#!/usr/bin/env perl
#
#                     The LLVM Compiler Infrastructure
#
# This file is distributed under the University of Illinois Open Source
# License. See LICENSE.TXT for details.
#
##===----------------------------------------------------------------------===##
#
# A script designed to wrap a build so that all calls to gcc are intercepted
# and piped to the static analyzer.
#
##===----------------------------------------------------------------------===##

use strict;
use warnings;
use File::Temp qw/ :mktemp /;

my $Verbose = 0;       # Verbose output from this script.
my $Prog = "scan-build";

##----------------------------------------------------------------------------##
# GetHTMLRunDir - Construct an HTML directory name for the current run.
##----------------------------------------------------------------------------##

sub GetHTMLRunDir {  

  die "Not enough arguments." if (@_ == 0);
  
  my $Dir = shift @_;
  
  # Get current date and time.
  
  my @CurrentTime = localtime();
  
  my $year  = $CurrentTime[5] + 1900;
  my $day   = $CurrentTime[3];
  my $month = $CurrentTime[4] + 1;
  
  my $DateString = "$year-$month-$day";
  
  # Determine the run number.
  
  my $RunNumber;
  
  if (-d $Dir) {
    
    if (! -r $Dir) {
      die "error: '$Dir' exists but is not readable.\n";
    }
    
    # Iterate over all files in the specified directory.
    
    my $max = 0;
    
    opendir(DIR, $Dir);
    my @FILES= readdir(DIR); 
    closedir(DIR);
    
    foreach my $f (@FILES) {

      my @x = split/-/, $f;
      
      next if (scalar(@x) != 4);
      next if ($x[0] != $year);
      next if ($x[1] != $month);
      next if ($x[2] != $day);
      
      if ($x[3] > $max) {
        $max = $x[3];
      }      
    }
    
    $RunNumber = $max + 1;
  }
  else {
    
    if (-x $Dir) {
      die "error: '$Dir' exists but is not a directory.\n";
    }
    
    # $Dir does not exist.  It will be automatically created by the 
    # clang driver.  Set the run number to 1.  
    
    $RunNumber = 1;
  }
  
  die "RunNumber must be defined!" if (!defined($RunNumber));
  
  # Append the run number.
  
  return "$Dir/$DateString-$RunNumber";  
}

sub SetHtmlEnv {
  
  die "Wrong number of arguments." if (scalar(@_) != 2);
  
  my $Args = shift;
  my $Dir = shift;
  
  die "No build command." if (scalar(@$Args) == 0);
  
  my $Cmd = $$Args[0];
  
  if ($Cmd =~ /configure/) {
    return;
  }
  
  if ($Verbose) {
    print "$Prog: Emitting reports for this run to '$Dir'.\n";  
  }
  
  $ENV{'CCC_ANALYZER_HTML'} = $Dir;
}

##----------------------------------------------------------------------------##
# Postprocess - Postprocess the results of an analysis scan.
##----------------------------------------------------------------------------##

sub Postprocess {
  
  my $Dir = shift;
  
  die "No directory specified." if (!defined($Dir));
  
  if (! -d $Dir) {
    return;
  }
  
  opendir(DIR, $Dir);
  my @files = grep(/^report-.*\.html$/,readdir(DIR));
  closedir(DIR);

  if (scalar(@files) == 0) {
    print "$Prog: Removing directory '$Dir' because it contains no reports.\n";
    `rm -fR $Dir`;
    return;
  }


