In checkcfgvar.pl, inline and eliminate read_file() and config_h_SH_reader().

config_h_SH_reader() was called once in one place, to generate a closure
passed to read_file(). In turn, read_file()'s use of a callback to process
lines of the file that it opened concealed the near-linear flow of control.

use autodie; to simplify the error handling.

diff --git a/Porting/checkcfgvar.pl b/Porting/checkcfgvar.pl
index b7022dc..e8342ea 100755 (executable)
--- a/Porting/checkcfgvar.pl
+++ b/Porting/checkcfgvar.pl
@@ -11,6 +11,7 @@
 
 use strict;
 use warnings;
+use autodie;
 
 sub usage
 {
@@ -52,38 +53,27 @@ my @CFG = (
           "Porting/config.sh",
          );
 
-sub read_file {
-    my ($fn, $sub) = @_;
-    if (open(my $fh, $fn)) {
-       local $_;
-       while (<$fh>) {
-           &$sub;
-       }
-    } else {
-       die "$0: Failed to open '$fn' for reading: $!\n";
-    }
-}
-
-sub config_h_SH_reader {
-    my $cfg = shift;
-    return sub {
+{
+    open my $fh, '<', $MASTER_CFG;
+    while (<$fh>) {
        while (/[^\\]\$([a-z]\w+)/g) {
            my $v = $1;
            next if $v =~ /^(CONFIG_H|CONFIG_SH)$/;
-           $cfg->{$v}++;
+           $MASTER_CFG{$v}++;
        }
     }
+    close $fh;
 }
 
-read_file($MASTER_CFG,
-         config_h_SH_reader(\%MASTER_CFG));
-
 my %MANIFEST;
 
-read_file("MANIFEST",
-         sub {
-             $MANIFEST{$1}++ if /^(.+?)\t/;
-         });
+{
+    open my $fh, '<', 'MANIFEST';
+    while (<$fh>) {
+       $MANIFEST{$1}++ if /^(.+?)\t/;
+    }
+    close $fh;
+}
 
 my @MASTER_CFG = sort keys %MASTER_CFG;
 
@@ -93,27 +83,30 @@ for my $cfg (@CFG) {
        next;
     }
     my %cfg;
-    read_file($cfg,
-             sub {
-                 return if /^\#/ || /^\s*$/ || /^\:/;
-                 if ($cfg eq 'configure.com') {
-                     s/(\s*!.*|\s*)$//; # remove trailing comments or whitespace
-                     return if ! /^\$\s+WC "(\w+)='(.*)'"$/;
-                 }
-                 # foo='bar'
-                 # foo=bar
-                 if (/^(\w+)='(.*)'$/) {
-                     $cfg{$1}++;
-                 }
-                 elsif (/^(\w+)=(.*)$/) {
-                     $cfg{$1}++;
-                 }
-                 elsif (/^\$\s+WC "(\w+)='(.*)'"$/) {
-                     $cfg{$1}++;
-                 } else {
-                     warn "$cfg:$.:$_";
-                 }
-             });
+
+    open my $fh, '<', $cfg;
+    while (<$fh>) {
+       next if /^\#/ || /^\s*$/ || /^\:/;
+       if ($cfg eq 'configure.com') {
+           s/(\s*!.*|\s*)$//; # remove trailing comments or whitespace
+           next if ! /^\$\s+WC "(\w+)='(.*)'"$/;
+       }
+       # foo='bar'
+       # foo=bar
+       if (/^(\w+)='(.*)'$/) {
+           $cfg{$1}++;
+       }
+       elsif (/^(\w+)=(.*)$/) {
+           $cfg{$1}++;
+       }
+       elsif (/^\$\s+WC "(\w+)='(.*)'"$/) {
+           $cfg{$1}++;
+       } else {
+           warn "$cfg:$.:$_";
+       }
+    }
+    close $fh;
+
     if ($cfg eq 'configure.com') {
        $cfg{startperl}++; # Cheat.
     }