improvements to `addInt` and `$` for integer types (#18592)

* improvements to $(SomeInteger) and addInt
* remove mIntToStr, mInt64ToStr
* improvements
* fix tests/pragmas/tinjectstmt.nim; the diff is harmless, cgen code is identical with -d:danger or debug mode
* rm tests/system/tstrmantle.nim
* revert compiler/jsgen.nim for -d:nimVersion140

4 files changed, 35 insertions, 79 deletions

diff --git a/lib/system/assertions.nim b/lib/system/assertions.nim
index cd789845b..6f64a55b7 100644
--- a/lib/system/assertions.nim
+++ b/lib/system/assertions.nim
@@ -12,7 +12,6 @@ import std/private/miscdollars
 
 type InstantiationInfo = tuple[filename: string, line: int, column: int]
 
-proc `$`(x: int): string {.magic: "IntToStr", noSideEffect.}
 proc `$`(info: InstantiationInfo): string =
   # The +1 is needed here
   # instead of overriding `$` (and changing its meaning), consider explicit name.
@@ -108,7 +107,9 @@ template doAssertRaises*(exception: typedesc, code: untyped) =
       wrong = true
     except exception:
       discard
-    except Exception as e: raiseAssert(begin & " raised '" & $e.name & "'" & msgEnd)
+    except Exception as e:
+      mixin `$` # alternatively, we could define $cstring in this module
+      raiseAssert(begin & " raised '" & $e.name & "'" & msgEnd)
     except: raisedForeign()
   if wrong:
     raiseAssert(begin & " nothing was raised" & msgEnd)
diff --git a/lib/system/dollars.nim b/lib/system/dollars.nim
index 8634db382..46085d2aa 100644
--- a/lib/system/dollars.nim
+++ b/lib/system/dollars.nim
@@ -1,45 +1,31 @@
+## `$` is Nim's general way of spelling `toString`:idx:.
+runnableExamples:
+  assert $0.1 == "0.1"
+  assert $(-2*3) == "-6"
+
 import std/private/digitsutils
 import system/formatfloat
 export addFloat
 
-proc `$`*(x: int): string {.magic: "IntToStr", noSideEffect.}
-  ## The stringify operator for an integer argument. Returns `x`
-  ## converted to a decimal string. `$` is Nim's general way of
-  ## spelling `toString`:idx:.
-
-template dollarImpl(x: uint | uint64, result: var string) =
-  addIntImpl(result, x)
-
-when defined(js):
-  import std/private/since
-  since (1, 3):
-    proc `$`*(x: uint): string =
-      ## Caveat: currently implemented as $(cast[int](x)), tied to current
-      ## semantics of js' Number type.
-      # for c, see strmantle.`$`
-      when nimvm:
-        dollarImpl(x, result)
-      else:
-        result = $(int(x))
-
-    proc `$`*(x: uint64): string =
-      ## Compatibility note:
-      ## the results may change in future releases if/when js target implements
-      ## 64bit ints.
-      # pending https://github.com/nim-lang/RFCs/issues/187
-      when nimvm:
-        dollarImpl(x, result)
-      else:
-        result = $(cast[int](x))
-else:
-  proc `$`*(x: uint64): string {.noSideEffect, raises: [].} =
-    ## The stringify operator for an unsigned integer argument. Returns `x`
-    ## converted to a decimal string.
-    dollarImpl(x, result)
-
-proc `$`*(x: int64): string {.magic: "Int64ToStr", noSideEffect.}
-  ## The stringify operator for an integer argument. Returns `x`
-  ## converted to a decimal string.
+proc `$`*(x: int): string {.raises: [].} =
+  ## Outplace version of `addInt`.
+  result.addInt(x)
+
+proc `$`*(x: int64): string {.raises: [].} =
+  ## Outplace version of `addInt`.
+  result.addInt(x)
+
+proc `$`*(x: uint64): string {.raises: [].} =
+  ## Outplace version of `addInt`.
+  addInt(result, x)
+
+# same as old `ctfeWhitelist` behavior, whether or not this is a good idea.
+template gen(T) =
+  # xxx simplify this by supporting this in compiler: int{lit} | uint64{lit} | int64{lit}
+  func `$`*(x: T{lit}): string {.compileTime.} = result.addInt(x)
+gen(int)
+gen(uint64)
+gen(int64)
 
 func `$`*(x: float | float32): string =
   ## Outplace version of `addFloat`.
diff --git a/lib/system/repr_v2.nim b/lib/system/repr_v2.nim
index ba94b881d..6ab5f3c3f 100644
--- a/lib/system/repr_v2.nim
+++ b/lib/system/repr_v2.nim
@@ -8,18 +8,17 @@ proc distinctBase(T: typedesc, recursive: static bool = true): typedesc {.magic:
 
 proc repr*(x: NimNode): string {.magic: "Repr", noSideEffect.}
 
-proc repr*(x: int): string {.magic: "IntToStr", noSideEffect.}
-  ## repr for an integer argument. Returns `x`
-  ## converted to a decimal string.
+proc repr*(x: int): string =
+  ## Same as $x
+  $x
 
-proc repr*(x: int64): string {.magic: "Int64ToStr", noSideEffect.}
-  ## repr for an integer argument. Returns `x`
-  ## converted to a decimal string.
+proc repr*(x: int64): string =
+  ## Same as $x
+  $x
 
 proc repr*(x: uint64): string {.noSideEffect.} =
-  ## repr for an unsigned integer argument. Returns `x`
-  ## converted to a decimal string.
-  $x #Calls `$` from system/strmantle.nim
+  ## Same as $x
+  $x
 
 proc repr*(x: float): string =
   ## Same as $x
diff --git a/lib/system/strmantle.nim b/lib/system/strmantle.nim
index f55168c01..9cf4f9e55 100644
--- a/lib/system/strmantle.nim
+++ b/lib/system/strmantle.nim
@@ -43,32 +43,6 @@ proc hashString(s: string): int {.compilerproc.} =
   h = h + h shl 15
   result = cast[int](h)
 
-proc addInt*(result: var string; x: int64) =
-  ## Converts integer to its string representation and appends it to `result`.
-  ##
-  ## .. code-block:: Nim
-  ##   var
-  ##     a = "123"
-  ##     b = 45
-  ##   a.addInt(b) # a <- "12345"
-  var num: uint64
-
-  if x < 0:
-    if x == low(int64):
-      num = uint64(x)
-    else:
-      num = uint64(-x)
-    let base = result.len
-    setLen(result, base + 1)
-    result[base] = '-'
-  else:
-    num = uint64(x)
-  addIntImpl(result, num)
-
-proc nimIntToStr(x: int): string {.compilerRtl.} =
-  result = newStringOfCap(sizeof(x)*4)
-  result.addInt x
-
 proc c_strtod(buf: cstring, endptr: ptr cstring): float64 {.
   importc: "strtod", header: "<stdlib.h>", noSideEffect.}
 
@@ -240,10 +214,6 @@ proc nimParseBiggestFloat(s: string, number: var BiggestFloat,
 when defined(nimHasInvariant):
   {.pop.} # staticBoundChecks
 
-proc nimInt64ToStr(x: int64): string {.compilerRtl.} =
-  result = newStringOfCap(sizeof(x)*4)
-  result.addInt x
-
 proc nimBoolToStr(x: bool): string {.compilerRtl.} =
   return if x: "true" else: "false"