Merge pull request #26805 from obsidiansystems/cross-elegant

Make cross compilation elegant

11 files changed, 113 insertions, 47 deletions

diff --git a/pkgs/build-support/bintools-wrapper/default.nix b/pkgs/build-support/bintools-wrapper/default.nix
index 57859b2f371b..bb0e6b82aa5d 100644
--- a/pkgs/build-support/bintools-wrapper/default.nix
+++ b/pkgs/build-support/bintools-wrapper/default.nix
@@ -178,7 +178,7 @@ stdenv.mkDerivation {
       else throw "unknown emulation for platform: " + targetPlatform.config;
     in targetPlatform.platform.bfdEmulation or (fmt + "-" + arch);
 
-  propagatedBuildInputs = extraPackages;
+  depsTargetTargetPropagated = extraPackages;
 
   setupHook = ./setup-hook.sh;
 
diff --git a/pkgs/build-support/bintools-wrapper/setup-hook.sh b/pkgs/build-support/bintools-wrapper/setup-hook.sh
index 43f79ec59200..48a00b0b9b07 100644
--- a/pkgs/build-support/bintools-wrapper/setup-hook.sh
+++ b/pkgs/build-support/bintools-wrapper/setup-hook.sh
@@ -2,12 +2,20 @@
 #
 # See comments in cc-wrapper's setup hook. This works exactly the same way.
 
+set -u
+
+# Skip setup hook if we're neither a build-time dep, nor, temporarily, doing a
+# native compile.
+#
+# TODO(@Ericson2314): No native exception
+[[ -z ${crossConfig-} ]] || (( "$hostOffset" < 0 )) || return 0
+
 bintoolsWrapper_addLDVars () {
-    case $depOffset in
+    case $depHostOffset in
         -1) local role='BUILD_' ;;
         0)  local role='' ;;
         1)  local role='TARGET_' ;;
-        *)  echo "bintools-wrapper: Error: Cannot be used with $depOffset-offset deps, " >2;
+        *)  echo "bintools-wrapper: Error: Cannot be used with $depHostOffset-offset deps" >2;
             return 1 ;;
     esac
 
@@ -20,17 +28,29 @@ bintoolsWrapper_addLDVars () {
     fi
 }
 
-if [ -n "${crossConfig:-}" ]; then
-    export NIX_BINTOOLS_WRAPPER_@infixSalt@_TARGET_BUILD=1
-    role_pre='BUILD_'
-    role_post='_FOR_BUILD'
-else
-    export NIX_BINTOOLS_WRAPPER_@infixSalt@_TARGET_HOST=1
-    role_pre=""
-    role_post=''
-fi
+case $targetOffset in
+    -1)
+        export NIX_BINTOOLS_WRAPPER_@infixSalt@_TARGET_BUILD=1
+        role_pre='BUILD_'
+        role_post='_FOR_BUILD'
+        ;;
+    0)
+        export NIX_BINTOOLS_WRAPPER_@infixSalt@_TARGET_HOST=1
+        role_pre=''
+        role_post=''
+        ;;
+    1)
+        export NIX_BINTOOLS_WRAPPER_@infixSalt@_TARGET_TARGET=1
+        role_pre='TARGET_'
+        role_post='_FOR_TARGET'
+        ;;
+    *)
+        echo "cc-wrapper: used as improper sort of dependency" >2;
+        return 1
+        ;;
+esac
 
-envHooks+=(bintoolsWrapper_addLDVars)
+addEnvHooks "$targetOffset" bintoolsWrapper_addLDVars
 
 # shellcheck disable=SC2157
 if [ -n "@bintools_bin@" ]; then
@@ -65,3 +85,4 @@ done
 
 # No local scope in sourced file
 unset -v role_pre role_post cmd upper_case
+set +u
diff --git a/pkgs/build-support/cc-wrapper/default.nix b/pkgs/build-support/cc-wrapper/default.nix
index 218e9f6b957f..5d878d219f18 100644
--- a/pkgs/build-support/cc-wrapper/default.nix
+++ b/pkgs/build-support/cc-wrapper/default.nix
@@ -201,7 +201,8 @@ stdenv.mkDerivation {
       ln -s $ccPath/${targetPrefix}ghdl $out/bin/${targetPrefix}ghdl
     '';
 
-  propagatedBuildInputs = [ bintools ] ++ extraPackages;
+  propagatedBuildInputs = [ bintools ];
+  depsTargetTargetPropagated = extraPackages;
 
   setupHook = ./setup-hook.sh;
 
diff --git a/pkgs/build-support/cc-wrapper/setup-hook.sh b/pkgs/build-support/cc-wrapper/setup-hook.sh
index a922193ad2e7..29a7306b9b7e 100644
--- a/pkgs/build-support/cc-wrapper/setup-hook.sh
+++ b/pkgs/build-support/cc-wrapper/setup-hook.sh
@@ -54,19 +54,26 @@
 # For more details, read the individual files where the mechanisms used to
 # accomplish this will be individually documented.
 
+set -u
+
+# Skip setup hook if we're neither a build-time dep, nor, temporarily, doing a
+# native compile.
+#
+# TODO(@Ericson2314): No native exception
+[[ -z ${crossConfig-} ]] || (( "$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 () {
-    # The `depOffset` describes how the platforms of the dependencies are slid
-    # relative to the depending package. It is brought into scope of the
-    # environment hook defined as the role of the dependency being applied.
-    case $depOffset in
+    # The `depHostOffset` describes how the host platform of the dependencies
+    # are slid relative to the depending package. It is brought into scope of
+    # the environment hook defined as the role of the dependency being applied.
+    case $depHostOffset in
         -1) local role='BUILD_' ;;
         0)  local role='' ;;
         1)  local role='TARGET_' ;;
-        *)  echo "cc-wrapper: Error: Cannot be used with $depOffset-offset deps, " >2;
+        *)  echo "cc-wrapper: Error: Cannot be used with $depHostOffset-offset deps" >2;
             return 1 ;;
     esac
 
@@ -87,20 +94,31 @@ ccWrapper_addCVars () {
 #
 # We also need to worry about what role is being added on *this* invocation of
 # setup-hook, which `role` tracks.
-if [ -n "${crossConfig:-}" ]; then
-    export NIX_CC_WRAPPER_@infixSalt@_TARGET_BUILD=1
-    role_pre='BUILD_'
-    role_post='_FOR_BUILD'
-else
-    export NIX_CC_WRAPPER_@infixSalt@_TARGET_HOST=1
-    role_pre=''
-    role_post=''
-fi
+case $targetOffset in
+    -1)
+        export NIX_CC_WRAPPER_@infixSalt@_TARGET_BUILD=1
+        role_pre='BUILD_'
+        role_post='_FOR_BUILD'
+        ;;
+    0)
+        export NIX_CC_WRAPPER_@infixSalt@_TARGET_HOST=1
+        role_pre=''
+        role_post=''
+        ;;
+    1)
+        export NIX_CC_WRAPPER_@infixSalt@_TARGET_TARGET=1
+        role_pre='TARGET_'
+        role_post='_FOR_TARGET'
+        ;;
+    *)
+        echo "cc-wrapper: used as improper sort of dependency" >2;
+        return 1
+        ;;
+esac
 
-# Eventually the exact sort of env-hook we create will depend on the role. This
-# is because based on what relative platform we are targeting, we use different
-# dependencies.
-envHooks+=(ccWrapper_addCVars)
+# 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* $out in the PATH (see setup.sh).
 # Note 2: phase separation makes this look useless to shellcheck.
@@ -131,3 +149,4 @@ export CXX${role_post}=@named_cxx@
 
 # No local scope in sourced file
 unset -v role_pre role_post
+set +u
diff --git a/pkgs/build-support/emacs/setup-hook.sh b/pkgs/build-support/emacs/setup-hook.sh
index defef45b55f5..e1db3e828fd7 100644
--- a/pkgs/build-support/emacs/setup-hook.sh
+++ b/pkgs/build-support/emacs/setup-hook.sh
@@ -4,4 +4,8 @@ addEmacsVars () {
   fi
 }
 
-envHooks+=(addEmacsVars)
+# If this is for a wrapper derivation, emacs and the dependencies are all
+# run-time dependencies. If this is for precompiling packages into bytecode,
+# emacs is a compile-time dependency of the package.
+addEnvHooks "$targetOffset" addEmacsVars
+addEnvHooks "$targetOffset" addEmacsVars
diff --git a/pkgs/build-support/gcc-wrapper-old/setup-hook.sh b/pkgs/build-support/gcc-wrapper-old/setup-hook.sh
index d8bdf858ae58..ad3ffeffbbbc 100644
--- a/pkgs/build-support/gcc-wrapper-old/setup-hook.sh
+++ b/pkgs/build-support/gcc-wrapper-old/setup-hook.sh
@@ -1,4 +1,4 @@
-addCVars () {
+gccWrapperOld_addCVars () {
     if test -d $1/include; then
         export NIX_CFLAGS_COMPILE="$NIX_CFLAGS_COMPILE -isystem $1/include"
     fi
@@ -12,7 +12,7 @@ addCVars () {
     fi
 }
 
-envHooks=(${envHooks[@]} addCVars)
+envBuildBuildHooks+=(gccWrapperOld_addCVars)
 
 # Note: these come *after* $out in the PATH (see setup.sh).
 
diff --git a/pkgs/build-support/setup-hooks/find-xml-catalogs.sh b/pkgs/build-support/setup-hooks/find-xml-catalogs.sh
index b742d5a8ffd9..85364a61f612 100644
--- a/pkgs/build-support/setup-hooks/find-xml-catalogs.sh
+++ b/pkgs/build-support/setup-hooks/find-xml-catalogs.sh
@@ -18,5 +18,5 @@ if [ -z "$libxmlHookDone" ]; then
     # xmllint and xsltproc from looking in /etc/xml/catalog.
     export XML_CATALOG_FILES
     if [ -z "$XML_CATALOG_FILES" ]; then XML_CATALOG_FILES=" "; fi
-    envHooks+=(addXMLCatalogs)
+    addEnvHooks "$hostOffset" addXMLCatalogs
 fi
diff --git a/pkgs/build-support/setup-hooks/set-java-classpath.sh b/pkgs/build-support/setup-hooks/set-java-classpath.sh
index 047da91bc97c..5d3548dc2e88 100644
--- a/pkgs/build-support/setup-hooks/set-java-classpath.sh
+++ b/pkgs/build-support/setup-hooks/set-java-classpath.sh
@@ -10,4 +10,4 @@ addPkgToClassPath () {
     done
 }
 
-envHooks+=(addPkgToClassPath)
+addEnvHooks "$targetOffset" addPkgToClassPath
diff --git a/pkgs/build-support/setup-hooks/setup-debug-info-dirs.sh b/pkgs/build-support/setup-hooks/setup-debug-info-dirs.sh
index 2fd2a2d6da6f..96bf48cf123a 100644
--- a/pkgs/build-support/setup-hooks/setup-debug-info-dirs.sh
+++ b/pkgs/build-support/setup-hooks/setup-debug-info-dirs.sh
@@ -2,4 +2,4 @@ setupDebugInfoDirs () {
     addToSearchPath NIX_DEBUG_INFO_DIRS $1/lib/debug
 }
 
-envHooks+=(setupDebugInfoDirs)
+addEnvHooks "$targetOffset" setupDebugInfoDirs
diff --git a/pkgs/build-support/setup-hooks/strip.sh b/pkgs/build-support/setup-hooks/strip.sh
index a33968ca18de..fc4c7bfbaf95 100644
--- a/pkgs/build-support/setup-hooks/strip.sh
+++ b/pkgs/build-support/setup-hooks/strip.sh
@@ -3,24 +3,45 @@
 fixupOutputHooks+=(_doStrip)
 
 _doStrip() {
-    if [ -z "$dontStrip" ]; then
+    # We don't bother to strip build platform code because it shouldn't make it
+    # to $out anyways---if it does, that's a bigger problem that a lack of
+    # stripping will help catch.
+    local -ra flags=(dontStripHost dontStripTarget)
+    local -ra stripCmds=(STRIP TARGET_STRIP)
+
+    # Optimization
+    if [[ "$STRIP" == "$TARGET_STRIP" ]]; then
+        dontStripTarget+=1
+    fi
+
+    local i
+    for i in ${!stripCmds[@]}; do
+        local -n flag="${flags[$i]}"
+        local -n stripCmd="${stripCmds[$i]}"
+
+        # `dontStrip` disables them all
+        if [[ "$dontStrip" || "$flag" ]] || ! type -f "$stripCmd" 2>/dev/null
+        then continue; fi
+
         stripDebugList=${stripDebugList:-lib lib32 lib64 libexec bin sbin}
         if [ -n "$stripDebugList" ]; then
-            stripDirs "$stripDebugList" "${stripDebugFlags:--S}"
+            stripDirs "$stripCmd" "$stripDebugList" "${stripDebugFlags:--S}"
         fi
 
         stripAllList=${stripAllList:-}
         if [ -n "$stripAllList" ]; then
-            stripDirs "$stripAllList" "${stripAllFlags:--s}"
+            stripDirs "$stripCmd" "$stripAllList" "${stripAllFlags:--s}"
         fi
-    fi
+    done
 }
 
 stripDirs() {
-    local dirs="$1"
-    local stripFlags="$2"
+    local cmd="$1"
+    local dirs="$2"
+    local stripFlags="$3"
     local dirsNew=
 
+    local d
     for d in ${dirs}; do
         if [ -d "$prefix/$d" ]; then
             dirsNew="${dirsNew} $prefix/$d "
@@ -29,8 +50,8 @@ stripDirs() {
     dirs=${dirsNew}
 
     if [ -n "${dirs}" ]; then
-        header "stripping (with flags $stripFlags) in$dirs"
-        find $dirs -type f -print0 | xargs -0 ${xargsFlags:--r} $STRIP $commonStripFlags $stripFlags 2>/dev/null || true
+        header "stripping (with command $cmd and flags $stripFlags) in$dirs"
+        find $dirs -type f -print0 | xargs -0 ${xargsFlags:--r} $cmd $commonStripFlags $stripFlags 2>/dev/null || true
         stopNest
     fi
 }
diff --git a/pkgs/build-support/setup-hooks/wrap-gapps-hook.sh b/pkgs/build-support/setup-hooks/wrap-gapps-hook.sh
index 79b8d5b73fa1..25ac12996cc1 100644
--- a/pkgs/build-support/setup-hooks/wrap-gapps-hook.sh
+++ b/pkgs/build-support/setup-hooks/wrap-gapps-hook.sh
@@ -6,7 +6,7 @@ find_gio_modules() {
     fi
 }
 
-envHooks+=(find_gio_modules)
+addEnvHooks "$targetOffset" find_gio_modules
 
 # Note: $gappsWrapperArgs still gets defined even if $dontWrapGApps is set.
 wrapGAppsHook() {