Merge pull request #13608 from lukaso/debug-symbols

Support for `--debug-symbols` for macos

Library/Homebrew/.rubocop.yml

@@ -21,6 +21,7 @@ Metrics/BlockLength:
     # TODO: extract more of the bottling logic
     - "dev-cmd/bottle.rb"
     - "test/**/*"
+    - "cmd/install.rb"
 Metrics/BlockNesting:
   Max: 5
 Metrics/ClassLength:

Library/Homebrew/build.rb

@@ -79,10 +79,11 @@ class Build
       ENV.deps = formula_deps
       ENV.run_time_deps = run_time_deps
       ENV.setup_build_environment(
-        formula:      formula,
+        formula:       formula,
-        cc:           args.cc,
+        cc:            args.cc,
-        build_bottle: args.build_bottle?,
+        build_bottle:  args.build_bottle?,
-        bottle_arch:  args.bottle_arch,
+        bottle_arch:   args.bottle_arch,
+        debug_symbols: args.debug_symbols?,
       )
       reqs.each do |req|
         req.modify_build_environment(
@@ -92,10 +93,11 @@ class Build
       deps.each(&:modify_build_environment)
     else
       ENV.setup_build_environment(
-        formula:      formula,
+        formula:       formula,
-        cc:           args.cc,
+        cc:            args.cc,
-        build_bottle: args.build_bottle?,
+        build_bottle:  args.build_bottle?,
-        bottle_arch:  args.bottle_arch,
+        bottle_arch:   args.bottle_arch,
+        debug_symbols: args.debug_symbols?,
       )
       reqs.each do |req|
         req.modify_build_environment(
@@ -127,9 +129,10 @@ class Build
       formula.update_head_version
 
       formula.brew(
-        fetch:       false,
+        fetch:         false,
-        keep_tmp:    args.keep_tmp?,
+        keep_tmp:      args.keep_tmp?,
-        interactive: args.interactive?,
+        debug_symbols: args.debug_symbols?,
+        interactive:   args.interactive?,
       ) do
         with_env(
           # For head builds, HOMEBREW_FORMULA_PREFIX should include the commit,

Library/Homebrew/cli/args.rbi

@@ -87,6 +87,9 @@ module Homebrew
       sig { returns(T::Boolean) }
       def keep_tmp?; end
 
+      sig { returns(T::Boolean) }
+      def debug_symbols?; end
+
       sig { returns(T::Boolean) }
       def overwrite?; end
 

Library/Homebrew/cmd/install.rb

@@ -91,6 +91,10 @@ module Homebrew
         [:switch, "--keep-tmp", {
           description: "Retain the temporary files created during installation.",
         }],
+        [:switch, "--debug-symbols", {
+          depends_on:  "--build-from-source",
+          description: "Generate debug symbols on build. Source will be retained in a cache directory. ",
+        }],
         [:switch, "--build-bottle", {
           description: "Prepare the formula for eventual bottling during installation, skipping any " \
                        "post-install steps.",
@@ -232,6 +236,7 @@ module Homebrew
       git:                        args.git?,
       interactive:                args.interactive?,
       keep_tmp:                   args.keep_tmp?,
+      debug_symbols:              args.debug_symbols?,
       force:                      args.force?,
       overwrite:                  args.overwrite?,
       debug:                      args.debug?,
@@ -247,6 +252,7 @@ module Homebrew
       build_from_source_formulae: args.build_from_source_formulae,
       interactive:                args.interactive?,
       keep_tmp:                   args.keep_tmp?,
+      debug_symbols:              args.debug_symbols?,
       force:                      args.force?,
       debug:                      args.debug?,
       quiet:                      args.quiet?,

Library/Homebrew/cmd/reinstall.rb

@@ -57,6 +57,10 @@ module Homebrew
         [:switch, "--keep-tmp", {
           description: "Retain the temporary files created during installation.",
         }],
+        [:switch, "--debug-symbols", {
+          depends_on:  "--build-from-source",
+          description: "Generate debug symbols on build. Source will be retained in a cache directory. ",
+        }],
         [:switch, "--display-times", {
           env:         :display_install_times,
           description: "Print install times for each formula at the end of the run.",
@@ -115,6 +119,7 @@ module Homebrew
         build_from_source_formulae: args.build_from_source_formulae,
         interactive:                args.interactive?,
         keep_tmp:                   args.keep_tmp?,
+        debug_symbols:              args.debug_symbols?,
         force:                      args.force?,
         debug:                      args.debug?,
         quiet:                      args.quiet?,
@@ -132,6 +137,7 @@ module Homebrew
       build_from_source_formulae: args.build_from_source_formulae,
       interactive:                args.interactive?,
       keep_tmp:                   args.keep_tmp?,
+      debug_symbols:              args.debug_symbols?,
       force:                      args.force?,
       debug:                      args.debug?,
       quiet:                      args.quiet?,

Library/Homebrew/cmd/upgrade.rb

@@ -68,6 +68,10 @@ module Homebrew
         [:switch, "--keep-tmp", {
           description: "Retain the temporary files created during installation.",
         }],
+        [:switch, "--debug-symbols", {
+          depends_on:  "--build-from-source",
+          description: "Generate debug symbols on build. Source will be retained in a cache directory. ",
+        }],
         [:switch, "--display-times", {
           env:         :display_install_times,
           description: "Print install times for each package at the end of the run.",
@@ -187,6 +191,7 @@ module Homebrew
       build_from_source_formulae: args.build_from_source_formulae,
       interactive:                args.interactive?,
       keep_tmp:                   args.keep_tmp?,
+      debug_symbols:              args.debug_symbols?,
       force:                      args.force?,
       debug:                      args.debug?,
       quiet:                      args.quiet?,
@@ -202,6 +207,7 @@ module Homebrew
       build_from_source_formulae: args.build_from_source_formulae,
       interactive:                args.interactive?,
       keep_tmp:                   args.keep_tmp?,
+      debug_symbols:              args.debug_symbols?,
       force:                      args.force?,
       debug:                      args.debug?,
       quiet:                      args.quiet?,

Library/Homebrew/extend/ENV.rb

@@ -33,19 +33,21 @@ module EnvActivation
 
   sig {
     params(
-      env:          T.nilable(String),
+      env:           T.nilable(String),
-      cc:           T.nilable(String),
+      cc:            T.nilable(String),
-      build_bottle: T::Boolean,
+      build_bottle:  T::Boolean,
-      bottle_arch:  T.nilable(String),
+      bottle_arch:   T.nilable(String),
-      _block:       T.proc.returns(T.untyped),
+      debug_symbols: T.nilable(T::Boolean),
+      _block:        T.proc.returns(T.untyped),
     ).returns(T.untyped)
   }
-  def with_build_environment(env: nil, cc: nil, build_bottle: false, bottle_arch: nil, &_block)
+  def with_build_environment(env: nil, cc: nil, build_bottle: false, bottle_arch: nil, debug_symbols: false, &_block)
     old_env = to_hash.dup
     tmp_env = to_hash.dup.extend(EnvActivation)
     T.cast(tmp_env, EnvActivation).activate_extensions!(env: env)
     T.cast(tmp_env, T.any(Superenv, Stdenv))
-     .setup_build_environment(cc: cc, build_bottle: build_bottle, bottle_arch: bottle_arch)
+     .setup_build_environment(cc: cc, build_bottle: build_bottle, bottle_arch: bottle_arch,
+                              debug_symbols: debug_symbols)
     replace(tmp_env)
 
     begin

Library/Homebrew/extend/ENV/shared.rb

@@ -40,13 +40,16 @@ module SharedEnvExtension
       build_bottle:    T.nilable(T::Boolean),
       bottle_arch:     T.nilable(String),
       testing_formula: T::Boolean,
+      debug_symbols:   T.nilable(T::Boolean),
     ).void
   }
-  def setup_build_environment(formula: nil, cc: nil, build_bottle: false, bottle_arch: nil, testing_formula: false)
+  def setup_build_environment(formula: nil, cc: nil, build_bottle: false, bottle_arch: nil, testing_formula: false,
+                              debug_symbols: false)
     @formula = formula
     @cc = cc
     @build_bottle = build_bottle
     @bottle_arch = bottle_arch
+    @debug_symbols = debug_symbols
     reset
   end
   private :setup_build_environment

