Improvements

Library/Homebrew/cask/cask.rb

@@ -252,21 +252,20 @@ module Cask
       if @dsl.on_system_blocks_exist?
         [:arm, :intel].each do |arch|
           MacOSVersions::SYMBOLS.each_key do |os_name|
-            # Big Sur is the first version of macOS that supports arm
-            next if arch == :arm && MacOS::Version.from_symbol(os_name) < MacOS::Version.from_symbol(:big_sur)
+            bottle_tag = ::Utils::Bottles::Tag.new(system: os_name, arch: arch)
+            next unless bottle_tag.valid_combination?
 
             Homebrew::SimulateSystem.os = os_name
             Homebrew::SimulateSystem.arch = arch
 
             refresh
 
-            bottle_tag = ::Utils::Bottles::Tag.new(system: os_name, arch: arch).to_sym
             to_hash.each do |key, value|
               next if hash_keys_to_skip.include? key
               next if value.to_s == hash[key].to_s
 
-              variations[bottle_tag] ||= {}
-              variations[bottle_tag][key] = value
+              variations[bottle_tag.to_sym] ||= {}
+              variations[bottle_tag.to_sym][key] = value
             end
           end
         end

Library/Homebrew/formula.rb

@@ -2010,40 +2010,29 @@ class Formula
     hash = to_hash_without_variations
     variations = {}
 
-    hash_keys_to_skip = %w[installed linked_keg pinned outdated]
-    os_versions = MacOSVersions::SYMBOLS.keys.append :linux
+    os_versions = [*MacOSVersions::SYMBOLS.keys, :linux]
 
-    if path.exist? && self.class.instance_eval { @on_system_blocks_exist }
+    if path.exist? && self.class.on_system_blocks_exist?
       formula_contents = path.read
-      [:arm, :intel].each do |arch|
+      [:arm64, :x86_64].each do |arch|
         os_versions.each do |os_name|
-          # Big Sur is the first version of macOS that supports arm
-          if os_name != :linux && arch == :arm &&
-             MacOS::Version.from_symbol(os_name) < MacOS::Version.from_symbol(:big_sur)
-            next
-          end
-
-          bottle_tag = if os_name == :linux
-            :linux
-          else
-            Utils::Bottles::Tag.new(system: os_name, arch: arch).to_sym
-          end
+          bottle_tag = Utils::Bottles::Tag.new(system: os_name, arch: arch)
+          next unless bottle_tag.valid_combination?
 
           Homebrew::SimulateSystem.os = os_name
           Homebrew::SimulateSystem.arch = arch
 
-          variations_namespace = Formulary.class_s("Variations#{bottle_tag.capitalize}")
+          variations_namespace = Formulary.class_s("Variations#{bottle_tag.to_sym.capitalize}")
           variations_formula_class = Formulary.load_formula(name, path, formula_contents, variations_namespace,
                                                             flags: self.class.build_flags, ignore_errors: true)
           variations_formula = variations_formula_class.new(name, path, :stable,
                                                             alias_path: alias_path, force_bottle: force_bottle)
 
           variations_formula.to_hash_without_variations.each do |key, value|
-            next if hash_keys_to_skip.include? key
             next if value.to_s == hash[key].to_s
 
-            variations[bottle_tag] ||= {}
-            variations[bottle_tag][key] = value
+            variations[bottle_tag.to_sym] ||= {}
+            variations[bottle_tag.to_sym][key] = value
           end
         end
       end
@@ -2519,6 +2508,7 @@ class Formula
 
   # The methods below define the formula DSL.
   class << self
+    extend Predicable
     include BuildEnvironment::DSL
     include OnSystem::MacOSAndLinux
 
@@ -2533,6 +2523,11 @@ class Formula
       end
     end
 
+    # Whether this formula contains OS/arch-specific blocks
+    # (e.g. `on_macos`, `on_arm`, `on_monterey :or_older`, `on_system :linux, macos: :big_sur_or_newer`).
+    # @private
+    attr_predicate :on_system_blocks_exist?
+
     # The reason for why this software is not linked (by default) to
     # {::HOMEBREW_PREFIX}.
     # @private

