Make raw_fd_ostream consider itself the owner of STDOUT_FILENO when

constructed with an output filename of "-". In particular, allow the
file descriptor to be closed, and close the file descriptor in the
destructor if it hasn't been explicitly closed already, to ensure
that any write errors are detected.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111436 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/Support/raw_ostream.h b/include/llvm/Support/raw_ostream.h
index bb9a52330d7f234f2ec8d150ee80b788edcc885e..b7eae0f300bed587437493ef1238a652babaae45 100644 (file)
--- a/include/llvm/Support/raw_ostream.h
+++ b/include/llvm/Support/raw_ostream.h
@@ -353,8 +353,11 @@ public:
   /// be immediately destroyed; the string will be empty if no error occurred.
   /// This allows optional flags to control how the file will be opened.
   ///
   /// be immediately destroyed; the string will be empty if no error occurred.
   /// This allows optional flags to control how the file will be opened.
   ///

-  /// \param Filename - The file to open. If this is "-" then the
-  /// stream will use stdout instead.
+  /// As a special case, if Filename is "-", then the stream will use
+  /// STDOUT_FILENO instead of opening a file. Note that it will still consider
+  /// itself to own the file descriptor. In particular, it will close the
+  /// file descriptor when it is done (this is necessary to detect
+  /// output errors).

   raw_fd_ostream(const char *Filename, std::string &ErrorInfo,
                  unsigned Flags = 0);
 
   raw_fd_ostream(const char *Filename, std::string &ErrorInfo,
                  unsigned Flags = 0);
 

diff --git a/lib/Support/raw_ostream.cpp b/lib/Support/raw_ostream.cpp
index ac118a91a3f6b19660d9002693dca3919a979d7c..71a2ac5e092a9620df144cc76b7cbd30a477da97 100644 (file)
--- a/lib/Support/raw_ostream.cpp
+++ b/lib/Support/raw_ostream.cpp
@@ -377,14 +377,17 @@ raw_fd_ostream::raw_fd_ostream(const char *Filename, std::string &ErrorInfo,
 
   ErrorInfo.clear();
 
 
   ErrorInfo.clear();
 

-  // Handle "-" as stdout.
+  // Handle "-" as stdout. Note that when we do this, we consider ourself
+  // the owner of stdout. This means that we can do things like close the
+  // file descriptor when we're done and set the "binary" flag globally.

   if (Filename[0] == '-' && Filename[1] == 0) {
     FD = STDOUT_FILENO;
     // If user requested binary then put stdout into binary mode if
     // possible.
     if (Flags & F_Binary)
       sys::Program::ChangeStdoutToBinary();
   if (Filename[0] == '-' && Filename[1] == 0) {
     FD = STDOUT_FILENO;
     // If user requested binary then put stdout into binary mode if
     // possible.
     if (Flags & F_Binary)
       sys::Program::ChangeStdoutToBinary();

-    ShouldClose = false;
+    // Close stdout when we're done, to detect any output errors.
+    ShouldClose = true;

     return;
   }
 
     return;
   }