[flang-commits] [flang] 35249cb - [Flang] Fix error messages on Windows.

[Mats Petersson via flang-commits]

Author: Ivan Zhechev
Date: 2021-08-12T18:35:54+01:00
New Revision: 35249cb7b1e82147ef08de12bdf34a29d8c58d53

URL: https://github.com/llvm/llvm-project/commit/35249cb7b1e82147ef08de12bdf34a29d8c58d53
DIFF: https://github.com/llvm/llvm-project/commit/35249cb7b1e82147ef08de12bdf34a29d8c58d53.diff

LOG: [Flang] Fix error messages on Windows.

Flang uses positional arguments for `messages::say()`, such as "%1$s" which is only supported in MS Compilers with the `_*printf_p` form of the function. This uses a conditional macro to convert the existing `vsnprintf` used to the one needed in MS-World.

7 tests in D107575 rely on this change.

Reviewed By: Meinersbur

Differential Revision: https://reviews.llvm.org/D107654

Added: 
    

Modified: 
    flang/lib/Parser/message.cpp

Removed: 
    


################################################################################
diff  --git a/flang/lib/Parser/message.cpp b/flang/lib/Parser/message.cpp
index f565112eb928d..fd4a52c895bf9 100644
--- a/flang/lib/Parser/message.cpp
+++ b/flang/lib/Parser/message.cpp
@@ -38,14 +38,26 @@ void MessageFormattedText::Format(const MessageFixedText *text, ...) {
   }
   va_list ap;
   va_start(ap, text);
+#ifdef _MSC_VER
+  // Microsoft has a separate function for "positional arguments", which is
+  // used in some messages.
+  int need{_vsprintf_p(nullptr, 0, p, ap)};
+#else
   int need{vsnprintf(nullptr, 0, p, ap)};
+#endif
+
   CHECK(need >= 0);
   char *buffer{
       static_cast<char *>(std::malloc(static_cast<std::size_t>(need) + 1))};
   CHECK(buffer);
   va_end(ap);
   va_start(ap, text);
+#ifdef _MSC_VER
+  // Use positional argument variant of printf.
+  int need2{_vsprintf_p(buffer, need + 1, p, ap)};
+#else
   int need2{vsnprintf(buffer, need + 1, p, ap)};
+#endif
   CHECK(need2 == need);
   va_end(ap);
   string_ = buffer;