tools: reduce bundle size of benchmarkTools.nix

.github/workflows/benchmark.yml

@@ -220,7 +220,7 @@ jobs:
           nix-shell \
             -I nixpkgs=./tools/nix/pkgs.nix \
             --pure \
-            -E '(import <nixpkgs> {}).mkShell { buildInputs = import ./tools/nix/benchmarkTools.nix { withHttpBenchmarkDeps = false; }; }' \
+            -E '(import <nixpkgs> {}).mkShellNoCC { buildInputs = import ./tools/nix/benchmarkTools.nix { withHttpBenchmarkDeps = false; }; }' \
             --run '
                 export LC_ALL=C.UTF-8
                 echo "> [!WARNING] "

tools/nix/R-overlay.nix

@@ -0,0 +1,180 @@
+# To be used as an overlay
+(final: prev: {
+  R =
+    let
+      inherit (final)
+        lib
+        stdenv
+        stdenvNoCC
+        fetchurl
+        blas
+        bzip2
+        curlMinimal
+        gfortran
+        lapack
+        ncurses
+        pcre2
+        readline
+        removeReferencesTo
+        runCommand
+        tzdata
+        which
+        xz
+        zlib
+        ;
+    in
+    prev.R.overrideAttrs {
+      buildInputs = [
+        blas
+        bzip2
+        gfortran
+        lapack
+        ncurses
+        pcre2
+        readline
+        which
+        xz
+        zlib
+      ];
+
+      nativeBuildInputs = prev.R.nativeBuildInputs ++ [ removeReferencesTo ];
+
+      preConfigure = ''
+        configureFlagsArray=(
+          --disable-lto
+          --without-recommended-packages
+          --with-blas="-L${blas}/lib -lblas"
+          --with-lapack="-L${lapack}/lib -llapack"
+          --with-readline
+          --without-aqua
+          --without-tcltk
+          --without-cairo
+          --without-libpng
+          --without-jpeglib
+          --without-libtiff
+          --without-ICU
+          --without-x
+          --disable-R-framework
+          --disable-java
+          AR=$(type -p ar)
+          AWK=$(type -p gawk)
+          CC=$(type -p cc)
+          CXX=$(type -p c++)
+          FC="${gfortran}/bin/gfortran" F77="${gfortran}/bin/gfortran"
+          RANLIB=$(type -p ranlib)
+          CURL_CONFIG="${lib.getExe' (lib.getDev curlMinimal) "curl-config"}"
+          r_cv_have_curl728=yes
+          R_SHELL="${stdenvNoCC.shell}"
+      ''
+      + lib.optionalString stdenv.hostPlatform.isDarwin ''
+        OBJC="clang"
+        CPPFLAGS="-isystem ${lib.getInclude stdenv.cc.libcxx}/include/c++/v1"
+        LDFLAGS="-L${lib.getLib stdenv.cc.libcxx}/lib"
+      ''
+      + ''
+        )
+        echo >>etc/Renviron.in "TZDIR=${tzdata}/share/zoneinfo"
+      '';
+
+      # Upstream postInstall link to the `tex` output, which we don't need
+      postInstall = "mv -T \"$out/lib/R/share/texmf\" \"$tex\"";
+      postFixup =
+        prev.R.postFixup
+        # Keep the C/C++ compiler out of R's runtime closure (enforced by
+        # outputChecks.disallowedReferences below). R records the absolute path of the
+        # compiler it was built with in Makeconf (and a couple of launchers); rewrite
+        # those to bare command names so packages are compiled with the toolchain
+        # provided by their own build environment. Only the compiler's runtime
+        # libraries (…-lib) are needed at run time, so repoint the recorded library
+        # search paths, and strip any residual paths recorded in compiled objects
+        # (e.g. debug/.comment sections).
+        + ''
+          compilers='cc|gcc|g\+\+|c\+\+|cpp|clang|clang\+\+|gccgo|gfortran|g77|ld|ld\.gold|ld\.bfd|ld\.lld|ar|ranlib|nm|as|strip|dsymutil|install_name_tool|libtool|lipo|otool'
+          for f in \
+            $out/lib/R/etc/Makeconf $out/lib/R/etc/Renviron \
+            $out/lib/R/bin/R $out/bin/R \
+            $out/lib/R/bin/libtool $out/lib/R/bin/javareconf \
+          ; do
+            [ -f "$f" ] && sed -i -E "s#/nix/store/[a-z0-9]{32}-[^/ \"')]*/bin/($compilers)#\1#g" "$f"
+          done
+
+          substituteInPlace \
+              $out/lib/R/etc/Makeconf \
+          ${
+            if stdenv.hostPlatform.isDarwin then
+              # On Darwin the toolchain is clang. After bare-naming, CC/CXX are plain
+              # `cc`/`c++`, which resolve via PATH to the gfortran cc-wrapper's GCC
+              # drivers in an R-package build env; GCC's libstdc++ headers are
+              # incompatible with the SDK libcxx (e.g. "'abort' has not been declared in
