doc: add script to compute texi files dependencies

Replace the inline awk script with a Perl script which tracks the
dependencies recursively.

This allows to correctly track dependencies for files including files
with a second level include (for example: ffmpeg-devices.texi ->
devices.texi -> outdevs.texi).

This also adds a dependency on perl for computing the dependencies, which
should not be a problem since perl is already required all the way for
building documentation.

1 files changed, 22 insertions, 0 deletions

diff --git a/doc/texidep.pl b/doc/texidep.pl
new file mode 100644
index 0000000000..0275e74709
--- /dev/null
+++ b/doc/texidep.pl
@@ -0,0 +1,22 @@
+#! /usr/bin/perl
+
+use warnings;
+use strict;
+
+my ($root, $target) = @ARGV;
+
+sub print_deps {
+    my ($file, $deps) = @_;
+    $deps->{$file} = 1;
+
+    open(my $fh, "$file") or die "Cannot open file '$file': $!";
+    while (<$fh>) {
+        /^@(?:verbatim)?include\s+(\S+)/ and do {
+            die "Circular dependency found in file $root\n" if exists $deps->{"doc/$1"};
+            print "$target: doc/$1\n";
+            print_deps("doc/$1", {%$deps});
+        }
+    }
+}
+
+print_deps($root, {});