WIP

azure-pipelines.yml

@@ -18,35 +18,35 @@ jobs:
 
   strategy:
     matrix:
-      Linux_amd64:
-        vmImage: 'ubuntu-18.04'
-        CPU: amd64
-      # regularly breaks, refs bug #17325
-      Linux_i386:
-        # on 'ubuntu-16.04' (not supported anymore anyways) it errored with:
-        # g++-multilib : Depends: gcc-multilib (>= 4:5.3.1-1ubuntu1) but it is not going to be installed
-        vmImage: 'ubuntu-18.04'
-        CPU: i386
-      OSX_amd64:
-        vmImage: 'macOS-10.15'
-        CPU: amd64
-      OSX_amd64_cpp:
-        vmImage: 'macOS-10.15'
-        CPU: amd64
-        NIM_COMPILE_TO_CPP: true
+      # Linux_amd64:
+      #   vmImage: 'ubuntu-18.04'
+      #   CPU: amd64
+      # # regularly breaks, refs bug #17325
+      # Linux_i386:
+      #   # on 'ubuntu-16.04' (not supported anymore anyways) it errored with:
+      #   # g++-multilib : Depends: gcc-multilib (>= 4:5.3.1-1ubuntu1) but it is not going to be installed
+      #   vmImage: 'ubuntu-18.04'
+      #   CPU: i386
+      # OSX_amd64:
+      #   vmImage: 'macOS-10.15'
+      #   CPU: amd64
+      # OSX_amd64_cpp:
+      #   vmImage: 'macOS-10.15'
+      #   CPU: amd64
+      #   NIM_COMPILE_TO_CPP: true
       Windows_amd64_batch0_3:
         vmImage: 'windows-2019'
         CPU: amd64
         # see also: `NIM_TEST_PACKAGES`
         NIM_TESTAMENT_BATCH: "0_3"
-      Windows_amd64_batch1_3:
-        vmImage: 'windows-2019'
-        CPU: amd64
-        NIM_TESTAMENT_BATCH: "1_3"
-      Windows_amd64_batch2_3:
-        vmImage: 'windows-2019'
-        CPU: amd64
-        NIM_TESTAMENT_BATCH: "2_3"
+      # Windows_amd64_batch1_3:
+      #   vmImage: 'windows-2019'
+      #   CPU: amd64
+      #   NIM_TESTAMENT_BATCH: "1_3"
+      # Windows_amd64_batch2_3:
+      #   vmImage: 'windows-2019'
+      #   CPU: amd64
+      #   NIM_TESTAMENT_BATCH: "2_3"
 
   pool:
     vmImage: $(vmImage)

compiler/commands.nim

@@ -931,6 +931,24 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
     else: conf.spellSuggestMax = parseInt(arg)
   of "declaredlocs":
     processOnOffSwitchG(conf, {optDeclaredLocs}, arg, pass, info)
+  of "moduleoverride":
+    # --moduleoverride:std/sequtils:pkg/foo/sequtils2:prefix1,prefix2/sub
+    proc validate(path: string): string =
+      if path.isAbsolute or path.isCanonicalPath: result = path
+      else: localError(conf, info, "module path must be canonical or absolute, got: $1" % path)
+    let args = arg.split(":")
+    if args.len notin {2, 3}:
+      localError(conf, info, "invalid arg: $1" % arg)
+    else:
+      let lhs = args[0].validate
+      let rhs = args[1].validate
+      if args.len == 2:
+        conf.localOverrides.add LocalOverride(lhs: lhs, rhs: rhs, prefix: "/")
+      elif args.len == 3:
+        let prefixes = args[2].split(",")
+        for a in prefixes:
+          let prefix = a.validate
+          conf.localOverrides.add LocalOverride(lhs: lhs, rhs: rhs, prefix: prefix)
   of "dynliboverride":
     dynlibOverride(conf, switch, arg, pass, info)
   of "dynliboverrideall":

compiler/debugutils.nim

@@ -54,3 +54,5 @@ proc isCompilerDebug*(): bool =
       {.undef(nimCompilerDebug).}
       echo 'x'
   conf0.isDefined("nimCompilerDebug")
+
+include timn/exp/nim_compiler_debugutils

compiler/options.nim

@@ -278,7 +278,12 @@ type
     foLegacyRelProj # legacy, shortest of (foAbs, foRelProject)
     foName # lastPathPart, e.g.: foo.nim
     foStacktrace # if optExcessiveStackTrace: foAbs else: foName
+  LocalOverrideAtom* = object
 
