#! @PERL@
# -*- perl -*-
# @configure_input@

# autoscan - Create configure.scan (a preliminary configure.ac) for a package.
# Copyright (C) 1994, 1999-2017, 2020-2021 Free Software Foundation,
# Inc.

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

# Written by David MacKenzie <djm@gnu.ai.mit.edu>.

eval 'case $# in 0) exec @PERL@ -S "$0";; *) exec @PERL@ -S "$0" "$@";; esac'
    if 0;

use 5.006;
use strict;
use warnings FATAL => 'all';

BEGIN
{
  my $pkgdatadir = $ENV{'autom4te_perllibdir'} || '@pkgdatadir@';
  unshift @INC, $pkgdatadir;

  # Override SHELL.  On DJGPP SHELL may not be set to a shell
  # that can handle redirection and quote arguments correctly,
  # e.g.: COMMAND.COM.  For DJGPP always use the shell that configure
  # has detected.
  $ENV{'SHELL'} = '@SHELL@' if ($^O eq 'dos');
}

use File::Basename;
use File::Find;

use Autom4te::ChannelDefs;
use Autom4te::Configure_ac;
use Autom4te::FileUtils;
use Autom4te::General;
use Autom4te::XFile;

my (@cfiles, @makefiles, @shfiles, @subdirs, %printed);

# The kind of the words we are looking for.
my @kinds = qw (function header identifier program
		makevar librarie);

# For each kind, the default macro.
my %generic_macro =
  (
   'function'   => 'AC_CHECK_FUNCS',
   'header'     => 'AC_CHECK_HEADERS',
   'identifier' => 'AC_CHECK_TYPES',
   'program'    => 'AC_CHECK_PROGS',
   'library'    => 'AC_CHECK_LIB'
  );

my %kind_comment =
  (
   'function'   => 'Checks for library functions.',
   'header'     => 'Checks for header files.',
   'identifier' => 'Checks for typedefs, structures, and compiler characteristics.',
   'program'    => 'Checks for programs.',
  );

# $USED{KIND}{ITEM} is the list of locations where the ITEM (of KIND) was
# used in the user package.
# For instance $USED{function}{alloca} is the list of 'file:line' where
# 'alloca (...)' appears.
my %used = ();

# $MACRO{KIND}{ITEM} is the list of macros to use to test ITEM.
# Initialized from lib/autoscan/*.  E.g., $MACRO{function}{alloca} contains
# the singleton AC_FUNC_ALLOCA.  Some require several checks.
my %macro = ();

# $NEEDED_MACROS{MACRO} is an array of locations requiring MACRO.
# E.g., $NEEDED_MACROS{AC_FUNC_ALLOC} the list of 'file:line' containing
# 'alloca (...)'.
my %needed_macros =
  (
   'AC_PREREQ' => [$me],
  );

my $log;

# Autoconf and lib files.
my $autom4te = $ENV{'AUTOM4TE'} || '@bindir@/@autom4te-name@';
my $autoconf = "$autom4te --language=autoconf";
my @prepend_include;
my @include = ('@pkgdatadir@');

# $help
# -----
$help = "Usage: $0 [OPTION]... [SRCDIR]

Examine source files in the directory tree rooted at SRCDIR, or the
current directory if none is given.  Search the source files for
common portability problems, check for incompleteness of
'configure.ac', and create a file 'configure.scan' which is a
preliminary 'configure.ac' for that package.

  -h, --help          print this help, then exit
  -V, --version       print version number, then exit
  -v, --verbose       verbosely report processing
  -d, --debug         don't remove temporary files

Library directories:
  -B, --prepend-include=DIR  prepend directory DIR to search path
  -I, --include=DIR          append directory DIR to search path

Report bugs to <bug-autoconf\@gnu.org>.
GNU Autoconf home page: <https://www.gnu.org/software/autoconf/>.
General help using GNU software: <https://www.gnu.org/gethelp/>.
";

# $version
# --------
$version = "autoscan (@PACKAGE_NAME@) @VERSION@
Copyright (C) @RELEASE_YEAR@ Free Software Foundation, Inc.
License GPLv3+/Autoconf: GNU GPL version 3 or later
<https://gnu.org/licenses/gpl.html>, <https://gnu.org/licenses/exceptions.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by David J. MacKenzie and Akim Demaille.
";




## ------------------------ ##
## Command line interface.  ##
## ------------------------ ##

# parse_args ()
# -------------
# Process any command line arguments.
sub parse_args ()
{
  getopt ('I|include=s' => \@include,
	  'B|prepend-include=s' => \@prepend_include);

  die "$me: too many arguments
Try '$me --help' for more information.\n"
    if @ARGV > 1;

  my $srcdir = $ARGV[0] || ".";

  verb "srcdir = $srcdir";
  chdir $srcdir || error "cannot cd to $srcdir: $!";
}


# init_tables ()
# --------------
# Put values in the tables of what to do with each token.
sub init_tables ()
{
  # The data file format supports only one line of macros per function.
  # If more than that is required for a common portability problem,
  # a new Autoconf macro should probably be written for that case,
  # instead of duplicating the code in lots of configure.ac files.
  my $file = find_file ("autoscan/autoscan.list",
			reverse (@prepend_include), @include);
  my $table = new Autom4te::XFile ($file, "<");
  my $tables_are_consistent = 1;

  while ($_ = $table->getline)
    {
      # Ignore blank lines and comments.
      next
	if /^\s*$/ || /^\s*\#/;

      # '<kind>: <word> <macro invocation>' or...
      # '<kind>: <word> warn: <message>'.
      if (/^(\S+):\s+(\S+)\s+(\S.*)$/)
	{
	  my ($kind, $word, $macro) = ($1, $2, $3);
	  error "$file:$.: invalid kind: $_"
	    unless grep { $_ eq $kind } @kinds;
	  push @{$macro{$kind}{$word}}, $macro;
	}
      else
	{
	  error "$file:$.: invalid definition: $_";
	}
    }

  if ($debug)
    {
      foreach my $kind (@kinds)
	{
	  foreach my $word (sort keys %{$macro{$kind}})
	    {
	      print "$kind: $word: @{$macro{$kind}{$word}}\n";
	    }
	}

    }
}


# used ($KIND, $WORD, [$WHERE])
# -----------------------------
# $WORD is used as a $KIND.
sub used ($$;$)
{
  my ($kind, $word, $where) = @_;
  $where ||= "$File::Find::name:$.";
  if (
      # Check for all the libraries.  But '-links' is certainly a
      # 'find' argument, and '-le', a 'test' argument.
      ($kind eq 'library' && $word !~ /^(e|inks)$/)
      # Other than libraries are to be checked only if listed in
      # the Autoscan library files.
      || defined $macro{$kind}{$word}
     )
    {
      push (@{$used{$kind}{$word}}, $where);
    }
}



## ----------------------- ##
## Scanning source files.  ##
## ----------------------- ##


# scan_c_file ($FILE-NAME)
# ------------------------
sub scan_c_file ($)
{
  my ($file_name) = @_;
  push @cfiles, $File::Find::name;

  # Nonzero if in a multiline comment.
  my $in_comment = 0;

  my $file = new Autom4te::XFile ($file_name, "<");

  while ($_ = $file->getline)
    {
      # Strip out comments.
      if ($in_comment && s,^.*?\*/,,)
	{
	  $in_comment = 0;
	}
      # The whole line is inside a comment.
      next if $in_comment;
      # All on one line.
      s,/\*.*?\*/,,g;

