diff --git a/lib/AsmParser/Lexer.l b/lib/AsmParser/Lexer.l
index 12a430af36b..062e00c4197 100644
--- a/lib/AsmParser/Lexer.l
+++ b/lib/AsmParser/Lexer.l
@@ -32,6 +32,13 @@
 #include <cctype>
 #include <cstdlib>
 
+void set_scan_file(FILE * F){
+  yy_switch_to_buffer(yy_create_buffer( F, YY_BUF_SIZE ) );
+}
+void set_scan_string (const char * str) {
+  yy_scan_string (str);
+}
+
 #define RET_TOK(type, Enum, sym) \
   llvmAsmlval.type = Instruction::Enum; return sym
 
diff --git a/lib/AsmParser/Parser.cpp b/lib/AsmParser/Parser.cpp
index 0111ea35df1..7bb4f0a362f 100644
--- a/lib/AsmParser/Parser.cpp
+++ b/lib/AsmParser/Parser.cpp
@@ -42,6 +42,10 @@ Module *llvm::ParseAssemblyFile(const std::string &Filename) {
   return Result;
 }
 
+Module *llvm::ParseAssemblyString(const char * AsmString, Module * M) {
+  return RunVMAsmParser(AsmString, M);
+}
+
 
 //===------------------------------------------------------------------------===
 //                              ParseException Class
diff --git a/lib/AsmParser/ParserInternals.h b/lib/AsmParser/ParserInternals.h
index 20961357c88..b21dea7a078 100644
--- a/lib/AsmParser/ParserInternals.h
+++ b/lib/AsmParser/ParserInternals.h
@@ -22,10 +22,17 @@
 #include "llvm/Assembly/Parser.h"
 #include "llvm/ADT/StringExtras.h"
 
+
 // Global variables exported from the lexer...
-extern std::FILE *llvmAsmin;
+
 extern int llvmAsmlineno;
 
+extern std::string &llvmAsmTextin;
+
+// functions exported from the lexer
+void set_scan_file(FILE * F);
+void set_scan_string (const char * str);
+
 // Globals exported by the parser...
 extern char* llvmAsmtext;
 extern int   llvmAsmleng;
@@ -38,6 +45,9 @@ extern std::string CurFilename;
 class Module;
 Module *RunVMAsmParser(const std::string &Filename, FILE *F);
 
+// Parse a string directly
+Module *RunVMAsmParser(const char * AsmString, Module * M);
+
 
 // UnEscapeLexed - Run through the specified buffer and change \xx codes to the
 // appropriate character.  If AllowNull is set to false, a \00 value will cause
diff --git a/lib/AsmParser/llvmAsmParser.y b/lib/AsmParser/llvmAsmParser.y
index c459a0eec0e..d73b008416a 100644
--- a/lib/AsmParser/llvmAsmParser.y
+++ b/lib/AsmParser/llvmAsmParser.y
@@ -719,26 +719,41 @@ static PATypeHolder HandleUpRefs(const Type *ty) {
 }
 
 
+// common code from the two 'RunVMAsmParser' functions
+ static Module * RunParser(Module * M) {
+
+  llvmAsmlineno = 1;      // Reset the current line number...
+
+  CurModule.CurrentModule = M;
+  yyparse();       // Parse the file, potentially throwing exception
+
+  Module *Result = ParserResult;
+  ParserResult = 0;
+
+  return Result;
+
+ }
+
 //===----------------------------------------------------------------------===//
 //            RunVMAsmParser - Define an interface to this parser
 //===----------------------------------------------------------------------===//
 //
 Module *llvm::RunVMAsmParser(const std::string &Filename, FILE *F) {
-  llvmAsmin = F;
+  set_scan_file(F);
+
   CurFilename = Filename;
-  llvmAsmlineno = 1;      // Reset the current line number...
+  return RunParser(new Module(CurFilename));
+}
 
-  // Allocate a new module to read
-  CurModule.CurrentModule = new Module(Filename);
+Module *llvm::RunVMAsmParser(const char * AsmString, Module * M) {
+  set_scan_string(AsmString);
 
-  yyparse();       // Parse the file, potentially throwing exception
-
-  Module *Result = ParserResult;
-
-  llvmAsmin = stdin;    // F is about to go away, don't use it anymore...
-  ParserResult = 0;
-
-  return Result;
+  CurFilename = "from_memory";
+  if (M == NULL) {
+    return RunParser(new Module (CurFilename));
+  } else {
+    return RunParser(M);
+  }
 }
 
 %}