Library/Homebrew/extend/ENV/std.rb

@@ -21,9 +21,11 @@ module Stdenv
       build_bottle:    T.nilable(T::Boolean),
       bottle_arch:     T.nilable(String),
       testing_formula: T::Boolean,
+      debug_symbols:   T.nilable(T::Boolean),
     ).void
   }
-  def setup_build_environment(formula: nil, cc: nil, build_bottle: false, bottle_arch: nil, testing_formula: false)
+  def setup_build_environment(formula: nil, cc: nil, build_bottle: false, bottle_arch: nil, testing_formula: false,
+                              debug_symbols: false)
     super
 
     self["HOMEBREW_ENV"] = "std"

Library/Homebrew/extend/ENV/super.rb

@@ -55,9 +55,11 @@ module Superenv
       build_bottle:    T.nilable(T::Boolean),
       bottle_arch:     T.nilable(String),
       testing_formula: T::Boolean,
+      debug_symbols:   T.nilable(T::Boolean),
     ).void
   }
-  def setup_build_environment(formula: nil, cc: nil, build_bottle: false, bottle_arch: nil, testing_formula: false)
+  def setup_build_environment(formula: nil, cc: nil, build_bottle: false, bottle_arch: nil, testing_formula: false,
+                              debug_symbols: false)
     super
     send(compiler)
 
@@ -87,6 +89,8 @@ module Superenv
     self["HOMEBREW_DEPENDENCIES"] = determine_dependencies
     self["HOMEBREW_FORMULA_PREFIX"] = @formula.prefix unless @formula.nil?
 
+    set_debug_symbols if debug_symbols
+
     # The HOMEBREW_CCCFG ENV variable is used by the ENV/cc tool to control
     # compiler flag stripping. It consists of a string of characters which act
     # as flags. Some of these flags are mutually exclusive.
@@ -100,6 +104,7 @@ module Superenv
     # d - Don't strip -march=<target>. Use only in formulae that
     #     have runtime detection of CPU features.
     # w - Pass -no_weak_imports to the linker
+    # D - Generate debugging information
     #
     # These flags will also be present:
     # a - apply fix for apr-1-config path
@@ -331,6 +336,11 @@ module Superenv
     append_to_cccfg "g" if compiler == :clang
   end
 
+  sig { void }
+  def set_debug_symbols
+    append_to_cccfg "D"
+  end
+
   # @private
   sig { void }
   def refurbish_args

Library/Homebrew/extend/os/linux/extend/ENV/std.rb

@@ -2,11 +2,10 @@
 # frozen_string_literal: true
 
 module Stdenv
-  def setup_build_environment(formula: nil, cc: nil, build_bottle: false, bottle_arch: nil, testing_formula: false)
+  def setup_build_environment(formula: nil, cc: nil, build_bottle: false, bottle_arch: nil, testing_formula: false,
-    generic_setup_build_environment(
+                              debug_symbols: false)
-      formula: formula, cc: cc, build_bottle: build_bottle,
+    generic_setup_build_environment(formula: formula, cc: cc, build_bottle: build_bottle, bottle_arch: bottle_arch,
-      bottle_arch: bottle_arch, testing_formula: testing_formula
+                                    testing_formula: testing_formula, debug_symbols: debug_symbols)
-    )
 
     prepend_path "CPATH", HOMEBREW_PREFIX/"include"
     prepend_path "LIBRARY_PATH", HOMEBREW_PREFIX/"lib"

Library/Homebrew/extend/os/linux/extend/ENV/super.rb

@@ -15,11 +15,10 @@ module Superenv
   end
 
   # @private
-  def setup_build_environment(formula: nil, cc: nil, build_bottle: false, bottle_arch: nil, testing_formula: false)
+  def setup_build_environment(formula: nil, cc: nil, build_bottle: false, bottle_arch: nil, testing_formula: false,
-    generic_setup_build_environment(
+                              debug_symbols: false)
-      formula: formula, cc: cc, build_bottle: build_bottle,
+    generic_setup_build_environment(formula: formula, cc: cc, build_bottle: build_bottle, bottle_arch: bottle_arch,
-      bottle_arch: bottle_arch, testing_formula: testing_formula
+                                    testing_formula: testing_formula, debug_symbols: debug_symbols)
-    )
     self["HOMEBREW_OPTIMIZATION_LEVEL"] = "O2"
     self["HOMEBREW_DYNAMIC_LINKER"] = determine_dynamic_linker_path
     self["HOMEBREW_RPATH_PATHS"] = determine_rpath_paths(@formula)

