From d177d6d6dd50093a8328d2658c7a394ee3f441d1 Mon Sep 17 00:00:00 2001
From: Greg Miller <9447643+devjgm@users.noreply.github.com>
Date: Wed, 31 Jul 2019 10:03:21 -0400
Subject: [PATCH 01/19] Added spanner/internal/build_info.cc.in and friends

---
 ci/kokoro/docker/build-in-docker-cmake.sh     |  6 +-
 ci/kokoro/docker/build.sh                     |  5 +
 google/cloud/spanner/BUILD                    | 24 ++++-
 google/cloud/spanner/CMakeLists.txt           | 62 ++++++++++++
 .../cloud/spanner/internal/build_info.cc.in   | 94 +++++++++++++++++++
 google/cloud/spanner/internal/build_info.h    | 47 ++++++++++
 .../cloud/spanner/internal/build_info_test.cc | 63 +++++++++++++
 google/cloud/spanner/spanner_client.bzl       |  1 +
 .../spanner/spanner_client_unit_tests.bzl     |  1 +
 .../cloud/spanner/spanner_client_version.bzl  | 19 ++++
 10 files changed, 316 insertions(+), 6 deletions(-)
 create mode 100644 google/cloud/spanner/internal/build_info.cc.in
 create mode 100644 google/cloud/spanner/internal/build_info.h
 create mode 100644 google/cloud/spanner/internal/build_info_test.cc
 create mode 100644 google/cloud/spanner/spanner_client_version.bzl

diff --git a/ci/kokoro/docker/build-in-docker-cmake.sh b/ci/kokoro/docker/build-in-docker-cmake.sh
index 41c1ed07..8b1952df 100755
--- a/ci/kokoro/docker/build-in-docker-cmake.sh
+++ b/ci/kokoro/docker/build-in-docker-cmake.sh
@@ -53,15 +53,11 @@ if [[ "${GOOGLE_CLOUD_CPP_CXX_STANDARD:-}" != "" ]]; then
     "-DGOOGLE_CLOUD_CPP_CXX_STANDARD=${GOOGLE_CLOUD_CPP_CXX_STANDARD}")
 fi
 
-if [[ "${CODE_COVERAGE:-}" == "yes" ]]; then
-  cmake_flags+=(
-    "-DCMAKE_BUILD_TYPE=Coverage")
-fi
-
 # We disable the shellcheck warning because we want ${CMAKE_FLAGS} to expand as
 # separate arguments.
 # shellcheck disable=SC2086
 cmake "-DCMAKE_INSTALL_PREFIX=$HOME/staging" \
+      -DCMAKE_BUILD_TYPE="${BUILD_TYPE}" \
       ${CMAKE_FLAGS:-} \
       "-H${SOURCE_DIR}" "-B${BINARY_DIR}" "${cmake_flags[@]}"
 cmake --build "${BINARY_DIR}" -- -j "$(nproc)"
diff --git a/ci/kokoro/docker/build.sh b/ci/kokoro/docker/build.sh
index 8b5b6901..39a091c6 100755
--- a/ci/kokoro/docker/build.sh
+++ b/ci/kokoro/docker/build.sh
@@ -52,6 +52,7 @@ if [[ "${BUILD_NAME}" = "clang-tidy" ]]; then
   export DISTRO_VERSION=30
   export CC=clang
   export CXX=clang++
+  export BUILD_TYPE=Debug
   export CHECK_STYLE=yes
   export GENERATE_DOCS=yes
   export CLANG_TIDY=yes
@@ -118,6 +119,7 @@ elif [[ "${BUILD_NAME}" = "cxx17" ]]; then
   export CXX=g++
   in_docker_script="ci/kokoro/docker/build-in-docker-cmake.sh"
 elif [[ "${BUILD_NAME}" = "coverage" ]]; then
+  export BUILD_TYPE=Coverage
   export CODE_COVERAGE=yes
   export RUN_INTEGRATION_TESTS=yes
   export DISTRO=fedora-install
@@ -234,6 +236,9 @@ docker_flags=(
     # If set, pass -DGOOGLE_CLOUD_CPP_CXX_STANDARD=<value> to CMake.
     "--env" "GOOGLE_CLOUD_CPP_CXX_STANDARD=${GOOGLE_CLOUD_CPP_CXX_STANDARD:-}"
 
+    # The type of the build for CMake
+    "--env" "BUILD_TYPE=${BUILD_TYPE:-Release}"
+
     # Additional flags to enable CMake features.
     "--env" "CMAKE_FLAGS=${CMAKE_FLAGS:-}"
 
diff --git a/google/cloud/spanner/BUILD b/google/cloud/spanner/BUILD
index 1dd55786..b50e6b7d 100644
--- a/google/cloud/spanner/BUILD
+++ b/google/cloud/spanner/BUILD
@@ -16,11 +16,33 @@ package(default_visibility = ["//visibility:public"])
 
 licenses(["notice"])  # Apache 2.0
 
+load(":spanner_client_version.bzl", "GOOGLE_CLOUD_CPP_SPANNER_IS_RELEASE")
+
+genrule(
+    name = "generate_build_info",
+    srcs = ["internal/build_info.cc.in"],
+    outs = ["internal/build_info.cc"],
+    cmd = """
+CC_COMPILER_VERSION=$$($(CC) --version | head -1);
+V=$$(git rev-parse --short HEAD 2>/dev/null || echo "unknown");
+sed -e "s;@CMAKE_CXX_COMPILER_ID@;$(C_COMPILER);" \
+    -e "s;@CMAKE_CXX_COMPILER_VERSION@;$${CC_COMPILER_VERSION};" \
+    -e "s;@CMAKE_CXX_FLAGS@;$(CC_FLAGS);" \
+    -e "s;\\$${CMAKE_CXX_FLAGS_.*};$(COMPILATION_MODE);" \
+    -e "s;@GOOGLE_CLOUD_CPP_SPANNER_IS_RELEASE@;%s;" \
+    -e "s;@GOOGLE_CLOUD_CPP_GIT_HEAD@;$${V};" < $< > $@
+  """ % (GOOGLE_CLOUD_CPP_SPANNER_IS_RELEASE),
+    toolchains = [
+        "@bazel_tools//tools/cpp:current_cc_toolchain",
+        "@bazel_tools//tools/cpp:cc_flags",
+    ],
+)
+
 load(":spanner_client.bzl", "spanner_client_hdrs", "spanner_client_srcs")
 
 cc_library(
     name = "spanner_client",
-    srcs = spanner_client_srcs,
+    srcs = spanner_client_srcs + ["internal/build_info.cc"],
     hdrs = spanner_client_hdrs,
     deps = [
         "@com_github_googleapis_google_cloud_cpp//google/cloud:google_cloud_cpp_common",
diff --git a/google/cloud/spanner/CMakeLists.txt b/google/cloud/spanner/CMakeLists.txt
index a7a07c88..d282759e 100644
--- a/google/cloud/spanner/CMakeLists.txt
+++ b/google/cloud/spanner/CMakeLists.txt
@@ -25,6 +25,62 @@ set(DOXYGEN_PROJECT_NUMBER "${SPANNER_VERSION}")
 set(DOXYGEN_EXAMPLE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/samples)
 include(EnableDoxygen)
 
+# Define a function to fetch the current git revision. Using a function creates
+# a new scope, so the CMake variables do not leak to the global namespace.
+function (google_cloud_cpp_spanner_initialize_git_head var)
+    set(result "")
+    # If we cannot find a `.git` directory do not even try to guess the git
+    # revision.
+    if (IS_DIRECTORY ${PROJECT_SOURCE_DIR}/.git)
+        set(result "unknown-commit")
+        # We need `git` to find the revision.
+        find_program(GOOGLE_CLOUD_CPP_SPANNER_GIT_PROGRAM NAMES git)
+        mark_as_advanced(GOOGLE_CLOUD_CPP_SPANNER_GIT_PROGRAM)
+        if (GOOGLE_CLOUD_CPP_SPANNER_GIT_PROGRAM)
+            # Run `git rev-parse --short HEAD` and capture the output in a
+            # variable.
+            execute_process(COMMAND "${GOOGLE_CLOUD_CPP_SPANNER_GIT_PROGRAM}" rev-parse
+                                    --short HEAD
+                            OUTPUT_VARIABLE GIT_HEAD_LOG
+                            ERROR_VARIABLE GIT_HEAD_LOG)
+            string(REPLACE "\n"
+                           ""
+                           result
+                           "${GIT_HEAD_LOG}")
+        endif ()
+    endif ()
+    set(${var} "${result}" PARENT_SCOPE)
+endfunction ()
+
+# Capture the compiler version and the git revision into variables, then
+# generate a config file with the values.
+if (NOT "${GOOGLE_CLOUD_CPP_SPANNER_BUILD_METADATA}" STREQUAL "")
+    # The build metadata flag is already defined, do not re-compute the
+    # initialization value. This works both when the user supplies
+    # -DGOOGLE_CLOUD_CPP_SPANNER_METADATA=value in the command line, and when
+    # GOOGLE_CLOUD_CPP_SPANNER_METADATA has a cached value
+    set(GOOGLE_CLOUD_CPP_SPANNER_GIT_HEAD "unused")
+else()
+    google_cloud_cpp_spanner_initialize_git_head(GOOGLE_CLOUD_CPP_SPANNER_GIT_HEAD)
+endif ()
+
+# Define a CMake configuration option to set the build metadata. By default this
+# is initialized from `git rev-parse --short HEAD`, but the developer (or the
+# script building via CMake) can override the value.
+set(GOOGLE_CLOUD_CPP_SPANNER_BUILD_METADATA "${GOOGLE_CLOUD_CPP_SPANNER_GIT_HEAD}"
+    CACHE STRING "Append build metadata to the library version number")
+# This option is rarely needed. Mark it as "advanced" to remove it from the
+# default CMake UIs.
+mark_as_advanced(GOOGLE_CLOUD_CPP_SPANNER_BUILD_METADATA)
+
+message(STATUS "google-cloud-cpp-spanner build metadata set to"
+               " ${GOOGLE_CLOUD_CPP_SPANNER_BUILD_METADATA}")
+
+# Create the file that captures build information. Having access to the compiler
+# and build flags at runtime allows us to print better benchmark results.
+string(TOUPPER "${CMAKE_BUILD_TYPE}" GOOGLE_CLOUD_CPP_SPANNER_BUILD_TYPE_UPPER)
+configure_file(internal/build_info.cc.in internal/build_info.cc)
+
 configure_file(version_info.h.in ${CMAKE_CURRENT_SOURCE_DIR}/version_info.h)
 add_library(spanner_client
             backoff_policy.h
@@ -38,6 +94,8 @@ add_library(spanner_client
             date.h
             internal/base64.cc
             internal/base64.h
+            internal/build_info.h
+            ${CMAKE_CURRENT_BINARY_DIR}/internal/build_info.cc
             internal/database_admin_retry.cc
             internal/database_admin_retry.h
             internal/database_admin_stub.cc
@@ -102,6 +160,9 @@ add_library(googleapis-c++::spanner_client ALIAS spanner_client)
 include(CreateBazelConfig)
 create_bazel_config(spanner_client)
 
+export_variables_to_bazel("spanner_client_version.bzl"
+                          GOOGLE_CLOUD_CPP_SPANNER_IS_RELEASE)
+
 # Define the tests in a function so we have a new scope for variable names.
 function (spanner_client_define_tests)
     # The tests require googletest to be installed. Force CMake to use the
@@ -133,6 +194,7 @@ function (spanner_client_define_tests)
         database_admin_client_test.cc
         date_test.cc
         internal/base64_test.cc
+        internal/build_info_test.cc
         internal/date_test.cc
         internal/merge_chunk_test.cc
         internal/polling_loop_test.cc
diff --git a/google/cloud/spanner/internal/build_info.cc.in b/google/cloud/spanner/internal/build_info.cc.in
new file mode 100644
index 00000000..9eccbe76
--- /dev/null
+++ b/google/cloud/spanner/internal/build_info.cc.in
@@ -0,0 +1,94 @@
+// Copyright 2017 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 "google/cloud/spanner/internal/build_info.h"
+#include "google/cloud/internal/port_platform.h"
+#include <algorithm>
+#include <cctype>
+#include <iterator>
+
+namespace google {
+namespace cloud {
+namespace spanner {
+inline namespace SPANNER_CLIENT_NS {
+namespace internal {
+
+std::string CompilerVersion() {
+  return R"""(@CMAKE_CXX_COMPILER_ID@ @CMAKE_CXX_COMPILER_VERSION@)""";
+}
+
+std::string CompilerFlags() {
+  static std::string const* const kFlags = [] {
+    auto* flags = new std::string(R"""(@CMAKE_CXX_FLAGS@)""");
+    if (!flags->empty()) *flags += ' ';
+    *flags +=
+        R"""(${CMAKE_CXX_FLAGS_${GOOGLE_CLOUD_CPP_SPANNER_BUILD_TYPE_UPPER}})""";
+    return flags;
+  }();
+  return *kFlags;
+}
+
+std::string LanguageVersion() {
+  static std::string const* const kLanguageVersion = [] {
+    auto* v = new auto(CompilerVersion());
+    for (char& c : *v) {
+      if (std::isspace(static_cast<unsigned char>(c))) c = '-';
+    }
+#if GOOGLE_CLOUD_CPP_HAVE_EXCEPTIONS
+    *v += "-ex";
+#else
+    *v += "-noex";
+#endif  // GOOGLE_CLOUD_CPP_HAVE_EXCEPTIONS
+    switch (__cplusplus) {
+      case 199711L:
+        *v += "-98";
+        break;
+      case 201103L:
+        *v += "-2011";
+        break;
+      case 201402L:
+        *v += "-2014";
+        break;
+      case 201703L:
+        *v += "-2017";
+        break;
+      default:
+        *v += "-unknown";
+    }
+    return v;
+  }();
+  return *kLanguageVersion;
+}
+
+bool IsRelease() {
+  static bool const kIsRelease = []() -> bool {
+    std::string value = R"""(@GOOGLE_CLOUD_CPP_SPANNER_IS_RELEASE@)""";
+    for (char& c : value) {
+      c = static_cast<char>(std::tolower(static_cast<unsigned char>(c)));
+    }
+    return value == "yes" || value == "1" || value == "true";
+  }();
+
+  return kIsRelease;
+}
+
+std::string BuildMetadata() {
+  return R"""(@GOOGLE_CLOUD_CPP_SPANNER_BUILD_METADATA@)""";
+}
+
+}  // namespace internal
+}  // namespace GOOGLE_CLOUD_CPP_NS
+}  // namespace spanner
+}  // namespace cloud
+}  // namespace google
diff --git a/google/cloud/spanner/internal/build_info.h b/google/cloud/spanner/internal/build_info.h
new file mode 100644
index 00000000..650adb69
--- /dev/null
+++ b/google/cloud/spanner/internal/build_info.h
@@ -0,0 +1,47 @@
+// Copyright 2017 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.
+
+#ifndef GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_SPANNER_INTERNAL_BUILD_INFO_H_
+#define GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_SPANNER_INTERNAL_BUILD_INFO_H_
+
+#include "google/cloud/spanner/version.h"
+
+namespace google {
+namespace cloud {
+namespace spanner {
+inline namespace SPANNER_CLIENT_NS {
+namespace internal {
+
+/// The compiler version.
+std::string CompilerVersion();
+
+/// The compiler flags.
+std::string CompilerFlags();
+
+/// The language version for user-agent header.
+std::string LanguageVersion();
+
+/// True if this is a release, false for the development branches.
+bool IsRelease();
+
+/// Build metadata injected by the build system.
+std::string BuildMetadata();
+
+}  // namespace internal
+}  // namespace SPANNER_CLIENT_NS
+}  // namespace spanner
+}  // namespace cloud
+}  // namespace google
+
+#endif  // GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_SPANNER_INTERNAL_BUILD_INFO_H_
diff --git a/google/cloud/spanner/internal/build_info_test.cc b/google/cloud/spanner/internal/build_info_test.cc
new file mode 100644
index 00000000..8683d350
--- /dev/null
+++ b/google/cloud/spanner/internal/build_info_test.cc
@@ -0,0 +1,63 @@
+// Copyright 2019 Google LLC
+//
+// 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 "google/cloud/spanner/internal/build_info.h"
+#include <gmock/gmock.h>
+
+namespace google {
+namespace cloud {
+namespace spanner {
+inline namespace SPANNER_CLIENT_NS {
+namespace internal {
+namespace {
+
+using ::testing::HasSubstr;
+using ::testing::MatchesRegex;
+
+TEST(BuildInfo, CompilerVersion) {
+  auto cv = CompilerVersion();
+  EXPECT_FALSE(cv.empty());
+}
+
+TEST(BuildInfo, CompilerFlags) {
+  auto cf = CompilerFlags();
+  EXPECT_FALSE(cf.empty());
+}
+
+TEST(BuildInfo, LanguageVersion) {
+  auto lv = LanguageVersion();
+  EXPECT_THAT(lv, ::testing::AnyOf(HasSubstr("-noex-"), HasSubstr("-ex-")));
+  EXPECT_THAT(lv, Not(HasSubstr(" ")));
+#ifndef _WIN32
+  // Brackets for regex don't work on windows.
+  EXPECT_THAT(lv, MatchesRegex(R"([0-9A-Za-z_.-]+)"));
+#endif
+}
+
+TEST(BuildInfo, IsRelease) {
+  bool const b = IsRelease();
+  EXPECT_TRUE(b || !b);
+}
+
+TEST(BuildInfo, BuildMetadata) {
+  auto const md = BuildMetadata();
+  EXPECT_FALSE(md.empty());
+}
+
+}  // namespace
+}  // namespace internal
+}  // namespace SPANNER_CLIENT_NS
+}  // namespace spanner
+}  // namespace cloud
+}  // namespace google
diff --git a/google/cloud/spanner/spanner_client.bzl b/google/cloud/spanner/spanner_client.bzl
index 1fd34e70..ba1ffc17 100644
--- a/google/cloud/spanner/spanner_client.bzl
+++ b/google/cloud/spanner/spanner_client.bzl
@@ -24,6 +24,7 @@ spanner_client_hdrs = [
     "database_admin_client.h",
     "date.h",
     "internal/base64.h",
+    "internal/build_info.h",
     "internal/database_admin_retry.h",
     "internal/database_admin_stub.h",
     "internal/date.h",
diff --git a/google/cloud/spanner/spanner_client_unit_tests.bzl b/google/cloud/spanner/spanner_client_unit_tests.bzl
index 287b0c13..0f1dd994 100644
--- a/google/cloud/spanner/spanner_client_unit_tests.bzl
+++ b/google/cloud/spanner/spanner_client_unit_tests.bzl
@@ -22,6 +22,7 @@ spanner_client_unit_tests = [
     "database_admin_client_test.cc",
     "date_test.cc",
     "internal/base64_test.cc",
+    "internal/build_info_test.cc",
     "internal/date_test.cc",
     "internal/merge_chunk_test.cc",
     "internal/polling_loop_test.cc",
diff --git a/google/cloud/spanner/spanner_client_version.bzl b/google/cloud/spanner/spanner_client_version.bzl
new file mode 100644
index 00000000..c540cb71
--- /dev/null
+++ b/google/cloud/spanner/spanner_client_version.bzl
@@ -0,0 +1,19 @@
+# Copyright 2019 Google LLC
+#
+# 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.
+#
+# DO NOT EDIT -- GENERATED BY CMake -- Change the CMakeLists.txt file if needed
+
+"""Automatically generated version numbers - DO NOT EDIT."""
+
+GOOGLE_CLOUD_CPP_SPANNER_IS_RELEASE = ""

From 31aa0563ba1cac2be748163eafa3baa179ca6674 Mon Sep 17 00:00:00 2001
From: Greg Miller <9447643+devjgm@users.noreply.github.com>
Date: Wed, 31 Jul 2019 10:08:26 -0400
Subject: [PATCH 02/19] formatted

