From 5d70abeacac94725bdaae5be8d32c9a50096571e Mon Sep 17 00:00:00 2001
From: silvanshade <silvanshade@users.noreply.github.com>
Date: Thu, 11 Apr 2024 15:06:25 -0600
Subject: [PATCH] Define gccFromSrc to allow building gcc from sources

---
 pkgs/development/compilers/gcc/default.nix | 12 +++++++---
 pkgs/top-level/all-packages.nix            | 28 ++++++++++++++++++++++
 2 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/pkgs/development/compilers/gcc/default.nix b/pkgs/development/compilers/gcc/default.nix
index cad5006ccff2d..0e0b7dcef3f37 100644
--- a/pkgs/development/compilers/gcc/default.nix
+++ b/pkgs/development/compilers/gcc/default.nix
@@ -1,4 +1,4 @@
-{ lib, stdenv, targetPackages, fetchurl, fetchpatch, noSysDirs
+{ lib, stdenv, targetPackages, fetchFromGitHub, fetchurl, fetchpatch, noSysDirs
 , langC ? true, langCC ? true, langFortran ? false
 , langAda ? false
 , langObjC ? stdenv.targetPlatform.isDarwin
@@ -45,11 +45,15 @@
 , libXrender ? null, xorgproto ? null
 , libXrandr ? null, libXi ? null
 , x11Support ? langJava
+
+, gccSrc ? null
 }:
 
 let
   versions = import ./versions.nix;
-  version = versions.fromMajorMinor majorMinorVersion;
+  version = if gccSrc != null
+    then majorMinorVersion
+    else versions.fromMajorMinor majorMinorVersion;
 
   majorVersion = lib.versions.major version;
   atLeast14 = lib.versionAtLeast version "14";
@@ -236,7 +240,9 @@ lib.pipe ((callFile ./common/builder.nix {}) ({
   pname = "${crossNameAddon}${name}";
   inherit version;
 
-  src = if is6 && stdenv.targetPlatform.isVc4 then fetchFromGitHub {
+  src = if gccSrc != null
+  then gccSrc
+  else if is6 && stdenv.targetPlatform.isVc4 then fetchFromGitHub {
     owner = "itszor";
     repo = "gcc-vc4";
     rev = "e90ff43f9671c760cf0d1dd62f569a0fb9bf8918";
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index cdaa063bcdd3e..5e5a03ec238c1 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -15631,6 +15631,34 @@ with pkgs;
   gccFun = callPackage ../development/compilers/gcc;
   gcc-unwrapped = gcc.cc;
 
+  gccFromSrc =
+    let
+      noSysDirs' = noSysDirs;
+    in
+    lib.makeOverridable
+      ({ stdenv ? pkgs.stdenv
+       , src
+       , majorMinorVersion ? lib.fileContents "${src}/gcc/BASE-VER"
+       , noSysDirs ? noSysDirs'
+       , profiledCompiler ? false
+       , reproducibleBuild ? true
+       , libcCross ? if stdenv.targetPlatform != stdenv.buildPlatform then pkgs.libcCross else null
+       , threadsCross ? if stdenv.targetPlatform != stdenv.buildPlatform then pkgs.threadsCrossFor majorMinorVersion else { }
+       , cloog ? if stdenv.isDarwin
+         then null
+         else if lib.versionAtLeast majorMinorVersion "4.9" then cloog_0_18_0
+         else pkgs.cloog
+       , isl ? if stdenv.isDarwin then null
+         else if lib.versionAtLeast majorMinorVersion "9" then isl_0_20
+         else if lib.versionAtLeast majorMinorVersion "7" then isl_0_17
+         else if lib.versionAtLeast majorMinorVersion "6" then (if stdenv.targetPlatform.isRedox then isl_0_17 else isl_0_14)
+         else if lib.versionAtLeast majorMinorVersion "4.9" then isl_0_11
+         else /* "4.8" */ isl_0_14
+       }: wrapCC (gccFun {
+        inherit stdenv majorMinorVersion noSysDirs profiledCompiler reproducibleBuild libcCross threadsCross cloog isl;
+        gccSrc = src;
+      }));
+
   wrapNonDeterministicGcc = stdenv: ccWrapper:
     if ccWrapper.isGNU then ccWrapper.overrideAttrs(old: {
       env = old.env // {