[llvm] r339802 - [Support] Add a basic C API for llvm::Error.
Lang Hames via llvm-commits
llvm-commits at lists.llvm.org
Wed Aug 15 11:42:12 PDT 2018
Author: lhames
Date: Wed Aug 15 11:42:11 2018
New Revision: 339802
URL: http://llvm.org/viewvc/llvm-project?rev=339802&view=rev
Log:
[Support] Add a basic C API for llvm::Error.
Summary:
The C-API supports consuming errors, converting an error to a string error
message, and querying an error's type. Other LLVM C APIs that wish to use
llvm::Error can supply error-type-id checkers and custom
error-to-structured-type converters for any custom errors they provide.
Reviewers: bogner, zturner, labath, dblaikie
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D50716
Added:
llvm/trunk/include/llvm-c/Error.h
Modified:
llvm/trunk/include/llvm/Support/Error.h
llvm/trunk/lib/Support/Error.cpp
llvm/trunk/unittests/Support/ErrorTest.cpp
Added: llvm/trunk/include/llvm-c/Error.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm-c/Error.h?rev=339802&view=auto
==============================================================================
--- llvm/trunk/include/llvm-c/Error.h (added)
+++ llvm/trunk/include/llvm-c/Error.h Wed Aug 15 11:42:11 2018
@@ -0,0 +1,65 @@
+/*===------- llvm-c/Error.h - llvm::Error class C Interface -------*- C -*-===*\
+|* *|
+|* The LLVM Compiler Infrastructure *|
+|* *|
+|* This file is distributed under the University of Illinois Open Source *|
+|* License. See LICENSE.TXT for details. *|
+|* *|
+|*===----------------------------------------------------------------------===*|
+|* *|
+|* This file defines the C interface to LLVM's Error class. *|
+|* *|
+\*===----------------------------------------------------------------------===*/
+
+#ifndef LLVM_C_ERROR_H
+#define LLVM_C_ERROR_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * Opaque reference to an error instance. Null serves as the 'success' value.
+ */
+typedef struct LLVMOpaqueError *LLVMErrorRef;
+
+/**
+ * Error type identifier.
+ */
+typedef const void *LLVMErrorTypeId;
+
+/**
+ * Returns the type id for the given error instance, which must be a failure
+ * value (i.e. non-null).
+ */
+LLVMErrorTypeId LLVMGetErrorTypeId(LLVMErrorRef Err);
+
+/**
+ * Dispose of the given error without handling it. This operation consumes the
+ * error, and the given LLVMErrorRef value is not usable once this call returns.
+ * Note: This method *only* needs to be called if the error is not being passed
+ * to some other consuming operation, e.g. LLVMGetErrorMessage.
+ */
+void LLVMConsumeError(LLVMErrorRef Err);
+
+/**
+ * Returns the given string's error message. This operation consumes the error,
+ * and the given LLVMErrorRef value is not usable once this call returns.
+ */
+char *LLVMGetErrorMessage(LLVMErrorRef Err);
+
+/**
+ * Dispose of the given error message.
+ */
+void LLVMDisposeErrorMessage(char *ErrMsg);
+
+/**
+ * Returns the type id for llvm StringError.
+ */
+LLVMErrorTypeId LLVMGetStringErrorTypeId();
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
Modified: llvm/trunk/include/llvm/Support/Error.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/Error.h?rev=339802&r1=339801&r2=339802&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Support/Error.h (original)
+++ llvm/trunk/include/llvm/Support/Error.h Wed Aug 15 11:42:11 2018
@@ -14,8 +14,9 @@
#ifndef LLVM_SUPPORT_ERROR_H
#define LLVM_SUPPORT_ERROR_H
-#include "llvm/ADT/SmallVector.h"
+#include "llvm-c/Error.h"
#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Config/abi-breaking.h"
@@ -167,6 +168,9 @@ class LLVM_NODISCARD Error {
// error.
template <typename T> friend class Expected;
+ // wrap needs to be able to steal the payload.
+ friend LLVMErrorRef wrap(Error);
+
protected:
/// Create a success value. Prefer using 'Error::success()' for readability
Error() {
@@ -1183,6 +1187,17 @@ private:
std::function<int(const Error &)> GetExitCode;
};
+/// Conversion from Error to LLVMErrorRef for C error bindings.