---
 google/cloud/spanner/CMakeLists.txt            | 14 ++++++++------
 google/cloud/spanner/internal/build_info.cc.in |  3 ++-
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/google/cloud/spanner/CMakeLists.txt b/google/cloud/spanner/CMakeLists.txt
index d282759e..59b1a31f 100644
--- a/google/cloud/spanner/CMakeLists.txt
+++ b/google/cloud/spanner/CMakeLists.txt
@@ -39,8 +39,8 @@ function (google_cloud_cpp_spanner_initialize_git_head var)
         if (GOOGLE_CLOUD_CPP_SPANNER_GIT_PROGRAM)
             # Run `git rev-parse --short HEAD` and capture the output in a
             # variable.
-            execute_process(COMMAND "${GOOGLE_CLOUD_CPP_SPANNER_GIT_PROGRAM}" rev-parse
-                                    --short HEAD
+            execute_process(COMMAND "${GOOGLE_CLOUD_CPP_SPANNER_GIT_PROGRAM}"
+                                    rev-parse --short HEAD
                             OUTPUT_VARIABLE GIT_HEAD_LOG
                             ERROR_VARIABLE GIT_HEAD_LOG)
             string(REPLACE "\n"
@@ -60,14 +60,16 @@ if (NOT "${GOOGLE_CLOUD_CPP_SPANNER_BUILD_METADATA}" STREQUAL "")
     # -DGOOGLE_CLOUD_CPP_SPANNER_METADATA=value in the command line, and when
     # GOOGLE_CLOUD_CPP_SPANNER_METADATA has a cached value
     set(GOOGLE_CLOUD_CPP_SPANNER_GIT_HEAD "unused")
-else()
-    google_cloud_cpp_spanner_initialize_git_head(GOOGLE_CLOUD_CPP_SPANNER_GIT_HEAD)
+else ()
+    google_cloud_cpp_spanner_initialize_git_head(
+        GOOGLE_CLOUD_CPP_SPANNER_GIT_HEAD)
 endif ()
 
 # Define a CMake configuration option to set the build metadata. By default this
 # is initialized from `git rev-parse --short HEAD`, but the developer (or the
 # script building via CMake) can override the value.
-set(GOOGLE_CLOUD_CPP_SPANNER_BUILD_METADATA "${GOOGLE_CLOUD_CPP_SPANNER_GIT_HEAD}"
+set(GOOGLE_CLOUD_CPP_SPANNER_BUILD_METADATA
+    "${GOOGLE_CLOUD_CPP_SPANNER_GIT_HEAD}"
     CACHE STRING "Append build metadata to the library version number")
 # This option is rarely needed. Mark it as "advanced" to remove it from the
 # default CMake UIs.
@@ -83,6 +85,7 @@ configure_file(internal/build_info.cc.in internal/build_info.cc)
 
 configure_file(version_info.h.in ${CMAKE_CURRENT_SOURCE_DIR}/version_info.h)
 add_library(spanner_client
+            ${CMAKE_CURRENT_BINARY_DIR}/internal/build_info.cc
             backoff_policy.h
             client.cc
             client.h
@@ -95,7 +98,6 @@ add_library(spanner_client
             internal/base64.cc
             internal/base64.h
             internal/build_info.h
-            ${CMAKE_CURRENT_BINARY_DIR}/internal/build_info.cc
             internal/database_admin_retry.cc
             internal/database_admin_retry.h
             internal/database_admin_stub.cc
diff --git a/google/cloud/spanner/internal/build_info.cc.in b/google/cloud/spanner/internal/build_info.cc.in
index 9eccbe76..ff3b267d 100644
--- a/google/cloud/spanner/internal/build_info.cc.in
+++ b/google/cloud/spanner/internal/build_info.cc.in
@@ -43,7 +43,7 @@ std::string LanguageVersion() {
   static std::string const* const kLanguageVersion = [] {
     auto* v = new auto(CompilerVersion());
     for (char& c : *v) {
-      if (std::isspace(static_cast<unsigned char>(c))) c = '-';
+      if (std::isspace(static_cast<unsigned char>(c)) != 0) c = '-';
     }
 #if GOOGLE_CLOUD_CPP_HAVE_EXCEPTIONS
     *v += "-ex";
@@ -73,6 +73,7 @@ std::string LanguageVersion() {
 
 bool IsRelease() {
   static bool const kIsRelease = []() -> bool {
+    // NOLINTNEXTLINE(readability-redundant-string-init)
     std::string value = R"""(@GOOGLE_CLOUD_CPP_SPANNER_IS_RELEASE@)""";
     for (char& c : value) {
       c = static_cast<char>(std::tolower(static_cast<unsigned char>(c)));

From d33d4b45967c236c431202e9497808607c2b89de Mon Sep 17 00:00:00 2001
From: Greg Miller <9447643+devjgm@users.noreply.github.com>
Date: Wed, 31 Jul 2019 11:17:54 -0400
Subject: [PATCH 03/19] fixed regex

---
 google/cloud/spanner/internal/build_info_test.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/google/cloud/spanner/internal/build_info_test.cc b/google/cloud/spanner/internal/build_info_test.cc
index 8683d350..2b4ee2a9 100644
--- a/google/cloud/spanner/internal/build_info_test.cc
+++ b/google/cloud/spanner/internal/build_info_test.cc
@@ -40,8 +40,8 @@ TEST(BuildInfo, LanguageVersion) {
   EXPECT_THAT(lv, ::testing::AnyOf(HasSubstr("-noex-"), HasSubstr("-ex-")));
   EXPECT_THAT(lv, Not(HasSubstr(" ")));
 #ifndef _WIN32
-  // Brackets for regex don't work on windows.
-  EXPECT_THAT(lv, MatchesRegex(R"([0-9A-Za-z_.-]+)"));
+  // Brackets don't work with MatchesRegex() on Windows.
+  EXPECT_THAT(lv, MatchesRegex(R"([0-9A-Za-z/()_.-]+)"));
 #endif
 }
 

From e0a155b585beb4b42a68a7867c3a73ee1a31b1fb Mon Sep 17 00:00:00 2001
From: Greg Miller <9447643+devjgm@users.noreply.github.com>
Date: Wed, 31 Jul 2019 13:29:42 -0400
Subject: [PATCH 04/19] fixed include guards

---
 google/cloud/spanner/internal/build_info.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/google/cloud/spanner/internal/build_info.h b/google/cloud/spanner/internal/build_info.h
index 650adb69..457efa84 100644
--- a/google/cloud/spanner/internal/build_info.h
+++ b/google/cloud/spanner/internal/build_info.h
@@ -12,8 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#ifndef GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_SPANNER_INTERNAL_BUILD_INFO_H_
-#define GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_SPANNER_INTERNAL_BUILD_INFO_H_
+#ifndef GOOGLE_CLOUD_CPP_SPANNER_GOOGLE_CLOUD_SPANNER_INTERNAL_BUILD_INFO_H_
+#define GOOGLE_CLOUD_CPP_SPANNER_GOOGLE_CLOUD_SPANNER_INTERNAL_BUILD_INFO_H_
 
 #include "google/cloud/spanner/version.h"
 
@@ -44,4 +44,4 @@ std::string BuildMetadata();
 }  // namespace cloud
 }  // namespace google
 
-#endif  // GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_SPANNER_INTERNAL_BUILD_INFO_H_
+#endif  // GOOGLE_CLOUD_CPP_SPANNER_GOOGLE_CLOUD_SPANNER_INTERNAL_BUILD_INFO_H_

From 669100d4a4e7406f0db873bbcb20b95aa88b9e3a Mon Sep 17 00:00:00 2001
From: Greg Miller <9447643+devjgm@users.noreply.github.com>
Date: Wed, 31 Jul 2019 16:55:21 -0400
Subject: [PATCH 05/19] changed formatting of most functions

---
 google/cloud/spanner/BUILD                    |  6 +-
 google/cloud/spanner/CMakeLists.txt           |  3 +-
 .../cloud/spanner/internal/build_info.cc.in   | 61 +++++++++++++------
 google/cloud/spanner/internal/build_info.h    | 45 ++++++++++++--
 .../cloud/spanner/internal/build_info_test.cc | 26 +++++---
 5 files changed, 104 insertions(+), 37 deletions(-)

diff --git a/google/cloud/spanner/BUILD b/google/cloud/spanner/BUILD
index b50e6b7d..9f78fed7 100644
--- a/google/cloud/spanner/BUILD
+++ b/google/cloud/spanner/BUILD
@@ -25,12 +25,12 @@ genrule(
     cmd = """
 CC_COMPILER_VERSION=$$($(CC) --version | head -1);
 V=$$(git rev-parse --short HEAD 2>/dev/null || echo "unknown");
-sed -e "s;@CMAKE_CXX_COMPILER_ID@;$(C_COMPILER);" \
+sed -e "s;@CMAKE_CXX_COMPILER@;$$(basename $(CC));" \
     -e "s;@CMAKE_CXX_COMPILER_VERSION@;$${CC_COMPILER_VERSION};" \
     -e "s;@CMAKE_CXX_FLAGS@;$(CC_FLAGS);" \
-    -e "s;\\$${CMAKE_CXX_FLAGS_.*};$(COMPILATION_MODE);" \
+    -e "s;\\$${CMAKE_CXX_FLAGS_.*};-c $(COMPILATION_MODE);" \
     -e "s;@GOOGLE_CLOUD_CPP_SPANNER_IS_RELEASE@;%s;" \
-    -e "s;@GOOGLE_CLOUD_CPP_GIT_HEAD@;$${V};" < $< > $@
+    -e "s;@GOOGLE_CLOUD_CPP_SPANNER_BUILD_METADATA@;$${V};" < $< > $@
   """ % (GOOGLE_CLOUD_CPP_SPANNER_IS_RELEASE),
     toolchains = [
         "@bazel_tools//tools/cpp:current_cc_toolchain",
diff --git a/google/cloud/spanner/CMakeLists.txt b/google/cloud/spanner/CMakeLists.txt
index 59b1a31f..7d8e360a 100644
--- a/google/cloud/spanner/CMakeLists.txt
+++ b/google/cloud/spanner/CMakeLists.txt
@@ -28,11 +28,10 @@ include(EnableDoxygen)
 # Define a function to fetch the current git revision. Using a function creates
 # a new scope, so the CMake variables do not leak to the global namespace.
 function (google_cloud_cpp_spanner_initialize_git_head var)
-    set(result "")
+    set(result "unknown")
     # If we cannot find a `.git` directory do not even try to guess the git
     # revision.
     if (IS_DIRECTORY ${PROJECT_SOURCE_DIR}/.git)
-        set(result "unknown-commit")
         # We need `git` to find the revision.
         find_program(GOOGLE_CLOUD_CPP_SPANNER_GIT_PROGRAM NAMES git)
         mark_as_advanced(GOOGLE_CLOUD_CPP_SPANNER_GIT_PROGRAM)
diff --git a/google/cloud/spanner/internal/build_info.cc.in b/google/cloud/spanner/internal/build_info.cc.in
index ff3b267d..b606b1ca 100644
--- a/google/cloud/spanner/internal/build_info.cc.in
+++ b/google/cloud/spanner/internal/build_info.cc.in
@@ -24,12 +24,37 @@ namespace spanner {
 inline namespace SPANNER_CLIENT_NS {
 namespace internal {
 
