diff --git a/BUILD.bazel b/BUILD.bazel
index a2342770e7..b83fd5aead 100644
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -456,7 +456,6 @@ cc_library(
     ],
     exclude = [
         "test/cpp_interface_test.cpp",
-        "test/log_test.cpp",
         "test/pch_test.cpp",
     ],
 )]
@@ -487,19 +486,6 @@ cc_test(
     ],
 )
 
-cc_test(
-    name = "base_log_test",
-    size = "small",
-    srcs = ["test/log_test.cpp"],
-    copts = TEST_COPTS,
-    linkstatic = 1,
-    deps = [
-        ":spirv_tools_opt_internal",
-        "@com_google_googletest//:gtest",
-        "@com_google_googletest//:gtest_main",
-    ],
-)
-
 cc_library(
     name = "link_test_lib",
     testonly = 1,
diff --git a/source/opt/log.h b/source/opt/log.h
index 68051002e2..4fb66fd455 100644
--- a/source/opt/log.h
+++ b/source/opt/log.h
@@ -23,7 +23,7 @@
 #include "spirv-tools/libspirv.hpp"
 
 // Asserts the given condition is true. Otherwise, sends a message to the
-// consumer and exits the problem with failure code. Accepts the following
+// consumer and exits the program with failure code. Accepts the following
 // formats:
 //
 // SPIRV_ASSERT(<message-consumer>, <condition-expression>);
@@ -36,7 +36,9 @@
 #if !defined(NDEBUG)
 #define SPIRV_ASSERT(consumer, ...) SPIRV_ASSERT_IMPL(consumer, __VA_ARGS__)
 #else
-#define SPIRV_ASSERT(consumer, ...)
+// Adding a use to avoid errors in the release build related to unused
+// consumers.
+#define SPIRV_ASSERT(consumer, ...) (void)(consumer)
 #endif
 
 // Logs a debug message to the consumer. Accepts the following formats:
@@ -49,26 +51,11 @@
 #if !defined(NDEBUG) && defined(SPIRV_LOG_DEBUG)
 #define SPIRV_DEBUG(consumer, ...) SPIRV_DEBUG_IMPL(consumer, __VA_ARGS__)
 #else
-#define SPIRV_DEBUG(consumer, ...)
+// Adding a use to avoid errors in the release build related to unused
+// consumers.
+#define SPIRV_DEBUG(consumer, ...) (void)(consumer)
 #endif
 
-// Logs an error message to the consumer saying the given feature is
-// unimplemented.
-#define SPIRV_UNIMPLEMENTED(consumer, feature)                \
-  do {                                                        \
-    spvtools::Log(consumer, SPV_MSG_INTERNAL_ERROR, __FILE__, \
-                  {static_cast<size_t>(__LINE__), 0, 0},      \
-                  "unimplemented: " feature);                 \
-  } while (0)
-
-// Logs an error message to the consumer saying the code location
-// should be unreachable.
-#define SPIRV_UNREACHABLE(consumer)                                      \
-  do {                                                                   \
-    spvtools::Log(consumer, SPV_MSG_INTERNAL_ERROR, __FILE__,            \
-                  {static_cast<size_t>(__LINE__), 0, 0}, "unreachable"); \
-  } while (0)
-
 // Helper macros for concatenating arguments.
 #define SPIRV_CONCATENATE(a, b) SPIRV_CONCATENATE_(a, b)
 #define SPIRV_CONCATENATE_(a, b) a##b
diff --git a/source/opt/type_manager.cpp b/source/opt/type_manager.cpp
index 2dcc25940c..ae320772df 100644
--- a/source/opt/type_manager.cpp
+++ b/source/opt/type_manager.cpp
@@ -901,7 +901,7 @@ Type* TypeManager::RecordIfTypeDefinition(const Instruction& inst) {
       type = new HitObjectNV();
       break;
     default:
-      SPIRV_UNIMPLEMENTED(consumer_, "unhandled type");
+      assert(false && "Type not handled by the type manager.");
       break;
   }
 
@@ -943,12 +943,10 @@ void TypeManager::AttachDecoration(const Instruction& inst, Type* type) {
       }
       if (Struct* st = type->AsStruct()) {
         st->AddMemberDecoration(index, std::move(data));
-      } else {
-        SPIRV_UNIMPLEMENTED(consumer_, "OpMemberDecorate non-struct type");
       }
     } break;
     default:
-      SPIRV_UNREACHABLE(consumer_);
+      assert(false && "Unexpected opcode for a decoration instruction.");
       break;
   }
 }
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 37c5e1d514..662c0bf4cb 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -111,7 +111,6 @@ set(TEST_SOURCES
   hex_float_test.cpp
   immediate_int_test.cpp
   libspirv_macros_test.cpp
-  log_test.cpp
   named_id_test.cpp
   name_mapper_test.cpp
   opcode_make_test.cpp
diff --git a/test/log_test.cpp b/test/log_test.cpp
deleted file mode 100644
index ec66aa1ece..0000000000
--- a/test/log_test.cpp
+++ /dev/null
@@ -1,53 +0,0 @@
-// Copyright (c) 2016 Google Inc.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include "source/opt/log.h"
-#include "gmock/gmock.h"
-#include "gtest/gtest.h"
-
-namespace spvtools {
-namespace {
-
-using ::testing::MatchesRegex;
-
-TEST(Log, Unimplemented) {
-  int invocation = 0;
-  auto consumer = [&invocation](spv_message_level_t level, const char* source,
-                                const spv_position_t&, const char* message) {
-    ++invocation;
-    EXPECT_EQ(SPV_MSG_INTERNAL_ERROR, level);
-    EXPECT_THAT(source, MatchesRegex(".*log_test.cpp$"));
-    EXPECT_STREQ("unimplemented: the-ultimite-feature", message);
-  };
-
-  SPIRV_UNIMPLEMENTED(consumer, "the-ultimite-feature");
-  EXPECT_EQ(1, invocation);
-}
-
-TEST(Log, Unreachable) {
-  int invocation = 0;
-  auto consumer = [&invocation](spv_message_level_t level, const char* source,
-                                const spv_position_t&, const char* message) {
-    ++invocation;
-    EXPECT_EQ(SPV_MSG_INTERNAL_ERROR, level);
-    EXPECT_THAT(source, MatchesRegex(".*log_test.cpp$"));
-    EXPECT_STREQ("unreachable", message);
-  };
-
-  SPIRV_UNREACHABLE(consumer);
-  EXPECT_EQ(1, invocation);
-}
-
-}  // namespace
-}  // namespace spvtools