[flang] Fix flang tests on MacOS

flang/test/Driver/ctofortran.f90

@@ -1,4 +1,5 @@
-! UNSUPPORTED: system-windows
+! MacOS needs -isysroot <osx_sysroot> with clang and flang to build binaries.
+! UNSUPPORTED: system-windows, system-darwin
 ! RUN: split-file %s %t
 ! RUN: chmod +x %t/runtest.sh
 ! RUN: %t/runtest.sh %t %flang $t/ffile.f90 $t/cfile.c

flang/test/Driver/lto-flags.f90

@@ -10,7 +10,9 @@
 ! RUN: %flang -### -S -flto=jobserver %s 2>&1 | FileCheck %s --check-prefix=FULL-LTO
 
 ! Also check linker plugin opt for Thin LTO
-! RUN: %flang -### -flto=thin %s 2>&1 | FileCheck %s --check-prefix=THIN-LTO
+! RUN: %flang -### -flto=thin %s 2>&1 | FileCheck %s \
+! RUN:        --check-prefixes=%if system-darwin %{THIN-LTO-ALL%} \
+! RUN:        %else %{THIN-LTO-ALL,THIN-LTO-LINKER-PLUGIN%}
 
 ! RUN: not %flang -### -S -flto=somelto %s 2>&1 | FileCheck %s --check-prefix=ERROR
 
@@ -25,9 +27,9 @@
 ! FULL-LTO: "-fc1"
 ! FULL-LTO-SAME: "-flto=full"
 
-! THIN-LTO: flang-new: warning: the option '-flto=thin' is a work in progress
-! THIN-LTO: "-fc1"
-! THIN-LTO-SAME: "-flto=thin"
-! THIN-LTO: "-plugin-opt=thinlto"
+! THIN-LTO-ALL: flang-new: warning: the option '-flto=thin' is a work in progress
+! THIN-LTO-ALL: "-fc1"
+! THIN-LTO-ALL-SAME: "-flto=thin"
+! THIN-LTO-LINKER-PLUGIN: "-plugin-opt=thinlto"
 
 ! ERROR: error: unsupported argument 'somelto' to option '-flto=

flang/test/Driver/save-mlir-temps.f90

@@ -6,8 +6,9 @@
 
 ! As `flang` does not implement `-fc1as` (i.e. a driver for the integrated
 ! assembler), we need to use `-fno-integrated-as` here.
-
-! UNSUPPORTED: system-windows
+! However, calling an external assembler on arm64 Macs fails, because it's
+! currently being invoked with the `-Q` flag, that is not supported on arm64.
+! UNSUPPORTED: system-windows, system-darwin
 
 !--------------------------
 ! Invalid output directory

flang/test/Evaluate/fold-out_of_range.f90

@@ -1,5 +1,5 @@
 ! RUN: %python %S/test_folding.py %s %flang_fc1
-! UNSUPPORTED: target=powerpc{{.*}}, target=aarch{{.*}}, system-windows, system-solaris
+! UNSUPPORTED: target=powerpc{{.*}}, target=aarch{{.*}}, target=arm{{.*}}, system-windows, system-solaris
 ! Tests folding of OUT_OF_RANGE().
 module m
   integer(1),  parameter :: i1v(*)  = [ -huge(1_1)  - 1_1,  huge(1_1) ]

flang/test/lit.cfg.py

@@ -163,7 +163,10 @@
         and os.path.isdir(include)
     ):
         config.available_features.add("c-compiler")
-        tools.append(ToolSubst("%cc", command=config.cc, unresolved="fatal"))
+        cc_cmd = config.cc
+        if config.osx_sysroot:
+            cc_cmd += " -isysroot " + config.osx_sysroot
+        tools.append(ToolSubst("%cc", command=cc_cmd, unresolved="fatal"))
         tools.append(ToolSubst("%libruntime", command=libruntime, unresolved="fatal"))
         tools.append(ToolSubst("%libdecimal", command=libdecimal, unresolved="fatal"))
         tools.append(ToolSubst("%include", command=include, unresolved="fatal"))

flang/test/lit.site.cfg.py.in

@@ -22,6 +22,7 @@ config.flang_standalone_build = @FLANG_STANDALONE_BUILD@
 config.has_plugins = @LLVM_ENABLE_PLUGINS@
 config.linked_bye_extension = @LLVM_BYE_LINK_INTO_TOOLS@
 config.cc = "@CMAKE_C_COMPILER@"
+config.osx_sysroot = path(r"@CMAKE_OSX_SYSROOT@")
 config.targets_to_build = "@TARGETS_TO_BUILD@"
 
 import lit.llvm