Library/Homebrew/extend/os/mac/extend/ENV/shared.rb

@@ -4,11 +4,11 @@
 module SharedEnvExtension
   extend T::Sig
 
-  def setup_build_environment(formula: nil, cc: nil, build_bottle: false, bottle_arch: nil, testing_formula: false)
+  def setup_build_environment(formula: nil, cc: nil, build_bottle: false, bottle_arch: nil, testing_formula: false,
-    generic_shared_setup_build_environment(
+                              debug_symbols: false)
-      formula: formula, cc: cc, build_bottle: build_bottle,
+    generic_shared_setup_build_environment(formula: formula, cc: cc, build_bottle: build_bottle,
-      bottle_arch: bottle_arch, testing_formula: testing_formula
+                                           bottle_arch: bottle_arch, testing_formula: testing_formula,
-    )
+                                           debug_symbols: debug_symbols)
 
     # Normalise the system Perl version used, where multiple may be available
     self["VERSIONER_PERL_VERSION"] = MacOS.preferred_perl_version

Library/Homebrew/extend/os/mac/extend/ENV/std.rb

@@ -10,11 +10,10 @@ module Stdenv
     ["#{HOMEBREW_LIBRARY}/Homebrew/os/mac/pkgconfig/#{MacOS.version}"]
   end
 
-  def setup_build_environment(formula: nil, cc: nil, build_bottle: false, bottle_arch: nil, testing_formula: false)
+  def setup_build_environment(formula: nil, cc: nil, build_bottle: false, bottle_arch: nil, testing_formula: false,
-    generic_setup_build_environment(
+                              debug_symbols: false)
-      formula: formula, cc: cc, build_bottle: build_bottle,
+    generic_setup_build_environment(formula: formula, cc: cc, build_bottle: build_bottle, bottle_arch: bottle_arch,
-      bottle_arch: bottle_arch, testing_formula: testing_formula
+                                    testing_formula: testing_formula, debug_symbols: debug_symbols)
-    )
 
     append "LDFLAGS", "-Wl,-headerpad_max_install_names"
 

Library/Homebrew/extend/os/mac/extend/ENV/super.rb

@@ -85,7 +85,8 @@ module Superenv
   end
 
   # @private
-  def setup_build_environment(formula: nil, cc: nil, build_bottle: false, bottle_arch: nil, testing_formula: false)
+  def setup_build_environment(formula: nil, cc: nil, build_bottle: false, bottle_arch: nil, testing_formula: false,
+                              debug_symbols: false)
     sdk = formula ? MacOS.sdk_for_formula(formula) : MacOS.sdk
     is_xcode_sdk = sdk&.source == :xcode
 
@@ -100,10 +101,8 @@ module Superenv
       MacOS::CLT::PKG_PATH
     end
 
-    generic_setup_build_environment(
+    generic_setup_build_environment(formula: formula, cc: cc, build_bottle: build_bottle, bottle_arch: bottle_arch,
-      formula: formula, cc: cc, build_bottle: build_bottle,
+                                    testing_formula: testing_formula, debug_symbols: debug_symbols)
-      bottle_arch: bottle_arch, testing_formula: testing_formula
-    )
 
     # Filter out symbols known not to be defined since GNU Autotools can't
     # reliably figure this out with Xcode 8 and above.

Library/Homebrew/extend/os/mac/keg.rb

@@ -62,4 +62,19 @@ class Keg
       #{result.stderr}
     EOS
   end
+
+  def prepare_debug_symbols
+    binary_executable_or_library_files.each do |file|
+      odebug "Extracting symbols #{file}"
+
+      result = system_command("dsymutil", args: [file], print_stderr: false)
+      next if result.success?
+
+      # If it fails again, error out
+      ofail <<~EOS
+        Failed to extract symbols from #{file}:
+        #{result.stderr}
+      EOS
+    end
+  end
 end

