trunner was not actually being tested in non-CTFFI mode; minor testament cleanups (#14377)

* use check
* trunner now works with cpp
* cleanup: move compiler/unittest_light => stdtest/unittest_light
* fix tests/readme.md
* remove deadcode references to rodfiles
* fix for windows

tests/misc/mbackend.nim

@@ -4,7 +4,6 @@ fixed would not trigger in that case.
 ]#
 
 import std/compilesettings
-import std/unittest
 
 static:
   ## bugfix 1: this used to CT error with: Error: unhandled exception: mimportcpp.nim(6, 18) `defined(cpp)`

tests/misc/msizeof5.nim

@@ -116,7 +116,7 @@ when defined caseBad:
     ensureCgen Foo5
 
   block:
-    type Foo6{.importc, completeStruct.} = object
+    type Foo6{.importc:"struct Foo6", completeStruct.} = object
       a1: cint
       # a2: bool # missing this should trigger assert fail
       a3: cfloat

tests/misc/tparseopt.nim

@@ -71,7 +71,7 @@ else:
 
   import osproc, os, strutils
   from stdtest/specialpaths import buildDir
-  import "../.." / compiler/unittest_light
+  import stdtest/unittest_light
 
   block: # fix #9951
     template runTest(parseoptCustom) =

tests/misc/trunner.nim

@@ -0,0 +1,144 @@
+discard """
+  targets: "c cpp"
+  joinable: false
+"""
+
+## tests that don't quite fit the mold and are easier to handle via `execCmdEx`
+## A few others could be added to here to simplify code.
+## Note: this test is a bit slow but tests a lot of things; please don't disable.
+
+import std/[strformat,os,osproc,unittest]
+
+const nim = getCurrentCompilerExe()
+
+const mode =
+  when defined(c): "c"
+  elif defined(cpp): "cpp"
+  else: static: doAssert false
+
+const testsDir = currentSourcePath.parentDir.parentDir
+const buildDir = testsDir.parentDir / "build"
+const nimcache = buildDir / "nimcacheTrunner"
+  # `querySetting(nimcacheDir)` would also be possible, but we thus
+  # avoid stomping on other parallel tests
+
+proc runCmd(file, options = ""): auto =
+  let fileabs = testsDir / file.unixToNativePath
+  doAssert fileabs.existsFile, fileabs
+  let cmd = fmt"{nim} {mode} {options} --hints:off {fileabs}"
+  result = execCmdEx(cmd)
+  when false:  echo result[0] & "\n" & result[1] # for debugging
+
+when defined(nimTrunnerFfi):
+  block: # mevalffi
+    when defined(openbsd):
+      #[
+      openbsd defines `#define stderr (&__sF[2])` which makes it cumbersome
+      for dlopen'ing inside `importcSymbol`. Instead of adding special rules
+      inside `importcSymbol` to handle this, we disable just the part that's
+      not working and will provide a more general, clean fix in future PR.
+      ]#
+      var opt = "-d:nimEvalffiStderrWorkaround"
+      let prefix = ""
+    else:
+      var opt = ""
+      let prefix = """
+hello world stderr
+hi stderr
+"""
+    let (output, exitCode) = runCmd("vm/mevalffi.nim", fmt"{opt} --experimental:compiletimeFFI")
+    let expected = fmt"""
+{prefix}foo
+foo:100
+foo:101
+foo:102:103
+foo:102:103:104
+foo:0.03:asdf:103:105
+ret=[s1:foobar s2:foobar age:25 pi:3.14]
+"""
+    doAssert output == expected, output
+    doAssert exitCode == 0
+
+else: # don't run twice the same test
+  import std/[strutils]
+  template check2(msg) = doAssert msg in output, output
+
+  block: # mstatic_assert
+    let (output, exitCode) = runCmd("ccgbugs/mstatic_assert.nim", "-d:caseBad")
+    check2 "sizeof(bool) == 2"
+    check exitCode != 0
+
+  block: # ABI checks
