From 97259a5ab37892bedca64b14ffc6e0b7d25dd789 Mon Sep 17 00:00:00 2001
From: ringabout <43030857+ringabout@users.noreply.github.com>
Date: Mon, 19 Sep 2022 15:16:54 +0800
Subject: [PATCH] fixes #19713; Revert "Remove tlsEmulation enabled from
 Windows + GCC config" (#19119) (#20327)

* Revert "Remove tlsEmulation enabled from Windows + GCC config (#19119) [backport:1.6]"

This reverts commit 77b696c2c92b5f478526290c5e184a4c41060f7b.

* increase nimTlsSize to 48000

* enable for windows

* fixes tests

* fixes tlsEmulation:on
---
 compiler/nim.cfg   | 1 +
 compiler/ropes.nim | 8 ++++++--
 config/nim.cfg     | 3 +++
 tests/config.nims  | 2 ++
 4 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/compiler/nim.cfg b/compiler/nim.cfg
index 7ed70fb5f2a3f..853a657b391e5 100644
--- a/compiler/nim.cfg
+++ b/compiler/nim.cfg
@@ -11,6 +11,7 @@ define:nimPreviewSlimSystem
 
 @if windows:
   cincludes: "$lib/wrappers/libffi/common"
+  tlsEmulation:off
 @end
 
 define:useStdoutAsStdmsg
diff --git a/compiler/ropes.nim b/compiler/ropes.nim
index 3a2fbe44e2739..b84cfad527ed4 100644
--- a/compiler/ropes.nim
+++ b/compiler/ropes.nim
@@ -86,8 +86,12 @@ proc newRope(data: string = ""): Rope =
   result.L = -data.len
   result.data = data
 
-var
-  cache {.threadvar.} : array[0..2048*2 - 1, Rope]
+when compileOption("tlsEmulation"): # fixme: be careful if you want to make ropes support multiple threads
+  var
+    cache: array[0..2048*2 - 1, Rope]
+else:
+  var
+    cache {.threadvar.} : array[0..2048*2 - 1, Rope]
 
 proc resetRopeCache* =
   for i in low(cache)..high(cache):
diff --git a/config/nim.cfg b/config/nim.cfg
index fd2642391b646..55b7a41c15c4c 100644
--- a/config/nim.cfg
+++ b/config/nim.cfg
@@ -169,6 +169,9 @@ nimblepath="$home/.nimble/pkgs/"
 # Configuration for the GNU C/C++ compiler:
 @if windows:
   #gcc.path = r"$nim\dist\mingw\bin"
+  @if gcc or tcc:
+    tlsEmulation:on
+  @end
 @end
 
 gcc.maxerrorsimpl = "-fmax-errors=3"
diff --git a/tests/config.nims b/tests/config.nims
index 894c4bea0adc1..5195ebcafbc0e 100644
--- a/tests/config.nims
+++ b/tests/config.nims
@@ -40,3 +40,5 @@ switch("define", "nimPreviewFloatRoundtrip")
 switch("define", "nimPreviewDotLikeOps")
 switch("define", "nimPreviewJsonutilsHoleyEnum")
 switch("define", "nimPreviewHashRef")
+when defined(windows):
+  switch("tlsEmulation", "off")