[flang] [LLVMify F18] Replace the use std::ostream with LLVM streams llvm::ostream

This patch replaces the occurrence of std::ostream by llvm::raw_ostream.
In  LLVM Coding Standards[1] "All new code should use raw_ostream
instead of ostream".[1]

As a consequence, this patch also replaces the use of:
   std::stringstream by llvm::raw_string_ostream or llvm::raw_ostream*
   std::ofstream by llvm::raw_fd_ostream
   std::endl by '\n' and flush()[2]
   std::cout by llvm::outs()   and
   std::cerr by llvm::errs()

It also replaces  std::strerro by llvm::sys::StrError** , but NOT in  Fortran
runtime libraries

*std::stringstream were replaced by llvm::raw_ostream in all methods that
used std::stringstream as a parameter. Moreover, it removes the pointers to
these streams.

[1]https://llvm.org/docs/CodingStandards.html
[2]https://releases.llvm.org/2.5/docs/CodingStandards.html#ll_avoidendl

Signed-off-by: Caroline Concatto <caroline.concatto@arm.com>

Running clang-format-7

Signed-off-by: Caroline Concatto <caroline.concatto@arm.com>

Removing residue of ostream library

Signed-off-by: Caroline Concatto <caroline.concatto@arm.com>

Original-commit: flang-compiler/f18@a3507d44b8911e6024033aa583c1dc54e0eb89fd
Reviewed-on: https://github.com/flang-compiler/f18/pull/1047

1 files changed, 3 insertions, 1 deletions

diff --git a/flang/lib/Semantics/pointer-assignment.cpp b/flang/lib/Semantics/pointer-assignment.cpp
index b59dc81..fdb6add 100644
--- a/flang/lib/Semantics/pointer-assignment.cpp
+++ b/flang/lib/Semantics/pointer-assignment.cpp
@@ -19,6 +19,7 @@
 #include "flang/Semantics/expression.h"
 #include "flang/Semantics/symbol.h"
 #include "flang/Semantics/tools.h"
+#include "llvm/Support/raw_ostream.h"
 #include <optional>
 #include <set>
 #include <string>
@@ -232,7 +233,8 @@ void PointerAssignmentChecker::Check(const evaluate::Designator<T> &d) {
   if (msg) {
     auto restorer{common::ScopedSet(lhs_, last)};
     if (auto *m{std::get_if<MessageFixedText>(&*msg)}) {
-      std::ostringstream ss;
+      std::string buf;
+      llvm::raw_string_ostream ss{buf};
       d.AsFortran(ss);
       Say(*m, description_, ss.str());
     } else {