[flang][lowering] Ignore compiler directives

[awarzynski]

Summary

This patch simply replaces a TODO with a warning.

This is part of the upstreaming effort from the fir-dev branch in [1].

[1] https://github.com/flang-compiler/f18-llvm-project

Co-authored-by: Eric Schweitz <[e-mail]>

[kiranchandramohan]

LGTM.

flang/test/Lower/compiler-directive.f90

3

Assuming for warnings, the RUN invocation does not fail

[awarzynski]

flang/test/Lower/compiler-directive.f90

3

Does not fail for warnings, fails for errors :)

flang/lib/Lower/Bridge.cpp

private:
   void genFIR(const Fortran::parser::ForallConstructStmt &stmt) {
     genFIR(std::get<
                Fortran::common::Indirection<Fortran::parser::ConcurrentHeader>>(
                stmt.t)
                .value());
   }
 
   void genFIR(const Fortran::parser::CompilerDirective &) {
-    TODO(toLocation(), "CompilerDirective lowering");
+    mlir::emitWarning(toLocation(), "ignoring all compiler directives");
   }
 
   void genFIR(const Fortran::parser::OpenACCConstruct &acc) {
     mlir::OpBuilder::InsertPoint insertPt = builder->saveInsertionPoint();
     genOpenACCConstruct(*this, getEval(), acc);
     for (Fortran::lower::pft::Evaluation &e : getEval().getNestedEvaluations())
       genFIR(e);
     builder->restoreInsertionPoint(insertPt);

flang/test/Lower/compiler-directive.f90

+! RUN: bbc %s -o - 2>&1 | FileCheck %s
+! RUN: %flang_fc1 -emit-fir %s -o - 2>&1 | FileCheck %s
+
+! CHECK: ignoring all compiler directives
+
+MODULE test_mod
+  CONTAINS
+  SUBROUTINE foo()
+    REAL :: var
+  !DIR$ VECTOR ALIGNED
+    var = 1.
+  END SUBROUTINE foo
+END MODULE test_mod