Add staticFileExists and staticDirExists (#22278)

compiler/vmops.nim

@@ -264,6 +264,10 @@ proc registerAdditionalOps*(c: PCtx) =
     systemop getCurrentException
     registerCallback c, "stdlib.osdirs.staticWalkDir", proc (a: VmArgs) {.nimcall.} =
       setResult(a, staticWalkDirImpl(getString(a, 0), getBool(a, 1)))
+    registerCallback c, "stdlib.staticos.staticDirExists", proc (a: VmArgs) {.nimcall.} =
+      setResult(a, dirExists(getString(a, 0)))
+    registerCallback c, "stdlib.staticos.staticFileExists", proc (a: VmArgs) {.nimcall.} =
+      setResult(a, fileExists(getString(a, 0)))
     registerCallback c, "stdlib.compilesettings.querySetting", proc (a: VmArgs) =
       setResult(a, querySettingImpl(c.config, getInt(a, 0)))
     registerCallback c, "stdlib.compilesettings.querySettingSeq", proc (a: VmArgs) =

lib/std/staticos.nim

@@ -0,0 +1,13 @@
+## This module implements path handling like os module but works at only compile-time.
+## This module works even when cross compiling to OS that is not supported by os module.
+
+proc staticFileExists*(filename: string): bool {.compileTime.} =
+  ## Returns true if `filename` exists and is a regular file or symlink.
+  ##
+  ## Directories, device files, named pipes and sockets return false.
+  discard
+
+proc staticDirExists*(dir: string): bool {.compileTime.} =
+  ## Returns true if the directory `dir` exists. If `dir` is a file, false
+  ## is returned. Follows symlinks.
+  discard

tests/stdlib/tstaticos.nim

@@ -0,0 +1,8 @@
+import std/[assertions, staticos, os]
+
+block:
+  static:
+    doAssert staticDirExists("MISSINGFILE") == false
+    doAssert staticFileExists("MISSINGDIR") == false
+    doAssert staticDirExists(currentSourcePath().parentDir)
+    doAssert staticFileExists(currentSourcePath())

tests/vm/tvmmisc.nim

@@ -82,6 +82,8 @@ block:
 
     doAssert fileExists("MISSINGFILE") == false
     doAssert dirExists("MISSINGDIR") == false
+    doAssert fileExists(currentSourcePath())
+    doAssert dirExists(currentSourcePath().parentDir)
 
 # bug #7210
 block: