1 files changed, 73 insertions, 0 deletions
diff --git a/Utilities/Scripts/pragma-once.pl b/Utilities/Scripts/pragma-once.pl
new file mode 100755
index 0000000..41162ec
--- /dev/null
+++ b/Utilities/Scripts/pragma-once.pl
@@ -0,0 +1,73 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+
+use constant {
+  START => 0,
+  HAVE_IFNDEF => 1,
+  HAVE_DEFINE => 2,
+  HAVE_ENDIF => 3,
+  HAVE_PRAGMA_ONCE => 4,
+};
+my $state = START;
+my $blank_count = 0;
+my $endif = '';
+while (<>) {
+  if ($state == START) {
+    if (/^#ifndef [a-zA-Z_][a-zA-Z0-9_]*$/) {
+      $state = HAVE_IFNDEF;
+      print "#pragma once\n";
+    } else {
+      if (/^#pragma once$/) {
+        $state = HAVE_PRAGMA_ONCE;
+      }
+      print;
+    }
+  } elsif ($state == HAVE_IFNDEF) {
+    if (/^#define [a-zA-Z_][a-zA-Z0-9_]*$/) {
+      $blank_count = 0;
+      $state = HAVE_DEFINE;
+    } else {
+      print;
+    }
+  } elsif ($state == HAVE_DEFINE) {
+    if (/^#endif/) {
+      $endif = $_;
+      $state = HAVE_ENDIF;
+    } elsif (/^$/) {
+      $blank_count++;
+    } else {
+      for (my $i = 0; $i < $blank_count; $i++) {
+        print "\n";
+      }
+      $blank_count = 0;
+      print;
+    }
+  } elsif ($state == HAVE_ENDIF) {
+    for (my $i = 0; $i < $blank_count; $i++) {
+      print "\n";
+    }
+    $blank_count = 0;
+    print $endif;
+    $state = HAVE_DEFINE;
+    if (/^#endif/) {
+      $endif = $_;
+      $state = HAVE_ENDIF;
+    } elsif (/^$/) {
+      $blank_count++;
+    } else {
+      print;
+    }
+  } elsif ($state == HAVE_PRAGMA_ONCE) {
+    print;
+  }
+  if (eof) {
+    if ($state != HAVE_ENDIF && $state != HAVE_PRAGMA_ONCE) {
+      print STDERR "Malformed header file: $ARGV\n";
+      exit 1;
+    }
+    $state = START;
+    $blank_count = 0;
+  }
+}