remove `std/sharedstrings` (#19228)

* remove std/sharedstrings

it has been broken since 0.18.0

* rephrase the changelog entry

3 files changed, 2 insertions, 155 deletions

diff --git a/changelog.md b/changelog.md
index a8f1920e9..ebad54fe4 100644
--- a/changelog.md
+++ b/changelog.md
@@ -14,6 +14,8 @@
 - Optional parameters in combination with `: body` syntax (RFC #405) are now opt-in via
   `experimental:flexibleOptionalParams`.
 
+- `std/sharedstrings` module is removed.
+
 ## Standard library additions and changes
 
 - `macros.parseExpr` and `macros.parseStmt` now accept an optional
diff --git a/lib/deprecated/pure/sharedstrings.nim b/lib/deprecated/pure/sharedstrings.nim
deleted file mode 100644
index 99963e1f2..000000000
--- a/lib/deprecated/pure/sharedstrings.nim
+++ /dev/null
@@ -1,154 +0,0 @@
-#
-#
-#            Nim's Runtime Library
-#        (c) Copyright 2015 Andreas Rumpf
-#
-#    See the file "copying.txt", included in this
-#    distribution, for details about the copyright.
-#
-
-## Shared string support for Nim.
-
-{.deprecated.}
-
-type
-  UncheckedCharArray = UncheckedArray[char]
-
-type
-  Buffer = ptr object
-    refcount: int
-    capacity, realLen: int
-    data: UncheckedCharArray
-
-  SharedString* = object ## A string that can be shared. Slicing is O(1).
-    buffer: Buffer
-    first, len: int
-
-proc decRef(b: Buffer) {.inline.} =
-  if atomicDec(b.refcount) <= 0:
-    deallocShared(b)
-
-proc incRef(b: Buffer) {.inline.} =
-  atomicInc(b.refcount)
-
-{.experimental.}
-
-proc `=destroy`*(s: SharedString) =
-  #echo "destroyed"
-  if not s.buffer.isNil:
-    decRef(s.buffer)
-
-when false:
-  proc `=copy`*(dest: var SharedString; src: SharedString) =
-    incRef(src.buffer)
-    if not dest.buffer.isNil:
-      decRef(dest.buffer)
-    dest.buffer = src.buffer
-    dest.first = src.first
-    dest.len = src.len
-
-proc len*(s: SharedString): int = s.len
-
-proc `[]`*(s: SharedString; i: Natural): char =
-  if i < s.len: result = s.buffer.data[i+s.first]
-  else: raise newException(IndexDefect, formatErrorIndexBound(i, s.len-1))
-
-proc `[]=`*(s: var SharedString; i: Natural; value: char) =
-  if i < s.len: s.buffer.data[i+s.first] = value
-  else: raise newException(IndexDefect, formatErrorIndexBound(i, s.len-1))
-
-proc `[]`*(s: SharedString; ab: HSlice[int, int]): SharedString =
-  #incRef(src.buffer)
-  if ab.a < s.len:
-    result.buffer = s.buffer
-    result.first = ab.a
-    result.len = min(s.len, ab.b - ab.a + 1)
-  # else: produce empty string ;-)
-
-proc newBuffer(cap, len: int): Buffer =
-  assert cap >= len
-  result = cast[Buffer](allocShared0(sizeof(int)*3 + cap))
-  result.refcount = 0
-  result.capacity = cap
-  result.realLen = len
-
-proc newSharedString*(len: Natural): SharedString =
-  if len != 0:
-    # optimization: Don't have an underlying buffer when 'len == 0'
-    result.buffer = newBuffer(len, len)
-  result.first = 0
-  result.len = len
-
-proc newSharedString*(s: string): SharedString =
-  let len = s.len
-  if len != 0:
-    # optimization: Don't have an underlying buffer when 'len == 0'
-    result.buffer = newBuffer(len, len)
-    copyMem(addr result.buffer.data[0], cstring(s), s.len)
-  result.first = 0
-  result.len = len
-
-when declared(atomicLoadN):
-  template load(x): untyped = atomicLoadN(addr x, ATOMIC_SEQ_CST)
-else:
-  # XXX Fixme
-  template load(x): untyped = x
-
-proc add*(s: var SharedString; t: cstring; len: Natural) =
-  if len == 0: return
-  let newLen = s.len + len
-  if s.buffer.isNil:
-    s.buffer = newBuffer(len, len)
-    copyMem(addr s.buffer.data[0], t, len)
-    s.len = len
-  elif newLen >= s.buffer.capacity or s.first != 0 or
-      s.len != s.buffer.realLen or load(s.buffer.refcount) > 1:
-    let oldBuf = s.buffer
-    s.buffer = newBuffer(max(s.buffer.capacity * 3 div 2, newLen), newLen)
-    copyMem(addr s.buffer.data[0], addr oldBuf.data[s.first], s.len)
-    copyMem(addr s.buffer.data[s.len], t, len)
-    decRef(oldBuf)
-  else:
-    copyMem(addr s.buffer.data[s.len], t, len)
-    s.buffer.realLen += len
-    s.len += len
-
-proc add*(s: var SharedString; t: string) =
-  s.add(t.cstring, t.len)
-
-proc rawData*(s: var SharedString): pointer =
-  if s.buffer.isNil: result = nil
-  else: result = addr s.buffer.data[s.first]
-
-proc add*(s: var SharedString; t: SharedString) =
-  if t.buffer.isNil: return
-  s.add(cast[cstring](addr s.buffer.data[s.first]), t.len)
-
-proc `$`*(s: SharedString): string =
-  result = newString(s.len)
-  if s.len > 0:
-    copyMem(addr result[0], addr s.buffer.data[s.first], s.len)
-
-proc `==`*(s: SharedString; t: string): bool =
-  if s.buffer.isNil: result = t.len == 0
-  else: result = t.len == s.len and equalMem(addr s.buffer.data[s.first],
-                                             cstring(t), t.len)
-
-proc `==`*(s, t: SharedString): bool =
-  if s.buffer.isNil: result = t.len == 0
-  else: result = t.len == s.len and equalMem(addr s.buffer.data[s.first],
-                                             addr t.buffer.data[t.first], t.len)
-
-iterator items*(s: SharedString): char =
-  let buf = s.buffer.data
-  let x = s.first
-  if buf != nil:
-    for i in 0..<s.len:
-      yield buf[i+x]
-
-import hashes
-
-proc hash*(s: SharedString): THash =
-  var h: THash = 0
-  for x in s: h = h !& x.hash
-  result = !$h
diff --git a/testament/testament.nim b/testament/testament.nim
index 105f00156..4b5a8a147 100644
--- a/testament/testament.nim
+++ b/testament/testament.nim
@@ -600,7 +600,6 @@ proc makeRawTest(test, options: string, cat: Category): TTest {.used.} =
 # TODO: fix these files
 const disabledFilesDefault = @[
   "LockFreeHash.nim",
-  "sharedstrings.nim",
   "tableimpl.nim",
   "setimpl.nim",
   "hashcommon.nim",