From 760c083c0c0c9934e4118b4669c8c8dfd0a3587d Mon Sep 17 00:00:00 2001
From: Max Howell
Date: Mon, 10 Aug 2009 16:48:30 +0100
Subject: Refactor

Large refactor to Formula, mostly improving reliability and error handling but
also layout and readability.

General improvements so testing can be more complete.

Patches are automatically downloaded and applied for Formula that return a
list of urls from Formula::patches.

Split out the brew command logic to facilitate testing.

Facility from Adam Vandenberg to allow selective cleaning of files, added
because Python doesn't work when stripped.
---
 Library/Homebrew/formula.rb | 315 +++++++++++++++++++++++---------------------
 1 file changed, 166 insertions(+), 149 deletions(-)

(limited to 'Library/Homebrew/formula.rb')

diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index 4f02e2077..f01798eba 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -15,30 +15,31 @@
 #  You should have received a copy of the GNU General Public License
 #  along with Homebrew.  If not, see <http://www.gnu.org/licenses/>.
 
-require 'utils'
 
-class BuildError <RuntimeError
-  def initialize cmd
-    super "Build failed during: #{cmd}"
+class ExecutionError <RuntimeError
+  def initialize cmd, args=[]
+    super "#{cmd} #{args*' '}"
   end
 end
 
-# the base class variety of formula, you don't get a prefix, so it's not really
-# useful. See the derived classes for fun and games.
-class AbstractFormula
-  require 'find'
-  require 'fileutils'
+class BuildError <ExecutionError; end
 
-private
-  class <<self
-    attr_reader :url, :version, :md5, :url, :homepage, :sha1
+class FormulaUnavailableError <RuntimeError
+  def initialize name
+    super "No available formula for #{name}"
   end
+end
 
-public
-  attr_reader :url, :version, :url, :homepage, :name
-  
-  # reimplement if your package has dependencies
-  def deps
+# the base class variety of formula, you don't get a prefix, so it's not
+# useful. See the derived classes for fun and games.
+class AbstractFormula
+  def initialize noop=nil
+    @version=self.class.version unless @version
+    @url=self.class.url unless @url
+    @homepage=self.class.homepage unless @homepage
+    @md5=self.class.md5 unless @md5
+    @sha1=self.class.sha1 unless @sha1
+    raise "@url is nil" if @url.nil?
   end
 
   # if the dir is there, but it's empty we consider it not installed
@@ -48,61 +49,115 @@ public
     return false
   end
 
-  def initialize name=nil
-    @name=name
-    @version=self.class.version unless @version
-    @url=self.class.url unless @url
-    @homepage=self.class.homepage unless @homepage
-    @md5=self.class.md5 unless @md5
-    @sha1=self.class.sha1 unless @sha1
-    raise "@url.nil?" if @url.nil?
-  end
-
   def prefix
-    raise "@name.nil!" if @name.nil?
-    raise "@version.nil?" if @version.nil?
+    raise "Invalid @name" if @name.nil? or @name.empty?
+    raise "Invalid @version" if @version.nil? or @version.empty?
     HOMEBREW_CELLAR+@name+@version
   end
 
-  def bin;  prefix+'bin' end
-  def doc;  prefix+'share'+'doc'+name end
-  def lib;  prefix+'lib' end
-  def man;  prefix+'share'+'man' end
+  def path
+    Formula.path name
+  end
+
+  attr_reader :url, :version, :url, :homepage, :name
+
+  def bin; prefix+'bin' end
+  def doc; prefix+'share'+'doc'+name end
+  def lib; prefix+'lib' end
+  def man; prefix+'share'+'man' end
   def man1; man+'man1' end
+  def info; prefix+'share'+'info' end
   def include; prefix+'include' end
 