+std::string CompilerName() {
+  static auto const* const kName = [] {
+    auto* s = new std::string(R"""(@CMAKE_CXX_COMPILER@)""");
+    auto pos = s->rfind('/');
+    if (pos != std::string::npos) s->erase(0, pos + 1);
+    for (char& c : *s) {
+      if (c == '+') c = 'x';
+    }
+    return s;
+  }();
+  return *kName;
+}
+
 std::string CompilerVersion() {
-  return R"""(@CMAKE_CXX_COMPILER_ID@ @CMAKE_CXX_COMPILER_VERSION@)""";
+  static auto const* const kVersion = [] {
+    auto* s = new std::string(R"""(@CMAKE_CXX_COMPILER_VERSION@)""");
+    auto illegal_punct = [](unsigned char c) -> bool {
+      if (c == '.' || c == '-') return false;  // allowed
+      return std::ispunct(c) != 0;
+    };
+    s->erase(std::remove_if(s->begin(), s->end(), illegal_punct), s->end());
+    for (char& c : *s) {
+      if (std::isspace(static_cast<unsigned char>(c)) != 0) c = '-';
+    }
+    return s;
+  }();
+  return *kVersion;
 }
 
 std::string CompilerFlags() {
-  static std::string const* const kFlags = [] {
+  static auto const* const kFlags = [] {
     auto* flags = new std::string(R"""(@CMAKE_CXX_FLAGS@)""");
     if (!flags->empty()) *flags += ' ';
     *flags +=
@@ -40,33 +65,30 @@ std::string CompilerFlags() {
 }
 
 std::string LanguageVersion() {
-  static std::string const* const kLanguageVersion = [] {
-    auto* v = new auto(CompilerVersion());
-    for (char& c : *v) {
-      if (std::isspace(static_cast<unsigned char>(c)) != 0) c = '-';
-    }
-#if GOOGLE_CLOUD_CPP_HAVE_EXCEPTIONS
-    *v += "-ex";
-#else
-    *v += "-noex";
-#endif  // GOOGLE_CLOUD_CPP_HAVE_EXCEPTIONS
+  static auto const* const kLanguageVersion = [] {
+    auto* s = new std::string;
     switch (__cplusplus) {
       case 199711L:
-        *v += "-98";
+        *s += "98";
         break;
       case 201103L:
-        *v += "-2011";
+        *s += "2011";
         break;
       case 201402L:
-        *v += "-2014";
+        *s += "2014";
         break;
       case 201703L:
-        *v += "-2017";
+        *s += "2017";
         break;
       default:
-        *v += "-unknown";
+        *s += "unknown";
     }
-    return v;
+#if GOOGLE_CLOUD_CPP_HAVE_EXCEPTIONS
+    *s += "-ex";
+#else
+    *s += "-noex";
+#endif  // GOOGLE_CLOUD_CPP_HAVE_EXCEPTIONS
+    return s;
   }();
   return *kLanguageVersion;
 }
@@ -80,12 +102,11 @@ bool IsRelease() {
     }
     return value == "yes" || value == "1" || value == "true";
   }();
-
   return kIsRelease;
 }
 
 std::string BuildMetadata() {
-  return R"""(@GOOGLE_CLOUD_CPP_SPANNER_BUILD_METADATA@)""";
+  return R"""(sha.@GOOGLE_CLOUD_CPP_SPANNER_BUILD_METADATA@)""";
 }
 
 }  // namespace internal
diff --git a/google/cloud/spanner/internal/build_info.h b/google/cloud/spanner/internal/build_info.h
index 457efa84..0026431d 100644
--- a/google/cloud/spanner/internal/build_info.h
+++ b/google/cloud/spanner/internal/build_info.h
@@ -23,19 +23,54 @@ namespace spanner {
 inline namespace SPANNER_CLIENT_NS {
 namespace internal {
 
-/// The compiler version.
+/**
+ * Returns the compiler.
+ *
+ * This is usually the basename of the compile command that was used. For
+ * example, "clang" or "gcc". In the case of "g++" or "clang++", they will be
+ * rewritten to "gxx" and "clangxx" since '+' is an illegal character for the
+ * server-side fields that look at these values.
+ */
+std::string CompilerName();
+
+/**
+ * Returns the compiler version.
+ *
+ * This string may be something simple like "9.1.1" or it may be something more
+ * verbose like "clang-version-8.0.0-Fedora-8.0.0-1.fc30".
+ */
 std::string CompilerVersion();
 
-/// The compiler flags.
+/**
+ * Returns the compiler flags.
+ *
+ * Examples include "-c fastbuild" or "-O2 -DNDEBUG".
+ */
 std::string CompilerFlags();
 
-/// The language version for user-agent header.
+/**
+ * Returns the 4-digit year of the C++ language standard along with an
+ * exception indicator.
+ *
+ * The returned string is suffixed with "-ex" or "-noex" to indicate whether or
+ * not the code was compiled with exceptions enabled.
+ *
+ * Example return values: "2011-ex", "2017-noex" "unknown-ex"
+ */
 std::string LanguageVersion();
 
-/// True if this is a release, false for the development branches.
+/**
+ * Returns true if this is a release branch.
+ */
 bool IsRelease();
 
-/// Build metadata injected by the build system.
+/**
+ * Returns the metadata injected by the build system.
+ *
+ * The returned info is the string "sha." followed by a short commit hash. See
+ * https://semver.org/#spec-item-10 for more details about the use and format
+ * of build metadata.
+ */
 std::string BuildMetadata();
 
 }  // namespace internal
diff --git a/google/cloud/spanner/internal/build_info_test.cc b/google/cloud/spanner/internal/build_info_test.cc
index 2b4ee2a9..5ec12e7e 100644
--- a/google/cloud/spanner/internal/build_info_test.cc
+++ b/google/cloud/spanner/internal/build_info_test.cc
@@ -22,37 +22,49 @@ inline namespace SPANNER_CLIENT_NS {
 namespace internal {
 namespace {
 
-using ::testing::HasSubstr;
-using ::testing::MatchesRegex;
+TEST(BuildInfo, CompilerName) {
+  auto cn = CompilerName();
+  EXPECT_FALSE(cn.empty());
+  EXPECT_THAT(cn, ::testing::Not(::testing::HasSubstr("@")));
+}
 
 TEST(BuildInfo, CompilerVersion) {
   auto cv = CompilerVersion();
   EXPECT_FALSE(cv.empty());
+  EXPECT_THAT(cv, ::testing::Not(::testing::HasSubstr("@")));
+#ifndef _WIN32  // gMock's regex brackets don't work on Windows.
+  // Look for something that looks vaguely like an X.Y version number.
+  EXPECT_THAT(cv, ::testing::ContainsRegex(R"([0-9].[0-9])"));
+#endif
 }
 
 TEST(BuildInfo, CompilerFlags) {
   auto cf = CompilerFlags();
   EXPECT_FALSE(cf.empty());
+  EXPECT_THAT(cf, ::testing::Not(::testing::HasSubstr("@")));
 }
 
 TEST(BuildInfo, LanguageVersion) {
+  using ::testing::HasSubstr;
   auto lv = LanguageVersion();
-  EXPECT_THAT(lv, ::testing::AnyOf(HasSubstr("-noex-"), HasSubstr("-ex-")));
+  EXPECT_THAT(lv, ::testing::AnyOf(HasSubstr("-noex"), HasSubstr("-ex")));
   EXPECT_THAT(lv, Not(HasSubstr(" ")));
-#ifndef _WIN32
-  // Brackets don't work with MatchesRegex() on Windows.
-  EXPECT_THAT(lv, MatchesRegex(R"([0-9A-Za-z/()_.-]+)"));
+  EXPECT_THAT(lv, ::testing::Not(::testing::HasSubstr("@")));
+#ifndef _WIN32  // gMock's regex brackets don't work on Windows.
+  EXPECT_THAT(lv, ::testing::MatchesRegex(R"([0-9A-Za-z/()_.-]+)"));
 #endif
 }
 
 TEST(BuildInfo, IsRelease) {
   bool const b = IsRelease();
+  // We want to test this, but either value is fine.
   EXPECT_TRUE(b || !b);
 }
 
 TEST(BuildInfo, BuildMetadata) {
   auto const md = BuildMetadata();
-  EXPECT_FALSE(md.empty());
+  EXPECT_THAT(md, ::testing::MatchesRegex(R"(sha\..+)"));
+  EXPECT_THAT(md, ::testing::Not(::testing::HasSubstr("@")));
 }
 
 }  // namespace

From 2ed2a450c28ccda18ef5e62ed630d8c4d1dc611d Mon Sep 17 00:00:00 2001
From: Greg Miller <9447643+devjgm@users.noreply.github.com>
Date: Thu, 1 Aug 2019 08:59:07 -0400
Subject: [PATCH 06/19] reverted regex changes

---
 google/cloud/spanner/internal/build_info_test.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/google/cloud/spanner/internal/build_info_test.cc b/google/cloud/spanner/internal/build_info_test.cc
index 5ec12e7e..afed5e37 100644
--- a/google/cloud/spanner/internal/build_info_test.cc
+++ b/google/cloud/spanner/internal/build_info_test.cc
@@ -51,7 +51,7 @@ TEST(BuildInfo, LanguageVersion) {
   EXPECT_THAT(lv, Not(HasSubstr(" ")));
   EXPECT_THAT(lv, ::testing::Not(::testing::HasSubstr("@")));
 #ifndef _WIN32  // gMock's regex brackets don't work on Windows.
-  EXPECT_THAT(lv, ::testing::MatchesRegex(R"([0-9A-Za-z/()_.-]+)"));
+  EXPECT_THAT(lv, ::testing::MatchesRegex(R"([0-9A-Za-z_.-]+)"));
 #endif
 }
 

From efb2886e433635f635fcfc62e92947302480638d Mon Sep 17 00:00:00 2001
From: Greg Miller <9447643+devjgm@users.noreply.github.com>
Date: Thu, 1 Aug 2019 09:46:10 -0400
Subject: [PATCH 07/19] better deduping of punct

