Subzero: Reduce the amount of #ifdef'd code.

src/IceBuildDefs.h

Index: src/IceBuildDefs.h
diff --git a/src/IceBuildDefs.h b/src/IceBuildDefs.h
new file mode 100644
index 0000000000000000000000000000000000000000..6af41f1d2e3ab2f3d8da282a8871ade39135d77b
--- /dev/null
+++ b/src/IceBuildDefs.h
@@ -0,0 +1,50 @@
+//===- subzero/src/IceBuildDefs.h - Translator build defines ----*- C++ -*-===//
+//
+//                        The Subzero Code Generator
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines constexpr functions to query various #define values.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SUBZERO_SRC_ICEBUILDDEFS_H
+#define SUBZERO_SRC_ICEBUILDDEFS_H
+
+namespace Ice {
+namespace BuildDefs {
+
+// The ALLOW_* etc. symbols must be #defined to zero or non-zero.
+constexpr bool disableIrGen() { return ALLOW_DISABLE_IR_GEN; }
+constexpr bool dump() { return ALLOW_DUMP; }
+constexpr bool llvmCl() { return ALLOW_LLVM_CL; }
+constexpr bool llvmIr() { return ALLOW_LLVM_IR; }
+constexpr bool llvmIrAsInput() { return ALLOW_LLVM_IR_AS_INPUT; }
+constexpr bool minimal() { return ALLOW_MINIMAL_BUILD; }
+constexpr bool textualBitcode() { return INPUT_IS_TEXTUAL_BITCODE; }
+
+// NDEBUG can be undefined, or defined to something arbitrary.
+constexpr bool asserts() {
+#ifdef NDEBUG
+  return false;
+#else  // !NDEBUG
+  return true;
+#endif // !NDEBUG
+}
+
+// ALLOW_EXTRA_VALIDATION can be undefined, or defined to something non-zero.
+constexpr bool extraValidation() {
+#if ALLOW_EXTRA_VALIDATION
+  return true;
+#else  // !ALLOW_EXTRA_VALIDATION
+  return false;
+#endif // !ALLOW_EXTRA_VALIDATION
+}
+
+} // end of namespace BuildDefs
+} // end of namespace Ice
+
+#endif // SUBZERO_SRC_ICEBUILDDEFS_H