}

##----------------------------------------------------------------------------##
# RunBuildCommand - Run the build command.
##----------------------------------------------------------------------------##

sub RunBuildCommand {
  
  my $Args = shift;
  my $IgnoreErrors = shift;
  my $Cmd = $Args->[0];
  
  if ($Cmd eq "gcc" or $Cmd eq "cc" or $Cmd eq "llvm-gcc") {
    shift @$Args;
    unshift @$Args, "ccc-analyzer"
  }
  elsif ($IgnoreErrors) {
    if ($Cmd eq "make" or $Cmd eq "gmake") {
      push @$Args, "-k";
    }
    elsif ($Cmd eq "xcodebuild") {
      push @$Args, "-PBXBuildsContinueAfterErrors=YES";
    }
  }
  
  system(@$Args);
}

##----------------------------------------------------------------------------##
# DisplayHelp - Utility function to display all help options.
##----------------------------------------------------------------------------##

sub DisplayHelp {
  
print <<ENDTEXT
USAGE: $Prog [options] <build command> [build options]

OPTIONS:

  -o            - Target directory for HTML report files.  Subdirectories
                  will be created as needed to represent separate "runs" of
                  the analyzer.  If this option is not specified, a directory
                  is created in /tmp to store the reports.
                
  -?, -h        - Display this message.
  --help
  
  -k            - Add a "keep on going" option to the specified build command.
  --keep-going    This command currently supports make and xcodebuild.
                  This is a convenience option; one can specify this behavior
                  directly as build options.

  -v            - Verbose output from $Prog and the analyzer.
                  A second "-v" increases verbosity.

BUILD OPTIONS

  You can specify any build option acceptable to the build command.  For
  example:

     $Prog -o /tmp/myhtmldir make -j4
     
  The above causes analysis reports to be deposited in /tmp/myhtmldir (or
  rather a subdirectory corresponding to this particular running of the
  analyzer), and causes "make" to be run with the "-j4" option, allowing
  parallel builds (and parallel invocations of the analyzer).
  
  NOTE: The analyzer will work for most parallel builds, but not distributed
        builds (such as using distcc).

ENDTEXT
}

##----------------------------------------------------------------------------##
# Process command-line arguments.
##----------------------------------------------------------------------------##

my $HtmlDir;           # Parent directory to store HTML files.
my $IgnoreErrors = 0;  # Ignore build errors.

if (!@ARGV) {
  DisplayHelp();
  exit 1;
}

while (@ARGV) {
  
  # Scan for options we recognize.
  
  my $arg = $ARGV[0];

  if ($arg eq "-?" or $arg eq "-h" or $arg eq "--help") {
    DisplayHelp();
    exit 0;
  }
  
  if ($arg eq "-o") {
    shift @ARGV;
        
    if (!@ARGV) {
      die "$Prog: '-o' option requires a target directory name.\n";
    }
    
    $HtmlDir = shift @ARGV;
    next;
  }
  
  if ($arg eq "-k" or $arg eq "--keep-going") {
    shift @ARGV;
    $IgnoreErrors = 1;
    next;
  }
  
  if ($arg eq "-v") {
    shift @ARGV;
    $Verbose++;
    next;
  }
  
  die "$Prog: unrecognized option '$arg'\n" if ($arg =~ /^-/);
  
  last;
}

if (!@ARGV) {
  print STDERR "$Prog: No build command specified.\n\n";
  DisplayHelp();
  exit 1;
}

# Determine the output directory for the HTML reports.

if (!defined($HtmlDir)) {
  
  $HtmlDir = mkdtemp("/tmp/$Prog-XXXXXX");
  
  if (!defined($HtmlDir)) {
    die "error: Cannot create HTML directory in /tmp.\n";
  }
  
  if (!$Verbose) {
    print "$Prog: Using '$HtmlDir' as base HTML report directory.\n";
  }
}

$HtmlDir = GetHTMLRunDir($HtmlDir);

# Set the appropriate environment variables.

SetHtmlEnv(\@ARGV, $HtmlDir);

$ENV{'CC'} = "ccc-analyzer";

if ($Verbose >= 2) {
  $ENV{'CCC_ANALYZER_VERBOSE'} = 1;
}

# Run the build.

RunBuildCommand(\@ARGV, $IgnoreErrors);

# Postprocess the HTML directory.

Postprocess($HtmlDir);