[Runner] Improve compile-only flags checks and fix objc wrapper

The `objc` wrapper is currently roughly equivalent to `clang -x objective-c`,
the problem is that `-x <LANG>` can't be used when linking, otherwise the
compiler driver will assume that the input files are plain text source code
files.

As a simple rule, we assume that we are compiling (as opposed to linking) when
no argument is an object file (ending with `.o` extension) and make the `objc`
wrapper pass the `-x objective-c` flag only when compiling (and not linking),
instead of doing so unconditionally.

Project.toml

@@ -1,7 +1,7 @@
 name = "BinaryBuilderBase"
 uuid = "7f725544-6523-48cd-82d1-3fa08ff4056e"
 authors = ["Elliot Saba <[email protected]>"]
-version = "0.6.5"
+version = "0.6.6"
 
 [deps]
 CodecZlib = "944b1d66-785c-5afd-91f1-9de20f533193"

src/Runner.jl

@@ -126,10 +126,11 @@ function generate_compiler_wrappers!(platform::AbstractPlatform; bin_path::Abstr
             println(io)
         end
 
-        # If we're given compile-only flags, include them only if `-x assembler` is not provided
+        # If we're given compile-only flags, include them only if `-x assembler` is not provided,
+        # or no object files (*.o) are passed in input
         if !isempty(compile_only_flags)
             println(io)
-            println(io, "if [[ \" \${ARGS[@]} \" != *' -x assembler '* ]]; then")
+            println(io, "if [[ \" \${ARGS[@]} \" != *' -x assembler '* ]] && [[ \" \${ARGS[@]} \" != *'.o '* ]]; then")
             for cf in compile_only_flags
                 println(io, "    PRE_FLAGS+=( $cf )")
             end
@@ -389,13 +390,12 @@ function generate_compiler_wrappers!(platform::AbstractPlatform; bin_path::Abstr
         )
     end
 
-    function clang_wrapper(io::IO, tool::String, p::AbstractPlatform, extra_flags::Vector{String} = String[])
+    function clang_wrapper(io::IO, tool::String, p::AbstractPlatform, compile_flags::Vector{String} = String[])
         flags = clang_flags!(p)
-        append!(flags, extra_flags)
         return wrapper(io,
             "/opt/$(host_target)/bin/$(tool)";
             flags=flags,
-            compile_only_flags=clang_compile_flags!(p),
+            compile_only_flags=clang_compile_flags!(p, compile_flags),
             link_only_flags=clang_link_flags!(p),
             no_soft_float=arch(p) in ("armv6l", "armv7l"),
         )

test/runners.jl

@@ -148,6 +148,34 @@ end
                     @test endswith(readchomp(iobuff), "Hello World!")
                 end
             end
+
+            @testset "Objective-C - $(platform)" for platform in filter(Sys.isapple, supported_platforms())
+                ur = preferred_runner()(dir; platform=platform)
+                iobuff = IOBuffer()
+                test_objc = """
+                #import <Foundation/Foundation.h>
+                void test() {
+                    @autoreleasepool {
+                        NSLog(@"Hello, World!");
+                    }
+                }
+                """
+                script = """
+                echo '$(test_objc)' > test.m
+                # Build the shared library in two steps: first compile object file...
+                objc -c -o test.o test.m
+                # ...and then link it to a shared library.
+                objc -shared -o test.dylib -framework Foundation test.o
+                file test.dylib
+                """
+                cmd = `/bin/bash -c "$(script)"`
+                @test run(ur, cmd, iobuff; tee_stream=devnull)
+                seekstart(iobuff)
+                # Test that we get the output we expect
+                _arch = arch(platform) == "aarch64" ? "arm64" : arch(platform)
+                @test occursin(r"^test.dylib: Mach-O $(_arch) dynamically linked shared library", readchomp(iobuff))
+            end
+
         end
     end