+              # 'std'"). Pin them to clang/clang++, which the gfortran wrapper does not
+              # provide (so PATH resolves to the real clang) and which are not store
+              # paths (so the disallowedReferences check still passes).
+              ''
+                --replace-fail 'CC = cc' 'CC = clang' \
+                --replace-fail 'CXX = c++' 'CXX = clang++' \
+                --replace-fail 'CXX17 = c++' 'CXX17 = clang++' \
+                --replace-fail 'CXX20 = c++' 'CXX20 = clang++' \
+                --replace-fail 'CXX23 = c++' 'CXX23 = clang++'
+              ''
+            else
+              # On Linux gfortran.cc is the same derivation as stdenv.cc.cc (the full
+              # gcc), which the disallowedReferences check forbids, so repoint its
+              # recorded library search paths to the -lib output. This must NOT run on
+              # Darwin: there gfortran is a separate derivation from clang (so the check
+              # already passes) and its -lib output lacks lib/gcc/<triple>/<ver> and the
+              # libemutls_w/libheapt_w archives that Fortran packages link against.
+              ''
+                  $out/lib/R/etc/ldpaths \
+                --replace-fail "${gfortran.cc}" "${lib.getLib gfortran.cc}"
+              ''
+          }
+
+          ${lib.optionalString (!stdenv.hostPlatform.isDarwin) ''
+            substituteInPlace $out/lib/R/bin/libtool \
+                  --replace-fail "${stdenv.cc.cc}" "${lib.getLib stdenv.cc.cc}"''}
+
+          # Neutralise any residual references that are not a plain /bin/<tool> path,
+          # e.g. the compiler resource dir baked into libtool's library search path.
+          for f in $out/lib/R/etc/Makeconf $out/lib/R/bin/libtool; do
+            [ -f "$f" ] && remove-references-to -t ${stdenv.cc} "$f"
+          done
+
+          rm $out/lib/R/bin/javareconf
+
+          find $out -type f -name '*.${stdenv.hostPlatform.extensions.sharedLibrary}' -exec \
+            remove-references-to -t ${stdenv.cc} -t ${stdenv.cc.cc} {} +
+
+          find $out -type f -exec remove-references-to -t "$man" {} +
+
+          # 1) Drop recorded `# configure …` / comment lines that pin build-time
+          #    store paths (R-man via --mandir, the *-dev pkgconfig set, …).
+          #    Pure metadata — never used at run time.
+          sed -i -E '\|^#.*/nix/store/[a-z0-9]{32}|d' $out/lib/R/etc/Makeconf
+
+          # 2) Bare-name the external tool commands R records for
+          #    install.packages()/vignettes (gzip, bzip2, sed, tar, …). R uses
+          #    libz/libbz2 internally to *read* compressed data, so dropping the
+          #    store path (keeping the bare name, resolved from PATH if present)
+          #    doesn't affect running scripts or loading packages.
+          tools='gzip|bzip2|bunzip2|sed|tar|gtar|make|gmake|unzip|zip|xz|gawk|awk'
+          for f in $out/lib/R/etc/Renviron $out/lib/R/etc/Makeconf; do
+            [ -f "$f" ] && sed -i -E "s#/nix/store/[a-z0-9]{32}-[^/ \"')]*/bin/($tools)#\1#g" "$f"
+          done
+
+          # 3) full gfortran (its lib/gcc/<triple>/<ver> crt dir) baked into libtool.
+          [ -f $out/lib/R/bin/libtool ] && \
+            remove-references-to -t ${gfortran.cc} -t ${final.coreutils} -t ${final.gnugrep} -t ${final.gnused} $out/lib/R/bin/libtool
+        '';
+
+      # Enforce that the compiler wrapper and the unwrapped compiler do not end up in
+      # R's runtime closure. On Linux the postFixup above scrubs the references that
+      # would otherwise pull them in.
+      __structuredAttrs = true;
+      outputChecks.out.disallowedReferences = [
+        "man"
+        "tex"
+        stdenv.cc
+        stdenv.cc.cc
+      ];
+    };
+})

tools/nix/benchmarkTools.nix

@@ -8,4 +8,3 @@
   pkgs.rPackages.plyr
 ]
 ++ pkgs.lib.optional withHttpBenchmarkDeps pkgs.wrk
-++ pkgs.lib.optional pkgs.stdenv.buildPlatform.isLinux pkgs.glibcLocales

tools/nix/pkgs.nix

@@ -5,7 +5,7 @@ let
   nixpkgs = import (builtins.fetchTarball {
     url = "${repo}/archive/${rev}.tar.gz";
     sha256 = "0vi99516bn335vdzcjmvrkff8ikj0brpmjfcfdrjnb8bfd0wlr5j";
-  }) arg;
+  }) (arg // { overlays = (arg.overlays or [ ]) ++ [ (import ./R-overlay.nix) ]; });
 in
 # Unstable channel no longer supports Intel architecture for macOS. We can use the 26.05 channel
 # to keep testing on that platform for a little longer.