+    let file = "misc/msizeof5.nim"
+    block:
+      let (output, exitCode) = runCmd(file, "-d:checkAbi")
+      doAssert exitCode == 0, output
+    block:
+      let (output, exitCode) = runCmd(file, "-d:checkAbi -d:caseBad")
+      # on platforms that support _StaticAssert natively, errors will show full context, eg:
+      # error: static_assert failed due to requirement 'sizeof(unsigned char) == 8'
+      # "backend & Nim disagree on size for: BadImportcType{int64} [declared in mabi_check.nim(1, 6)]"
+      check2 "sizeof(unsigned char) == 8"
+      check2 "sizeof(struct Foo2) == 1"
+      check2 "sizeof(Foo5) == 16"
+      check2 "sizeof(Foo5) == 3"
+      check2 "sizeof(struct Foo6) == "
+      check exitCode != 0
+
+  import streams
+  block: # stdin input
+    let nimcmd = fmt"""{nim} r --hints:off - -firstparam "-second param" """
+    let expected = """@["-firstparam", "-second param"]"""
+    block:
+      let p = startProcess(nimcmd, options = {poEvalCommand})
+      p.inputStream.write("import os; echo commandLineParams()")
+      p.inputStream.close
+      var output = p.outputStream.readAll
+      let error = p.errorStream.readAll
+      doAssert p.waitForExit == 0
+      doAssert error.len == 0, $error
+      output.stripLineEnd
+      check output == expected
+      p.errorStream.close
+      p.outputStream.close
+
+    block:
+      when defined posix:
+        # xxx on windows, `poEvalCommand` should imply `/cmd`, (which should
+        # make this work), but currently doesn't
+        let cmd = fmt"""echo "import os; echo commandLineParams()" | {nimcmd}"""
+        var (output, exitCode) = execCmdEx(cmd)
+        output.stripLineEnd
+        check output == expected
+        doAssert exitCode == 0
+
+  block: # nim doc --backend:$backend --doccmd:$cmd
+    # test for https://github.com/nim-lang/Nim/issues/13129
+    # test for https://github.com/nim-lang/Nim/issues/13891
+    let file = testsDir / "nimdoc/m13129.nim"
+    for backend in fmt"{mode} js".split:
+      # pending #14343 this fails on windows: --doccmd:"-d:m13129Foo2 --hints:off"
+      let cmd = fmt"""{nim} doc -b:{backend} --nimcache:{nimcache} -d:m13129Foo1 "--doccmd:-d:m13129Foo2 --hints:off" --usenimcache --hints:off {file}"""
+      check execCmdEx(cmd) == (&"ok1:{backend}\nok2: backend: {backend}\n", 0)
+    # checks that --usenimcache works with `nim doc`
+    check fileExists(nimcache / "m13129.html")
+
+    block: # mak sure --backend works with `nim r`
+      let cmd = fmt"{nim} r --backend:{mode} --hints:off --nimcache:{nimcache} {file}"
+      check execCmdEx(cmd) == ("ok3\n", 0)
+
+  block: # further issues with `--backend`
+    let file = testsDir / "misc/mbackend.nim"
+    var cmd = fmt"{nim} doc -b:cpp --hints:off --nimcache:{nimcache} {file}"
+    check execCmdEx(cmd) == ("", 0)
+    cmd = fmt"{nim} check -b:c -b:cpp --hints:off --nimcache:{nimcache} {file}"
+    check execCmdEx(cmd) == ("", 0)
+    # issue https://github.com/timotheecour/Nim/issues/175
+    cmd = fmt"{nim} c -b:js -b:cpp --hints:off --nimcache:{nimcache} {file}"
+    check execCmdEx(cmd) == ("", 0)
+
+  block: # some importc tests
+    # issue #14314
+    let file = testsDir / "misc/mimportc.nim"
+    let cmd = fmt"{nim} r -b:cpp --hints:off --nimcache:{nimcache} --warningAsError:ProveInit {file}"
+    check execCmdEx(cmd) == ("witness\n", 0)