Created Ice::Instrumentation base class and accompanying hooks.

src/IceInstrumentation.cpp

+//===- subzero/src/IceInstrumentation.cpp - ICE instrumentation framework -===//
+//
+//                        The Subzero Code Generator
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// \brief Implements the Ice::Instrumentation class.
+///
+/// Subclasses can override particular instrumentation methods to specify how
+/// the the target program should be instrumented.
+///
+//===----------------------------------------------------------------------===//
+
+#include "IceInstrumentation.h"
+
+#include "IceCfg.h"
+#include "IceInst.h"
+#include "IceTargetLowering.h"
+
+namespace Ice {
+
+// Iterate through the instructions in the given CFG and instrument each one.
+// Also instrument the beginning of the function.
+void Instrumentation::instrumentFunc(Cfg *Func) {
+  assert(Func);
+  assert(!Func->getNodes().empty());
+
+  LoweringContext Context;
+  Context.init(Func->getNodes().front());
+  instrumentFuncStart(Context);
+  for (CfgNode *Node : Func->getNodes()) {
+    Context.init(Node);
+    while (!Context.atEnd())
+      instrumentInst(Context);
+  }
+}
+
+void Instrumentation::instrumentInst(LoweringContext &Context) {
+  assert(!Context.atEnd());
+  Inst *Instr = iteratorToInst(Context.getCur());

[Karl, 2016/06/07 14:42:41]

You probably should check to verify the instruction hasn't been deleted. The
model of instructions is that a pass may delete an instruction. When this
happens, the instruction isn't actually deleted, it is just marked as deleted.

While your sanitizer may run first now (avoiding this issue), it is better to be
safe, in case some new pass is added at a later date.

Add check on

   !Instr->isDeleted()

[tlively, 2016/06/07 18:14:42]

Context.advanceNext() skips deleted instructions. I Moved advanceCur() and
advanceNext() into the loop to be more clear and added a comment explaining this
issue.

+  switch (Instr->getKind()) {
+    case Inst::Alloca:
+      instrumentAlloca(Context, llvm::cast<InstAlloca>(Instr));
+      break;
+    case Inst::Arithmetic:
+      instrumentArithmetic(Context, llvm::cast<InstArithmetic>(Instr));
+      break;
+    case Inst::Br:
+      instrumentBr(Context, llvm::cast<InstBr>(Instr));
+      break;
+    case Inst::Call:
+      instrumentCall(Context, llvm::cast<InstCall>(Instr));
+      break;
+    case Inst::Cast:
+      instrumentCast(Context, llvm::cast<InstCast>(Instr));
+      break;
+    case Inst::ExtractElement:
+      instrumentExtractElement(Context, llvm::cast<InstExtractElement>(Instr));
+      break;
+    case Inst::Fcmp:
+      instrumentFcmp(Context, llvm::cast<InstFcmp>(Instr));
+      break;
+    case Inst::Icmp:
+      instrumentIcmp(Context, llvm::cast<InstIcmp>(Instr));
+      break;
+    case Inst::InsertElement:
+      instrumentInsertElement(Context, llvm::cast<InstInsertElement>(Instr));
+      break;
+    case Inst::IntrinsicCall:
+      instrumentIntrinsicCall(Context, llvm::cast<InstIntrinsicCall>(Instr));
+      break;
+    case Inst::Load:
+      instrumentLoad(Context, llvm::cast<InstLoad>(Instr));
+      break;
+    case Inst::Phi:
+      instrumentPhi(Context, llvm::cast<InstPhi>(Instr));
+      break;
+    case Inst::Ret:
+      instrumentRet(Context, llvm::cast<InstRet>(Instr));
+      break;
+    case Inst::Select:
+      instrumentSelect(Context, llvm::cast<InstSelect>(Instr));
+      break;
+    case Inst::Store:
+      instrumentStore(Context, llvm::cast<InstStore>(Instr));
+      break;
+    case Inst::Switch:
+      instrumentSwitch(Context, llvm::cast<InstSwitch>(Instr));
+      break;
+    case Inst::Unreachable:
+      instrumentUnreachable(Context, llvm::cast<InstUnreachable>(Instr));
+      break;
+    default:
+      // Only instrument high-level ICE instructions
+      assert(false && "Instrumentation encountered an unexpected instruction");
+      break;
+  }
+
+  Context.advanceCur();
+  Context.advanceNext();
+}
+
+} // end of namespace Ice