File nim-fix-gcc-major-version-detection.patch of Package nim.17613

Index: nim-1.6.6/compiler/extccomp.nim
===================================================================
--- nim-1.6.6.orig/compiler/extccomp.nim
+++ nim-1.6.6/compiler/extccomp.nim
@@ -14,7 +14,7 @@
 
 import ropes, platform, condsyms, options, msgs, lineinfos, pathutils
 
-import std/[os, strutils, osproc, sha1, streams, sequtils, times, strtabs, json, jsonutils, sugar]
+import std/[os, strutils, osproc, sha1, streams, sequtils, times, strtabs, json, jsonutils, sugar, parseutils]
 
 type
   TInfoCCProp* = enum         # properties of the C compiler:
@@ -512,26 +512,11 @@ proc ccHasSaneOverflow*(conf: ConfigRef)
     result = false # assume an old or crappy GCC
     var exe = getConfigVar(conf, conf.cCompiler, ".exe")
     if exe.len == 0: exe = CC[conf.cCompiler].compilerExe
-    let (s, exitCode) = try: execCmdEx(exe & " --version") except: ("", 1)
+    let (s, exitCode) = try: execCmdEx(exe & " -dumpversion") except: ("", 1)
     if exitCode == 0:
-      var i = 0
-      var j = 0
-      # the version is the last part of the first line:
-      while i < s.len and s[i] != '\n':
-        if s[i] in {' ', '\t'}: j = i+1
-        inc i
-      if j > 0:
-        var major = 0
-        while j < s.len and s[j] in {'0'..'9'}:
-          major = major * 10 + (ord(s[j]) - ord('0'))
-          inc j
-        if i < s.len and s[j] == '.': inc j
-        while j < s.len and s[j] in {'0'..'9'}:
-          inc j
-        if j+1 < s.len and s[j] == '.' and s[j+1] in {'0'..'9'}:
-          # we found a third version number, chances are high
-          # we really parsed the version:
-          result = major >= 5
+      var major: int
+      discard parseInt(s, major)
+      result = major > 5
   else:
     result = conf.cCompiler == ccCLang