From ae688aa7f54d820ac7addcd080ff1c7bffbe9237 Mon Sep 17 00:00:00 2001
From: Andreas Rumpf <rumpf_a@web.de>
Date: Mon, 31 Aug 2020 14:46:23 +0200
Subject: [PATCH] fixes #15210 [backport:1.2] (#15237)

* fixes #15210 [backport:1.2]

* use patched version of bigints library

(cherry picked from commit ff13f8cc3c74d4048b6c2604fe4b8e5365f5c13f)
---
 compiler/ccgexprs.nim            | 43 +++++++++++++++++---------------
 lib/system/chcks.nim             |  3 +++
 testament/important_packages.nim |  2 +-
 tests/misc/tunsignedconv.nim     | 11 ++++++++
 4 files changed, 38 insertions(+), 21 deletions(-)

diff --git a/compiler/ccgexprs.nim b/compiler/ccgexprs.nim
index 6ed4c54b28..edb6640564 100644
--- a/compiler/ccgexprs.nim
+++ b/compiler/ccgexprs.nim
@@ -1981,25 +1981,30 @@ proc genRangeChck(p: BProc, n: PNode, d: var TLoc) =
       checkUnsignedConversions notin p.config.legacyFeatures):
     discard "no need to generate a check because it was disabled"
   else:
-    let raiser =
-      case skipTypes(n.typ, abstractVarRange).kind
-      of tyUInt..tyUInt64, tyChar: "raiseRangeErrorU"
-      of tyFloat..tyFloat128: "raiseRangeErrorF"
-      else: "raiseRangeErrorI"
-    discard cgsym(p.module, raiser)
-    # This seems to be bug-compatible with Nim version 1 but what we
-    # should really do here is to check if uint64Value < high(int)
     let n0t = n[0].typ
-    let boundaryCast =
-      if n0t.skipTypes(abstractVarRange).kind in {tyUInt, tyUInt32, tyUInt64} or
-          (n0t.sym != nil and sfSystemModule in n0t.sym.owner.flags and n0t.sym.name.s == "csize"):
-        "(NI64)"
-      else:
-        ""
+
     # emit range check:
-    linefmt(p, cpsStmts, "if ($6($1) < $2 || $6($1) > $3){ $4($1, $2, $3); $5}$n",
-      [rdCharLoc(a), genLiteral(p, n[1], dest), genLiteral(p, n[2], dest),
-      raiser, raiseInstr(p), boundaryCast])
+    if n0t.kind in {tyUInt, tyUInt64}:
+      linefmt(p, cpsStmts, "if ($1 > ($6)($3)){ #raiseRangeErrorNoArgs(); $5}$n",
+        [rdCharLoc(a), genLiteral(p, n[1], dest), genLiteral(p, n[2], dest),
+        raiser, raiseInstr(p), getTypeDesc(p.module, n0t)])
+    else:
+      let raiser =
+        case skipTypes(n.typ, abstractVarRange).kind
+        of tyUInt..tyUInt64, tyChar: "raiseRangeErrorU"
+        of tyFloat..tyFloat128: "raiseRangeErrorF"
+        else: "raiseRangeErrorI"
+      discard cgsym(p.module, raiser)
+
+      let boundaryCast =
+        if n0t.skipTypes(abstractVarRange).kind in {tyUInt, tyUInt32, tyUInt64} or
+            (n0t.sym != nil and sfSystemModule in n0t.sym.owner.flags and n0t.sym.name.s == "csize"):
+          "(NI64)"
+        else:
+          ""
+      linefmt(p, cpsStmts, "if ($6($1) < $2 || $6($1) > $3){ $4($1, $2, $3); $5}$n",
+        [rdCharLoc(a), genLiteral(p, n[1], dest), genLiteral(p, n[2], dest),
+        raiser, raiseInstr(p), boundaryCast])
   putIntoDest(p, d, n, "(($1) ($2))" %
       [getTypeDesc(p.module, dest), rdCharLoc(a)], a.storage)
 
@@ -2665,9 +2670,7 @@ proc expr(p: BProc, n: PNode, d: var TLoc) =
     expr(p, n[1][0], d)
   of nkObjDownConv: downConv(p, n, d)
   of nkObjUpConv: upConv(p, n, d)
-  of nkChckRangeF: genRangeChck(p, n, d)
-  of nkChckRange64: genRangeChck(p, n, d)
-  of nkChckRange: genRangeChck(p, n, d)
+  of nkChckRangeF, nkChckRange64, nkChckRange: genRangeChck(p, n, d)
   of nkStringToCString: convStrToCStr(p, n, d)
   of nkCStringToString: convCStrToStr(p, n, d)
   of nkLambdaKinds:
diff --git a/lib/system/chcks.nim b/lib/system/chcks.nim
index 117543fcda..25ba6f5b9b 100644
--- a/lib/system/chcks.nim
+++ b/lib/system/chcks.nim
@@ -38,6 +38,9 @@ proc raiseRangeErrorU(i, a, b: uint64) {.compilerproc, noinline.} =
   # todo: better error reporting
   sysFatal(RangeError, "value out of range")
 
+proc raiseRangeErrorNoArgs() {.compilerproc, noinline.} =
+  sysFatal(RangeDefect, "value out of range")
+
 proc raiseObjectConversionError() {.compilerproc, noinline.} =
   sysFatal(ObjectConversionError, "invalid object conversion")
 
diff --git a/testament/important_packages.nim b/testament/important_packages.nim
index 5ff2ceebd3..f68735c9e3 100644
--- a/testament/important_packages.nim
+++ b/testament/important_packages.nim
@@ -9,7 +9,7 @@ pkg "argparse"
 pkg "arraymancer", true, "nim c tests/tests_cpu.nim"
 pkg "ast_pattern_matching", false, "nim c -r --oldgensym:on tests/test1.nim"
 pkg "asyncmysql", true
-pkg "bigints"
+pkg "bigints", url = "https://github.com/Araq/nim-bigints"
 pkg "binaryheap", false, "nim c -r binaryheap.nim"
 # pkg "blscurve", true # pending https://github.com/status-im/nim-blscurve/issues/39
 pkg "bncurve", true
diff --git a/tests/misc/tunsignedconv.nim b/tests/misc/tunsignedconv.nim
index e255d9cf75..601deee0d3 100644
--- a/tests/misc/tunsignedconv.nim
+++ b/tests/misc/tunsignedconv.nim
@@ -75,3 +75,14 @@ let rangeVar = 0'u64 ..< limit
 doAssert repr(rangeVar) == """[a = 0,
 b = 0]
 """
+
+# bug #15210
+
+let a3 = not 0'u64
+var success = false
+try:
+  discard a3.int64
+except RangeDefect:
+  success = true
+
+doAssert success, "conversion should fail at runtime"