Library/Homebrew/formula.rb

@@ -1270,11 +1270,11 @@ class Formula
   # Yields |self,staging| with current working directory set to the uncompressed tarball
   # where staging is a {Mktemp} staging context.
   # @private
-  def brew(fetch: true, keep_tmp: false, interactive: false)
+  def brew(fetch: true, keep_tmp: false, debug_symbols: false, interactive: false)
     @prefix_returns_versioned_prefix = true
     active_spec.fetch if fetch
-    stage(interactive: interactive) do |staging|
+    stage(interactive: interactive, debug_symbols: debug_symbols) do |staging|
-      staging.retain! if keep_tmp
+      staging.retain! if keep_tmp || debug_symbols
 
       prepare_patches
       fetch_patches if fetch
@@ -2529,8 +2529,8 @@ class Formula
     }
   end
 
-  def stage(interactive: false)
+  def stage(interactive: false, debug_symbols: false)
-    active_spec.stage do |staging|
+    active_spec.stage(debug_symbols: debug_symbols) do |staging|
       @source_modified_time = active_spec.source_modified_time
       @buildpath = Pathname.pwd
       env_home = buildpath/".brew_home"

Library/Homebrew/formula_installer.rb

@@ -39,6 +39,7 @@ class FormulaInstaller
   attr_predicate :installed_as_dependency?, :installed_on_request?
   attr_predicate :show_summary_heading?, :show_header?
   attr_predicate :force_bottle?, :ignore_deps?, :only_deps?, :interactive?, :git?, :force?, :overwrite?, :keep_tmp?
+  attr_predicate :debug_symbols?
   attr_predicate :verbose?, :debug?, :quiet?
 
   def initialize(
@@ -58,6 +59,7 @@ class FormulaInstaller
     git: false,
     interactive: false,
     keep_tmp: false,
+    debug_symbols: false,
     cc: nil,
     options: Options.new,
     force: false,
@@ -71,6 +73,7 @@ class FormulaInstaller
     @force = force
     @overwrite = overwrite
     @keep_tmp = keep_tmp
+    @debug_symbols = debug_symbols
     @link_keg = !formula.keg_only? || link_keg
     @show_header = show_header
     @ignore_deps = ignore_deps
@@ -688,6 +691,7 @@ class FormulaInstaller
       include_test_formulae:      @include_test_formulae,
       build_from_source_formulae: @build_from_source_formulae,
       keep_tmp:                   keep_tmp?,
+      debug_symbols:              debug_symbols?,
       force:                      force?,
       debug:                      debug?,
       quiet:                      quiet?,
@@ -741,6 +745,7 @@ class FormulaInstaller
         include_test_formulae:      @include_test_formulae,
         build_from_source_formulae: @build_from_source_formulae,
         keep_tmp:                   keep_tmp?,
+        debug_symbols:              debug_symbols?,
         force:                      force?,
         debug:                      debug?,
         quiet:                      quiet?,
@@ -802,6 +807,8 @@ class FormulaInstaller
       post_install
     end
 
+    keg.prepare_debug_symbols if debug_symbols?
+
     # Updates the cache for a particular formula after doing an install
     CacheStoreDatabase.use(:linkage) do |db|
       break unless db.created?
@@ -873,6 +880,11 @@ class FormulaInstaller
     args << "--cc=#{@cc}" if @cc
     args << "--keep-tmp" if keep_tmp?
 
+    if debug_symbols?
+      args << "--debug-symbols"
+      args << "--build-from-source"
+    end
+
     if @env.present?
       args << "--env=#{@env}"
     elsif formula.env.std? || formula.deps.select(&:build?).any? { |d| d.name == "scons" }

Library/Homebrew/install.rb

@@ -269,6 +269,7 @@ module Homebrew
       git: false,
       interactive: false,
       keep_tmp: false,
+      debug_symbols: false,
       force: false,
       overwrite: false,
       debug: false,
@@ -293,6 +294,7 @@ module Homebrew
           git:                        git,
           interactive:                interactive,
           keep_tmp:                   keep_tmp,
+          debug_symbols:              debug_symbols,
           force:                      force,
           overwrite:                  overwrite,
           debug:                      debug,

Library/Homebrew/keg.rb

@@ -483,6 +483,8 @@ class Keg
     ObserverPathnameExtension.n
   end
 
+  def prepare_debug_symbols; end
+
   def remove_oldname_opt_record
     return unless oldname_opt_record
     return if oldname_opt_record.resolved_path != path

Library/Homebrew/mktemp.rb

@@ -13,7 +13,8 @@ class Mktemp
 
   def initialize(prefix, opts = {})
     @prefix = prefix
-    @retain = opts[:retain]
+    @retain_in_cache = opts[:retain_in_cache]
+    @retain = opts[:retain] || @retain_in_cache
     @quiet = false
   end
 
@@ -28,6 +29,11 @@ class Mktemp
     @retain
   end
 
+  # True if the source files should be retained.
+  def retain_in_cache?
+    @retain_in_cache
+  end
+
   # Instructs this Mktemp to not emit messages when retention is triggered.
   sig { void }
   def quiet!
@@ -40,7 +46,15 @@ class Mktemp
   end
 
   def run
-    @tmpdir = Pathname.new(Dir.mktmpdir("#{@prefix.tr "@", "AT"}-", HOMEBREW_TEMP))
+    prefix_name = @prefix.tr "@", "AT"
+    @tmpdir = if retain_in_cache?
+      tmp_dir = HOMEBREW_CACHE/"Sources/#{prefix_name}"
+      chmod_rm_rf(tmpdir) # clear out previous staging directory
+      tmp_dir.mkpath
+      tmp_dir
+    else
+      Pathname.new(Dir.mktmpdir("#{prefix_name}-", HOMEBREW_TEMP))
+    end
 
     # Make sure files inside the temporary directory have the same group as the
     # brew instance.
@@ -54,18 +68,21 @@ class Mktemp
       Process.gid
     end
     begin
-      chown(nil, group_id, tmpdir)
+      chown(nil, group_id, @tmpdir)
     rescue Errno::EPERM
-      opoo "Failed setting group \"#{Etc.getgrgid(group_id).name}\" on #{tmpdir}"
+      opoo "Failed setting group \"#{Etc.getgrgid(group_id).name}\" on #{@tmpdir}"
     end
 
     begin
       Dir.chdir(tmpdir) { yield self }
     ensure
-      ignore_interrupts { chmod_rm_rf(tmpdir) } unless retain?
+      ignore_interrupts { chmod_rm_rf(@tmpdir) } unless retain?
     end
   ensure
-    ohai "Temporary files retained at:", @tmpdir.to_s if retain? && !@tmpdir.nil? && !@quiet
+    if retain? && @tmpdir.present? && !@quiet
+      message = retain_in_cache? ? "Source files for debugging available at:" : "Temporary files retained at:"
+      ohai message, @tmpdir.to_s
+    end
   end
 
   private

Library/Homebrew/reinstall.rb

@@ -16,6 +16,7 @@ module Homebrew
     build_from_source_formulae: [],
     interactive: false,
     keep_tmp: false,
+    debug_symbols: false,
     force: false,
     debug: false,
     quiet: false,
@@ -48,6 +49,7 @@ module Homebrew
         git:                        git,
         interactive:                interactive,
         keep_tmp:                   keep_tmp,
+        debug_symbols:              debug_symbols,
         force:                      force,
         debug:                      debug,
         quiet:                      quiet,

Library/Homebrew/resource.rb

@@ -89,14 +89,14 @@ class Resource
   # dir using {Mktemp} so that works with all subtypes.
   #
   # @api public
-  def stage(target = nil, &block)
+  def stage(target = nil, debug_symbols: false, &block)
     raise ArgumentError, "target directory or block is required" if !target && block.blank?
 
     prepare_patches
     fetch_patches(skip_downloaded: true)
     fetch unless downloaded?
 
-    unpack(target, &block)
+    unpack(target, debug_symbols: debug_symbols, &block)
   end
 
   def prepare_patches
@@ -120,9 +120,9 @@ class Resource
   # If block is given, yield to that block with `|stage|`, where stage
   # is a {ResourceStageContext}.
   # A target or a block must be given, but not both.
-  def unpack(target = nil)
+  def unpack(target = nil, debug_symbols: false)
     current_working_directory = Pathname.pwd
-    mktemp(download_name) do |staging|
+    stage_resource(download_name, debug_symbols: debug_symbols) do |staging|
       downloader.stage do
         @source_modified_time = downloader.source_modified_time
         apply_patches
@@ -235,8 +235,8 @@ class Resource
 
   protected
 
-  def mktemp(prefix, &block)
+  def stage_resource(prefix, debug_symbols: false, &block)
-    Mktemp.new(prefix).run(&block)
+    Mktemp.new(prefix, retain_in_cache: debug_symbols).run(&block)
   end
 
   private

Library/Homebrew/shims/super/cc

@@ -292,6 +292,7 @@ class Cmd
     args.concat(optflags) unless runtime_cpu_detection?
     args.concat(archflags)
     args << "-std=#{@arg0}" if /c[89]9/.match?(@arg0)
+    args << "-g" if debug_symbols?
     args
   end
 
