[StreamExecutor] getOrDie and dieIfError utils
Reviewers: jlebar
Subscribers: jprice, parallel_libs-commits
Differential Revision: https://reviews.llvm.org/D24107
llvm-svn: 280312
GitOrigin-RevId: c1e2b83d099112721b57fc8451c184401b93efaf
diff --git a/streamexecutor/examples/Example.cpp b/streamexecutor/examples/Example.cpp
index 5b0befc..af1994d 100644
--- a/streamexecutor/examples/Example.cpp
+++ b/streamexecutor/examples/Example.cpp
@@ -23,27 +23,6 @@
#include "streamexecutor/StreamExecutor.h"
-/// [Example saxpy host helper functions]
-// Example handler for streamexecutor::Expected return values.
-template <typename T> T getOrDie(streamexecutor::Expected<T> &&E) {
- if (!E) {
- std::fprintf(stderr, "Error extracting an expected value: %s.\n",
- streamexecutor::consumeAndGetMessage(E.takeError()).c_str());
- std::exit(EXIT_FAILURE);
- }
- return std::move(*E);
-}
-
-// Example handler for streamexecutor::Error return values.
-void check(streamexecutor::Error &&E) {
- if (E) {
- std::fprintf(stderr, "Error encountered: %s.\n",
- streamexecutor::consumeAndGetMessage(std::move(E)).c_str());
- std::exit(EXIT_FAILURE);
- }
-}
-/// [Example saxpy host helper functions]
-
/// [Example saxpy compiler-generated]
// Code in this namespace is generated by the compiler (e.g. clang).
//
@@ -148,7 +127,7 @@
.thenLaunch(ArraySize, 1, *Kernel, A, X, Y)
.thenCopyD2H<float>(X, HostX);
// Wait for the stream to complete.
- check(Stream->blockHostUntilDone());
+ se::dieIfError(Stream->blockHostUntilDone());
// Process output data in HostX.
std::vector<float> ExpectedX = {4, 47, 90, 133};
@@ -157,7 +136,7 @@
}
// Free device memory.
- check(Device->freeDeviceMemory(X));
- check(Device->freeDeviceMemory(Y));
+ se::dieIfError(Device->freeDeviceMemory(X));
+ se::dieIfError(Device->freeDeviceMemory(Y));
/// [Example saxpy host main]
}
diff --git a/streamexecutor/include/streamexecutor/StreamExecutor.h b/streamexecutor/include/streamexecutor/StreamExecutor.h
index 2d6a892..d25da01 100644
--- a/streamexecutor/include/streamexecutor/StreamExecutor.h
+++ b/streamexecutor/include/streamexecutor/StreamExecutor.h
@@ -23,15 +23,12 @@
///
/// \snippet examples/Example.cpp Example saxpy host main
///
-/// In the example, a couple of handler functions are used to handle error
-/// return values in the StreamExecutor API:
-///
-/// \snippet examples/Example.cpp Example saxpy host helper functions
-///
-/// These are just example handler functions. A real application will likely
-/// want to define similar handlers of its own that log errors in an
-/// application-specific way, convert errors to the application's own
-/// error-handling framework, or try to recover from errors as appropriate.
+/// In the example, a couple of handler functions, \c getOrDie and \c
+/// dieIfError, are used to handle error return values in the StreamExecutor
+/// API. These functions are provided by StreamExecutor for quick-and-dirty
+/// error handling, but real applications will likely want to define their own
+/// versions of these handlers so that errors are handled more gracefully than
+/// just exiting the program.
///
/// The example also references some symbols from a compiler-generated
/// namespace:
diff --git a/streamexecutor/include/streamexecutor/Utils/Error.h b/streamexecutor/include/streamexecutor/Utils/Error.h
index e7b313e..96eccfa 100644
--- a/streamexecutor/include/streamexecutor/Utils/Error.h
+++ b/streamexecutor/include/streamexecutor/Utils/Error.h
@@ -65,6 +65,8 @@
/// There is also a function consumeError that consumes an error value without
/// fetching the error message. This is useful when we want to ignore an error.
///
+/// The dieIfError function is also provided for quick-and-dirty error handling.
+///
///
/// \section expected The Expected Class
///
@@ -137,6 +139,8 @@
/// }
/// \endcode
///
+/// The getOrDie function is also available for quick-and-dirty error handling.
+///
///
/// \section llvm Relation to llvm::Error and llvm::Expected
///
@@ -159,6 +163,8 @@
#ifndef STREAMEXECUTOR_UTILS_ERROR_H
#define STREAMEXECUTOR_UTILS_ERROR_H
+#include <cstdio>
+#include <cstdlib>
#include <memory>
#include <string>
@@ -171,14 +177,39 @@
using llvm::Expected;
using llvm::Twine;
-// Makes an Error object from an error message.
+/// Makes an Error object from an error message.
Error make_error(Twine Message);
-// Consumes the input error and returns its error message.
-//
-// Assumes the input was created by the make_error function above.
+/// Consumes the input error and returns its error message.
+///
+/// Assumes the input was created by the make_error function above.
std::string consumeAndGetMessage(Error &&E);
+/// Extracts the T value from an Expected<T> or prints an error message to
+/// stderr and exits the program with code EXIT_FAILURE if the Expected<T> is an
+/// error.
+///
+/// This function and the dieIfError function are provided for applications that
+/// are OK with aborting the program if an error occurs, and which don't have
+/// any special error logging needs. Applications with different error handling
+/// needs will likely want to declare their own functions with similar
+/// signatures but which log error messages in a different way or attempt to
+/// recover from errors instead of aborting the program.
+template <typename T> T getOrDie(Expected<T> &&E) {
+ if (!E) {
+ std::fprintf(stderr, "Error extracting an expected value: %s.\n",
+ consumeAndGetMessage(E.takeError()).c_str());
+ std::exit(EXIT_FAILURE);
+ }
+ return std::move(*E);
+}
+
+/// Prints an error message to stderr and exits the program with code
+/// EXIT_FAILURE if the input is an error.
+///
+/// \sa getOrDie
+void dieIfError(Error &&E);
+
} // namespace streamexecutor
#endif // STREAMEXECUTOR_UTILS_ERROR_H
diff --git a/streamexecutor/lib/Utils/Error.cpp b/streamexecutor/lib/Utils/Error.cpp
index f3d0967..15a9ccb 100644
--- a/streamexecutor/lib/Utils/Error.cpp
+++ b/streamexecutor/lib/Utils/Error.cpp
@@ -60,4 +60,12 @@
return Message;
}
+void dieIfError(Error &&E) {
+ if (E) {
+ std::fprintf(stderr, "Error encountered: %s.\n",
+ streamexecutor::consumeAndGetMessage(std::move(E)).c_str());
+ std::exit(EXIT_FAILURE);
+ }
+}
+
} // namespace streamexecutor