      # Starting on this line.
      if (s,/\*.*$,,)
	{
	  $in_comment = 1;
	}

      # Preprocessor directives.
      if (s/^\s*\#\s*//)
	{
	  if (/^include\s*<([^>]*)>/)
	    {
	      used ('header', $1);
	    }
	  if (s/^(if|ifdef|ifndef|elif)\s+//)
	    {
	      foreach my $word (split (/\W+/))
		{
		  used ('identifier', $word)
		    unless $word eq 'defined' || $word !~ /^[a-zA-Z_]/;
		}
	    }
	  # Ignore other preprocessor directives.
	  next;
	}

      # Remove string and character constants.
      s,\"[^\"]*\",,g;
      s,\'[^\']*\',,g;

      # Tokens in the code.
      # Maybe we should ignore function definitions (in column 0)?
      while (s/\b([a-zA-Z_]\w*)\s*\(/ /)
	{
	  used ('function', $1);
	}
      while (s/\b([a-zA-Z_]\w*)\b/ /)
	{
	  used ('identifier', $1);
	}
    }

  $file->close;
}


# scan_makefile($MAKEFILE-NAME)
# -----------------------------
sub scan_makefile ($)
{
  my ($file_name) = @_;
  push @makefiles, $File::Find::name;

  my $file = new Autom4te::XFile ($file_name, "<");

  while ($_ = $file->getline)
    {
      # Strip out comments.
      s/#.*//;

      # Variable assignments.
      while (s/\b([a-zA-Z_]\w*)\s*=/ /)
	{
	  used ('makevar', $1);
	}
      # Be sure to catch a whole word.  For instance 'lex$U.$(OBJEXT)'
      # is a single token.  Otherwise we might believe 'lex' is needed.
      foreach my $word (split (/\s+/))
	{
	  # Libraries.
	  if ($word =~ /^-l([a-zA-Z_]\w*)$/)
	    {
	      used ('library', $1);
	    }
	  # Tokens in the code.
	  # We allow some additional characters, e.g., '+', since
	  # autoscan/programs includes 'c++'.
	  if ($word =~ /^[a-zA-Z_][\w+]*$/)
	    {
	      used ('program', $word);
	    }
	}
    }

  $file->close;
}


# scan_sh_file($SHELL-SCRIPT-NAME)
# --------------------------------
sub scan_sh_file ($)
{
  my ($file_name) = @_;
  push @shfiles, $File::Find::name;

  my $file = new Autom4te::XFile ($file_name, "<");

  while ($_ = $file->getline)
    {
      # Strip out comments and variable references.
      s/#.*//;
      s/\$\{[^\}]*}//g;
      s/@[^@]*@//g;

      # Tokens in the code.
      while (s/\b([a-zA-Z_]\w*)\b/ /)
	{
	  used ('program', $1);
	}
    }

  $file->close;
}


# scan_file ()
# ------------
# Called by &find on each file.  $_ contains the current file name with
# the current directory of the walk through.
sub scan_file ()
{
  # Wanted only if there is no corresponding FILE.in.
  return
    if -f "$_.in";

  # Save $_ as Find::File requires it to be preserved.
  local $_ = $_;

  # Strip a useless leading './'.
  $File::Find::name =~ s,^\./,,;

  if ($_ ne '.' and -d $_ and
      -f "$_/configure.in"  ||
      -f "$_/configure.ac"  ||
      -f "$_/configure.gnu" ||
      -f "$_/configure")
    {
      $File::Find::prune = 1;
      push @subdirs, $File::Find::name;
    }
  if (/\.[chlym](\.in)?$/)
    {
      used 'program', 'cc', $File::Find::name;
      scan_c_file ($_);
    }
  elsif (/\.(cc|cpp|cxx|CC|C|hh|hpp|hxx|HH|H|yy|ypp|ll|lpp)(\.in)?$/)
    {
      used 'program', 'c++', $File::Find::name;
      scan_c_file ($_);
    }
  elsif ((/^((?:GNUm|M|m)akefile)(\.in)?$/ && ! -f "$1.am")
	 || /^(?:GNUm|M|m)akefile(\.am)?$/)
    {
      scan_makefile ($_);
    }
  elsif (/\.sh(\.in)?$/)
    {
      scan_sh_file ($_);
    }
}


# scan_files ()
# -------------
# Read through the files and collect lists of tokens in them
# that might create nonportabilities.
sub scan_files ()
{
  find (\&scan_file, '.');

  if ($verbose)
    {
      print "cfiles: @cfiles\n";
      print "makefiles: @makefiles\n";
      print "shfiles: @shfiles\n";

      foreach my $kind (@kinds)
	{
	  print "\n$kind:\n";
	  foreach my $word (sort keys %{$used{$kind}})
	    {
	      print "$word: @{$used{$kind}{$word}}\n";
	    }
	}
    }
}


## ----------------------- ##
## Output configure.scan.  ##
## ----------------------- ##


# output_kind ($FILE, $KIND)
# --------------------------
sub output_kind ($$)
{
  my ($file, $kind) = @_;
  # Lists of words to be checked with the generic macro.
  my @have;

  print $file "\n# $kind_comment{$kind}\n"
    if exists $kind_comment{$kind};
  foreach my $word (sort keys %{$used{$kind}})
    {
      # Output the needed macro invocations in configure.scan if not
      # already printed, and remember these macros are needed.
      foreach my $macro (@{$macro{$kind}{$word}})
	{
	  if ($macro =~ /^warn:\s+(.*)/)
	    {
	      my $message = $1;
	      foreach my $location (@{$used{$kind}{$word}})
		{
		  warn "$location: warning: $message\n";
		}
	    }
	  elsif (exists $generic_macro{$kind}
	      && $macro eq $generic_macro{$kind})
	    {
	      push (@have, $word);
	      push (@{$needed_macros{"$generic_macro{$kind}([$word])"}},
		    @{$used{$kind}{$word}});
	    }
	  else
	    {
	      if (! $printed{$macro})
		{
		  print $file "$macro\n";
		  $printed{$macro} = 1;
		}
	      push (@{$needed_macros{$macro}},
		    @{$used{$kind}{$word}});
	    }
	}
    }
  print $file "$generic_macro{$kind}([" . join(' ', sort(@have)) . "])\n"
    if @have;
}


# output_libraries ($FILE)
# ------------------------
sub output_libraries ($)
{
  my ($file) = @_;

  print $file "\n# Checks for libraries.\n";
  foreach my $word (sort keys %{$used{'library'}})
    {
      print $file "# FIXME: Replace 'main' with a function in '-l$word':\n";
      print $file "AC_CHECK_LIB([$word], [main])\n";
    }
}


# output ($CONFIGURE_SCAN)
# ------------------------
# Print a proto configure.ac.
sub output ($)
{
  my $configure_scan = shift;
  my %unique_makefiles;

  my $file = new Autom4te::XFile ($configure_scan, ">");

  print $file
    ("#                                               -*- Autoconf -*-\n" .
     "# Process this file with autoconf to produce a configure script.\n" .
     "\n" .
     "AC_PREREQ([@VERSION@])\n" .
     "AC_INIT([FULL-PACKAGE-NAME], [VERSION], [BUG-REPORT-ADDRESS])\n");
  if (defined $cfiles[0])
    {
      print $file "AC_CONFIG_SRCDIR([$cfiles[0]])\n";
      print $file "AC_CONFIG_HEADERS([config.h])\n";
    }

  output_kind ($file, 'program');
  output_kind ($file, 'makevar');
  output_libraries ($file);
  output_kind ($file, 'header');
  output_kind ($file, 'identifier');
  output_kind ($file, 'function');

  print $file "\n";
  if (@makefiles)
    {
      # Change DIR/Makefile.in to DIR/Makefile.
      foreach my $m (@makefiles)
	{
	  $m =~ s/\.(?:in|am)$//;
	  $unique_makefiles{$m}++;
	}
      print $file ("AC_CONFIG_FILES([",
		   join ("\n                 ",
			 sort keys %unique_makefiles), "])\n");
    }
  if (@subdirs)
    {
      print $file ("AC_CONFIG_SUBDIRS([",
		   join ("\n                   ",
			 sort @subdirs), "])\n");
    }
  print $file "AC_OUTPUT\n";

  $file->close;
}



## --------------------------------------- ##
## Checking the accuracy of configure.ac.  ##
## --------------------------------------- ##


# &check_configure_ac ($CONFIGURE_AC)
# -----------------------------------
# Use autoconf to check if all the suggested macros are included
# in CONFIGURE_AC.
sub check_configure_ac ($)
{
  my ($configure_ac) = @_;

  # Find what needed macros are invoked in CONFIGURE_AC.
  # I'd be very happy if someone could explain to me why sort (uniq ...)
  # doesn't work properly: I need 'uniq (sort ...)'.  --akim
  my $trace_option =
    join (' --trace=', '',
	  uniq (sort (map { s/\(.*//; $_ } keys %needed_macros)));

  # Suppress all warnings from the subsidiary autoconf invocation.
  local $ENV{WARNINGS} = 'none';

  verb "running: WARNINGS=none $autoconf $trace_option $configure_ac";
  my $traces =
    new Autom4te::XFile "$autoconf $trace_option $configure_ac |";

  while ($_ = $traces->getline)
    {
      chomp;
      my ($file, $line, $macro, @args) = split (/:/, $_);
      if ($macro =~ /^AC_CHECK_(HEADER|FUNC|TYPE|MEMBER)S$/)
	{
	  # To be rigorous, we should distinguish between space and comma
	  # separated macros.  But there is no point.
	  foreach my $word (split (/\s|,/, $args[0]))
	    {
	      # AC_CHECK_MEMBERS wants 'struct' or 'union'.
	      if ($macro eq "AC_CHECK_MEMBERS"
		  && $word =~ /^stat.st_/)
		{
		  $word = "struct " . $word;
		}
	      delete $needed_macros{"$macro([$word])"};
	    }
	}
      else
	{
	  delete $needed_macros{$macro};
	}
    }

  $traces->close;

  # Report the missing macros.
  foreach my $macro (sort keys %needed_macros)
    {
      warn ("$configure_ac: warning: missing $macro wanted by: "
	    . (${$needed_macros{$macro}}[0])
	    . "\n");
      print $log "$me: warning: missing $macro wanted by: \n";
      foreach my $need (@{$needed_macros{$macro}})
	{
	  print $log "\t$need\n";
	}
    }
}


## -------------- ##
## Main program.  ##
## -------------- ##

parse_args;
$log = new Autom4te::XFile ("$me.log", ">");

$autoconf .= " --debug" if $debug;
$autoconf .= " --verbose" if $verbose;
$autoconf .= join (' --include=', '', map { shell_quote ($_) } @include);
$autoconf .= join (' --prepend-include=', '', map { shell_quote ($_) } @prepend_include);

my $configure_ac = find_configure_ac;
init_tables;
scan_files;
output ('configure.scan');
if (-f $configure_ac)
  {
    check_configure_ac ($configure_ac);
  }
# This close is really needed.  For some reason, probably best named
# a bug, it seems that the dtor of $LOG is not called automatically
# at END.  It results in a truncated file.
$log->close;
exit 0;

### Setup "GNU" style for perl-mode and cperl-mode.
## Local Variables:
## perl-indent-level: 2
## perl-continued-statement-offset: 2
## perl-continued-brace-offset: 0
## perl-brace-offset: 0
## perl-brace-imaginary-offset: 0
## perl-label-offset: -2
## cperl-indent-level: 2
## cperl-brace-offset: 0
## cperl-continued-brace-offset: 0
## cperl-label-offset: -2
## cperl-extra-newline-before-brace: t
## cperl-merge-trailing-else: nil
## cperl-continued-statement-offset: 2
## End:
