Change raw_ostream so that it doesn't call llvm_report_error

immediately on every output error. Instead, add a flag to
raw_ostream, and set the flag whenever an error is detected.

The flag can be queried and cleared from the public API. This
gives applications more flexibility to handling errors in
application-specific ways.

If the flag is not cleared when the raw_ostream is destructed,
llvm_report_error is called from the destructor. This ensures
that errors are not implicitly silenced, and provides
convenient default behavior for tools like llc and opt.
Clients wishing to avoid llvm_report_error calls from
raw_ostream should check for errors and clear the error flag.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75857 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Support/raw_ostream.cpp

@@ -44,6 +44,16 @@
 
 using namespace llvm;
 
+raw_ostream::~raw_ostream() {
+  delete [] OutBufStart;
+
+  // If there are any pending errors, report them now. Clients wishing
+  // to avoid llvm_report_error calls should check for errors with
+  // has_error() and clear the error flag with clear_error() before
+  // destructing raw_ostream objects which may have errors.
+  if (Error)
+    llvm_report_error("IO failure on output stream.");
+}
 
 // An out of line virtual method to provide a home for the class vtable.
 void raw_ostream::handle() {}
@@ -282,7 +292,7 @@ raw_fd_ostream::~raw_fd_ostream() {
     flush();
     if (ShouldClose)
       if (::close(FD) != 0)
-        llvm_report_error("IO failure closing output stream.");
+        error_detected();
   }
 }
 
@@ -290,7 +300,7 @@ void raw_fd_ostream::write_impl(const char *Ptr, unsigned Size) {
   assert (FD >= 0 && "File already closed.");
   pos += Size;
   if (::write(FD, Ptr, Size) != (ssize_t) Size)
-    llvm_report_error("IO failure writing to output stream.");
+    error_detected();
 }
 
 void raw_fd_ostream::close() {
@@ -298,7 +308,7 @@ void raw_fd_ostream::close() {
   ShouldClose = false;
   flush();
   if (::close(FD) != 0)
-    llvm_report_error("IO failure closing output stream.");
+    error_detected();
   FD = -1;
 }
 
@@ -306,7 +316,7 @@ uint64_t raw_fd_ostream::seek(uint64_t off) {
   flush();
   pos = ::lseek(FD, off, SEEK_SET);
   if (pos != off)
-    llvm_report_error("IO failure seeking on output stream.");
+    error_detected();
   return pos;  
 }