lib.systems: replace gcc attributes with cpu options

NixOS · Jan 24, 2025 · 403bf3b · 403bf3b
1 parent d30faab
commit 403bf3b
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Showing 4 changed files with 112 additions and 61 deletions.
diff --git a/lib/systems/default.nix b/lib/systems/default.nix
@@ -66,7 +66,9 @@ let
   # `parsed` is inferred from args, both because there are two options with one
   # clearly preferred, and to prevent cycles. A simpler fixed point where the RHS
   # always just used `final.*` would fail on both counts.
-  elaborate = systemOrArgs: let
+  elaborate = systemOrArgs:
+    assert lib.assertMsg (!(lib.oldestSupportedReleaseIsAtLeast 2511 && systemOrArgs ? gcc)) "The gcc attribute has been deprecated in favor of the cpu attributes.";
+    let
     allArgs = systemToAttrs systemOrArgs;
 
     # Those two will always be derived from "config", if given, so they should NOT
@@ -319,6 +321,30 @@ let
     }) // mapAttrs (n: v: v final.parsed) inspect.predicates
       // mapAttrs (n: v: v final.gcc.arch or "default") architectures.predicates
       // args // {
+        cpu = parse.mkCpu final.parsed
+          (if args ? gcc then
+            let
+              # For gcc attribute compatibility until 25.11 is released
+              cpuModels = parse.cpuModels final.parsed;
+              gccModels = lib.listToAttrs (lib.attrValues (lib.mapAttrs (name: value: lib.nameValuePair value.gnu name) cpuModels));
+
+              gccModel = args.gcc.model or args.gcc.arch or "generic";
+            in {
+              model = gccModels.${gccModel}
+                or (throw "${gccModel} is not supported in ${final.parsed.cpu.name} with gcc.model compatibility");
+            }
+          else (args.cpu or {}));
+
+        gcc = lib.warnIf
+          (lib.oldestSupportedReleaseIsAtLeast 2511)
+          "The gcc attribute in platform was deprecated in 25.11"
+          (lib.optionalAttrs (final.cpu.model.gnu != "generic") {
+            cpu = final.cpu.model.gnu;
+          } // lib.optionalAttrs (final.isAarch64 && final.cpu.model.gnu == "generic") {
+            # TODO: find when to use this.
+            arch = "armv8-a";
+          });
+
         rust = rust // {
           # Once args.rustc.platform.target-family is deprecated and
           # removed, there will no longer be any need to modify any

diff --git a/lib/systems/examples.nix b/lib/systems/examples.nix
@@ -26,7 +26,7 @@ rec {
   };
   ppc64-musl = {
     config = "powerpc64-unknown-linux-musl";
-    gcc = { abi = "elfv2"; };
+    abi = "elfv2";
   };
 
   sheevaplug = {
@@ -198,7 +198,7 @@ rec {
     libc = "newlib";
     # GCC8+ does not build without this
     # (https://www.mail-archive.com/[email protected]/msg552339.html):
-    gcc = {
+    cpu = {
       arch = "armv5t";
       fpu = "vfp";
     };

diff --git a/lib/systems/parse.nix b/lib/systems/parse.nix
@@ -424,6 +424,54 @@ rec {
 
   ################################################################################
 
+  types.openCpuModel = mkOptionType {
+    name = "cpu-model";
+    description = "cpu model";
+    merge = mergeOneOption;
+  };
+
+  types.cpuModel = platform: enum (attrValues (cpuModels platform));
+
+  cpuModels = platform:
+    let
+      mkCpuModel = { zig ? "baseline", gnu ? "generic", llvm ? "generic", inferiors ? [], features ? [] }@args:
+        { zig = "baseline"; gnu = "generic"; llvm = "generic"; inferiors = []; features = []; } // args;
+
+      generic = mkCpuModel {};
+
+      sets = {};
+    in setTypes types.openCpuModel ((sets.${platform.cpu.name} or {}) // { inherit generic; });
+
+  ################################################################################
+
+  types.cpu = mkOptionType {
+    name = "cpu";
+    description = "cpu options to pass to various compilers";
+    merge = mergeOneOption;
+    check = { platform, model }:
+      types.parsedPlatform.check platform
+      && types.cpuModel.check model;
+  };
+
+  isCpu = isType "cpu";
+
+  mkCpu = platform:
+    {
+      model ? "generic",
+      float ? null,
+      float-abi ? null,
+      fpu ? null,
+    }:
+    let
+      cpuModels' = cpuModels platform;
+    in
+      setType "cpu" {
+        inherit platform;
+        model = cpuModels'."${model}" or (throw "Unknown CPU model ${model} for CPU architecture ${platform.cpu.name}");
+      };
+
+  ################################################################################
+
   types.parsedPlatform = mkOptionType {
     name = "system";
     description = "fully parsed representation of llvm- or nix-style platform tuple";

diff --git a/lib/systems/platforms.nix b/lib/systems/platforms.nix
@@ -67,9 +67,7 @@ rec {
       # TODO reenable once manual-config's config actually builds a .dtb and this is checked to be working
       #DTB = true;
     };
-    gcc = {
-      arch = "armv5te";
-    };
+    cpu.model = "armv5te";
   };
 
   sheevaplug = {
@@ -180,9 +178,7 @@ rec {
       target = "uImage";
       DTB = true; # Beyond 3.10
     };
-    gcc = {
-      arch = "armv5te";
-    };
+    cpu.model = "armv5te";
   };
 
   raspberrypi = {
@@ -200,9 +196,9 @@ rec {
       '';
       target = "zImage";
     };
-    gcc = {
+    cpu = {
       # https://en.wikipedia.org/wiki/Raspberry_Pi#Specifications
-      arch = "armv6kz";
+      model = "armv6kz";
       fpu = "vfpv2";
     };
   };
@@ -212,9 +208,7 @@ rec {
 
