From 822c7acd3cafc2a3713ff7b6f5c3b1ac02252d68 Mon Sep 17 00:00:00 2001
From: Andreas Rumpf <rumpf_a@web.de>
Date: Mon, 4 Jan 2021 19:44:50 +0100
Subject: [PATCH] make --gc:arc --exceptions:quirky work again [backport:1.4]
 (#16583)

* make --gc:arc --exceptions:quirky work again [backport:1.4]

* fixes #16404 [backport:1.4]

(cherry picked from commit 6317e4004dded87d698b41274e31d318fe52e877)
---
 compiler/commands.nim                       |  4 ++++
 compiler/main.nim                           |  2 --
 lib/system/embedded.nim                     | 10 ++++++++++
 tests/manyloc/standalone/panicoverride.nim  |  5 -----
 tests/manyloc/standalone2/panicoverride.nim | 14 ++++++++++++++
 tests/manyloc/standalone2/tavr.nim          |  7 +++++++
 tests/manyloc/standalone2/tavr.nim.cfg      |  4 ++++
 7 files changed, 39 insertions(+), 7 deletions(-)
 create mode 100644 tests/manyloc/standalone2/panicoverride.nim
 create mode 100644 tests/manyloc/standalone2/tavr.nim
 create mode 100644 tests/manyloc/standalone2/tavr.nim.cfg

diff --git a/compiler/commands.nim b/compiler/commands.nim
index e6080689cf..fa981133fe 100644
--- a/compiler/commands.nim
+++ b/compiler/commands.nim
@@ -513,6 +513,8 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
         if pass in {passCmd2, passPP}:
           defineSymbol(conf.symbols, "nimSeqsV2")
           defineSymbol(conf.symbols, "nimV2")
+        if conf.exc == excNone and conf.backend != backendCpp:
+          conf.exc = excGoto
       of "orc":
         conf.selectedGC = gcOrc
         defineSymbol(conf.symbols, "gcdestructors")
@@ -522,6 +524,8 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
         if pass in {passCmd2, passPP}:
           defineSymbol(conf.symbols, "nimSeqsV2")
           defineSymbol(conf.symbols, "nimV2")
+        if conf.exc == excNone and conf.backend != backendCpp:
+          conf.exc = excGoto
       of "hooks":
         conf.selectedGC = gcHooks
         defineSymbol(conf.symbols, "gchooks")
diff --git a/compiler/main.nim b/compiler/main.nim
index c4feffeabe..fc37407847 100644
--- a/compiler/main.nim
+++ b/compiler/main.nim
@@ -197,8 +197,6 @@ proc mainCommand*(graph: ModuleGraph) =
         # A better solution might be to fix system.nim
         undefSymbol(conf.symbols, "useNimRtl")
     of backendInvalid: doAssert false
-    if conf.selectedGC in {gcArc, gcOrc} and conf.backend != backendCpp:
-      conf.exc = excGoto
 
   var commandAlreadyProcessed = false
 
diff --git a/lib/system/embedded.nim b/lib/system/embedded.nim
index c4f15a3360..258558c3f6 100644
--- a/lib/system/embedded.nim
+++ b/lib/system/embedded.nim
@@ -44,3 +44,13 @@ proc setControlCHook(hook: proc () {.noconv.}) = discard
 
 proc closureIterSetupExc(e: ref Exception) {.compilerproc, inline.} =
   sysFatal(ReraiseDefect, "exception handling is not available")
+
+when gotoBasedExceptions:
+  var nimInErrorMode {.threadvar.}: bool
+
+  proc nimErrorFlag(): ptr bool {.compilerRtl, inl.} =
+    result = addr(nimInErrorMode)
+
+  proc nimTestErrorFlag() {.compilerRtl.} =
+    if nimInErrorMode:
+      sysFatal(ReraiseDefect, "exception handling is not available")
diff --git a/tests/manyloc/standalone/panicoverride.nim b/tests/manyloc/standalone/panicoverride.nim
index d9b3f43886..c0b8bb030e 100644
--- a/tests/manyloc/standalone/panicoverride.nim
+++ b/tests/manyloc/standalone/panicoverride.nim
@@ -11,9 +11,4 @@ proc panic(s: string) {.noreturn.} =
   rawoutput(s)
   exit(1)
 
-# Alternatively we also could implement these 2 here:
-#
-# proc sysFatal(exceptn: typeDesc, message: string) {.noReturn.}
-# proc sysFatal(exceptn: typeDesc, message, arg: string) {.noReturn.}
-
 {.pop.}
diff --git a/tests/manyloc/standalone2/panicoverride.nim b/tests/manyloc/standalone2/panicoverride.nim
new file mode 100644
index 0000000000..c0b8bb030e
--- /dev/null
+++ b/tests/manyloc/standalone2/panicoverride.nim
@@ -0,0 +1,14 @@
+
+proc printf(frmt: cstring) {.varargs, importc, header: "<stdio.h>", cdecl.}
+proc exit(code: int) {.importc, header: "<stdlib.h>", cdecl.}
+
+{.push stack_trace: off, profiler:off.}
+
+proc rawoutput(s: string) =
+  printf("%s\n", s)
+
+proc panic(s: string) {.noreturn.} =
+  rawoutput(s)
+  exit(1)
+
+{.pop.}
diff --git a/tests/manyloc/standalone2/tavr.nim b/tests/manyloc/standalone2/tavr.nim
new file mode 100644
index 0000000000..6cbc5c6990
--- /dev/null
+++ b/tests/manyloc/standalone2/tavr.nim
@@ -0,0 +1,7 @@
+# bug #16404
+
+proc printf(frmt: cstring) {.varargs, header: "<stdio.h>", cdecl.}
+
+var x = 0
+inc x
+printf("hi %ld\n", x+4777)
diff --git a/tests/manyloc/standalone2/tavr.nim.cfg b/tests/manyloc/standalone2/tavr.nim.cfg
new file mode 100644
index 0000000000..e5291969dd
--- /dev/null
+++ b/tests/manyloc/standalone2/tavr.nim.cfg
@@ -0,0 +1,4 @@
+--gc:arc
+--cpu:avr
+--os:standalone
+--compileOnly