+  LocalOverride* = object
+    lhs*: string
+    rhs*: string
+    prefix*: string
   ConfigRef* {.acyclic.} = ref object ## every global configuration
                           ## fields marked with '*' are subject to
                           ## the incremental compilation mechanisms
@@ -344,6 +349,7 @@ type
     jsonBuildFile*: AbsoluteFile
     prefixDir*, libpath*, nimcacheDir*: AbsoluteDir
     dllOverrides, moduleOverrides*, cfileSpecificOptions*: StringTableRef
+    localOverrides*: seq[LocalOverride]
     projectName*: string # holds a name like 'nim'
     projectPath*: AbsoluteDir # holds a path like /home/alice/projects/nim/compiler/
     projectFull*: AbsoluteFile # projectPath/projectName
@@ -823,6 +829,12 @@ const stdlibDirs = [
 const
   pkgPrefix = "pkg/"
   stdPrefix = "std/"
+  systemPrefix = "system/"
+
+proc isCanonicalPath*(path: string): bool =
+  # in future work we can support also `this/` for current package.
+  let path = path & '/'
+  result = path.startsWith(stdPrefix) or path.startsWith(systemPrefix) or path.startsWith(pkgPrefix)
 
 proc getRelativePathFromConfigPath*(conf: ConfigRef; f: AbsoluteFile, isTitle = false): RelativeFile =
   let f = $f
@@ -852,7 +864,24 @@ proc findFile*(conf: ConfigRef; f: string; suppressStdlib = false): AbsoluteFile
           result = rawFindFile2(conf, RelativeFile f.toLowerAscii)
   patchModule(conf)
 
-proc findModule*(conf: ConfigRef; modulename, currentModule: string): AbsoluteFile =
+proc canonicalImport*(conf: ConfigRef, file: AbsoluteFile): string
+
+proc canonicalImportPkg*(conf: ConfigRef, file: AbsoluteFile): string =
+  result = canonicalImport(conf, file)
+  let tmp = result & '/'
+  if not (tmp.startsWith(stdPrefix) or tmp.startsWith(systemPrefix)):
+    result = pkgPrefix & result
+
+proc pathMatchesPrefix(conf: ConfigRef, path: string, prefix: string): bool =
+  # see also `prefixmatches.prefixMatch`
+  if prefix == "/": result = true
+  elif prefix.isAbsolute:
+    result = path.isRelativeTo(prefix)
+  else: # canonical, eg std/foo or pkg/fusion/bar
+    let canon = canonicalImportPkg(conf, AbsoluteFile(path)) & '/'
+    result = canon.startsWith(prefix & '/')
+
+proc findModule*(conf: ConfigRef; modulename, currentModule: string, depth = 0): AbsoluteFile =
   # returns path to module
   var m = addFileExt(modulename, NimExt)
   if m.startsWith(pkgPrefix):
@@ -870,6 +899,19 @@ proc findModule*(conf: ConfigRef; modulename, currentModule: string): AbsoluteFi
       result = AbsoluteFile currentPath / m
     if not fileExists(result):
       result = findFile(conf, m)
+  if not result.isEmpty:
+    let canon = canonicalImportPkg(conf, result)
+    for ai in conf.localOverrides:
+      if ai.lhs == canon:
+        if pathMatchesPrefix(conf, currentModule, ai.prefix):
+          if depth > 10:
+            # can happen with: `--moduleoverride:std/foo2:std/foo2` or `--moduleoverride:std/foo2:/pathto/std/foo2`
+            # or more complex cases with cycles. Future work could improve things but this is a rare edge case.
+            # `localError` not defined in scope, alternative is some simple refactoring.
+            stderr.write "module resolution too deep, possible cyclic overrides detected\n"
+            return AbsoluteFile""
+          result = findModule(conf, ai.rhs, currentModule, depth + 1)
+          break
   patchModule(conf)
 
 proc findProjectNimFile*(conf: ConfigRef; pkg: string): string =
@@ -918,17 +960,22 @@ proc canonicalImportAux*(conf: ConfigRef, file: AbsoluteFile): string =
   system, std/tables, fusion/pointers, system/assertions, std/private/asciitables
   ]##
   var ret = getRelativePathFromConfigPath(conf, file, isTitle = true)
+  echo "D20210715T122459"
   let dir = getNimbleFile(conf, $file).parentDir.AbsoluteDir
+  echo file, " ", ret, " ", getNimbleFile(conf, $file), " ", dir
   if not dir.isEmpty:
     let relPath = relativeTo(file, dir)
+    echo "relPath: ", relPath
     if not relPath.isEmpty and (ret.isEmpty or relPath.string.len < ret.string.len):
       ret = relPath
   if ret.isEmpty:
     ret = relativeTo(file, conf.projectPath)
+    echo "ret: ", ret
   result = ret.string
 
 proc canonicalImport*(conf: ConfigRef, file: AbsoluteFile): string =
   let ret = canonicalImportAux(conf, file)
+  echo "canonicalImport: ret: ", ret, " file: ", file
   result = ret.nativeToUnixPath.changeFileExt("")
 
 proc canonDynlibName(s: string): string =