scripts: get_abi.pl: better generate regex from what fields

Using repeating sequencies of .* seem to slow down the
processing speed on some cases. Also, currently, a "."
character is not properly handled as such.

Change the way regexes are created, in order to produce
better search expressions.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/c69c01c12b1b30466177dcb17e45f833fb47713d.1632994565.git.mchehab+huawei@kernel.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scripts/get_abi.pl

@@ -842,8 +842,8 @@ sub undefined_symbols {
 
 			# Convert what into regular expressions
 
-			$what =~ s,/\.\.\./,/*/,g;
-			$what =~ s,\*,.*,g;
+			# Escape dot characters
+			$what =~ s/\./\xf6/g;
 
 			# Temporarily change [0-9]+ type of patterns
 			$what =~ s/\[0\-9\]\+/\xff/g;
@@ -859,6 +859,8 @@ sub undefined_symbols {
 			$what =~ s/[\{\<\[]([\w_]+)(?:[,|]+([\w_]+)){1,}[\}\>\]]/($1|$2)/g;
 
 			# Handle wildcards
+			$what =~ s,\*,.*,g;
+			$what =~ s,/\xf6..,/.*,g;
 			$what =~ s/\<[^\>]+\>/.*/g;
 			$what =~ s/\{[^\}]+\}/.*/g;
 			$what =~ s/\[[^\]]+\]/.*/g;
@@ -891,6 +893,13 @@ sub undefined_symbols {
 			# Special case: IIO ABI which a parenthesis.
 			$what =~ s/sqrt(.*)/sqrt\(.*\)/;
 
+			# Simplify regexes with multiple .*
+			$what =~ s#(?:\.\*){2,}##g;
+#			$what =~ s#\.\*/\.\*#.*#g;
+
+			# Recover dot characters
+			$what =~ s/\xf6/\./g;
+
 			my $leave = get_leave($what);
 
 			my $added = 0;