diffseq: Silence gcc warning

[Bruno Haible]

In gettext and diffutils, I'm still seeing these warnings:

diffseq.h:424:36: warning: 'fxbest' may be used uninitialized 
[-Wmaybe-uninitialized]
diffseq.h:431:36: warning: 'bxbest' may be used uninitialized 
[-Wmaybe-uninitialized]

Like done on 2023-05-18, I'm silencing this through a #pragma GCC diagnostic.
But in this case, it seems worthwhile to keep a way to have the
-Wmaybe-uninitialized warnings still enabled if the developer wishes to see
warnings about other variables in this complicated function; namely by using
-Dlint or -DGCC_LINT.


2023-05-24  Bruno Haible  <bruno@clisp.org>

        diffseq: Silence gcc warning.
        * lib/diffseq.h: Add #pragma GCC diagnostic.

diff --git a/lib/diffseq.h b/lib/diffseq.h
index c9375cd696..bab8256f64 100644
--- a/lib/diffseq.h
+++ b/lib/diffseq.h
@@ -94,11 +94,17 @@
 
 /* Use this to suppress gcc's "...may be used before initialized" warnings.
    Beware: The Code argument must not contain commas.  */
+#if __GNUC__ + (__GNUC_MINOR__ >= 7) > 4
+# pragma GCC diagnostic push
+#endif
 #ifndef IF_LINT
 # if defined GCC_LINT || defined lint
 #  define IF_LINT(Code) Code
 # else
 #  define IF_LINT(Code) /* empty */
+#  if __GNUC__ + (__GNUC_MINOR__ >= 7) > 4
+#   pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
+#  endif
 # endif
 #endif
 
@@ -444,6 +450,10 @@ diag (OFFSET xoff, OFFSET xlim, OFFSET yoff, OFFSET ylim, 
bool find_minimal,
   #undef XREF_YREF_EQUAL
 }
 
+#if __GNUC__ + (__GNUC_MINOR__ >= 7) > 4
+# pragma GCC diagnostic pop
+#endif
+
 
 /* Compare in detail contiguous subsequences of the two vectors
    which are known, as a whole, to match each other.