fix(build): stop forcing a relink on every incremental build

metadata-generator/build-step-metadata-generator.py

@@ -3,6 +3,7 @@
 import os
 import shlex
 import subprocess
+import filecmp
 import sys
 
 print("Python version: " + sys.version)
@@ -126,7 +127,7 @@ def save_stream_to_file(filename, stream):
 def generate_metadata(arch):
     # metadata generator arguments
     generator_call = ["./objc-metadata-generator", "-verbose",
-                      "-output-bin", "{}/metadata-{}.bin".format(conf_build_dir, arch),
+                      "-output-bin", "{}/metadata-{}.bin.tmp".format(conf_build_dir, arch),
                       "-output-umbrella", "{}/umbrella-{}.h".format(conf_build_dir, arch),
                       "-docset-path", docset_path]
 
@@ -192,6 +193,14 @@ def generate_metadata(arch):
         print(error_stream_content)
         sys.exit(1)
 
+    # Generated during linking, but also an input of the link (-sectcreate):
+    # replacing unchanged metadata would make Xcode relink on every build.
+    output_bin = "{}/metadata-{}.bin".format(conf_build_dir, arch)
+    if os.path.exists(output_bin) and filecmp.cmp(output_bin + ".tmp", output_bin, shallow=False):
+        os.remove(output_bin + ".tmp")
+    else:
+        os.replace(output_bin + ".tmp", output_bin)
+
 
 for arch in env("ARCHS").split():
     # skip metadata generation for architectures different than the one specified in the command line

project-template-ios/internal/nativescript-pre-build

@@ -1,10 +1,30 @@
 #!/usr/bin/env bash
 
 # Ignore errors while inserting environment variables (some could be readonly)
-(echo "set +e"; echo "set +o posix"; export; echo "set -o posix"; echo "set -e";) > ./.build_env_vars.sh
+ENV_FILE=./.build_env_vars.sh
+(echo "set +e"; echo "set +o posix"; export; echo "set -o posix"; echo "set -e";) > "$ENV_FILE.tmp"
+if cmp -s "$ENV_FILE.tmp" "$ENV_FILE"; then
+    rm "$ENV_FILE.tmp"
+else
+    mv "$ENV_FILE.tmp" "$ENV_FILE"
+fi
 
-# create temporary empty metadata files for XCode LD/LDPLUSPLUS flag analysis
+# create temporary empty metadata files for XCode LD/LDPLUSPLUS flag analysis.
+# Never touch existing ones: the link step reads them, so a newer timestamp
+# would make Xcode relink on every build.
 for arch in $VALID_ARCHS
 do :
-    touch "$CONFIGURATION_BUILD_DIR/metadata-$arch.bin"
+    [ -e "$CONFIGURATION_BUILD_DIR/metadata-$arch.bin" ] || touch "$CONFIGURATION_BUILD_DIR/metadata-$arch.bin"
 done
+
+# The metadata generator reads these during linking, which Xcode would skip when
+# only they changed.
+FILTERS_STAMP="$CONFIGURATION_BUILD_DIR/metadata-filters.stamp"
+FILTERS_HASH=$(cd "$SRCROOT" && shasum whitelist.mdg blacklist.mdg 2>/dev/null || true)
+if [ ! -e "$FILTERS_STAMP" ] || [ "$FILTERS_HASH" != "$(cat "$FILTERS_STAMP")" ]; then
+    for arch in $VALID_ARCHS
+    do :
+        touch "$CONFIGURATION_BUILD_DIR/metadata-$arch.bin"
+    done
+    printf '%s' "$FILTERS_HASH" > "$FILTERS_STAMP"
+fi

project-template-ios/internal/strip-dynamic-framework-architectures.sh

@@ -41,16 +41,21 @@ if [ ! -e "${BUILT_PRODUCTS_DIR}/${FRAMEWORKS_FOLDER_PATH}" ]; then
   exit 0
 fi
 
-echo "Stripping frameworks"
+# Simulator builds never ship, so extra architectures in them are harmless.
+if [[ "${PLATFORM_NAME}" == *simulator ]]; then
+  exit 0
+fi
+
 cd "${BUILT_PRODUCTS_DIR}/${FRAMEWORKS_FOLDER_PATH}"
 
