fix compile_commands.json generation

.gitignore

@@ -1,3 +1,5 @@
 /obj
 /files/cfg
 /.direnv
+.cache
+compile_commands.json

src/l4/tool/bin/gen_ccj

@@ -0,0 +1,71 @@
+#! /usr/bin/env perl
+
+use strict;
+use warnings;
+use File::Basename;
+use File::Find;
+
+my $searchdir = shift;
+my $outfile = shift;
+
+if (not defined $outfile)
+  {
+    print "Usage: $0 search-dir outfile\n";
+    print "\n";
+    print "Example: $0 /path/to/obj-dir /path/to/your/l4re/src/dir/compile_commands.json\n";
+    exit 1;
+  }
+
+open(my $out, ">$outfile") or die "Cannot open '$outfile': $!";
+
+my @db;
+
+sub add_cmd
+{
+  return unless /\.cmd$/;
+
+  open(my $fh_cmd, $_) or die "Cannot open '$File::Find::name': $!";
+  my $cmd;
+  my $source;
+  my $obj;
+  while (<$fh_cmd>)
+    {
+      chomp;
+      $cmd    = $1 if /^savedcmd_\S+\s+:=\s+(.+)/;
+      $source = $1 if /^source_\S+\s+:=\s+(.+)/;
+      $obj    = $1 if /^savedcmd_(\S+)\s+:=\s+.+/;
+    }
+
+  return unless defined $cmd and defined $source and defined $obj;
+
+  my $obj_dir = dirname($obj);
+  my $obj_path = $File::Find::dir =~ s|\Q/$obj_dir\E$||r;
+
+  sub json_escape { return shift =~ s/(["\\])/\\$1/gr; }
+
+  push @db, {
+    "file"      => json_escape($source),
+    "directory" => json_escape($obj_path),
+    "command"   => json_escape($cmd),
+    "output"    => json_escape("$obj_path/$obj"),
+  }
+}
+
+find(\&add_cmd, $searchdir);
+
+my @sorted = sort { $b->{file} cmp $a->{file} } @db;
+
+print $out "[\n";
+my $comma = "";
+for my $entry (@sorted)
+  {
+    print $out $comma;
+    print $out "  {\n";
+    print $out "    \"file\": \"$entry->{file}\",\n";
+    print $out "    \"directory\": \"$entry->{directory}\",\n";
+    print $out "    \"command\": \"$entry->{command}\",\n";
+    print $out "    \"output\": \"$entry->{output}\"\n";
+    print $out "  }";
+    $comma = ",\n";
+  }
+print $out "\n]\n";