fixes #11131

compiler/renderer.nim

@@ -323,9 +323,10 @@ proc litAux(g: TSrcGen; n: PNode, x: BiggestInt, size: int): string =
         result &= e.sym.name.s
         return
 
-  if nfBase2 in n.flags: result = "0b" & toBin(x, size * 8)
-  elif nfBase8 in n.flags: result = "0o" & toOct(x, size * 3)
-  elif nfBase16 in n.flags: result = "0x" & toHex(x, size * 2)
+  let y = x and ((1 shl (size*8)) - 1)
+  if nfBase2 in n.flags: result = "0b" & toBin(y, size * 8)
+  elif nfBase8 in n.flags: result = "0o" & toOct(y, size * 3)
+  elif nfBase16 in n.flags: result = "0x" & toHex(y, size * 2)
   else: result = $x
 
 proc ulitAux(g: TSrcGen; n: PNode, x: BiggestInt, size: int): string =

tests/macros/tmacros_issues.nim

@@ -26,6 +26,7 @@ range[0 .. 100]
 array[0 .. 100, int]
 10
 test
+0o377'i8
 '''
 """
 
@@ -236,3 +237,10 @@ block tbugs:
   sampleMacroInt(42)
   sampleMacroBool(false)
   sampleMacroBool(system.true)
+
+
+# bug #11131
+macro toRendererBug(n): untyped =
+  result = newLit repr(n)
+
+echo toRendererBug(0o377'i8)