Extract correct line numbers to use in line number test

This makes the test much less fragile as now all that is need is for
@line@ and __LINE__ to be on the same line (the comment gets substituted
too, but it's a comment...)

tests/.gitignore

@@ -80,7 +80,7 @@ lexcompat*
 !lexcompat.rules
 !lexcompat.txt
 lineno*
-!lineno_generated.l
+!lineno_generated.l.in
 !lineno.rules
 !lineno.txt
 mem_nr

tests/Makefile.am

@@ -135,6 +135,8 @@ include_by_buffer_direct_SOURCES = include_by_buffer.direct.l
 include_by_push_direct_SOURCES = include_by_push.direct.l
 include_by_reentrant_direct_SOURCES = include_by_reentrant.direct.l
 lineno_generated_SOURCES = lineno_generated.l
+lineno_generated.l: lineno_generated.l.in
+	grep -n '@LINE@' $^ | sed -e 's%^\([0-9]\+\):.*%\1s/@LINE@/\1/%' | sed -f - $^ > $@.t && mv $@.t $@
 mem_nr_SOURCES = mem_nr.l
 mem_r_SOURCES = mem_r.l
 mem_c99_SOURCES = mem_c99.l

tests/lineno_generated.l → tests/lineno_generated.l.in

@@ -24,30 +24,31 @@
 %{
 /* Test generated line numbers. Be careful editing this file
    as it's all about ensuring flex generates correct line
-   directives.
+   directives, so the @LINE@ markers must be on the same line as a
+   their corresponding __LINE__ macros.
 */
 #include <stdio.h>
 #include "config.h"
 
-static int defs_percent_expect = 32, defs_percent_got = __LINE__;
+static int defs_percent_expect = @LINE@, defs_percent_got = __LINE__;
 static int error_count = 0;
 
 static void test_line (const char *desc, int expect, int got);
 
 %}
 
-    static int defs_indent_expect = 39, defs_indent_got = __LINE__;
+    static int defs_indent_expect = @LINE@, defs_indent_got = __LINE__;
 
 %option nounput noyywrap noinput
 %option warn
 
 %%
-        test_line ("prolog indent", 45, __LINE__);
+        test_line ("prolog indent", @LINE@, __LINE__);
 %{
-        test_line ("prolog percent", 47, __LINE__);
+        test_line ("prolog percent", @LINE@, __LINE__);
 %}
-\n      { test_line ("rules braced", 49, __LINE__); }
-.       test_line ("rules bare", 50, __LINE__);
+\n      { test_line ("rules braced", @LINE@, __LINE__); }
+.       test_line ("rules bare", @LINE@, __LINE__);
 
 %%
 
@@ -66,7 +67,7 @@ main (void)
     yy_delete_buffer (buffer);
     test_line ("defs percent", defs_percent_expect, defs_percent_got);
     test_line ("defs indent", defs_indent_expect, defs_indent_got);
-    test_line ("user code", 69, __LINE__);
+    test_line ("user code", @LINE@, __LINE__);
 
     return error_count != 0;
 }