   # Nvidia Bluefield 2 (w. crypto support)
   bluefield2 = {
-    gcc = {
-      arch = "armv8-a+fp+simd+crc+crypto";
-    };
+    cpu.model = "armv8-a+fp+simd+crc+crypto";
   };
 
   zero-gravitas = {
@@ -227,9 +221,9 @@ rec {
       autoModules = false;
       DTB = true;
     };
-    gcc = {
+    cpu = {
+      model = "cortex-a9";
       fpu = "neon";
-      cpu = "cortex-a9";
     };
   };
 
@@ -243,8 +237,8 @@ rec {
       preferBuiltin = true;
       target = "zImage";
     };
-    gcc = {
-      cpu = "cortex-a7";
+    cpu = {
+      model = "cortex-a7";
       fpu = "neon-vfpv4";
       float-abi = "hard";
     };
@@ -269,8 +263,8 @@ rec {
       target = "uImage";
       DTB = true;
     };
-    gcc = {
-      cpu = "cortex-a9";
+    cpu = {
+      model = "cortex-a9";
       fpu = "neon";
     };
   };
@@ -296,8 +290,8 @@ rec {
   # https://developer.android.com/ndk/guides/abis#v7a
   armv7a-android = {
     linux-kernel.name = "armeabi-v7a";
-    gcc = {
-      arch = "armv7-a";
+    cpu = {
+      model = "armv7-a";
       float-abi = "softfp";
       fpu = "vfpv3-d16";
     };
@@ -333,7 +327,7 @@ rec {
         KS8851_MLL y
       '';
     };
-    gcc = {
+    cpu = {
       # Some table about fpu flags:
       # http://community.arm.com/servlet/JiveServlet/showImage/38-1981-3827/blogentry-103749-004812900+1365712953_thumb.png
       # Cortex-A5: -mfpu=neon-fp16
@@ -347,11 +341,11 @@ rec {
 
       # vfpv3-d16 is what Debian uses and seems to be the best compromise: NEON is not supported in e.g. Scaleway or Tegra 2,
       # and the above page suggests NEON is only an improvement with hand-written assembly.
-      arch = "armv7-a";
+      model = "armv7-a";
       fpu = "vfpv3-d16";
 
       # For Raspberry Pi the 2 the best would be:
-      #   cpu = "cortex-a7";
+      #   model = "cortex-a7";
       #   fpu = "neon-vfpv4";
     };
   };
@@ -386,16 +380,11 @@ rec {
       '';
       target = "Image";
     };
-    gcc = {
-      arch = "armv8-a";
-    };
+    cpu.model = "armv8-a";
   };
 
   apple-m1 = {
-    gcc = {
-      arch = "armv8.3-a+crypto+sha2+aes+crc+fp16+lse+simd+ras+rdm+rcpc";
-      cpu = "apple-a13";
-    };
+    cpu.model = "apple-m1";
   };
 
   ##
@@ -406,8 +395,8 @@ rec {
     linux-kernel = {
       name = "ben_nanonote";
     };
-    gcc = {
-      arch = "mips32";
+    cpu = {
+      model = "mips32";
       float = "soft";
     };
   };
@@ -483,49 +472,37 @@ rec {
       '';
       target = "vmlinux";
     };
-    gcc = {
-      arch = "loongson2f";
+    cpu = {
+      model = "loongson2f";
       float = "hard";
-      abi = "n32";
     };
+    abi = "n32";
   };
 
   # can execute on 32bit chip
   gcc_mips32r2_o32 = {
-    gcc = {
-      arch = "mips32r2";
-      abi = "32";
-    };
+    cpu.model = "mips32r2";
+    abi = "32";
   };
   gcc_mips32r6_o32 = {
-    gcc = {
-      arch = "mips32r6";
-      abi = "32";
-    };
+    cpu.model = "mips32r6";
+    abi = "32";
   };
   gcc_mips64r2_n32 = {
-    gcc = {
-      arch = "mips64r2";
-      abi = "n32";
-    };
+    cpu.model = "mips64r2";
+    abi = "n32";
   };
   gcc_mips64r6_n32 = {
-    gcc = {
-      arch = "mips64r6";
-      abi = "n32";
-    };
+    cpu.model = "mips64r6";
+    abi = "n32";
   };
   gcc_mips64r2_64 = {
-    gcc = {
-      arch = "mips64r2";
-      abi = "64";
-    };
+    cpu.model = "mips64r2";
+    abi = "64";
   };
   gcc_mips64r6_64 = {
-    gcc = {
-      arch = "mips64r6";
-      abi = "64";
-    };
+    cpu.model = "mips64r6";
+    abi = "64";
   };
 
   # based on: