Revert "Merge #191724: cc-wrapper: remove duplicate include flags"

Let's redo this later, with more testing and less bugs.
This reverts commits 4f6e99870b and d700d8e8a2.

pkgs/build-support/cc-wrapper/default.nix

@@ -274,9 +274,7 @@ stdenv.mkDerivation {
 
   setupHooks = [
     ../setup-hooks/role.bash
-  ] ++ lib.optional (cc.langC or true)
-        # Temporary hack; see https://github.com/NixOS/nixpkgs/pull/191724#issuecomment-1278602576
-        (if stdenv.isLinux then ./setup-hook.sh else ./setup-hook-nonlinux.sh)
+  ] ++ lib.optional (cc.langC or true) ./setup-hook.sh
     ++ lib.optional (cc.langFortran or false) ./fortran-hook.sh;
 
   postFixup =

pkgs/build-support/cc-wrapper/setup-hook-nonlinux.sh

@@ -1,120 +0,0 @@
-# CC Wrapper hygiene
-#
-# For at least cross compilation, we need to depend on multiple cc-wrappers at
-# once---specifically up to one per sort of dependency. This follows from having
-# different tools targeting different platforms, and different flags for those
-# tools. For example:
-#
-#   # Flags for compiling (whether or not linking) C code for the...
-#   NIX_CFLAGS_COMPILE_FOR_BUILD  # ...build platform
-#   NIX_CFLAGS_COMPILE            # ...host platform
-#   NIX_CFLAGS_COMPILE_FOR_TARGET # ...target platform
-#
-# Notice that these platforms are the 3 *relative* to the package using
-# cc-wrapper, not absolute like `x86_64-pc-linux-gnu`.
-#
-# The simplest solution would be to have separate cc-wrappers per (3 intended
-# use-cases * n absolute concrete platforms). For the use-case axis, we would
-# @-splice in 'BUILD_' '' 'TARGET_' to use the write environment variables when
-# building the cc-wrapper, and likewise prefix the binaries' names so they didn't
-# clobber each other on the PATH. But the need for 3x cc-wrappers, along with
-# non-standard name prefixes, is annoying and liable to break packages' build
-# systems.
-#
-# Instead, we opt to have just one cc-wrapper per absolute platform. Matching
-# convention, the binaries' names can just be prefixed with their target
-# platform. On the other hand, that means packages will depend on not just
-# multiple cc-wrappers, but the exact same cc-wrapper derivation multiple ways.
-# That means the exact same cc-wrapper derivation must be able to avoid
-# conflicting with itself, despite the fact that `setup-hook.sh`, the `addCvars`
-# function, and `add-flags.sh` are all communicating with each other with
-# environment variables. Yuck.
-#
-# The basic strategy is:
-#
-#  - Everyone exclusively *adds information* to relative-platform-specific
-#    environment variables, like `NIX_CFLAGS_COMPILE_FOR_TARGET`, to communicate
-#    with the wrapped binaries.
-#
-#  - The wrapped binaries will exclusively *read* cc-wrapper-derivation-specific
-#    environment variables distinguished with with `suffixSalt`, like
-#    `NIX_CFLAGS_COMPILE_@suffixSalt@`.
-#
-#  - `add-flags`, beyond its old task of reading extra flags stuck inside the
-#    cc-wrapper derivation, will convert the relative-platform-specific
-#    variables to cc-wrapper-derivation-specific variables. This conversion is
-#    the only time all but one of the cc-wrapper-derivation-specific variables
-#    are set.
-#
-# This ensures the flow of information is exclusive from
-# relative-platform-specific variables to cc-wrapper-derivation-specific
-# variables. This allows us to support the general case of a many--many relation
-# between relative platforms and cc-wrapper derivations.
-#
-# For more details, read the individual files where the mechanisms used to
-# accomplish this will be individually documented.
-
-# Skip setup hook if we're neither a build-time dep, nor, temporarily, doing a
-# native compile.
-#
-# TODO(@Ericson2314): No native exception
-[[ -z ${strictDeps-} ]] || (( "$hostOffset" < 0 )) || return 0
-
-# It's fine that any other cc-wrapper will redefine this. Bash functions close
-# over no state, and there's no @-substitutions within, so any redefined
-# function is guaranteed to be exactly the same.
-ccWrapper_addCVars () {
-    # See ../setup-hooks/role.bash
-    local role_post
-    getHostRoleEnvHook
-
-    if [ -d "$1/include" ]; then
-        export NIX_CFLAGS_COMPILE${role_post}+=" -isystem $1/include"
-    fi
-
-    if [ -d "$1/Library/Frameworks" ]; then
-        export NIX_CFLAGS_COMPILE${role_post}+=" -iframework $1/Library/Frameworks"
-    fi
-}
-
-# See ../setup-hooks/role.bash
-getTargetRole
-getTargetRoleWrapper
-
-# We use the `targetOffset` to choose the right env hook to accumulate the right
-# sort of deps (those with that offset).
-addEnvHooks "$targetOffset" ccWrapper_addCVars
-
-# Note 1: these come *after* $out in the PATH (see setup.sh).
-# Note 2: phase separation makes this look useless to shellcheck.
-
-# shellcheck disable=SC2157
-if [ -n "@cc@" ]; then
-    addToSearchPath _PATH @cc@/bin
-fi
-
-# shellcheck disable=SC2157
-if [ -n "@libc_bin@" ]; then
-    addToSearchPath _PATH @libc_bin@/bin
-fi
-
-# shellcheck disable=SC2157
-if [ -n "@coreutils_bin@" ]; then
-    addToSearchPath _PATH @coreutils_bin@/bin
-fi
-
-# Export tool environment variables so various build systems use the right ones.
-
-export NIX_CC${role_post}=@out@
-
-export CC${role_post}=@named_cc@
-export CXX${role_post}=@named_cxx@
-export CC${role_post}=@named_cc@
-export CXX${role_post}=@named_cxx@
-
-# If unset, assume the default hardening flags.
-: ${NIX_HARDENING_ENABLE="fortify stackprotector pic strictoverflow format relro bindnow"}
-export NIX_HARDENING_ENABLE
-
-# No local scope in sourced file
-unset -v role_post

pkgs/build-support/cc-wrapper/setup-hook.sh

@@ -69,12 +69,10 @@ ccWrapper_addCVars () {
     getHostRoleEnvHook
 
     if [ -d "$1/include" ]; then
-        (! echo "$NIX_CFLAGS_COMPILE" | grep -q -F "$1/include") &&
         export NIX_CFLAGS_COMPILE${role_post}+=" -isystem $1/include"
     fi
 
     if [ -d "$1/Library/Frameworks" ]; then
-        (! echo "$NIX_CFLAGS_COMPILE" | grep -q -F "$1/Library/Frameworks") &&
         export NIX_CFLAGS_COMPILE${role_post}+=" -iframework $1/Library/Frameworks"
     fi
 }