Bazel client, Windows: implement ReadFile

Implement blaze_util::ReadFile on top of the
::ReadFile Windows API function.

Also implement blaze_util::AsWindowsPath so we can
convert MSYS paths to Windows widechar paths.

Add tests.

See https://github.com/bazelbuild/bazel/issues/2107

--
PiperOrigin-RevId: 142659955
MOS_MIGRATED_REVID=142659955

1 files changed, 23 insertions, 1 deletions

diff --git a/src/test/cpp/util/file_test.cc b/src/test/cpp/util/file_test.cc
index f98ed9975a..7c15ceb816 100644
--- a/src/test/cpp/util/file_test.cc
+++ b/src/test/cpp/util/file_test.cc
@@ -11,10 +11,11 @@
 // 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 <stdio.h>
 #include <string.h>
 
 #include <memory>  // unique_ptr
-#include <thread>  // NOLINT (to slience Google-internal linter)
+#include <thread>  // NOLINT (to silence Google-internal linter)
 
 #include "src/main/cpp/util/file.h"
 #include "src/main/cpp/util/file_platform.h"
@@ -22,6 +23,8 @@
 
 namespace blaze_util {
 
+using std::string;
+
 TEST(FileTest, TestNormalizePath) {
   ASSERT_EQ(string(""), NormalizePath(""));
   ASSERT_EQ(string(""), NormalizePath("."));
@@ -66,4 +69,23 @@ TEST(FileTest, TestMultiThreadedPipe) {
   ASSERT_EQ(0, strncmp(buffer, "hello world", 11));
 }
 
+TEST(FileTest, TestReadFile) {
+  const char* tempdir = getenv("TEST_TMPDIR");
+  ASSERT_NE(nullptr, tempdir);
+  ASSERT_NE(0, tempdir[0]);
+
+  std::string filename(JoinPath(tempdir, "test.readfile"));
+  FILE* fh = fopen(filename.c_str(), "wt");
+  ASSERT_NE(nullptr, fh);
+  ASSERT_EQ(11, fwrite("hello world", 1, 11, fh));
+  fclose(fh);
+
+  std::string actual;
+  ASSERT_TRUE(ReadFile(filename, &actual));
+  ASSERT_EQ(std::string("hello world"), actual);
+
+  ASSERT_TRUE(ReadFile(filename, &actual, 5));
+  ASSERT_EQ(std::string("hello"), actual);
+}
+
 }  // namespace blaze_util