improved trimcc tool

tools/trimcc.nim

@@ -1,29 +1,127 @@
 # Trim C compiler installation to a minimum
 
-import strutils, os
-
-proc newName(f: string): string =
-  var (dir, name, ext) = splitFile(f)
-  return dir / "trim_" & name & ext
-
-proc walker(dir: string) = 
+import strutils, os, pegs, strtabs, math, threadpool, times
+
+proc fakeCppDep(x: ptr float) {.importcpp: "fakeCppDep", header: "<vector>".}
+
+const
+  Essential = """gcc.exe g++.exe gdb.exe ld.exe as.exe c++.exe cpp.exe cc1.exe
+crtbegin.o crtend.o crt2.o dllcrt2.o
+libexpat-1.dll libwinpthread-1.dll
+
+aio.h
+dlfcn.h
+fcntl.h fenv.h fmtmsg.h fnmatch.h ftw.h
+errno.h
+glob.h gtmath.h
+if.h in.h ipc.h
+langinfo.h locale.h
+math.h mman.h
+netdb.h nl_types.h
+poll.h pthread.h pwd.h
+sched.h select.h semaphore.h signal.h
+socket.h spawn.h stat.h statvfs.h stdio.h stdlib.h string.h strings.h
+tcp.h time.h types.h
+ucontext.h uio.h utsname.h unistd.h
+wait.h
+varargs.h
+windows.h
+zlib.h
+""".split
+  BucketSize = 40
+
+proc includes(headerpath, headerfile: string, whitelist: StringTableRef) =
+  whitelist[headerfile] = "processed"
+  for line in lines(headerpath):
+    if line =~ peg"""s <- ws '#include' ws ('"' / '<') {[^">]+} ('"' / '>') ws
+                     comment <- '/*' @ '*/' / '//' .*
+                     ws <- (comment / \s+)* """:
+      let m = matches[0].extractFilename
+      if whitelist[m] != "processed":
+        whitelist[m] = "found"
+
+proc processIncludes(dir: string, whitelist: StringTableRef) =
   for kind, path in walkDir(dir):
     case kind
-    of pcFile:
-      moveFile(dest=newName(path), source=path)
-      # test if installation still works:
-      if execShellCmd(r"nimrod c --force_build koch") == 0:
-        echo "Optional: ", path
-        removeFile(newName(path))
-      else:
-        echo "Required: ", path
-        # copy back:
-        moveFile(dest=path, source=newName(path))
-    of pcDir:
-      walker(path)
+    of pcFile:
+      let name = extractFilename(path)
+      if ('.' notin name and "include" in path) or ("c++" in path):
+        let n = whitelist[name]
+        if n != "processed": whitelist[name] = "found"
+      if name.endswith(".h"):
+        let n = whitelist[name]
+        if n == "found": includes(path, name, whitelist)
+    of pcDir: processIncludes(path, whitelist)
+    else: discard
+
+proc gatherFiles(dir: string, whitelist: StringTableRef, result: var seq[string]) =
+  for kind, path in walkDir(dir):
+    case kind
+    of pcFile:
+      let name = extractFilename(path)
+      if not whitelist.hasKey(name):
+        result.add(path)
+    of pcDir: gatherFiles(path, whitelist, result)
     else: discard
 
-if paramCount() == 1:
-  walker(paramStr(1))
+proc newName(f: string): string =
+  let (dir, name, ext) = splitFile(f)
+  return dir / "trim_" & name & ext
+
+proc ccStillWorks(): bool =
+  const
+    c1 = r"nim c --force_build koch"
+    c2 = r"nim c --force_build --threads:on --out:temp.exe tools/trimcc"
+  result = execShellCmd(c1) == 0 and execShellCmd(c2) == 0
+
+proc trialDeletion(files: seq[string], a, b: int) =
+  for i in a .. min(b, files.high):
+    let path = files[i]
+    moveFile(dest=newName(path), source=path)
+  if ccStillWorks():
+    for i in a .. min(b, files.high):
+      let path = files[i]
+      echo "Optional: ", path
+      removeFile(newName(path))
+  else:
+    for i in a .. min(b, files.high):
+      let path = files[i]
+      echo "Required: ", path
+      # copy back:
+      moveFile(dest=path, source=newName(path))
+
+proc main(dir: string) =
+  var whitelist = newStringTable(modeCaseInsensitive)
+  for e in Essential:
+    whitelist[e] = "found"
+  while true:
+    let oldLen = whitelist.len
+    processIncludes(dir, whitelist)
+    if oldLen == whitelist.len: break
+  var allFiles: seq[string] = @[]
+  gatherFiles(dir, whitelist, allFiles)
+  when true:
+    var i = 0
+    while i < allFiles.len:
+      trialDeletion(allFiles, i, i+BucketSize-1)
+      inc i, BucketSize
+  else:
+    for x in allFiles: echo x
+
+proc fakeTimeDep() = echo(times.getDateStr())
+
+proc fakedeps() =
+  var x = 0.4
+  {.emit: "#if 0\n".}
+  fakeCppDep(addr x)
+  {.emit: "#endif\n".}
+
+  # this is not true:
+  if math.sin(x) > 0.6:
+    spawn(fakeTimeDep())
+
+if paramCount() == 1:
+  doAssert ccStillWorks()
+  fakedeps()
   main(paramStr(1))
 else: