X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=folly%2FException.h;h=19d7509d15a64768c4d1da557d104f6f0ee93531;hb=HEAD;hp=5820f68b58dd23399c70aa2a815aac146de3d245;hpb=8f45b8d51e9fe5cab83d5e62aeae24aa19c3ae80;p=folly.git

diff --git a/folly/Exception.h b/folly/Exception.h
index 5820f68b..19d7509d 100644
--- a/folly/Exception.h
+++ b/folly/Exception.h
@@ -1,5 +1,5 @@
 /*
- * Copyright 2013 Facebook, Inc.
+ * Copyright 2013-present Facebook, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,60 +14,129 @@
  * limitations under the License.
  */
 
-#ifndef FOLLY_EXCEPTION_H_
-#define FOLLY_EXCEPTION_H_
+#pragma once
 
 #include <errno.h>
 
+#include <cstdio>
 #include <stdexcept>
 #include <system_error>
 
-#include "folly/Likely.h"
+#include <folly/Conv.h>
+#include <folly/FBString.h>
+#include <folly/Likely.h>
+#include <folly/Portability.h>
 
 namespace folly {
 
+// Various helpers to throw appropriate std::system_error exceptions from C
+// library errors (returned in errno, as positive return values (many POSIX
+// functions), or as negative return values (Linux syscalls))
+//
+// The *Explicit functions take an explicit value for errno.
+
+inline std::system_error makeSystemErrorExplicit(int err, const char* msg) {
+  // TODO: The C++ standard indicates that std::generic_category() should be
+  // used for POSIX errno codes.
+  //
+  // We should ideally change this to use std::generic_category() instead of
+  // std::system_category().  However, undertaking this change will require
+  // updating existing call sites that currently catch exceptions thrown by
+  // this code and currently expect std::system_category.
+  return std::system_error(err, std::system_category(), msg);
+}
+
+template <class... Args>
+std::system_error makeSystemErrorExplicit(int err, Args&&... args) {
+  return makeSystemErrorExplicit(
+      err, to<fbstring>(std::forward<Args>(args)...).c_str());
+}
+
+inline std::system_error makeSystemError(const char* msg) {
+  return makeSystemErrorExplicit(errno, msg);
+}
+
+template <class... Args>
+std::system_error makeSystemError(Args&&... args) {
+  return makeSystemErrorExplicit(errno, std::forward<Args>(args)...);
+}
+
 // Helper to throw std::system_error
-void throwSystemError(int err, const char* msg) __attribute__((noreturn));
-inline void throwSystemError(int err, const char* msg) {
-  throw std::system_error(err, std::system_category(), msg);
+[[noreturn]] inline void throwSystemErrorExplicit(int err, const char* msg) {
+  throw makeSystemErrorExplicit(err, msg);
 }
 
-// Helper to throw std::system_error from errno
-void throwSystemError(const char* msg) __attribute__((noreturn));
-inline void throwSystemError(const char* msg) {
-  throwSystemError(errno, msg);
+template <class... Args>
+[[noreturn]] void throwSystemErrorExplicit(int err, Args&&... args) {
+  throw makeSystemErrorExplicit(err, std::forward<Args>(args)...);
+}
+
+// Helper to throw std::system_error from errno and components of a string
+template <class... Args>
+[[noreturn]] void throwSystemError(Args&&... args) {
+  throwSystemErrorExplicit(errno, std::forward<Args>(args)...);
 }
 
 // Check a Posix return code (0 on success, error number on error), throw
 // on error.
-inline void checkPosixError(int err, const char* msg) {
+template <class... Args>
+void checkPosixError(int err, Args&&... args) {
   if (UNLIKELY(err != 0)) {
-    throwSystemError(err, msg);
+    throwSystemErrorExplicit(err, std::forward<Args>(args)...);
   }
 }
 
 // Check a Linux kernel-style return code (>= 0 on success, negative error
 // number on error), throw on error.
-inline void checkKernelError(ssize_t ret, const char* msg) {
+template <class... Args>
+void checkKernelError(ssize_t ret, Args&&... args) {
   if (UNLIKELY(ret < 0)) {
-    throwSystemError(-ret, msg);
+    throwSystemErrorExplicit(int(-ret), std::forward<Args>(args)...);
   }
 }
 
-// Check a traditional Uinx return code (-1 and sets errno on error), throw
+// Check a traditional Unix return code (-1 and sets errno on error), throw
 // on error.
-inline void checkUnixError(ssize_t ret, const char* msg) {
+template <class... Args>
+void checkUnixError(ssize_t ret, Args&&... args) {
   if (UNLIKELY(ret == -1)) {
-    throwSystemError(msg);
+    throwSystemError(std::forward<Args>(args)...);
   }
 }
-inline void checkUnixError(ssize_t ret, int savedErrno, const char* msg) {
+
+template <class... Args>
+void checkUnixErrorExplicit(ssize_t ret, int savedErrno, Args&&... args) {
   if (UNLIKELY(ret == -1)) {
-    throwSystemError(savedErrno, msg);
+    throwSystemErrorExplicit(savedErrno, std::forward<Args>(args)...);
   }
 }
 
-}  // namespace folly
+// Check the return code from a fopen-style function (returns a non-nullptr
+// FILE* on success, nullptr on error, sets errno).  Works with fopen, fdopen,
+// freopen, tmpfile, etc.
+template <class... Args>
+void checkFopenError(FILE* fp, Args&&... args) {
+  if (UNLIKELY(!fp)) {
+    throwSystemError(std::forward<Args>(args)...);
+  }
+}
 
-#endif /* FOLLY_EXCEPTION_H_ */
+template <class... Args>
+void checkFopenErrorExplicit(FILE* fp, int savedErrno, Args&&... args) {
+  if (UNLIKELY(!fp)) {
+    throwSystemErrorExplicit(savedErrno, std::forward<Args>(args)...);
+  }
+}
+
+/**
+ * If cond is not true, raise an exception of type E.  E must have a ctor that
+ * works with const char* (a description of the failure).
+ */
+#define CHECK_THROW(cond, E)           \
+  do {                                 \
+    if (!(cond)) {                     \
+      throw E("Check failed: " #cond); \
+    }                                  \
+  } while (0)
 
+} // namespace folly