fix regression: -d:nimHasLibFFI was not being tested anymore (#14234)

* * fix regression: -d:nimHasLibFFI was not being tested anymore,
in part because testament was silently treating some errors as easy to overlook messages
* turned that message into an error
* -d:nimHasLibFFI is now being tested with nim cpp
* use correct signatures for importc procs
* workaround for openbsd to unblock ctffi testing

koch.nim

@@ -289,11 +289,13 @@ proc findStartNim: string =
 proc thVersion(i: int): string =
   result = ("compiler" / "nim" & $i).exe
 
+template doUseCpp(): bool = getEnv("NIM_COMPILE_TO_CPP", "false") == "true"
+
 proc boot(args: string) =
   var output = "compiler" / "nim".exe
   var finalDest = "bin" / "nim".exe
   # default to use the 'c' command:
-  let useCpp = getEnv("NIM_COMPILE_TO_CPP", "false") == "true"
+  let useCpp = doUseCpp()
   let smartNimcache = (if "release" in args or "danger" in args: "nimcache/r_" else: "nimcache/d_") &
                       hostOS & "_" & hostCPU
 
@@ -542,8 +544,9 @@ proc runCI(cmd: string) =
         execFold("nimble install -y libffi", "nimble install -y libffi")
         const nimFFI = "./bin/nim.ctffi"
         # no need to bootstrap with koch boot (would be slower)
-        execFold("build with -d:nimHasLibFFI", "nim c -d:release -d:nimHasLibFFI -o:$1 compiler/nim.nim" % [nimFFI])
-        execFold("test with -d:nimHasLibFFI", "$1 c -r testament/testament --nim:$1 r tests/vm/tevalffi.nim" % [nimFFI])
+        let backend = if doUseCpp(): "cpp" else: "c"
+        execFold("build with -d:nimHasLibFFI", "nim $1 -d:release -d:nimHasLibFFI -o:$2 compiler/nim.nim" % [backend, nimFFI])
+        execFold("test with -d:nimHasLibFFI", "$1 $2 -r testament/testament --nim:$1 r tests/trunner.nim" % [nimFFI, backend])
 
     execFold("Run nimdoc tests", "nim c -r nimdoc/tester")
     execFold("Run nimpretty tests", "nim c -r nimpretty/tester.nim")

testament/categories.nim

@@ -545,7 +545,7 @@ proc processSingleTest(r: var TResults, cat: Category, options, test: string) =
   if existsFile(test):
     testSpec r, makeTest(test, options, cat), {target}
   else:
-    echo "[Warning] - ", test, " test does not exist"
+    doAssert false, test & " test does not exist"
 
 proc isJoinableSpec(spec: TSpec): bool =
   result = not spec.sortoutput and

tests/trunner.nim

@@ -1,43 +1,60 @@
 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.
 
-import std/[strformat,os,osproc,strutils]
+import std/[strformat,os,osproc]
 
 const nim = getCurrentCompilerExe()
 
+const mode =
+  when defined(c): "c"
+  elif defined(cpp): "cpp"
+  else: static: doAssert false
+
 proc runCmd(file, options = ""): auto =
-  let mode = if existsEnv("NIM_COMPILE_TO_CPP"): "cpp" else: "c"
   const testsDir = currentSourcePath().parentDir
   let fileabs = testsDir / file.unixToNativePath
   doAssert fileabs.existsFile, fileabs
   let cmd = fmt"{nim} {mode} {options} --hints:off {fileabs}"
   result = execCmdEx(cmd)
-  when false: # uncomment if you need to debug
-    echo result[0]
-    echo result[1]
+  when false:  echo result[0] & "\n" & result[1] # for debugging
 
 when defined(nimHasLibFFIEnabled):
   block: # mevalffi
-    let (output, exitCode) = runCmd("vm/mevalffi.nim", "--experimental:compiletimeFFI")
-    let expected = """
+    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
-foo
+"""
+    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}
+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 check(msg) = doAssert msg in output, output
 
   block: # mstatic_assert

tests/vm/mevalffi.nim

@@ -8,9 +8,9 @@ proc c_exp(a: float64): float64 {.importc: "exp", header: "<math.h>".}
 proc c_printf(frmt: cstring): cint {.importc: "printf", header: "<stdio.h>", varargs, discardable.}
 
 const snprintfName = when defined(windows): "_snprintf" else: "snprintf"
-proc c_snprintf*(buffer: pointer, buf_size: uint, format: cstring): cint {.importc: snprintfName, header: "<stdio.h>", varargs .}
+proc c_snprintf*(str: cstring, size: csize_t, format: cstring): cint {.importc: snprintfName, header: "<stdio.h>", varargs .}
 
-proc c_malloc(size:uint):pointer {.importc:"malloc", header: "<stdlib.h>".}
+proc c_malloc(size: csize_t): pointer {.importc:"malloc", header: "<stdlib.h>".}
 proc c_free(p: pointer) {.importc:"free", header: "<stdlib.h>".}
 
 proc fun() =
@@ -35,12 +35,15 @@ proc fun() =
 
   block: # c_snprintf, c_malloc, c_free
     let n: uint = 50
-    var buffer2: pointer = c_malloc(n)
+    var buffer2 = cstring(cast[ptr char](c_malloc(n)))
+
     var s: cstring = "foobar"
     var age: cint = 25
-    discard c_snprintf(buffer2, n, "s1:%s s2:%s age:%d pi:%g", s, s, age, 3.14)
-    c_printf("ret={%s}\n", buffer2)
-    c_free(buffer2) # not sure it has an effect
+    let num = c_snprintf(buffer2, n, "s1:%s s2:%s age:%d pi:%g", s, s, age, 3.14)
+    let numExp = 34 
+    doAssert num == numExp
+    c_printf("ret=[%s]\n", buffer2)
+    c_free(buffer2)
 
   block: # c_printf bug
     var a = 123
@@ -58,10 +61,11 @@ static:
   fun()
 fun()
 
-import system/ansi_c
-block:
-  proc fun2()=
-    c_fprintf(cstderr, "hello world stderr\n")
-    write(stderr, "hi stderr\n")
-  static: fun2()
-  fun2()
+when not defined nimEvalffiStderrWorkaround:
+  import system/ansi_c
+  block:
+    proc fun2()=
+      c_fprintf(cstderr, "hello world stderr\n")
+      write(stderr, "hi stderr\n")
+    static: fun2()
+    fun2()