+inline LLVMErrorRef wrap(Error Err) {
+ return reinterpret_cast<LLVMErrorRef>(Err.takePayload().release());
+}
+
+/// Conversion from LLVMErrorRef to Error for C error bindings.
+inline Error unwrap(LLVMErrorRef ErrRef) {
+ return Error(std::unique_ptr<ErrorInfoBase>(
+ reinterpret_cast<ErrorInfoBase *>(ErrRef)));
+}
+
} // end namespace llvm
#endif // LLVM_SUPPORT_ERROR_H
Modified: llvm/trunk/lib/Support/Error.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/Error.cpp?rev=339802&r1=339801&r2=339802&view=diff
==============================================================================
--- llvm/trunk/lib/Support/Error.cpp (original)
+++ llvm/trunk/lib/Support/Error.cpp Wed Aug 15 11:42:11 2018
@@ -126,6 +126,26 @@ void report_fatal_error(Error Err, bool
report_fatal_error(ErrMsg);
}
+} // end namespace llvm
+
+LLVMErrorTypeId LLVMGetErrorTypeId(LLVMErrorRef Err) {
+ return reinterpret_cast<ErrorInfoBase *>(Err)->dynamicClassID();
+}
+
+void LLVMConsumeError(LLVMErrorRef Err) { consumeError(unwrap(Err)); }
+
+char *LLVMGetErrorMessage(LLVMErrorRef Err) {
+ std::string Tmp = toString(unwrap(Err));
+ char *ErrMsg = new char[Tmp.size() + 1];
+ memcpy(ErrMsg, Tmp.data(), Tmp.size());
+ ErrMsg[Tmp.size()] = '\0';
+ return ErrMsg;
+}
+
+void LLVMDisposeErrorMessage(char *ErrMsg) { delete[] ErrMsg; }
+
+LLVMErrorTypeId LLVMGetStringErrorTypeId() {
+ return reinterpret_cast<void *>(&StringError::ID);
}
#ifndef _MSC_VER
Modified: llvm/trunk/unittests/Support/ErrorTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/Support/ErrorTest.cpp?rev=339802&r1=339801&r2=339802&view=diff
==============================================================================
--- llvm/trunk/unittests/Support/ErrorTest.cpp (original)
+++ llvm/trunk/unittests/Support/ErrorTest.cpp Wed Aug 15 11:42:11 2018
@@ -8,6 +8,7 @@
//===----------------------------------------------------------------------===//
#include "llvm/Support/Error.h"
+#include "llvm-c/Error.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Support/Errc.h"
@@ -832,4 +833,35 @@ TEST(Error, ErrorMatchers) {
" Actual: failed (CustomError {0})");
}
+TEST(Error, C_API) {
+ EXPECT_THAT_ERROR(unwrap(wrap(Error::success())), Succeeded())
+ << "Failed to round-trip Error success value via C API";
+ EXPECT_THAT_ERROR(unwrap(wrap(make_error<CustomError>(0))),
+ Failed<CustomError>())
+ << "Failed to round-trip Error failure value via C API";
+
+ auto Err =
+ wrap(make_error<StringError>("test message", inconvertibleErrorCode()));
+ EXPECT_EQ(LLVMGetErrorTypeId(Err), LLVMGetStringErrorTypeId())
+ << "Failed to match error type ids via C API";
+ char *ErrMsg = LLVMGetErrorMessage(Err);
+ EXPECT_STREQ(ErrMsg, "test message")
+ << "Failed to roundtrip StringError error message via C API";
+ LLVMDisposeErrorMessage(ErrMsg);
+
+ bool GotCSE = false;
+ bool GotCE = false;
+ handleAllErrors(
+ unwrap(wrap(joinErrors(make_error<CustomSubError>(42, 7),
+ make_error<CustomError>(42)))),
+ [&](CustomSubError &CSE) {
+ GotCSE = true;
+ },
+ [&](CustomError &CE) {
+ GotCE = true;
+ });
+ EXPECT_TRUE(GotCSE) << "Failed to round-trip ErrorList via C API";
+ EXPECT_TRUE(GotCE) << "Failed to round-trip ErrorList via C API";
+}
+
} // end anon namespace
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