[flang-commits] [flang] 563ea45 - [flang][driver] Fix -fdefault* family bug

[Andrzej Warzynski via flang-commits]

Author: Arnamoy Bhattacharyya
Date: 2021-03-02T17:37:02Z
New Revision: 563ea45052bdff336fcf1e89bdbe36d2a44ab52d

URL: https://github.com/llvm/llvm-project/commit/563ea45052bdff336fcf1e89bdbe36d2a44ab52d
DIFF: https://github.com/llvm/llvm-project/commit/563ea45052bdff336fcf1e89bdbe36d2a44ab52d.diff

LOG: [flang][driver] Fix -fdefault* family bug

This patch provides a fix for the `fdefault-*` family in f18

(Please consult `D96344` for details)

Differential Revision: https://reviews.llvm.org/D97724

Added: 
    

Modified: 
    flang/tools/f18/f18.cpp

Removed: 
    


################################################################################
diff  --git a/flang/tools/f18/f18.cpp b/flang/tools/f18/f18.cpp
index 5c16199c865b..720ca7e251a0 100644
--- a/flang/tools/f18/f18.cpp
+++ b/flang/tools/f18/f18.cpp
@@ -102,6 +102,7 @@ struct DriverOptions {
   bool dumpSymbols{false};
   bool debugNoSemantics{false};
   bool debugModuleWriter{false};
+  bool defaultReal8{false};
   bool measureTree{false};
   bool unparseTypedExprsToF18_FC{false};
   std::vector<std::string> F18_FCArgs;
@@ -563,10 +564,20 @@ int main(int argc, char *const argv[]) {
       }
     } else if (arg.substr(0, 2) == "-U") {
       predefinitions.emplace_back(arg.substr(2), std::optional<std::string>{});
-    } else if (arg == "-fdefault-double-8") {
-      defaultKinds.set_defaultRealKind(4);
     } else if (arg == "-r8" || arg == "-fdefault-real-8") {
+      driver.defaultReal8 = true;
       defaultKinds.set_defaultRealKind(8);
+      defaultKinds.set_doublePrecisionKind(16);
+    } else if (arg == "-fdefault-double-8") {
+      if (!driver.defaultReal8) {
+        // -fdefault-double-8 has to be used with -fdefault-real-8
+        // to be compatible with gfortran. See:
+        // https://gcc.gnu.org/onlinedocs/gfortran/Fortran-Dialect-Options.html
+        llvm::errs()
+            << "Use of `-fdefault-double-8` requires `-fdefault-real-8`\n";
+        return EXIT_FAILURE;
+      }
+      defaultKinds.set_doublePrecisionKind(8);
     } else if (arg == "-i8" || arg == "-fdefault-integer-8") {
       defaultKinds.set_defaultIntegerKind(8);
       defaultKinds.set_subscriptIntegerKind(8);