[test-suite] Disable Fortran FM509 test when -std=legacy is not supported

This test requires -std=legacy which is not supported by flang.
Currently we check if the flag is supported and add if so,
but run the test anyway if not supported.

This has been failing on our bots for a long time but was not
noticed due to some issues reporting NOEXE failures.

https://lab.llvm.org/buildbot/#/builders/179/builds/3132

Executable Missing Tests (1):
  test-suite :: Fortran/UnitTests/fcvs21_f95/FM509.test

This fixes llvm_singlesource to allow you to pass a list
of source files (which used to work when it was a macro).

(this was done for multisource in cecca64)

If the flag is not supported we remove the test from the list
of source files. This means it's disabled for flang and
enabled for gfortran.

Reviewed By: awarzynski

Differential Revision: https://reviews.llvm.org/D121287

Author: DavidSpickett

Fortran/UnitTests/fcvs21_f95/CMakeLists.txt

@@ -33,13 +33,19 @@
 # clean-up fort.* files otherwise one of the tests will fail
 llvm_test_prepare(rm -f %S/fort.*)
 
-# Test 509 requires this flag in more recent versions of GCC
+file(GLOB Source CONFIGURE_DEPENDS *.f)
+
+# Test 509 requires this flag in more recent versions of GCC.
+# If this flag is not supported, the test should be excluded.
 check_fortran_compiler_flag("-std=legacy" SUPPORTS_LEGACY)
 if (SUPPORTS_LEGACY)
   add_compile_options(-std=legacy)
-endif ()
+else()
+  # Regex because the GLOB returns the full path to each file
+  list(FILTER Source EXCLUDE REGEX "FM509\.f$")
+endif()
 
 set(FP_TOLERANCE 1.0e-11) # set by the most sensitive numerical test
-llvm_singlesource()
+llvm_singlesource(${Source})
 
 file(COPY lit.local.cfg DESTINATION "${CMAKE_CURRENT_BINARY_DIR}")

cmake/modules/SingleMultiSource.cmake

@@ -7,16 +7,16 @@
 #
 # Defines helpers to add executables and tests. The entry points to this
 # file are:
-#   `llvm_singlesource([PREFIX p])`, and
+#   `llvm_singlesource([PREFIX p] [sources...])`, and
 #   `llvm_multisource()`
 #
 # Following convenience functions provide shortcuts for common test cases:
 #
-# llvm_singlesource([PREFIX p])
+# llvm_singlesource([PREFIX p] [sources...])
 #
-#   Invokes llvm_test_executable() for each c/c++ source file.  If
-#   'sources is emptyno sources are specified, creates test executables
-#   for all C/C++ files in current directory.
+#   Invokes llvm_test_executable() for each C/C++/Fortran source file.
+#   If sources is empty, creates test executables for all C/C++/Fortran
+#   files in current directory.
 #   Passes optional PREFIX parameter to llvm_test_executable().
 #
 # llvm_multisource(target)
@@ -27,14 +27,22 @@
 include(TestSuite)
 
 # Configure the current directory as a SingleSource subdirectory - i.e. every
-# file in *.{c,cpp,cc} is treated as its own test.
+# C/C++/Fortran file is treated as its own test.
 function(llvm_singlesource)
+  # PREFIX is optional so it cannot be a named argument.
   cmake_parse_arguments(_LSARG "" "PREFIX" "" ${ARGN})
-  if(DEFINED Source)
-    set(sources ${Source})
-  else()
+  if(DEFINED _LSARG_PREFIX)
+    # Remove "PREFIX" and the associated value from ARGN so that it only
+    # contains sources.
+    list(REMOVE_AT ARGN 0)
+    list(REMOVE_AT ARGN 0)
+  endif()
+
+  set(sources ${ARGN})
+  if(NOT sources)
     file(GLOB sources *.c *.cpp *.cc *.f *.F *.f90 *.F90)
   endif()
+
   foreach(source ${sources})
     basename(name ${source})
     set(_target ${_LSARG_PREFIX}${name})