1 files changed, 57 insertions, 16 deletions
diff --git a/compiler/pathutils.nim b/compiler/pathutils.nim
index e3dd69628..5f6212bb2 100644
--- a/compiler/pathutils.nim
+++ b/compiler/pathutils.nim
@@ -10,7 +10,10 @@
 ## Path handling utilities for Nim. Strictly typed code in order
 ## to avoid the never ending time sink in getting path handling right.
 
-import os, pathnorm
+import std/[os, pathnorm, strutils]
+
+when defined(nimPreviewSlimSystem):
+  import std/[syncio, assertions]
 
 type
   AbsoluteFile* = distinct string
@@ -67,7 +70,7 @@ when true:
 
   proc `/`*(base: AbsoluteDir; f: RelativeFile): AbsoluteFile =
     let base = postProcessBase(base)
-    assert(not isAbsolute(f.string))
+    assert(not isAbsolute(f.string), f.string)
     result = AbsoluteFile newStringOfCap(base.string.len + f.string.len)
     var state = 0
     addNormalizePath(base.string, result.string, state)
@@ -83,7 +86,10 @@ when true:
 
   proc relativeTo*(fullPath: AbsoluteFile, baseFilename: AbsoluteDir;
                    sep = DirSep): RelativeFile =
-    RelativeFile(relativePath(fullPath.string, baseFilename.string, sep))
+    # this currently fails for `tests/compilerapi/tcompilerapi.nim`
+    # it's needed otherwise would returns an absolute path
+    # assert not baseFilename.isEmpty, $fullPath
+    result = RelativeFile(relativePath(fullPath.string, baseFilename.string, sep))
 
   proc toAbsolute*(file: string; base: AbsoluteDir): AbsoluteFile =
     if isAbsolute(file): result = AbsoluteFile(file)
@@ -97,16 +103,51 @@ when true:
 
   proc writeFile*(x: AbsoluteFile; content: string) {.borrow.}
 
-when isMainModule:
-  doAssert AbsoluteDir"/Users/me///" / RelativeFile"z.nim" == AbsoluteFile"/Users/me/z.nim"
-  doAssert relativePath("/foo/bar.nim", "/foo/", '/') == "bar.nim"
-  doAssert $RelativeDir"foo/bar" == "foo/bar"
-  doAssert RelativeDir"foo/bar" == RelativeDir"foo/bar"
-  doAssert RelativeFile"foo/bar".changeFileExt(".txt") == RelativeFile"foo/bar.txt"
-  doAssert RelativeFile"foo/bar".addFileExt(".txt") == RelativeFile"foo/bar.txt"
-  doAssert not RelativeDir"foo/bar".isEmpty
-  doAssert RelativeDir"".isEmpty
-
-when isMainModule and defined(windows):
-  let nasty = string(AbsoluteDir(r"C:\Users\rumpf\projects\nim\tests\nimble\nimbleDir\linkedPkgs\pkgB-#head\../../simplePkgs/pkgB-#head/") / RelativeFile"pkgA/module.nim")
-  doAssert nasty.replace('/', '\\') == r"C:\Users\rumpf\projects\nim\tests\nimble\nimbleDir\simplePkgs\pkgB-#head\pkgA\module.nim"
+proc skipHomeDir(x: string): int =
+  when defined(windows):
+    if x.continuesWith("Users/", len("C:/")):
+      result = 3
+    else:
+      result = 0
+  else:
+    if x.startsWith("/home/") or x.startsWith("/Users/"):
+      result = 3
+    elif x.startsWith("/mnt/") and x.continuesWith("/Users/", len("/mnt/c")):
+      result = 5
+    else:
+      result = 0
+
+proc relevantPart(s: string; afterSlashX: int): string =
+  result = newStringOfCap(s.len - 8)
+  var slashes = afterSlashX
+  for i in 0..<s.len:
+    if slashes == 0:
+      result.add s[i]
+    elif s[i] == '/':
+      dec slashes
+
+template canonSlashes(x: string): string =
+  when defined(windows):
+    x.replace('\\', '/')
+  else:
+    x
+
+proc customPathImpl(x: string): string =
+  # Idea: Encode a "protocol" via "//protocol/path" which is not ambiguous
+  # as path canonicalization would have removed the double slashes.
+  # /mnt/X/Users/Y
+  # X:\\Users\Y
+  # /home/Y
+  # -->
+  # //user/
+  if not isAbsolute(x):
+    result = customPathImpl(canonSlashes(getCurrentDir() / x))
+  else:
+    let slashes = skipHomeDir(x)
+    if slashes > 0:
+      result = "//user/" & relevantPart(x, slashes)
+    else:
+      result = x
+
+proc customPath*(x: string): string =
+  customPathImpl canonSlashes x