@@ -410,6 +411,10 @@ class Cmd
     config.include?("w")
   end
 
+  def debug_symbols?
+    config.include?("D")
+  end
+
   def canonical_path(path)
     path = Pathname.new(path)
     path = path.realpath if path.exist?

Library/Homebrew/test/ENV_spec.rb

@@ -205,5 +205,12 @@ describe "ENV" do
         expect(env["HOMEBREW_CCCFG"]).to include("g")
       end
     end
+
+    describe "#set_debug_symbols" do
+      it "sets the debug symbols flag" do
+        env.set_debug_symbols
+        expect(env["HOMEBREW_CCCFG"]).to include("D")
+      end
+    end
   end
 end

Library/Homebrew/test/cmd/install_spec.rb

@@ -72,4 +72,16 @@ describe "brew install" do
       .and be_a_success
     expect(HOMEBREW_CELLAR/"testball1/HEAD-d5eb689/foo/test").not_to be_a_file
   end
+
+  it "installs formulae with debug symbols", :integration_test do
+    setup_test_formula "testball1"
+
+    expect { brew "install", "testball1", "--debug-symbols", "--build-from-source" }
+      .to output(%r{#{HOMEBREW_CELLAR}/testball1/0\.1}o).to_stdout
+      .and not_to_output.to_stderr
+      .and be_a_success
+    expect(HOMEBREW_CELLAR/"testball1/0.1/bin/test").to be_a_file
+    expect(HOMEBREW_CELLAR/"testball1/0.1/bin/test.dSYM/Contents/Resources/DWARF/test").to be_a_file if OS.mac?
+    expect(HOMEBREW_CACHE/"Sources/testball1").to be_a_directory
+  end
 end

Library/Homebrew/upgrade.rb

@@ -24,6 +24,7 @@ module Homebrew
       build_from_source_formulae: [],
       interactive: false,
       keep_tmp: false,
+      debug_symbols: false,
       force: false,
       debug: false,
       quiet: false,
@@ -61,6 +62,7 @@ module Homebrew
             build_from_source_formulae: build_from_source_formulae,
             interactive:                interactive,
             keep_tmp:                   keep_tmp,
+            debug_symbols:              debug_symbols,
             force:                      force,
             debug:                      debug,
             quiet:                      quiet,
@@ -128,6 +130,7 @@ module Homebrew
       build_from_source_formulae: [],
       interactive: false,
       keep_tmp: false,
+      debug_symbols: false,
       force: false,
       debug: false,
       quiet: false,
@@ -161,6 +164,7 @@ module Homebrew
           build_from_source_formulae: build_from_source_formulae,
           interactive:                interactive,
           keep_tmp:                   keep_tmp,
+          debug_symbols:              debug_symbols,
           force:                      force,
           debug:                      debug,
           quiet:                      quiet,
@@ -254,6 +258,7 @@ module Homebrew
       build_from_source_formulae: [],
       interactive: false,
       keep_tmp: false,
+      debug_symbols: false,
       force: false,
       debug: false,
       quiet: false,
@@ -339,6 +344,7 @@ module Homebrew
           build_from_source_formulae: build_from_source_formulae,
           interactive:                interactive,
           keep_tmp:                   keep_tmp,
+          debug_symbols:              debug_symbols,
           force:                      force,
           debug:                      debug,
           quiet:                      quiet,
@@ -407,6 +413,7 @@ module Homebrew
           build_from_source_formulae: build_from_source_formulae + [formula.full_name],
           interactive:                interactive,
           keep_tmp:                   keep_tmp,
+          debug_symbols:              debug_symbols,
           force:                      force,
           debug:                      debug,
           quiet:                      quiet,