compilers: drop support for GCC 4.9

Also update documentation and tests to use non-disabled GCC.

Library/Homebrew/cmd/install.rb

@@ -63,7 +63,7 @@ class InstallCmd < AbstractCommand
           }],
           [:flag, "--cc=", {
             description: "Attempt to compile using the specified <compiler>, which should be the name of the " \
-                         "compiler's executable, e.g. `gcc-7` for GCC 7. In order to use LLVM's clang, specify " \
+                         "compiler's executable, e.g. `gcc-9` for GCC 9. In order to use LLVM's clang, specify " \
                          "`llvm_clang`. To use the Apple-provided clang, specify `clang`. This option will only " \
                          "accept compilers that are provided by Homebrew or bundled with macOS. Please do not " \
                          "file issues if you encounter errors while using this option.",

Library/Homebrew/compilers.rb

@@ -2,8 +2,8 @@
 # frozen_string_literal: true
 
 module CompilerConstants
-  GNU_GCC_VERSIONS = %w[4.9 5 6 7 8 9 10 11 12 13 14].freeze
-  GNU_GCC_REGEXP = /^gcc-(4\.9|[5-9]|10|11|12|13|14)$/
+  GNU_GCC_VERSIONS = %w[5 6 7 8 9 10 11 12 13 14].freeze
+  GNU_GCC_REGEXP = /^gcc-(#{GNU_GCC_VERSIONS.join("|")})$/
   COMPILER_SYMBOL_MAP = {
     "gcc"        => :gcc,
     "clang"      => :clang,

Library/Homebrew/test/ENV_spec.rb

@@ -129,8 +129,8 @@
 
     describe "#compiler" do
       it "allows switching compilers" do
-        subject.public_send(:"gcc-6")
-        expect(subject.compiler).to eq("gcc-6")
+        subject.public_send(:"gcc-9")
+        expect(subject.compiler).to eq("gcc-9")
       end
     end
 
@@ -179,14 +179,8 @@
     end
 
     describe "#cxx11" do
-      it "supports gcc-5" do
-        env["HOMEBREW_CC"] = "gcc-5"
-        env.cxx11
-        expect(env["HOMEBREW_CCCFG"]).to include("x")
-      end
-
-      example "supports gcc-6" do
-        env["HOMEBREW_CC"] = "gcc-6"
+      it "supports gcc-9" do
+        env["HOMEBREW_CC"] = "gcc-9"
         env.cxx11
         expect(env["HOMEBREW_CCCFG"]).to include("x")
       end

Library/Homebrew/test/compiler_selector_spec.rb

@@ -14,10 +14,10 @@
   before do
     allow(versions).to receive(:gcc_version) do |name|
       case name
-      when "gcc-7" then Version.new("7.1")
-      when "gcc-6" then Version.new("6.1")
-      when "gcc-5" then Version.new("5.1")
-      when "gcc-4.9" then Version.new("4.9.1")
+      when "gcc-12" then Version.new("12.1")
+      when "gcc-11" then Version.new("11.1")
+      when "gcc-10" then Version.new("10.1")
+      when "gcc-9" then Version.new("9.1")
       else Version::NULL
       end
     end
@@ -29,68 +29,68 @@
     end
 
     it "returns clang if it fails with non-Apple gcc" do
-      software_spec.fails_with(gcc: "7")
+      software_spec.fails_with(gcc: "12")
       expect(selector.compiler).to eq(:clang)
     end
 
-    it "still returns gcc-7 if it fails with gcc without a specific version" do
+    it "still returns gcc-12 if it fails with gcc without a specific version" do
       software_spec.fails_with(:clang)
-      expect(selector.compiler).to eq("gcc-7")
+      expect(selector.compiler).to eq("gcc-12")
     end
 
-    it "returns gcc-6 if gcc formula offers gcc-6 on mac", :needs_macos do
+    it "returns gcc-11 if gcc formula offers gcc-11 on mac", :needs_macos do
       software_spec.fails_with(:clang)
       allow(Formulary).to receive(:factory)
         .with("gcc")
-        .and_return(instance_double(Formula, version: Version.new("6.0")))
-      expect(selector.compiler).to eq("gcc-6")
+        .and_return(instance_double(Formula, version: Version.new("11.0")))
+      expect(selector.compiler).to eq("gcc-11")
     end
 
-    it "returns gcc-5 if gcc formula offers gcc-5 on linux", :needs_linux do
+    it "returns gcc-10 if gcc formula offers gcc-10 on linux", :needs_linux do
       software_spec.fails_with(:clang)
       allow(Formulary).to receive(:factory)
         .with("gcc@11")
-        .and_return(instance_double(Formula, version: Version.new("5.0")))
-      expect(selector.compiler).to eq("gcc-5")
+        .and_return(instance_double(Formula, version: Version.new("10.0")))
+      expect(selector.compiler).to eq("gcc-10")
     end
 
-    it "returns gcc-6 if gcc formula offers gcc-5 and fails with gcc-5 and gcc-7 on linux", :needs_linux do
+    it "returns gcc-11 if gcc formula offers gcc-10 and fails with gcc-10 and gcc-12 on linux", :needs_linux do
       software_spec.fails_with(:clang)
-      software_spec.fails_with(gcc: "5")
-      software_spec.fails_with(gcc: "7")
+      software_spec.fails_with(gcc: "10")
+      software_spec.fails_with(gcc: "12")
       allow(Formulary).to receive(:factory)
         .with("gcc@11")
-        .and_return(instance_double(Formula, version: Version.new("5.0")))
-      expect(selector.compiler).to eq("gcc-6")
+        .and_return(instance_double(Formula, version: Version.new("10.0")))
+      expect(selector.compiler).to eq("gcc-11")
     end
 
