ef5fbc96a2c0442..5ef6f682bfa8a2586d2fb0450f154a9c300ac9b5 100644 (file)
--- a/lib/MC/MCParser/AsmParser.cpp
+++ b/lib/MC/MCParser/AsmParser.cpp
@@ -238,6 +238,9 @@ public:
     AddDirectiveHandler<&GenericAsmParser::ParseDirectiveMacro>(".macro");
     AddDirectiveHandler<&GenericAsmParser::ParseDirectiveEndMacro>(".endm");
     AddDirectiveHandler<&GenericAsmParser::ParseDirectiveEndMacro>(".endmacro");
+
+    AddDirectiveHandler<&GenericAsmParser::ParseDirectiveLEB128>(".sleb128");
+    AddDirectiveHandler<&GenericAsmParser::ParseDirectiveLEB128>(".uleb128");
   }
 
   bool ParseDirectiveFile(StringRef, SMLoc DirectiveLoc);
@@ -247,6 +250,10 @@ public:
   bool ParseDirectiveMacrosOnOff(StringRef, SMLoc DirectiveLoc);
   bool ParseDirectiveMacro(StringRef, SMLoc DirectiveLoc);
   bool ParseDirectiveEndMacro(StringRef, SMLoc DirectiveLoc);
+
+  void ParseUleb128(uint64_t Value);
+  void ParseSleb128(int64_t Value);
+  bool ParseDirectiveLEB128(StringRef, SMLoc);
 };
 
 }
@@ -2049,6 +2056,48 @@ bool GenericAsmParser::ParseDirectiveEndMacro(StringRef Directive,
                   "no current macro definition");
 }
 
+void GenericAsmParser::ParseUleb128(uint64_t Value) {
+  const uint64_t Mask = (1 << 7) - 1;
+  do {
+    unsigned Byte = Value & Mask;
+    Value >>= 7;
+    if (Value) // Not the last one
+      Byte |= (1 << 7);
+    getStreamer().EmitIntValue(Byte, 1, DEFAULT_ADDRSPACE);
+  } while (Value);
+}
+
+void GenericAsmParser::ParseSleb128(int64_t Value) {
+  const int64_t Mask = (1 << 7) - 1;
+  for(;;) {
+    unsigned Byte = Value & Mask;
+    Value >>= 7;
+    bool Done = ((Value ==  0 && (Byte & 0x40) == 0) ||
+                 (Value == -1 && (Byte & 0x40) != 0));
+    if (!Done)
+      Byte |= (1 << 7);
+    getStreamer().EmitIntValue(Byte, 1, DEFAULT_ADDRSPACE);
+    if (Done)
+      break;
+  }
+}
+
+bool GenericAsmParser::ParseDirectiveLEB128(StringRef DirName, SMLoc) {
+  int64_t Value;
+  if (getParser().ParseAbsoluteExpression(Value))
+    return true;
+
+  if (getLexer().isNot(AsmToken::EndOfStatement))
+    return TokError("unexpected token in directive");
+
+  if (DirName[1] == 's')
+    ParseSleb128(Value);
+  else
+    ParseUleb128(Value);
+  return false;
+}
+
+
 /// \brief Create an MCAsmParser instance.
 MCAsmParser *llvm::createMCAsmParser(const Target &T, SourceMgr &SM,
                                      MCContext &C, MCStreamer &Out,