[gobject-introspection] giscanner: fix EOF check with flex >= 2.6.1

[Rico Tzschichholz <ricotz src gnome org>]

commit cf04292691625e8abcd8cc8af9436809f273e5a0
Author: Jan de Groot <jgc archlinux org>
Date:   Thu Oct 20 12:14:19 2016 +0000

    giscanner: fix EOF check with flex >= 2.6.1
    
    It looks like flex 2.6.1 changed [1] the return code for EOF in
    yyinput.  Therefore, use the right value depending on the version of
    flex which generates the lexer.
    
    [1] https://github.com/westes/flex/commit/f863c9490e6912ffcaeb12965fb3a567a10745ff
    
    https://bugzilla.gnome.org/show_bug.cgi?id=773272

 giscanner/scannerlexer.l |   21 +++++++++++++++------
 1 files changed, 15 insertions(+), 6 deletions(-)
---
diff --git a/giscanner/scannerlexer.l b/giscanner/scannerlexer.l
index 61c0a92..7dbab5c 100644
--- a/giscanner/scannerlexer.l
+++ b/giscanner/scannerlexer.l
@@ -59,6 +59,15 @@ static void process_linemarks (GISourceScanner *scanner, gboolean has_line);
 static int check_identifier (GISourceScanner *scanner, const char *);
 static int parse_ignored_macro (void);
 static void print_error (GISourceScanner *scanner);
+
+#if (YY_FLEX_MAJOR_VERSION > 2) \
+  || ((YY_FLEX_MAJOR_VERSION == 2) && (YY_FLEX_MINOR_VERSION > 6)) \
+  || ((YY_FLEX_MAJOR_VERSION == 2) && (YY_FLEX_MINOR_VERSION == 6) && (YY_FLEX_SUBMINOR_VERSION >= 1))
+#define IS_EOF 0
+#else
+#define IS_EOF EOF
+#endif
+
 %}
 
 %option nounput
@@ -273,7 +282,7 @@ parse_comment (GISourceScanner *scanner)
   c1 = input();
   c2 = input();
 
-  if (c2 != EOF && (c1 == '*' && c2 != '*' && c2 != '/')) {
+  if (c2 != IS_EOF && (c1 == '*' && c2 != '*' && c2 != '/')) {
     /*
      * Store GTK-Doc comment blocks,
      * starts with one '/' followed by exactly two '*' and not followed by a '/'
@@ -286,7 +295,7 @@ parse_comment (GISourceScanner *scanner)
 
     comment_lineno = lineno;
 
-    while (c2 != EOF && !(c1 == '*' && c2 == '/'))
+    while (c2 != IS_EOF && !(c1 == '*' && c2 == '/'))
       {
         if (!skip)
           g_string_append_c (string, c1);
@@ -314,7 +323,7 @@ parse_comment (GISourceScanner *scanner)
     /*
      * Ignore all other comment blocks
      */
-    while (c2 != EOF && !(c1 == '*' && c2 == '/'))
+    while (c2 != IS_EOF && !(c1 == '*' && c2 == '/'))
       {
         if (c1 == '\n')
           lineno++;
@@ -439,19 +448,19 @@ parse_ignored_macro (void)
        int c;
        int nest;
 
-       while ((c = input ()) != EOF && isspace (c))
+       while ((c = input ()) != IS_EOF && isspace (c))
                ;
        if (c != '(')
                return FALSE;
 
        nest = 0;
-       while ((c = input ()) != EOF && (nest > 0 || c != ')')) {
+       while ((c = input ()) != IS_EOF && (nest > 0 || c != ')')) {
                if (c == '(')
                        nest++;
                else if (c == ')')
                        nest--;
                else if (c == '"') {
-                       while ((c = input ()) != EOF && c != '"') {
+                       while ((c = input ()) != IS_EOF && c != '"') {
                                if (c == '\\')
                                        c = input ();
                        }