Allow the use of FileCheck

Author: vchuravy

test/Project.toml

@@ -2,8 +2,10 @@
 Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
 Dates = "ade2ca70-3891-5945-98fb-dc099432e06a"
 Distributed = "8ba89e20-285c-5b6f-9357-94700520ee1b"
+IOCapture = "b5f81e59-6552-4d32-b1f0-c071b021bf89"
 InteractiveUtils = "b77e0a4c-d291-57a0-90e8-8db25a27a240"
 LLVM = "929cbde3-209d-540e-8aea-75f648917ca0"
+LLVM_jll = "86de99a1-58d6-5da7-8064-bd56ce2e322c"
 Logging = "56ddb016-857b-54e1-b83d-db4d58db5568"
 PrecompileTools = "aea7be01-6a6a-4083-8856-8a6e6704d82a"
 Printf = "de0858da-6303-5e67-8744-51eddeeeb8d7"

test/helpers/test.jl

@@ -35,3 +35,55 @@ end
                      ret i64 %value"""
     return :(Base.llvmcall($llvmcall_str, T, Tuple{T}, i))
 end
+
+# filecheck utils
+
+module FileCheck
+    import LLVM_jll
+    import IOCapture
+
+    export filecheck
+
+    global filecheck_path::String
+    function __init__()
+        # TODO: Windows
+        global filecheck_path = joinpath(LLVM_jll.artifact_dir, "tools", "FileCheck")
+    end
+
+    function filecheck_exe(; adjust_PATH::Bool=true, adjust_LIBPATH::Bool=true)
+        env = Base.invokelatest(
+            LLVM_jll.JLLWrappers.adjust_ENV!,
+            copy(ENV),
+            LLVM_jll.PATH[],
+            LLVM_jll.LIBPATH[],
+            adjust_PATH,
+            adjust_LIBPATH
+        )
+
+        return Cmd(Cmd([filecheck_path]); env)
+    end
+
+    function filecheck(f, input)
+        # FileCheck assumes that the input is available as a file
+        path, io = mktemp()
+        write(io, input)
+        close(io)
+
+        # Now execute `f` with IOCapture
+        # XXX: See if Suppressor is a better fit
+        value, output, error, backtrace = IOCapture.capture(()->f(input); rethrow=Union{})
+
+        @show error
+        io = IOBuffer()
+        write(io, output)
+        println(io)
+
+        if error
+            showerror(io, value, backtrace)
+        end
+
+        seekstart(io)
+        cmd = `$(filecheck_exe()) $path`
+        value, success(pipeline(cmd; stdin=io, stdout, stderr))
+    end
+end

test/setup.jl

@@ -9,6 +9,7 @@ for file in readdir(joinpath(@__DIR__, "helpers"))
         include(joinpath(@__DIR__, "helpers", file))
     end
 end
+using .FileCheck
 
 
 ## entry point

test/utils.jl

@@ -92,3 +92,14 @@ end
         @test occursin(ansi_color, highlighted) skip = !can_highlight
     end
 end
+
+# Test FileCheck
+_, success = filecheck(_->println("works"), "# CHECK: works")
+@test success
+
+_, success = filecheck(_->@assert(false),
+"""
+; CHECK: AssertionError: false
+; CHECK-NEXT: Stacktrace:
+""")
+@test success