---
 google/cloud/spanner/internal/build_info.cc.in | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/google/cloud/spanner/internal/build_info.cc.in b/google/cloud/spanner/internal/build_info.cc.in
index b606b1ca..caaf5d6b 100644
--- a/google/cloud/spanner/internal/build_info.cc.in
+++ b/google/cloud/spanner/internal/build_info.cc.in
@@ -40,14 +40,15 @@ std::string CompilerName() {
 std::string CompilerVersion() {
   static auto const* const kVersion = [] {
     auto* s = new std::string(R"""(@CMAKE_CXX_COMPILER_VERSION@)""");
-    auto illegal_punct = [](unsigned char c) -> bool {
-      if (c == '.' || c == '-') return false;  // allowed
-      return std::ispunct(c) != 0;
-    };
-    s->erase(std::remove_if(s->begin(), s->end(), illegal_punct), s->end());
+    if (s->empty()) *s = "unknown";  // should never be empty.
     for (char& c : *s) {
-      if (std::isspace(static_cast<unsigned char>(c)) != 0) c = '-';
+      if (c != '.' && c != '-' && !std::isalnum(static_cast<unsigned char>(c)))
+        c = '-';
     }
+    std::unique(s->begin(), s->end(), [](char a, char b) -> bool {
+      return std::ispunct(a) && std::ispunct(b);
+    });
+    if (s->back() == '-') s->pop_back();
     return s;
   }();
   return *kVersion;

From 364db20ade5888f9c6cb2537a5eeb113a364f1d1 Mon Sep 17 00:00:00 2001
From: Greg Miller <9447643+devjgm@users.noreply.github.com>
Date: Thu, 1 Aug 2019 11:12:13 -0400
Subject: [PATCH 08/19] added scripts to make bazel build look like cmake build

---
 bazel/BUILD                                   |  5 +++
 bazel/compiler_id.sh                          | 32 ++++++++++++++
 bazel/compiler_version.sh                     | 12 ++++++
 google/cloud/spanner/BUILD                    | 11 +++--
 .../cloud/spanner/internal/build_info.cc.in   | 43 +++++--------------
 google/cloud/spanner/internal/build_info.h    | 25 ++++++-----
 .../cloud/spanner/internal/build_info_test.cc | 29 ++++++++++++-
 7 files changed, 106 insertions(+), 51 deletions(-)
 create mode 100755 bazel/compiler_id.sh
 create mode 100755 bazel/compiler_version.sh

diff --git a/bazel/BUILD b/bazel/BUILD
index 9da2a22a..56e54ba6 100644
--- a/bazel/BUILD
+++ b/bazel/BUILD
@@ -15,3 +15,8 @@
 licenses(["notice"])  # Apache v2
 
 package(default_visibility = ["//:__subpackages__"])
+
+exports_files([
+    "compiler_id.sh",
+    "compiler_version.sh",
+])
diff --git a/bazel/compiler_id.sh b/bazel/compiler_id.sh
new file mode 100755
index 00000000..20c30255
--- /dev/null
+++ b/bazel/compiler_id.sh
@@ -0,0 +1,32 @@
+#!/bin/bash
+#
+# Given an argument that is the path to a compiler, tries to determine an
+# identification string for the compiler according to the CMake-defined IDs:
+# https://cmake.org/cmake/help/v3.5/variable/CMAKE_LANG_COMPILER_ID.html
+
+if [[ ! -e "${1}" ]]; then
+  echo "Usage: $0 <path-to-compiler>"
+  exit 1
+fi
+
+version="$(${1} --version 2> /dev/null \
+  | head -1 \
+  | tr '[:upper:]' '[:lower:]')"
+
+case "${version}" in
+  *gcc* | *g++*)
+    echo "GNU"
+    ;;
+
+  *clang*)
+    echo "Clang"
+    ;;
+
+  *msvc* | *microsoft*)
+    echo "Clang"
+    ;;
+
+  *)
+    echo "unknown"
+    ;;
+esac
diff --git a/bazel/compiler_version.sh b/bazel/compiler_version.sh
new file mode 100755
index 00000000..f0876000
--- /dev/null
+++ b/bazel/compiler_version.sh
@@ -0,0 +1,12 @@
+#!/bin/bash
+#
+# Given an argument that is the path to a compiler, tries to determine
+# the compiler's version by looking for the first string that looks like
+# X.Y with more optional numbers '.', '-', and '+'.
+
+if [[ ! -e "${1}" ]]; then
+  echo "Usage: $0 <path-to-compiler>"
+  exit 1
+fi
+
+${1} --version 2> /dev/null | grep -Eo "[0-9]+\.[0-9.+-]+" | head -1
diff --git a/google/cloud/spanner/BUILD b/google/cloud/spanner/BUILD
index 9f78fed7..9bb95c41 100644
--- a/google/cloud/spanner/BUILD
+++ b/google/cloud/spanner/BUILD
@@ -23,10 +23,11 @@ genrule(
     srcs = ["internal/build_info.cc.in"],
     outs = ["internal/build_info.cc"],
     cmd = """
-CC_COMPILER_VERSION=$$($(CC) --version | head -1);
 V=$$(git rev-parse --short HEAD 2>/dev/null || echo "unknown");
-sed -e "s;@CMAKE_CXX_COMPILER@;$$(basename $(CC));" \
-    -e "s;@CMAKE_CXX_COMPILER_VERSION@;$${CC_COMPILER_VERSION};" \
+CC_VERSION=$$(bazel/compiler_version.sh $(CC));
+CC_ID=$$(bazel/compiler_id.sh $(CC));
+sed -e "s;@CMAKE_CXX_COMPILER_ID@;$${CC_ID};" \
+    -e "s;@CMAKE_CXX_COMPILER_VERSION@;$${CC_VERSION};" \
     -e "s;@CMAKE_CXX_FLAGS@;$(CC_FLAGS);" \
     -e "s;\\$${CMAKE_CXX_FLAGS_.*};-c $(COMPILATION_MODE);" \
     -e "s;@GOOGLE_CLOUD_CPP_SPANNER_IS_RELEASE@;%s;" \
@@ -36,6 +37,10 @@ sed -e "s;@CMAKE_CXX_COMPILER@;$$(basename $(CC));" \
         "@bazel_tools//tools/cpp:current_cc_toolchain",
         "@bazel_tools//tools/cpp:cc_flags",
     ],
+    tools = [
+        "//bazel:compiler_id.sh",
+        "//bazel:compiler_version.sh",
+    ]
 )
 
 load(":spanner_client.bzl", "spanner_client_hdrs", "spanner_client_srcs")
diff --git a/google/cloud/spanner/internal/build_info.cc.in b/google/cloud/spanner/internal/build_info.cc.in
index caaf5d6b..90aa8bc8 100644
--- a/google/cloud/spanner/internal/build_info.cc.in
+++ b/google/cloud/spanner/internal/build_info.cc.in
@@ -24,35 +24,9 @@ namespace spanner {
 inline namespace SPANNER_CLIENT_NS {
 namespace internal {
 
-std::string CompilerName() {
-  static auto const* const kName = [] {
-    auto* s = new std::string(R"""(@CMAKE_CXX_COMPILER@)""");
-    auto pos = s->rfind('/');
-    if (pos != std::string::npos) s->erase(0, pos + 1);
-    for (char& c : *s) {
-      if (c == '+') c = 'x';
-    }
-    return s;
-  }();
-  return *kName;
-}
+std::string CompilerName() { return R"""(@CMAKE_CXX_COMPILER_ID@)"""; }
 
-std::string CompilerVersion() {
-  static auto const* const kVersion = [] {
-    auto* s = new std::string(R"""(@CMAKE_CXX_COMPILER_VERSION@)""");
-    if (s->empty()) *s = "unknown";  // should never be empty.
-    for (char& c : *s) {
-      if (c != '.' && c != '-' && !std::isalnum(static_cast<unsigned char>(c)))
-        c = '-';
-    }
-    std::unique(s->begin(), s->end(), [](char a, char b) -> bool {
-      return std::ispunct(a) && std::ispunct(b);
-    });
-    if (s->back() == '-') s->pop_back();
-    return s;
-  }();
-  return *kVersion;
-}
+std::string CompilerVersion() { return R"""(@CMAKE_CXX_COMPILER_VERSION@)"""; }
 
 std::string CompilerFlags() {
   static auto const* const kFlags = [] {
@@ -65,6 +39,14 @@ std::string CompilerFlags() {
   return *kFlags;
 }
 
+std::string CompilerFeatures() {
+#if GOOGLE_CLOUD_CPP_HAVE_EXCEPTIONS
+    return "ex";
+#else
+    return "noex";
+#endif  // GOOGLE_CLOUD_CPP_HAVE_EXCEPTIONS
+}
+
 std::string LanguageVersion() {
   static auto const* const kLanguageVersion = [] {
     auto* s = new std::string;
@@ -84,11 +66,6 @@ std::string LanguageVersion() {
       default:
         *s += "unknown";
     }
-#if GOOGLE_CLOUD_CPP_HAVE_EXCEPTIONS
-    *s += "-ex";
-#else
-    *s += "-noex";
-#endif  // GOOGLE_CLOUD_CPP_HAVE_EXCEPTIONS
     return s;
   }();
   return *kLanguageVersion;
diff --git a/google/cloud/spanner/internal/build_info.h b/google/cloud/spanner/internal/build_info.h
index 0026431d..a63f2e1f 100644
--- a/google/cloud/spanner/internal/build_info.h
+++ b/google/cloud/spanner/internal/build_info.h
@@ -24,20 +24,17 @@ inline namespace SPANNER_CLIENT_NS {
 namespace internal {
 
 /**
- * Returns the compiler.
+ * Returns the compiler ID.
  *
- * This is usually the basename of the compile command that was used. For
- * example, "clang" or "gcc". In the case of "g++" or "clang++", they will be
- * rewritten to "gxx" and "clangxx" since '+' is an illegal character for the
- * server-side fields that look at these values.
+ * The Compiler ID is a string like "GNU" or "Clang", as described by
+ * https://cmake.org/cmake/help/v3.5/variable/CMAKE_LANG_COMPILER_ID.html
  */
 std::string CompilerName();
 
 /**
  * Returns the compiler version.
  *
- * This string may be something simple like "9.1.1" or it may be something more
- * verbose like "clang-version-8.0.0-Fedora-8.0.0-1.fc30".
+ * This string will be something like "9.1.1".
  */
 std::string CompilerVersion();
 
@@ -49,13 +46,15 @@ std::string CompilerVersion();
 std::string CompilerFlags();
 
 /**
- * Returns the 4-digit year of the C++ language standard along with an
- * exception indicator.
+ * Returns certain interesting compiler features.
  *
- * The returned string is suffixed with "-ex" or "-noex" to indicate whether or
- * not the code was compiled with exceptions enabled.
- *
- * Example return values: "2011-ex", "2017-noex" "unknown-ex"
+ * Currently this returns one of "ex" or "noex" to indicate whether or not
+ * C++ exceptions are enabled.
+ */
+std::string CompilerFeatures();
+
+/**
+ * Returns the 4-digit year of the C++ language standard.
  */
 std::string LanguageVersion();
 
diff --git a/google/cloud/spanner/internal/build_info_test.cc b/google/cloud/spanner/internal/build_info_test.cc
index afed5e37..e5878568 100644
--- a/google/cloud/spanner/internal/build_info_test.cc
+++ b/google/cloud/spanner/internal/build_info_test.cc
@@ -44,11 +44,16 @@ TEST(BuildInfo, CompilerFlags) {
   EXPECT_THAT(cf, ::testing::Not(::testing::HasSubstr("@")));
 }
 
+TEST(BuildInfo, CompilerFeatures) {
+  using ::testing::Eq;
+  auto cf = CompilerFeatures();
+  EXPECT_THAT(cf, ::testing::AnyOf(Eq("noex"), Eq("ex")));
+}
+
 TEST(BuildInfo, LanguageVersion) {
   using ::testing::HasSubstr;
   auto lv = LanguageVersion();
-  EXPECT_THAT(lv, ::testing::AnyOf(HasSubstr("-noex"), HasSubstr("-ex")));
-  EXPECT_THAT(lv, Not(HasSubstr(" ")));
+  EXPECT_FALSE(lv.empty());
   EXPECT_THAT(lv, ::testing::Not(::testing::HasSubstr("@")));
 #ifndef _WIN32  // gMock's regex brackets don't work on Windows.
   EXPECT_THAT(lv, ::testing::MatchesRegex(R"([0-9A-Za-z_.-]+)"));
@@ -67,6 +72,26 @@ TEST(BuildInfo, BuildMetadata) {
   EXPECT_THAT(md, ::testing::Not(::testing::HasSubstr("@")));
 }
 
+TEST(BuildInfo, ApiClientHeader) {
+  // The build info is used to generate the "API Client Header", which is a
+  // gRPC metadata attribute with the name 'x-goog-api-client'. This test
+  // generates that whole string as a sanity check that it will contain the
+  // desired format.
+
+  std::string const api_client_header = "gl-cpp/" +                 //
+                                        CompilerName() + '-' +      //
+                                        CompilerVersion() + '-' +   //
+                                        CompilerFeatures() + '-' +  //
+                                        LanguageVersion();
+  EXPECT_THAT(api_client_header, ::testing::Not(::testing::HasSubstr("@")));
+
+#ifndef _WIN32  // gMock's regex brackets don't work on Windows.
+  EXPECT_THAT(api_client_header,
+              ::testing::MatchesRegex(
+                  R"(gl-cpp/(Clang|GNU)-[0-9.+-]+-(no)?ex-20[1-9][0-9])"));
+#endif
+}
+
 }  // namespace
 }  // namespace internal
 }  // namespace SPANNER_CLIENT_NS

From 8f298feac64066272c48be6f71dc6ec714844840 Mon Sep 17 00:00:00 2001
From: Greg Miller <9447643+devjgm@users.noreply.github.com>
Date: Thu, 1 Aug 2019 11:17:09 -0400
Subject: [PATCH 09/19] formatted

---
 google/cloud/spanner/BUILD | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/google/cloud/spanner/BUILD b/google/cloud/spanner/BUILD
index 9bb95c41..7e03d1b4 100644
--- a/google/cloud/spanner/BUILD
+++ b/google/cloud/spanner/BUILD
@@ -40,7 +40,7 @@ sed -e "s;@CMAKE_CXX_COMPILER_ID@;$${CC_ID};" \
     tools = [
         "//bazel:compiler_id.sh",
         "//bazel:compiler_version.sh",
-    ]
+    ],
 )
 
 load(":spanner_client.bzl", "spanner_client_hdrs", "spanner_client_srcs")

From b648b606e0feac085b33a0915b013bcab92a6019 Mon Sep 17 00:00:00 2001
From: Greg Miller <9447643+devjgm@users.noreply.github.com>
Date: Thu, 1 Aug 2019 13:16:11 -0400
Subject: [PATCH 10/19] wording

---
 bazel/compiler_id.sh                             | 2 +-
 bazel/compiler_version.sh                        | 4 ++--
 google/cloud/spanner/internal/build_info.cc.in   | 2 +-
 google/cloud/spanner/internal/build_info.h       | 2 +-
 google/cloud/spanner/internal/build_info_test.cc | 8 ++++----
 5 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/bazel/compiler_id.sh b/bazel/compiler_id.sh
index 20c30255..fa56a658 100755
--- a/bazel/compiler_id.sh
+++ b/bazel/compiler_id.sh
@@ -9,7 +9,7 @@ if [[ ! -e "${1}" ]]; then
   exit 1
 fi
 
-version="$(${1} --version 2> /dev/null \
+version="$("${1}" --version 2> /dev/null \
   | head -1 \
   | tr '[:upper:]' '[:lower:]')"
 
diff --git a/bazel/compiler_version.sh b/bazel/compiler_version.sh
index f0876000..686f7b4d 100755
--- a/bazel/compiler_version.sh
+++ b/bazel/compiler_version.sh
@@ -2,11 +2,11 @@
 #
 # Given an argument that is the path to a compiler, tries to determine
 # the compiler's version by looking for the first string that looks like
-# X.Y with more optional numbers '.', '-', and '+'.
+# X.Y with more optional numbers, '.', '-', and '+'.
 
 if [[ ! -e "${1}" ]]; then
   echo "Usage: $0 <path-to-compiler>"
   exit 1
 fi
 
-${1} --version 2> /dev/null | grep -Eo "[0-9]+\.[0-9.+-]+" | head -1
+"${1}" --version 2> /dev/null | grep -Eo "[0-9]+\.[0-9.+-]+" | head -1
diff --git a/google/cloud/spanner/internal/build_info.cc.in b/google/cloud/spanner/internal/build_info.cc.in
index 90aa8bc8..1780cf66 100644
--- a/google/cloud/spanner/internal/build_info.cc.in
+++ b/google/cloud/spanner/internal/build_info.cc.in
@@ -24,7 +24,7 @@ namespace spanner {
 inline namespace SPANNER_CLIENT_NS {
 namespace internal {
 
-std::string CompilerName() { return R"""(@CMAKE_CXX_COMPILER_ID@)"""; }
+std::string CompilerId() { return R"""(@CMAKE_CXX_COMPILER_ID@)"""; }
 
 std::string CompilerVersion() { return R"""(@CMAKE_CXX_COMPILER_VERSION@)"""; }
 
diff --git a/google/cloud/spanner/internal/build_info.h b/google/cloud/spanner/internal/build_info.h
index a63f2e1f..6c0ec1a8 100644
--- a/google/cloud/spanner/internal/build_info.h
+++ b/google/cloud/spanner/internal/build_info.h
@@ -29,7 +29,7 @@ namespace internal {
  * The Compiler ID is a string like "GNU" or "Clang", as described by
  * https://cmake.org/cmake/help/v3.5/variable/CMAKE_LANG_COMPILER_ID.html
  */
-std::string CompilerName();
+std::string CompilerId();
 
 /**
  * Returns the compiler version.
diff --git a/google/cloud/spanner/internal/build_info_test.cc b/google/cloud/spanner/internal/build_info_test.cc
index e5878568..f5294550 100644
--- a/google/cloud/spanner/internal/build_info_test.cc
+++ b/google/cloud/spanner/internal/build_info_test.cc
@@ -22,8 +22,8 @@ inline namespace SPANNER_CLIENT_NS {
 namespace internal {
 namespace {
 
-TEST(BuildInfo, CompilerName) {
-  auto cn = CompilerName();
+TEST(BuildInfo, CompilerId) {
+  auto cn = CompilerId();
   EXPECT_FALSE(cn.empty());
   EXPECT_THAT(cn, ::testing::Not(::testing::HasSubstr("@")));
 }
@@ -40,13 +40,13 @@ TEST(BuildInfo, CompilerVersion) {
 
 TEST(BuildInfo, CompilerFlags) {
   auto cf = CompilerFlags();
-  EXPECT_FALSE(cf.empty());
   EXPECT_THAT(cf, ::testing::Not(::testing::HasSubstr("@")));
 }
 
 TEST(BuildInfo, CompilerFeatures) {
   using ::testing::Eq;
   auto cf = CompilerFeatures();
+  EXPECT_FALSE(cf.empty());
   EXPECT_THAT(cf, ::testing::AnyOf(Eq("noex"), Eq("ex")));
 }
 
@@ -79,7 +79,7 @@ TEST(BuildInfo, ApiClientHeader) {
   // desired format.
 
   std::string const api_client_header = "gl-cpp/" +                 //
-                                        CompilerName() + '-' +      //
+                                        CompilerId() + '-' +        //
                                         CompilerVersion() + '-' +   //
                                         CompilerFeatures() + '-' +  //
                                         LanguageVersion();

From 10260e56871f50da51b15d08db0b3c8a1278d8de Mon Sep 17 00:00:00 2001
From: Greg Miller <9447643+devjgm@users.noreply.github.com>
Date: Thu, 1 Aug 2019 13:46:13 -0400
Subject: [PATCH 11/19] use bazel's location function to find scripts

---
 google/cloud/spanner/BUILD | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/google/cloud/spanner/BUILD b/google/cloud/spanner/BUILD
index 7e03d1b4..fc7e1d89 100644
--- a/google/cloud/spanner/BUILD
+++ b/google/cloud/spanner/BUILD
@@ -24,8 +24,8 @@ genrule(
     outs = ["internal/build_info.cc"],
     cmd = """
 V=$$(git rev-parse --short HEAD 2>/dev/null || echo "unknown");
-CC_VERSION=$$(bazel/compiler_version.sh $(CC));
-CC_ID=$$(bazel/compiler_id.sh $(CC));
+CC_VERSION=$$($(location //bazel:compiler_version.sh) $(CC));
+CC_ID=$$($(location //bazel:compiler_id.sh) $(CC));
 sed -e "s;@CMAKE_CXX_COMPILER_ID@;$${CC_ID};" \
     -e "s;@CMAKE_CXX_COMPILER_VERSION@;$${CC_VERSION};" \
     -e "s;@CMAKE_CXX_FLAGS@;$(CC_FLAGS);" \

From 1fbc12a095e543bc06faf5a7701fbfb8e275bb1f Mon Sep 17 00:00:00 2001
From: Greg Miller <9447643+devjgm@users.noreply.github.com>
Date: Thu, 1 Aug 2019 21:48:13 -0400
Subject: [PATCH 12/19] PR comments: fixed some //build and //ci scripts

---
 bazel/compiler_id.sh                | 18 +++++++++++++++++-
 bazel/compiler_version.sh           | 14 ++++++++++++++
 ci/kokoro/docker/build.sh           |  5 -----
 ci/kokoro/docker/upload-coverage.sh |  2 +-
 4 files changed, 32 insertions(+), 7 deletions(-)

diff --git a/bazel/compiler_id.sh b/bazel/compiler_id.sh
index fa56a658..a41d073a 100755
--- a/bazel/compiler_id.sh
+++ b/bazel/compiler_id.sh
@@ -1,5 +1,19 @@
 #!/bin/bash
 #
+# Copyright 2019 Google LLC
+#
+# 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.
+#
 # Given an argument that is the path to a compiler, tries to determine an
 # identification string for the compiler according to the CMake-defined IDs:
 # https://cmake.org/cmake/help/v3.5/variable/CMAKE_LANG_COMPILER_ID.html
@@ -23,7 +37,9 @@ case "${version}" in
     ;;
 
   *msvc* | *microsoft*)
-    echo "Clang"
+    # I don't think "--version" above will actually work on Windows, so we
+    # should figure out how to do that correctly. See #281.
+    echo "MSVC"
     ;;
 
   *)
diff --git a/bazel/compiler_version.sh b/bazel/compiler_version.sh
index 686f7b4d..20b13484 100755
--- a/bazel/compiler_version.sh
+++ b/bazel/compiler_version.sh
@@ -1,5 +1,19 @@
 #!/bin/bash
 #
+# Copyright 2019 Google LLC
+#
+# 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.
+#
 # Given an argument that is the path to a compiler, tries to determine
 # the compiler's version by looking for the first string that looks like
 # X.Y with more optional numbers, '.', '-', and '+'.
diff --git a/ci/kokoro/docker/build.sh b/ci/kokoro/docker/build.sh
index 39a091c6..71be69a6 100755
--- a/ci/kokoro/docker/build.sh
+++ b/ci/kokoro/docker/build.sh
@@ -120,7 +120,6 @@ elif [[ "${BUILD_NAME}" = "cxx17" ]]; then
   in_docker_script="ci/kokoro/docker/build-in-docker-cmake.sh"
 elif [[ "${BUILD_NAME}" = "coverage" ]]; then
   export BUILD_TYPE=Coverage
-  export CODE_COVERAGE=yes
   export RUN_INTEGRATION_TESTS=yes
   export DISTRO=fedora-install
   export DISTRO_VERSION=30
@@ -229,10 +228,6 @@ docker_flags=(
     # installations.
     "--env" "TEST_INSTALL=${TEST_INSTALL:-}"
 
-    # If set to 'yes', run compile with code coverage flags. Currently only the
-    # CMake builds use this flag.
-    "--env" "CODE_COVERAGE=${CODE_COVERAGE:-}"
-
     # If set, pass -DGOOGLE_CLOUD_CPP_CXX_STANDARD=<value> to CMake.
     "--env" "GOOGLE_CLOUD_CPP_CXX_STANDARD=${GOOGLE_CLOUD_CPP_CXX_STANDARD:-}"
 
diff --git a/ci/kokoro/docker/upload-coverage.sh b/ci/kokoro/docker/upload-coverage.sh
index 82d05af1..542a28bf 100755
--- a/ci/kokoro/docker/upload-coverage.sh
+++ b/ci/kokoro/docker/upload-coverage.sh
@@ -21,7 +21,7 @@ fi
 source "${PROJECT_ROOT}/ci/kokoro/define-docker-variables.sh"
 source "${PROJECT_ROOT}/ci/define-dump-log.sh"
 
-if [[ "${CODE_COVERAGE:-}" != "yes" ]]; then
+if [[ "${BUILD_NAME:-}" != "coverage" ]]; then
   # Not a code coverage build, exit silently.
   exit 0
 fi

From 2bf41cb88114d046dbb60a115496780e40f5810b Mon Sep 17 00:00:00 2001
From: Greg Miller <9447643+devjgm@users.noreply.github.com>
Date: Fri, 2 Aug 2019 07:58:19 -0400
Subject: [PATCH 13/19] changed usage-check in scripts

---
 bazel/compiler_id.sh      |  2 +-
 bazel/compiler_version.sh | 12 ++++++++++--
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/bazel/compiler_id.sh b/bazel/compiler_id.sh
index a41d073a..5e6b8f0e 100755
--- a/bazel/compiler_id.sh
+++ b/bazel/compiler_id.sh
@@ -18,7 +18,7 @@
 # identification string for the compiler according to the CMake-defined IDs:
 # https://cmake.org/cmake/help/v3.5/variable/CMAKE_LANG_COMPILER_ID.html
 
-if [[ ! -e "${1}" ]]; then
+if [[ $# -ne 1 ]]; then
   echo "Usage: $0 <path-to-compiler>"
   exit 1
 fi
diff --git a/bazel/compiler_version.sh b/bazel/compiler_version.sh
index 20b13484..846ea05b 100755
--- a/bazel/compiler_version.sh
+++ b/bazel/compiler_version.sh
@@ -18,9 +18,17 @@
 # the compiler's version by looking for the first string that looks like
 # X.Y with more optional numbers, '.', '-', and '+'.
 
-if [[ ! -e "${1}" ]]; then
+if [[ $# -ne 1 ]]; then
   echo "Usage: $0 <path-to-compiler>"
   exit 1
 fi
 
-"${1}" --version 2> /dev/null | grep -Eo "[0-9]+\.[0-9.+-]+" | head -1
+version="$("${1}" --version 2> /dev/null \
+  | grep -Eo "[0-9]+\.[0-9.+-]+" \
+  | head -1)"
+
+if [[ -n "${version}" ]]; then
+  echo "${version}"
+else
+  echo unknown
+fi

From b98657794c6f679dd214b3edccdb07ffc48d0175 Mon Sep 17 00:00:00 2001
From: Greg Miller <9447643+devjgm@users.noreply.github.com>
Date: Fri, 2 Aug 2019 09:20:45 -0400
Subject: [PATCH 14/19] fixed bazel's git commit stamping

---
 .bazelrc                   |  2 ++
 bazel/workspace_status.sh  | 24 ++++++++++++++++++++++++
 google/cloud/spanner/BUILD |  6 +++++-
 3 files changed, 31 insertions(+), 1 deletion(-)
 create mode 100755 bazel/workspace_status.sh

diff --git a/.bazelrc b/.bazelrc
index 8a1133e9..faab31ef 100644
--- a/.bazelrc
+++ b/.bazelrc
@@ -12,6 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+build --workspace_status_command=bazel/workspace_status.sh
+
 # Clang Sanitizers, use with (for example):
 #
 # --client_env=CXX=clang++ --client_env=CC=clang --config asan
diff --git a/bazel/workspace_status.sh b/bazel/workspace_status.sh
new file mode 100755
index 00000000..a1c029f2
--- /dev/null
+++ b/bazel/workspace_status.sh
@@ -0,0 +1,24 @@
+#!/bin/bash
+#
+# Copyright 2019 Google LLC
+#
+# 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.
+#
+# This script is meant to be run as bazel's `--workspace_status_command=<cmd>`
+# command. It should output space-separated "KEY value" pairs that bazel will
+# store in the file bazel-out/stable-status.txt, which can be accessed from
+# genrules(). For more info, see:
+# https://docs.bazel.build/versions/master/user-manual.html#flag--workspace_status_command
+
+readonly commit="$(git rev-parse --short HEAD 2> /dev/null || echo unknown)"
+echo "STABLE_GIT_COMMIT ${commit}"
diff --git a/google/cloud/spanner/BUILD b/google/cloud/spanner/BUILD
index fc7e1d89..f4fa2b61 100644
--- a/google/cloud/spanner/BUILD
+++ b/google/cloud/spanner/BUILD
@@ -22,8 +22,9 @@ genrule(
     name = "generate_build_info",
     srcs = ["internal/build_info.cc.in"],
     outs = ["internal/build_info.cc"],
+    stamp = 1,
     cmd = """
-V=$$(git rev-parse --short HEAD 2>/dev/null || echo "unknown");
+V=$$(grep STABLE_GIT_COMMIT bazel-out/stable-status.txt | cut -f2 -d' ');
 CC_VERSION=$$($(location //bazel:compiler_version.sh) $(CC));
 CC_ID=$$($(location //bazel:compiler_id.sh) $(CC));
 sed -e "s;@CMAKE_CXX_COMPILER_ID@;$${CC_ID};" \
@@ -55,6 +56,9 @@ cc_library(
         "@com_google_googleapis//:bigtable_protos",
         "@com_google_googleapis//:spanner_protos",
     ],
+    data = [
+        ":generate_build_info",
+    ],
 )
 
 load(":spanner_client_testing.bzl", "spanner_client_testing_hdrs", "spanner_client_testing_srcs")

From b68b38bab2d90f9c01c60c404505f04c7d76f91b Mon Sep 17 00:00:00 2001
From: Greg Miller <9447643+devjgm@users.noreply.github.com>
Date: Fri, 2 Aug 2019 09:34:11 -0400
Subject: [PATCH 15/19] relax compiler ID regex to work with AppleClang and
 others

---
 google/cloud/spanner/internal/build_info_test.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/google/cloud/spanner/internal/build_info_test.cc b/google/cloud/spanner/internal/build_info_test.cc
index f5294550..9df6e293 100644
--- a/google/cloud/spanner/internal/build_info_test.cc
+++ b/google/cloud/spanner/internal/build_info_test.cc
@@ -88,7 +88,7 @@ TEST(BuildInfo, ApiClientHeader) {
 #ifndef _WIN32  // gMock's regex brackets don't work on Windows.
   EXPECT_THAT(api_client_header,
               ::testing::MatchesRegex(
-                  R"(gl-cpp/(Clang|GNU)-[0-9.+-]+-(no)?ex-20[1-9][0-9])"));
+                  R"(gl-cpp/[A-Za-z0-9]+-[0-9.+-]+-(no)?ex-20[1-9][0-9])"));
 #endif
 }
 

From a01f00e2e5a51674f83b9f0e890122ae5fffb96f Mon Sep 17 00:00:00 2001
From: Greg Miller <9447643+devjgm@users.noreply.github.com>
Date: Fri, 2 Aug 2019 09:41:58 -0400
Subject: [PATCH 16/19] formatted

---
 google/cloud/spanner/BUILD | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/google/cloud/spanner/BUILD b/google/cloud/spanner/BUILD
index f4fa2b61..33513131 100644
--- a/google/cloud/spanner/BUILD
+++ b/google/cloud/spanner/BUILD
@@ -22,7 +22,6 @@ genrule(
     name = "generate_build_info",
     srcs = ["internal/build_info.cc.in"],
     outs = ["internal/build_info.cc"],
-    stamp = 1,
     cmd = """
 V=$$(grep STABLE_GIT_COMMIT bazel-out/stable-status.txt | cut -f2 -d' ');
 CC_VERSION=$$($(location //bazel:compiler_version.sh) $(CC));
@@ -34,6 +33,7 @@ sed -e "s;@CMAKE_CXX_COMPILER_ID@;$${CC_ID};" \
     -e "s;@GOOGLE_CLOUD_CPP_SPANNER_IS_RELEASE@;%s;" \
     -e "s;@GOOGLE_CLOUD_CPP_SPANNER_BUILD_METADATA@;$${V};" < $< > $@
   """ % (GOOGLE_CLOUD_CPP_SPANNER_IS_RELEASE),
+    stamp = 1,
     toolchains = [
         "@bazel_tools//tools/cpp:current_cc_toolchain",
         "@bazel_tools//tools/cpp:cc_flags",
@@ -50,15 +50,15 @@ cc_library(
     name = "spanner_client",
     srcs = spanner_client_srcs + ["internal/build_info.cc"],
     hdrs = spanner_client_hdrs,
+    data = [
+        ":generate_build_info",
+    ],
     deps = [
         "@com_github_googleapis_google_cloud_cpp//google/cloud:google_cloud_cpp_common",
         "@com_github_googleapis_google_cloud_cpp//google/cloud/grpc_utils:google_cloud_cpp_grpc_utils",
         "@com_google_googleapis//:bigtable_protos",
         "@com_google_googleapis//:spanner_protos",
     ],
-    data = [
-        ":generate_build_info",
-    ],
 )
 
 load(":spanner_client_testing.bzl", "spanner_client_testing_hdrs", "spanner_client_testing_srcs")

From 8994355d546dc49bbd0ef9d01135a597ef9155bd Mon Sep 17 00:00:00 2001
From: Greg Miller <9447643+devjgm@users.noreply.github.com>
Date: Fri, 2 Aug 2019 12:15:24 -0400
Subject: [PATCH 17/19] renamed CompilerFlags -> BuildFlags

---
 google/cloud/spanner/internal/build_info.cc.in   | 2 +-
 google/cloud/spanner/internal/build_info.h       | 4 ++--
 google/cloud/spanner/internal/build_info_test.cc | 6 +++---
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/google/cloud/spanner/internal/build_info.cc.in b/google/cloud/spanner/internal/build_info.cc.in
index 1780cf66..90f5db1b 100644
--- a/google/cloud/spanner/internal/build_info.cc.in
+++ b/google/cloud/spanner/internal/build_info.cc.in
@@ -28,7 +28,7 @@ std::string CompilerId() { return R"""(@CMAKE_CXX_COMPILER_ID@)"""; }
 
 std::string CompilerVersion() { return R"""(@CMAKE_CXX_COMPILER_VERSION@)"""; }
 
-std::string CompilerFlags() {
+std::string BuildFlags() {
   static auto const* const kFlags = [] {
     auto* flags = new std::string(R"""(@CMAKE_CXX_FLAGS@)""");
     if (!flags->empty()) *flags += ' ';
diff --git a/google/cloud/spanner/internal/build_info.h b/google/cloud/spanner/internal/build_info.h
index 6c0ec1a8..750bb721 100644
--- a/google/cloud/spanner/internal/build_info.h
+++ b/google/cloud/spanner/internal/build_info.h
@@ -39,11 +39,11 @@ std::string CompilerId();
 std::string CompilerVersion();
 
 /**
- * Returns the compiler flags.
+ * Returns the build flags.
  *
  * Examples include "-c fastbuild" or "-O2 -DNDEBUG".
  */
-std::string CompilerFlags();
+std::string BuildFlags();
 
 /**
  * Returns certain interesting compiler features.
diff --git a/google/cloud/spanner/internal/build_info_test.cc b/google/cloud/spanner/internal/build_info_test.cc
index 9df6e293..84690b2a 100644
--- a/google/cloud/spanner/internal/build_info_test.cc
+++ b/google/cloud/spanner/internal/build_info_test.cc
@@ -38,9 +38,9 @@ TEST(BuildInfo, CompilerVersion) {
 #endif
 }
 
-TEST(BuildInfo, CompilerFlags) {
-  auto cf = CompilerFlags();
-  EXPECT_THAT(cf, ::testing::Not(::testing::HasSubstr("@")));
+TEST(BuildInfo, BuildFlags) {
+  auto bf = BuildFlags();
+  EXPECT_THAT(bf, ::testing::Not(::testing::HasSubstr("@")));
 }
 
 TEST(BuildInfo, CompilerFeatures) {

From 8ac854d8ed487b9c5ba0e9b998e4b6246944c19c Mon Sep 17 00:00:00 2001
From: Greg Miller <9447643+devjgm@users.noreply.github.com>
Date: Fri, 2 Aug 2019 12:17:32 -0400
Subject: [PATCH 18/19] removes 'sha.' prefix from build metadata

---
 google/cloud/spanner/internal/build_info.cc.in   | 2 +-
 google/cloud/spanner/internal/build_info.h       | 6 +++---
 google/cloud/spanner/internal/build_info_test.cc | 2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/google/cloud/spanner/internal/build_info.cc.in b/google/cloud/spanner/internal/build_info.cc.in
index 90f5db1b..f1b4a533 100644
--- a/google/cloud/spanner/internal/build_info.cc.in
+++ b/google/cloud/spanner/internal/build_info.cc.in
@@ -84,7 +84,7 @@ bool IsRelease() {
 }
 
 std::string BuildMetadata() {
-  return R"""(sha.@GOOGLE_CLOUD_CPP_SPANNER_BUILD_METADATA@)""";
+  return R"""(@GOOGLE_CLOUD_CPP_SPANNER_BUILD_METADATA@)""";
 }
 
 }  // namespace internal
diff --git a/google/cloud/spanner/internal/build_info.h b/google/cloud/spanner/internal/build_info.h
index 750bb721..c450bd63 100644
--- a/google/cloud/spanner/internal/build_info.h
+++ b/google/cloud/spanner/internal/build_info.h
@@ -66,9 +66,9 @@ bool IsRelease();
 /**
  * Returns the metadata injected by the build system.
  *
- * The returned info is the string "sha." followed by a short commit hash. See
- * https://semver.org/#spec-item-10 for more details about the use and format
- * of build metadata.
+ * See https://semver.org/#spec-item-10 for more details about the use and
+ * format of build metadata. Typically, the the value returned here is a hash
+ * indicating a git commit.
  */
 std::string BuildMetadata();
 
diff --git a/google/cloud/spanner/internal/build_info_test.cc b/google/cloud/spanner/internal/build_info_test.cc
index 84690b2a..bff0784d 100644
--- a/google/cloud/spanner/internal/build_info_test.cc
+++ b/google/cloud/spanner/internal/build_info_test.cc
@@ -68,7 +68,7 @@ TEST(BuildInfo, IsRelease) {
 
 TEST(BuildInfo, BuildMetadata) {
   auto const md = BuildMetadata();
-  EXPECT_THAT(md, ::testing::MatchesRegex(R"(sha\..+)"));
+  EXPECT_FALSE(md.empty());
   EXPECT_THAT(md, ::testing::Not(::testing::HasSubstr("@")));
 }
 

From 12b9a536f3c211d81dff43cdeea62fcc35277cdd Mon Sep 17 00:00:00 2001
From: Greg Miller <9447643+devjgm@users.noreply.github.com>
Date: Fri, 2 Aug 2019 12:21:07 -0400
Subject: [PATCH 19/19] removed workspace_status_command; bazel builds never
 know git commit

---
 .bazelrc                   |  2 --
 bazel/workspace_status.sh  | 24 ------------------------
 google/cloud/spanner/BUILD |  3 +--
 3 files changed, 1 insertion(+), 28 deletions(-)
 delete mode 100755 bazel/workspace_status.sh

diff --git a/.bazelrc b/.bazelrc
index faab31ef..8a1133e9 100644
--- a/.bazelrc
+++ b/.bazelrc
@@ -12,8 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-build --workspace_status_command=bazel/workspace_status.sh
-
 # Clang Sanitizers, use with (for example):
 #
 # --client_env=CXX=clang++ --client_env=CC=clang --config asan
diff --git a/bazel/workspace_status.sh b/bazel/workspace_status.sh
deleted file mode 100755
index a1c029f2..00000000
--- a/bazel/workspace_status.sh
+++ /dev/null
@@ -1,24 +0,0 @@
-#!/bin/bash
-#
-# Copyright 2019 Google LLC
-#
-# 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.
-#
-# This script is meant to be run as bazel's `--workspace_status_command=<cmd>`
-# command. It should output space-separated "KEY value" pairs that bazel will
-# store in the file bazel-out/stable-status.txt, which can be accessed from
-# genrules(). For more info, see:
-# https://docs.bazel.build/versions/master/user-manual.html#flag--workspace_status_command
-
-readonly commit="$(git rev-parse --short HEAD 2> /dev/null || echo unknown)"
-echo "STABLE_GIT_COMMIT ${commit}"
diff --git a/google/cloud/spanner/BUILD b/google/cloud/spanner/BUILD
index 33513131..71dbe1ca 100644
--- a/google/cloud/spanner/BUILD
+++ b/google/cloud/spanner/BUILD
@@ -23,7 +23,7 @@ genrule(
     srcs = ["internal/build_info.cc.in"],
     outs = ["internal/build_info.cc"],
     cmd = """
-V=$$(grep STABLE_GIT_COMMIT bazel-out/stable-status.txt | cut -f2 -d' ');
+V="unknown";
 CC_VERSION=$$($(location //bazel:compiler_version.sh) $(CC));
 CC_ID=$$($(location //bazel:compiler_id.sh) $(CC));
 sed -e "s;@CMAKE_CXX_COMPILER_ID@;$${CC_ID};" \
@@ -33,7 +33,6 @@ sed -e "s;@CMAKE_CXX_COMPILER_ID@;$${CC_ID};" \
     -e "s;@GOOGLE_CLOUD_CPP_SPANNER_IS_RELEASE@;%s;" \
     -e "s;@GOOGLE_CLOUD_CPP_SPANNER_BUILD_METADATA@;$${V};" < $< > $@
   """ % (GOOGLE_CLOUD_CPP_SPANNER_IS_RELEASE),
-    stamp = 1,
     toolchains = [
         "@bazel_tools//tools/cpp:current_cc_toolchain",
         "@bazel_tools//tools/cpp:cc_flags",