llvmPackages.compiler-rt: drop libc-free patch

pkgs/development/compilers/llvm/20/compiler-rt/libc-free.patch

@@ -1,68 +0,0 @@
-From 5eaae2daff7722ee01eee239e131ee1f62643abe Mon Sep 17 00:00:00 2001
-From: Peter Waller <peter.waller@arm.com>
-Date: Wed, 5 Feb 2025 19:46:15 +0000
-Subject: [PATCH] [compiler-rt][AArch64] Enable libc-free builtins Linux build
-
-Without this change, libc++abi.so.1.0 fails to link with:
-
-```
-error: undefined sybol: __aarch64_sme_accessible
-```
-
-This symbol is provided by baremetal libc's such as newlib.
-
-In order to compile a libc with compiler-rt, it is necessary first to
-build a compiler-rt with no dependency on libc to acquire the builtins.
-The intended linux test requires getauxval which is provided by libc.
-
-To that end, there are examples in the wild of building a compiler-rt
-without libc by specifying -DCOMPILER_RT_BAREMETAL_BUILD=ON.
-On Linux, this gives a builtins build with (almost) no libc dependencies.
-
-See for example:
-
-https://github.com/NixOS/nixpkgs/blob/d7fe3bcaca37e79d8b3cbde4dd69edeafbd35313/pkgs/development/compilers/llvm/common/compiler-rt/default.nix#L116-L118
-
-```
-  ] ++ lib.optionals (!haveLibc || bareMetal) [
-    "-DCMAKE_C_COMPILER_WORKS=ON"
-    "-DCOMPILER_RT_BAREMETAL_BUILD=ON"
-```
-
-The above specifies that a !haveLibc build sets
-`-DCOMPILER_RT_BAREMETAL_BUILD`, which is done for example in a `pkgsLLVM` build.
-
-AIUI, acquiring such a builtins build of compiler-rt is necessary to build a
-pure LLVM toolchain, since builtins are required to build libc (and
-libcxx is required to build a full compiler-rt).
-
-The effect of falling back to unimplemented is that this early-stage
-builtins build is incapable of doing function multiversioning tests and
-falls back to behaving as-if the feature is unavailable.
-
-This behaviour changed in
-https://github.com/llvm/llvm-project/pull/119414, which introduced a
-subtle change in semantics in the removal of
-compiler-rt/lib/builtins/aarch64/sme-abi-init.c (definition of getauxval
-macro, which was bracketed by `#if defined(__linux__)`) vs the new
-definition which does not test for linux.
-
-The proposed change is reinstating things as they were before #119414.
----
- compiler-rt/lib/builtins/cpu_model/aarch64.c | 2 +-
- 1 file changed, 1 insertion(+), 1 deletion(-)
-
-diff --git a/lib/builtins/cpu_model/aarch64.c b/lib/builtins/cpu_model/aarch64.c
-index 4082fd62ea11a25..50438bcc7ddd885 100644
---- a/lib/builtins/cpu_model/aarch64.c
-+++ b/lib/builtins/cpu_model/aarch64.c
-@@ -80,7 +80,7 @@ struct {
- #include "aarch64/fmv/getauxval.inc"
- #elif defined(_WIN32)
- #include "aarch64/fmv/windows.inc"
--#elif defined(ENABLE_BAREMETAL_AARCH64_FMV)
-+#elif defined(ENABLE_BAREMETAL_AARCH64_FMV) && !defined(__linux__)
- #include "aarch64/fmv/baremetal.inc"
- #else
- #include "aarch64/fmv/unimplemented.inc"
-

pkgs/development/compilers/llvm/common/default.nix

@@ -1086,12 +1086,7 @@ let
           url = "https://github.com/llvm/llvm-project/pull/99837/commits/14ae0a660a38e1feb151928a14f35ff0f4487351.patch";
           hash = "sha256-JykABCaNNhYhZQxCvKiBn54DZ5ZguksgCHnpdwWF2no=";
           relative = "compiler-rt";
-        })
-        # Fixes baremetal
-        # PR: https://github.com/llvm/llvm-project/pull/125922
-        ++ lib.optional (lib.versionAtLeast metadata.release_version "20") (
-          metadata.getVersionFile "compiler-rt/libc-free.patch"
-        );
+        });
     in
     (
       {