[Flang] RFC: Add support for -w option 1/n (#90420)

Add support for the -w option to switch OFF all Flang
warnings. This patch only supports switching OFF the
frontend warnings.

TODO : Support for MLIR, LLVM and Driver warnings.
TODO : Support interactions between -w, -pedantic, -Wall

1 files changed, 10 insertions, 0 deletions

diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
index f1b7b53..4318286 100644
--- a/flang/lib/Frontend/CompilerInvocation.cpp
+++ b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -975,6 +975,11 @@ static bool parseDialectArgs(CompilerInvocation &res, llvm::opt::ArgList &args,
     res.setEnableConformanceChecks();
     res.setEnableUsageChecks();
   }
+
+  // -w
+  if (args.hasArg(clang::driver::options::OPT_w))
+    res.setDisableWarnings();
+
   // -std=f2018
   // TODO: Set proper options when more fortran standards
   // are supported.
@@ -1403,6 +1408,11 @@ void CompilerInvocation::setFortranOpts() {
 
   if (getEnableUsageChecks())
     fortranOptions.features.WarnOnAllUsage();
+
+  if (getDisableWarnings()) {
+    fortranOptions.features.DisableAllNonstandardWarnings();
+    fortranOptions.features.DisableAllUsageWarnings();
+  }
 }
 
 std::unique_ptr<Fortran::semantics::SemanticsContext>