Merge pull request #36058 from edymtt/relocate-xdg-cache-home-in-linux-presets-5.4

[5.4][Build] Add and use option to alter default location of module cache in Linux

Author: shahmishal

utils/build-presets.ini

@@ -804,6 +804,13 @@ install-destdir=%(install_destdir)s
 # Path to the .tar.gz package we would create.
 installable-package=%(installable_package)s
 
+# This ensures the default module cache
+# location is local to this run, allowing
+# to schedule multiple builds safely
+# in Linux CI bots
+relocate-xdg-cache-home-under-build-subdir
+
+
 [preset: buildbot_linux]
 mixin-preset=mixin_linux_installation
 build-subdir=buildbot_linux
@@ -1036,6 +1043,13 @@ lit-args=-v
 build-ninja
 reconfigure
 
+# This ensures the default module cache
+# location is local to this run, allowing
+# to schedule multiple builds safely
+# in Linux CI bots
+relocate-xdg-cache-home-under-build-subdir
+
+
 [preset: buildbot_incremental_linux]
 mixin-preset=
     buildbot_incremental_linux_base

utils/build-script

@@ -336,6 +336,13 @@ def apply_default_arguments(toolchain, args):
         args.build_subdir = \
             workspace.compute_build_subdir(args)
 
+    if args.relocate_xdg_cache_home_under_build_subdir:
+        cache_under_build_subdir = os.path.join(
+            SWIFT_BUILD_ROOT, args.build_subdir, '.cache')
+        if args.verbose_build:
+            print("Relocating XDG_CACHE_HOME to {}".format(cache_under_build_subdir))
+        workspace.relocate_xdg_cache_home_under(cache_under_build_subdir)
+
     if args.install_destdir is None:
         args.install_destdir = os.path.join(
             SWIFT_BUILD_ROOT, args.build_subdir,

utils/build_swift/build_swift/driver_arguments.py

@@ -339,6 +339,12 @@ def create_argument_parser():
            metavar='PATH',
            help='name of the directory under $SWIFT_BUILD_ROOT where the '
                 'build products will be placed')
+    option('--relocate-xdg-cache-home-under-build-subdir',
+           store_true,
+           help='relocate $XDG_CACHE_HOME to the same location '
+                'where build products will be placed; '
+                'this supports having multiple runs for different branches '
+                'in CI bots for Linux')
     option('--install-prefix', store_path,
            default=targets.install_prefix(),
            help='The installation prefix. This is where built Swift products '

utils/build_swift/tests/expected_options.py

@@ -190,6 +190,7 @@
     'maccatalyst': False,
     'maccatalyst_ios_tests': False,
     'dump_config': False,
+    'relocate_xdg_cache_home_under_build_subdir': False,
     'show_sdks': False,
     'skip_build': False,
     'skip_local_build': False,
@@ -642,6 +643,7 @@ class BuildScriptImplOption(_BaseOption):
     PathOption('--android-icu-data'),
     PathOption('--android-ndk'),
     PathOption('--build-subdir'),
+    SetTrueOption('--relocate-xdg-cache-home-under-build-subdir'),
     PathOption('--clang-profile-instr-use'),
     PathOption('--cmake'),
     PathOption('--coverage-db'),

utils/swift_build_support/swift_build_support/workspace.py

@@ -102,3 +102,14 @@ def compute_build_subdir(args):
     if args.enable_tsan:
         build_subdir += "+tsan"
     return build_subdir
+
+
+def relocate_xdg_cache_home_under(new_cache_location):
+    """
+    This allows under Linux to relocate the default location
+    of the module cache -- this can be useful when there are
+    are lot of invocations to touch or when some invocations
+    can't be easily configured (as is the case for Swift
+    compiler detection in CMake)
+    """
+    os.environ['XDG_CACHE_HOME'] = new_cache_location

validation-test/BuildSystem/relocate_xdg_cache_home_under_build_subdir.test

@@ -0,0 +1,8 @@
+# RUN: %empty-directory(%t)
+# RUN: mkdir -p %t
+# RUN: SWIFT_BUILD_ROOT=%t %swift_src_root/utils/build-script --dry-run --install-all --llbuild --swiftpm --foundation --libdispatch --relocate-xdg-cache-home-under-build-subdir --verbose-build --cmake %cmake 2>&1 | %FileCheck %s
+
+# REQUIRES: standalone_build
+# REQUIRES: OS=linux-gnu
+
+# CHECK: Relocating XDG_CACHE_HOME

validation-test/Python/call_swiftc_after_relocate_xdg_cache_home_under.swift

@@ -0,0 +1,19 @@
+// REQUIRES: OS=linux-gnu
+
+// RUN: %empty-directory(%t)
+// RUN: mkdir -p %t
+// RUN: split-file %s %t
+//
+// RUN: PYTHONPATH=%utils %{python} %t/run_swiftc_with_relocated_xdg_cache_home.py %t/.cache %swiftc_driver_plain %t/hello.swift
+// RUN: ls %t/.cache/clang/ModuleCache
+
+//--- run_swiftc_with_relocated_xdg_cache_home.py
+import sys
+import subprocess
+from swift_build_support.swift_build_support import workspace
+
+workspace.relocate_xdg_cache_home_under(sys.argv[1])
+subprocess.run([sys.argv[2], sys.argv[3]])
+
+//--- hello.swift
+print("hello")