Subzero: Add a random number generator.

src/IceGlobalContext.h

Index: src/IceGlobalContext.h
diff --git a/src/IceGlobalContext.h b/src/IceGlobalContext.h
index e1b67ac555fd54b043234d6ff2bf7d0b63ee28ae..56a6c5a355ae6ccc7264e554fbb95266305805c4 100644
--- a/src/IceGlobalContext.h
+++ b/src/IceGlobalContext.h
@@ -22,6 +22,7 @@
 #include "IceDefs.h"
 #include "IceIntrinsics.h"
 #include "IceTypes.h"
+#include "IceRNG.h"

[Jim Stichnoth, 2014/08/08 05:05:38]

alphabetize includes

[wala, 2014/08/08 16:36:13]

Done.

 
 namespace Ice {
 
@@ -91,6 +92,8 @@ public:
 
   const Intrinsics &getIntrinsicsInfo() const { return IntrinsicsInfo; }
 
+  RandomNumberGenerator &getRNG() { return RNG; }

[Jim Stichnoth, 2014/08/08 05:05:38]

Please add TODOs in appropriate places:

1. Switch to RNG implementation from LLVM or C++11.

2. Make the RNG play nicely with multithreaded translation.

3. Make it possible to replay the RNG sequence in a subsequent run, for
reproducing a bug.  Print the seed/whatever in a comment in the asm output. 
Embed the seed in the binary via metadata that an attacker can't introspect.

[wala, 2014/08/08 16:36:13]

Done.

+
 private:
   Ostream *StrDump; // Stream for dumping / diagnostics
   Ostream *StrEmit; // Stream for code emission
@@ -103,6 +106,7 @@ private:
   const OptLevel Opt;
   const IceString TestPrefix;
   bool HasEmittedFirstMethod;
+  RandomNumberGenerator RNG;
   GlobalContext(const GlobalContext &) LLVM_DELETED_FUNCTION;
   GlobalContext &operator=(const GlobalContext &) LLVM_DELETED_FUNCTION;