-  def caveats
-    nil
+  # tell the user about any caveats regarding this package
+  def caveats; nil end
+  # patches are automatically applied after extracting the tarball
+  def patches; [] end
+  # reimplement and specify dependencies
+  def deps; end
+  # sometimes the clean process breaks things, return true to skip anything
+  def skip_clean? path; false end
+
+  # yields self with current working directory set to the uncompressed tarball
+  def brew
+    ohai "Downloading #{@url}"
+    tgz=HOMEBREW_CACHE+File.basename(@url)
+    unless tgz.exist?
+      HOMEBREW_CACHE.mkpath
+      curl @url, '-o', tgz
+    else
+      puts "File already downloaded and cached"
+    end
+
+    verify_download_integrity tgz
+
+    mktemp do
+      Dir.chdir uncompress(tgz)
+      begin
+        patch
+        yield self
+      rescue Interrupt, RuntimeError, SystemCallError => e
+        raise unless ARGV.debug?
+        onoe e.inspect
+        puts e.backtrace
+        ohai "Rescuing build..."
+        puts "Type `exit' and Homebrew will attempt to finalize the installation"
+        puts "If nothing is installed to #{prefix}, then Homebrew will abort"
+        interactive_shell
+      end
+    end
   end
-  
+
+protected
   # Pretty titles the command and buffers stdout/stderr
   # Throws if there's an error
-  def system cmd
-    ohai cmd
-    if ARGV.include? '--verbose'
-      Kernel.system cmd
+  def system cmd, *args
+    full="#{cmd} #{args*' '}".strip
+    ohai full
+    if ARGV.verbose?
+      safe_system cmd, *args
     else
       out=''
-      IO.popen "#{cmd} 2>&1" do |f|
+      # TODO write a ruby extension that does a good popen :P
+      IO.popen "#{full} 2>&1" do |f|
         until f.eof?
           out+=f.gets
         end
       end
-      puts out unless $? == 0
+      unless $? == 0
+        puts out
+        raise
+      end
     end
+  rescue
+    raise BuildError.new(cmd, args)
+  end
 
-    raise BuildError.new(cmd) unless $? == 0
+private
+  def mktemp
+    tmp=Pathname.new `mktemp -dt #{File.basename @url}`.strip
+    raise if not tmp.directory? or $? != 0
+    begin
+      wd=Dir.pwd
+      Dir.chdir tmp
+      yield
+    ensure
+      Dir.chdir wd
+      tmp.rmtree
+    end
   end
 
-  # we don't have a std_autotools variant because autotools is a lot less
-  # consistent and the standard parameters are more memorable
-  # really Homebrew should determine what works inside brew() then
-  # we could add --disable-dependency-tracking when it will work
-  def std_cmake_parameters
-    # The None part makes cmake use the environment's CFLAGS etc. settings
-    "-DCMAKE_INSTALL_PREFIX='#{prefix}' -DCMAKE_BUILD_TYPE=None"
+  # Kernel.system but with exceptions
+  def safe_system cmd, *args
+    puts "#{cmd} #{args*' '}" if ARGV.verbose?
+    # stderr is shown, so hopefully that will explain the problem
+    raise ExecutionError.new(cmd, args) unless Kernel.system cmd, *args and $? == 0
   end
-  
+
+  def curl url, *args
+    safe_system 'curl', '-f#LA', HOMEBREW_USER_AGENT, url, *args
+  end
+
   def verify_download_integrity fn
     require 'digest'
     type='MD5'
@@ -110,7 +165,7 @@ public
     supplied=eval "@#{type.downcase}"
     hash=eval("Digest::#{type}").hexdigest(fn.read)
 
-    if supplied
+    if supplied and not supplied.empty?
       raise "#{type} mismatch: #{hash}" unless supplied.upcase == hash.upcase
     else
       opoo "Cannot verify package integrity"
@@ -119,91 +174,69 @@ public
     end
   end
 
-  # yields self with current working directory set to the uncompressed tarball
-  def brew
-    ohai "Downloading #{@url}"
-    HOMEBREW_CACHE.mkpath
-    Dir.chdir HOMEBREW_CACHE do
-      tmp=nil
-      tgz=Pathname.new(fetch()).realpath
-      begin
-        verify_download_integrity tgz
-
-        # we make an additional subdirectory so know exactly what we are
-        # recursively deleting later
-        # we use mktemp rather than appsupport/blah because some build scripts
-        # can't handle being built in a directory with spaces in it :P
-        tmp=`mktemp -dt #{File.basename @url}`.strip
-        Dir.chdir tmp do
-          Dir.chdir uncompress(tgz) do
-            yield self
-          end
-        end
-      rescue Interrupt, RuntimeError
-        if ARGV.include? '--debug'
-          # debug mode allows the packager to intercept a failed build and
-          # investigate the problems
-          puts "Rescued build at: #{tmp}"
-          exit! 1
-        else
-          raise
-        end
-      ensure
-        FileUtils.rm_rf tmp if tmp
-      end
+  def patch
+    unless patches.empty?
+      ohai "Patching"
+      ff=(1..patches.length).collect {|n| '%03d-homebrew.patch'%n}
+      curl *patches+ff.collect {|f|"-o#{f}"}
+      ff.each {|f| safe_system 'patch', '-p0', '-i', f}
     end
   end
+  
+  class <<self
+    attr_reader :url, :version, :md5, :url, :homepage, :sha1
+  end
+end
 
-protected
-  # returns the directory where the archive was uncompressed
-  # in this Abstract case we assume there is no archive
-  def uncompress path
-    path.dirname
+# This is the meat. See the examples.
+class Formula <AbstractFormula
+  def initialize name=nil
+    super
+    @name=name
+    @version=Pathname.new(@url).version unless @version
   end
 
-private
-  def fetch
-    %r[http://(www.)?github.com/.*/(zip|tar)ball/].match @url
-    if $2
-      # curl doesn't do the redirect magic that we would like, so we get a
-      # stupidly named file, this is why wget would be beter, but oh well
-      tgz="#{@name}-#{@version}.#{$2=='tar' ? 'tgz' : $2}"
-      oarg="-o #{tgz}"
-    else
-      oarg='-O' #use the filename that curl gets
-      tgz=File.expand_path File.basename(@url)
-    end
+  def self.class name
+    #remove invalid characters and camelcase
+    name.capitalize.gsub(/[-_\s]([a-zA-Z0-9])/) { $1.upcase }
+  end
 
-    unless File.exists? tgz
-      `curl -#LA "#{HOMEBREW_USER_AGENT}" #{oarg} "#{@url}"`
-      raise "Download failed" unless $? == 0
-    else
-      puts "File already downloaded and cached"
-    end
-    return tgz
+  def self.factory name
+    require self.path(name)
+    return eval(self.class(name)).new(name)
+  rescue LoadError
+    raise FormulaUnavailableError.new(name)
   end
-end
 
-# somewhat useful, it'll raise if you call prefix, but it'll unpack a tar/zip
-# for you, check the md5, and allow you to yield from brew
-class UnidentifiedFormula <AbstractFormula
-  def initialize name=nil
-    super name
+  def self.path name
+    HOMEBREW_PREFIX+'Library'+'Formula'+"#{name.downcase}.rb"
+  end
+
+  # we don't have a std_autotools variant because autotools is a lot less
+  # consistent and the standard parameters are more memorable
+  # really Homebrew should determine what works inside brew() then
+  # we could add --disable-dependency-tracking when it will work
+  def std_cmake_parameters
+    # The None part makes cmake use the environment's CFLAGS etc. settings
+    "-DCMAKE_INSTALL_PREFIX='#{prefix}' -DCMAKE_BUILD_TYPE=None"
   end
 
 private
-  def uncompress(path)
-    if path.extname == '.zip'
-      `unzip -qq "#{path}"`
+  def uncompress_args
+    rx=%r[http://(www.)?github.com/.*/(zip|tar)ball/]
+    if rx.match @url and $2 == '.zip' or Pathname.new(@url).extname == '.zip'
+      %w[unzip -qq]
     else
-      `tar xf "#{path}"`
+      %w[tar xf]
     end
+  end
 
-    raise "Compression tool failed" if $? != 0
+  def uncompress path
+    safe_system *uncompress_args<<path
 
     entries=Dir['*']
-    if entries.nil? or entries.length == 0
-      raise "Empty tarball!" 
+    if entries.length == 0
+      raise "Empty archive"
     elsif entries.length == 1
       # if one dir enter it as that will be where the build is
       entries.first
@@ -211,30 +244,6 @@ private
       # if there's more than one dir, then this is the build directory already
       Dir.pwd
     end
-  end  
-end
-
-# this is what you will mostly use, reimplement install, prefix won't raise
-class Formula <UnidentifiedFormula
-  def initialize name
-    super name
-    @version=Pathname.new(@url).version unless @version
-  end
-
-  def self.class name
-    #remove invalid characters and camelcase
-    name.capitalize.gsub(/[-_\s]([a-zA-Z0-9])/) { $1.upcase }
-  end
-
-  def self.path name
-    Pathname.new(HOMEBREW_PREFIX)+'Library'+'Formula'+(name.downcase+'.rb')
-  end
-
-  def self.create name
-    require Formula.path(name)
-    return eval(Formula.class(name)).new(name)
-  rescue LoadError
-    raise "No formula for #{name}"
   end
 
   def method_added method
@@ -243,16 +252,24 @@ class Formula <UnidentifiedFormula
 end
 
 # see ack.rb for an example usage
-# you need to set @version and @name
 class ScriptFileFormula <AbstractFormula
+  def initialize name=nil
+    super
+    @name=name
+  end
+  def uncompress path
+    path.dirname
+  end
   def install
-    bin.install name
+    bin.install File.basename(@url)
   end
 end
 
+# see flac.rb for example usage
 class GithubGistFormula <ScriptFileFormula
-  def initialize
-    super File.basename(self.class.url)
+  def initialize name=nil
+    super
+    @name=name
     @version=File.basename(File.dirname(url))[0,6]
   end
 end
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