Add access to TEST_UNDECLARED_OUTPUTS_DIR which takes into account Bazel's use

of `/` as a path separator on Windows.

Note: This will have no impact until a later change to use `\` as path separator
is checked in.
PiperOrigin-RevId: 296005736
Change-Id: Id7ada3b06e38399fd17df76fb5c8d3b0ea70e0e2

tensorflow/core/platform/path.cc

@@ -40,6 +40,27 @@ namespace {
 
 const char kPathSep[] = "/";
 
+bool FixBazelEnvPath(const char* path, string* out) {
+  if (path == nullptr) return false;
+  if (out == nullptr) return true;
+
+  *out = path;
+
+#ifdef PLATFORM_WINDOWS
+  // On Windows, paths generated by Bazel are always use `/` as the path
+  // separator. This prevents normal path management. In the event there are no
+  // `\` in the path, we convert all `/` to `\`.
+  if (out->find('\\') != string::npos) return path;
+
+  for (size_t pos = out->find('/'); pos != string::npos;
+       pos = out->find('/', pos + 1)) {
+    (*out)[pos] = kPathSep[0];
+  }
+#endif
+
+  return true;
+}
+
 }  // namespace
 
 string JoinPathImpl(std::initializer_list<StringPiece> paths) {
@@ -308,5 +329,9 @@ string GetTempFilename(const string& extension) {
 #endif
 }
 
+bool GetTestUndeclaredOutputsDir(string* dir) {
+  return internal::FixBazelEnvPath(getenv("TEST_UNDECLARED_OUTPUTS_DIR"), dir);
+}
+
 }  // namespace io
 }  // namespace tensorflow

tensorflow/core/platform/path.h

@@ -92,6 +92,15 @@ string CreateURI(tensorflow::StringPiece scheme, tensorflow::StringPiece host,
 // Creates a temporary file name with an extension.
 string GetTempFilename(const string& extension);
 
+// Reads the TEST_UNDECLARED_OUTPUTS_DIR environment variable, and if set
+// assigns `dir` to the value. `dir` is not modified if the environment variable
+// is unset. Returns true if the environment variable is set, otherwise false.
+// Passing `dir` as nullptr, will just probe for the environment variable.
+//
+// Note: This function obviates the need to deal with Bazel's odd path decisions
+// on Windows, and should be preferred over a simple `getenv`.
+bool GetTestUndeclaredOutputsDir(string* dir);
+
 }  // namespace io
 }  // namespace tensorflow
 

tensorflow/core/util/dump_graph.cc

@@ -23,6 +23,7 @@ limitations under the License.
 #include "tensorflow/core/lib/strings/proto_serialization.h"
 #include "tensorflow/core/platform/env.h"
 #include "tensorflow/core/platform/mutex.h"
+#include "tensorflow/core/platform/path.h"
 
 namespace tensorflow {
 
@@ -78,13 +79,14 @@ template <class T>
 string WriteTextProtoToUniqueFile(Env* env, const string& name,
                                   const char* proto_type, T& proto,
                                   const string& dirname) {
-  const char* dir = nullptr;
+  string dir;
   if (!dirname.empty()) {
-    dir = dirname.c_str();
+    dir = dirname;
   } else {
-    dir = getenv("TF_DUMP_GRAPH_PREFIX");
+    const char* prefix = getenv("TF_DUMP_GRAPH_PREFIX");
+    if (prefix != nullptr) dir = prefix;
   }
-  if (!dir) {
+  if (dir.empty()) {
     LOG(WARNING)
         << "Failed to dump " << name << " because dump location is not "
         << " specified through either TF_DUMP_GRAPH_PREFIX environment "
@@ -94,18 +96,15 @@ string WriteTextProtoToUniqueFile(Env* env, const string& name,
 
   if (absl::EqualsIgnoreCase(dir, "sponge") ||
       absl::EqualsIgnoreCase(dir, "test_undeclared_outputs_dir")) {
-    const char* tmp_dir = getenv("TEST_UNDECLARED_OUTPUTS_DIR");
-    if (tmp_dir == nullptr) {
+    if (!io::GetTestUndeclaredOutputsDir(&dir)) {
       LOG(WARNING) << "TF_DUMP_GRAPH_PREFIX=sponge, but "
                       "TEST_UNDECLARED_OUTPUT_DIRS is not set, dumping to log";
       dir = "-";
-    } else {
-      dir = tmp_dir;
     }
   }
 
   string filepath = "NULL";
-  if (std::strncmp(dir, "-", 2) == 0) {
+  if (dir == "-") {
     LOG(INFO) << proto.DebugString();
     filepath = "LOG(INFO)";
   } else {