-for file in $(find . -type f); do
-  # Skip non-dynamic libraries
-  if ! [[ "$(file "$file")" == *"dynamically linked shared library"* ]]; then
+shopt -s nullglob
+for file in *.framework/* *.dylib; do
+  # Only a framework's main binary (named after it) and loose dylibs are Mach-O
+  if [[ "$file" == *.framework/* && "$(basename "$file")" != "$(basename "$(dirname "$file")" .framework)" ]]; then
     continue
   fi
-  # Get architectures for current file
-  archs="$(lipo -info "${file}" | rev | cut -d ':' -f1 | rev)"
+
+  archs="$(lipo -archs "$file" 2>/dev/null)" || continue
   stripped=""
   for arch in $archs; do
     if ! [[ "${VALID_ARCHS}" == *"$arch"* ]]; then
@@ -59,6 +64,7 @@ for file in $(find . -type f); do
       stripped="$stripped $arch"
     fi
   done
+
   if [[ "$stripped" != "" ]]; then
     echo "Stripped $file of architectures:$stripped"
     if [ "${CODE_SIGNING_ALLOWED}" == "YES" ]; then

project-template-vision/internal/nativescript-pre-build

@@ -1,10 +1,30 @@
 #!/usr/bin/env bash
 
 # Ignore errors while inserting environment variables (some could be readonly)
-(echo "set +e"; echo "set +o posix"; export; echo "set -o posix"; echo "set -e";) > ./.build_env_vars.sh
+ENV_FILE=./.build_env_vars.sh
+(echo "set +e"; echo "set +o posix"; export; echo "set -o posix"; echo "set -e";) > "$ENV_FILE.tmp"
+if cmp -s "$ENV_FILE.tmp" "$ENV_FILE"; then
+    rm "$ENV_FILE.tmp"
+else
+    mv "$ENV_FILE.tmp" "$ENV_FILE"
+fi
 
-# create temporary empty metadata files for XCode LD/LDPLUSPLUS flag analysis
+# create temporary empty metadata files for XCode LD/LDPLUSPLUS flag analysis.
+# Never touch existing ones: the link step reads them, so a newer timestamp
+# would make Xcode relink on every build.
 for arch in $VALID_ARCHS
 do :
-    touch "$CONFIGURATION_BUILD_DIR/metadata-$arch.bin"
+    [ -e "$CONFIGURATION_BUILD_DIR/metadata-$arch.bin" ] || touch "$CONFIGURATION_BUILD_DIR/metadata-$arch.bin"
 done
+
+# The metadata generator reads these during linking, which Xcode would skip when
+# only they changed.
+FILTERS_STAMP="$CONFIGURATION_BUILD_DIR/metadata-filters.stamp"
+FILTERS_HASH=$(cd "$SRCROOT" && shasum whitelist.mdg blacklist.mdg 2>/dev/null || true)
+if [ ! -e "$FILTERS_STAMP" ] || [ "$FILTERS_HASH" != "$(cat "$FILTERS_STAMP")" ]; then
+    for arch in $VALID_ARCHS
+    do :
+        touch "$CONFIGURATION_BUILD_DIR/metadata-$arch.bin"
+    done
+    printf '%s' "$FILTERS_HASH" > "$FILTERS_STAMP"
+fi

project-template-vision/internal/strip-dynamic-framework-architectures.sh

@@ -41,16 +41,21 @@ if [ ! -e "${BUILT_PRODUCTS_DIR}/${FRAMEWORKS_FOLDER_PATH}" ]; then
   exit 0
 fi
 
-echo "Stripping frameworks"
+# Simulator builds never ship, so extra architectures in them are harmless.
+if [[ "${PLATFORM_NAME}" == *simulator ]]; then
+  exit 0
+fi
+
 cd "${BUILT_PRODUCTS_DIR}/${FRAMEWORKS_FOLDER_PATH}"
 
-for file in $(find . -type f); do
-  # Skip non-dynamic libraries
-  if ! [[ "$(file "$file")" == *"dynamically linked shared library"* ]]; then
+shopt -s nullglob
+for file in *.framework/* *.dylib; do
+  # Only a framework's main binary (named after it) and loose dylibs are Mach-O
+  if [[ "$file" == *.framework/* && "$(basename "$file")" != "$(basename "$(dirname "$file")" .framework)" ]]; then
     continue
   fi
-  # Get architectures for current file
-  archs="$(lipo -info "${file}" | rev | cut -d ':' -f1 | rev)"
+
+  archs="$(lipo -archs "$file" 2>/dev/null)" || continue
   stripped=""
   for arch in $archs; do
     if ! [[ "${VALID_ARCHS}" == *"$arch"* ]]; then
@@ -59,6 +64,7 @@ for file in $(find . -type f); do
       stripped="$stripped $arch"
     fi
   done
+
   if [[ "$stripped" != "" ]]; then
     echo "Stripped $file of architectures:$stripped"
     if [ "${CODE_SIGNING_ALLOWED}" == "YES" ]; then