Library/Homebrew/test/cask/cmd/list_spec.rb

@@ -187,25 +187,25 @@ describe Cask::Cmd::List, :cask do
             "container": null,
             "auto_updates": null,
             "variations": {
-              "arm_big_sur": {
+              "arm64_big_sur": {
                 "url": "file://#{TEST_FIXTURE_DIR}/cask/caffeine/1.2.0/arm.zip",
                 "version": "1.2.0",
                 "sha256": "8c62a2b791cf5f0da6066a0a4b6e85f62949cd60975da062df44adf887f4370b"
               },
-              "intel_monterey": {
+              "monterey": {
                 "url": "file://#{TEST_FIXTURE_DIR}/cask/caffeine/1.2.3/intel.zip"
               },
-              "intel_big_sur": {
+              "big_sur": {
                 "url": "file://#{TEST_FIXTURE_DIR}/cask/caffeine/1.2.0/intel.zip",
                 "version": "1.2.0",
                 "sha256": "8c62a2b791cf5f0da6066a0a4b6e85f62949cd60975da062df44adf887f4370b"
               },
-              "intel_catalina": {
+              "catalina": {
                 "url": "file://#{TEST_FIXTURE_DIR}/cask/caffeine/1.0.0/intel.zip",
                 "version": "1.0.0",
                 "sha256": "1866dfa833b123bb8fe7fa7185ebf24d28d300d0643d75798bc23730af734216"
               },
-              "intel_mojave": {
+              "mojave": {
                 "url": "file://#{TEST_FIXTURE_DIR}/cask/caffeine/1.0.0/intel.zip",
                 "version": "1.0.0",
                 "sha256": "1866dfa833b123bb8fe7fa7185ebf24d28d300d0643d75798bc23730af734216"

Library/Homebrew/test/utils/bottles/tag_spec.rb

@@ -36,4 +36,37 @@ describe Utils::Bottles::Tag do
     expect(tag.linux?).to be true
     expect(tag.to_sym).to eq(symbol)
   end
+
+  describe "#standardized_arch" do
+    it "returns :x86_64 for :intel" do
+      expect(described_class.new(system: :all, arch: :intel).standardized_arch).to eq(:x86_64)
+    end
+
+    it "returns :arm64 for :arm" do
+      expect(described_class.new(system: :all, arch: :arm).standardized_arch).to eq(:arm64)
+    end
+  end
+
+  describe "#valid_combination?" do
+    it "returns true for intel archs" do
+      tag = described_class.new(system: :big_sur, arch: :intel)
+      expect(tag.valid_combination?).to be true
+      tag = described_class.new(system: :linux, arch: :x86_64)
+      expect(tag.valid_combination?).to be true
+    end
+
+    it "returns false for arm archs and macos versions older than big_sur" do
+      tag = described_class.new(system: :catalina, arch: :arm64)
+      expect(tag.valid_combination?).to be false
+      tag = described_class.new(system: :mojave, arch: :arm)
+      expect(tag.valid_combination?).to be false
+    end
+
+    it "returns false for arm archs and linux " do
+      tag = described_class.new(system: :linux, arch: :arm64)
+      expect(tag.valid_combination?).to be false
+      tag = described_class.new(system: :linux, arch: :arm)
+      expect(tag.valid_combination?).to be false
+    end
+  end
 end

Library/Homebrew/utils/bottles.rb

@@ -169,14 +169,21 @@ module Utils
         [system, arch].hash
       end
 
+      def standardized_arch
+        return :x86_64 if [:x86_64, :intel].include? arch
+        return :arm64 if [:arm64, :arm].include? arch
+
+        arch
+      end
+
       sig { returns(Symbol) }
       def to_sym
         if system == :all && arch == :all
           :all
-        elsif macos? && arch == :x86_64
+        elsif macos? && [:x86_64, :intel].include?(arch)
           system
         else
-          "#{arch}_#{system}".to_sym
+          "#{standardized_arch}_#{system}".to_sym
         end
       end
 
@@ -203,6 +210,15 @@ module Utils
         false
       end
 
+      sig { returns(T::Boolean) }
+      def valid_combination?
+        return true unless [:arm64, :arm].include? arch
+        return false if linux?
+
+        # Big Sur is the first version of macOS that runs on ARM
+        to_macos_version >= :big_sur
+      end
+
       sig { returns(String) }
       def default_prefix
         if linux?