-    it "returns gcc-7 if gcc formula offers gcc-5 and fails with gcc <= 6 on linux", :needs_linux do
+    it "returns gcc-12 if gcc formula offers gcc-11 and fails with gcc <= 11 on linux", :needs_linux do
       software_spec.fails_with(:clang)
-      software_spec.fails_with(:gcc) { version "6" }
+      software_spec.fails_with(:gcc) { version "11" }
       allow(Formulary).to receive(:factory)
         .with("gcc@11")
-        .and_return(instance_double(Formula, version: Version.new("5.0")))
-      expect(selector.compiler).to eq("gcc-7")
+        .and_return(instance_double(Formula, version: Version.new("11.0")))
+      expect(selector.compiler).to eq("gcc-12")
     end
 
-    it "returns gcc-7 if gcc-7 is version 7.1 but spec fails with gcc-7 <= 7.0" do
+    it "returns gcc-12 if gcc-12 is version 12.1 but spec fails with gcc-12 <= 12.0" do
       software_spec.fails_with(:clang)
-      software_spec.fails_with(gcc: "7") { version "7.0" }
-      expect(selector.compiler).to eq("gcc-7")
+      software_spec.fails_with(gcc: "12") { version "12.0" }
+      expect(selector.compiler).to eq("gcc-12")
     end
 
-    it "returns gcc-6 if gcc-7 is version 7.1 but spec fails with gcc-7 <= 7.1" do
+    it "returns gcc-11 if gcc-12 is version 12.1 but spec fails with gcc-12 <= 12.1" do
       software_spec.fails_with(:clang)
-      software_spec.fails_with(gcc: "7") { version "7.1" }
-      expect(selector.compiler).to eq("gcc-6")
+      software_spec.fails_with(gcc: "12") { version "12.1" }
+      expect(selector.compiler).to eq("gcc-11")
     end
 
     it "raises an error when gcc or llvm is missing (hash syntax)" do
       software_spec.fails_with(:clang)
-      software_spec.fails_with(gcc: "7")
-      software_spec.fails_with(gcc: "6")
-      software_spec.fails_with(gcc: "5")
-      software_spec.fails_with(gcc: "4.9")
+      software_spec.fails_with(gcc: "12")
+      software_spec.fails_with(gcc: "11")
+      software_spec.fails_with(gcc: "10")
+      software_spec.fails_with(gcc: "9")
 
       expect { selector.compiler }.to raise_error(CompilerSelectionError)
     end

docs/C++-Standard-Libraries.md

@@ -20,9 +20,9 @@ dependencies that you built on 10.8 or earlier. If you're reading this page beca
 you were directed here by a build error, you can most likely fix the issue if
 you reinstall all the dependencies of the package you're trying to build.
 
-Example install using GCC 7:
+Example install using GCC 9:
 
 ```sh
-brew install gcc@7
-brew install --cc=gcc-7 <formula>
+brew install gcc@9
+brew install --cc=gcc-9 <formula>
 ```

docs/Custom-GCC-and-cross-compilers.md

@@ -5,7 +5,7 @@ Homebrew depends on having an up-to-date version of Xcode because it comes with
 Rather than merging formulae for either of these cases at this time, we're listing them on this page. If you come up with a formula for a new version of GCC or cross-compiler suite, please link to it here.
 
 - Homebrew provides a `gcc` formula for use with Xcode 4.2+.
-- Homebrew provides older GCC formulae, e.g. `gcc@7`.
+- Homebrew provides older GCC formulae, e.g. `gcc@9`.
 - Homebrew provides some cross-compilers and toolchains, but these are named to avoid clashing with the default tools, e.g. `i686-elf-gcc`, `x86_64-elf-gcc`.
 - Homebrew provides LLVM's Clang, which is bundled with the `llvm` formula.
 - [RISC-V](https://github.com/riscv/homebrew-riscv) provides the RISC-V toolchain including binutils and GCC.

docs/Manpage.md

@@ -587,7 +587,7 @@ upgrade *`formula`* if it is already installed but outdated.
 `--cc`
 
 : Attempt to compile using the specified *`compiler`*, which should be the name
-  of the compiler's executable, e.g. `gcc-7` for GCC 7. In order to use LLVM's
+  of the compiler's executable, e.g. `gcc-9` for GCC 9. In order to use LLVM's
   clang, specify `llvm_clang`. To use the Apple-provided clang, specify `clang`.
   This option will only accept compilers that are provided by Homebrew or
   bundled with macOS. Please do not file issues if you encounter errors while

docs/Tips-N'-Tricks.md

@@ -2,7 +2,7 @@
 
 ## Install previous versions of formulae
 
-Some formulae in `homebrew/core` are made available as [versioned formulae](Versions.md) using a special naming format, e.g. `gcc@7`. If the version you're looking for isn't available, consider using `brew extract`.
+Some formulae in `homebrew/core` are made available as [versioned formulae](Versions.md) using a special naming format, e.g. `gcc@9`. If the version you're looking for isn't available, consider using `brew extract`.
 
 ## Quickly remove something from Homebrew's prefix
 

docs/Versions.md

@@ -1,6 +1,6 @@
 # Formulae Versions
 
-[homebrew/core](https://github.com/homebrew/homebrew-core) supports multiple versions of formulae by using a special naming format. For example, the formula for GCC 6 is named `gcc@6.rb` and begins with `class GccAT6 < Formula`.
+[homebrew/core](https://github.com/homebrew/homebrew-core) supports multiple versions of formulae by using a special naming format. For example, the formula for GCC 9 is named `gcc@9.rb` and begins with `class GccAT9 < Formula`.
 
 ## Acceptable versioned formulae