Enable -disable-preallocated-instantiation-caches for the freestanding stdlib

stdlib/cmake/modules/StdlibOptions.cmake

@@ -139,6 +139,10 @@ option(SWIFT_STDLIB_PASSTHROUGH_METADATA_ALLOCATOR
        "Build stdlib without a custom implementation of MetadataAllocator, relying on malloc+free instead."
        FALSE)
 
+option(SWIFT_STDLIB_DISABLE_INSTANTIATION_CACHES
+       "Build stdlib with -disable-preallocated-instantiation-caches"
+       FALSE)
+
 option(SWIFT_STDLIB_HAS_COMMANDLINE
        "Build stdlib with the CommandLine enum and support for argv/argc."
        TRUE)

stdlib/cmake/modules/SwiftSource.cmake

@@ -526,6 +526,10 @@ function(_compile_swift_files
     list(APPEND swift_flags "-experimental-hermetic-seal-at-link")
   endif()
 
+  if(SWIFT_STDLIB_DISABLE_INSTANTIATION_CACHES)
+    list(APPEND swift_flags "-Xfrontend -disable-preallocated-instantiation-caches")
+  endif()
+
   list(APPEND swift_flags ${SWIFT_STDLIB_EXTRA_SWIFT_COMPILE_FLAGS})
 
   list(APPEND swift_flags ${SWIFT_EXPERIMENTAL_EXTRA_FLAGS})

test/lit.cfg

@@ -1002,6 +1002,9 @@ if run_vendor == 'apple':
         if not config.swift_freestanding_is_darwin:
             swift_execution_tests_extra_flags += ' -experimental-hermetic-seal-at-link -lto=llvm-full'
 
+        if not config.swift_freestanding_is_darwin:
+            swift_execution_tests_extra_flags += ' -Xfrontend -disable-preallocated-instantiation-caches'
+
         # Build a resource dir for freestanding tests.
         new_resource_dir = os.path.join(config.test_exec_root, "resource_dir")
         if not os.path.exists(new_resource_dir): os.mkdir(new_resource_dir)

utils/build-presets.ini

@@ -2527,6 +2527,7 @@ swift-stdlib-enable-prespecialization=0
 swift-stdlib-passthrough-metadata-allocator=1
 swift-stdlib-short-mangling-lookups=0
 swift-stdlib-experimental-hermetic-seal-at-link=1
+swift-stdlib-disable-instantiation-caches=1
 swift-stdlib-has-type-printing=0
 
 [preset: stdlib_S_standalone_minimal_macho_x86_64,build]

utils/build-script-impl

@@ -219,6 +219,7 @@ KNOWN_SETTINGS=(
     swift-stdlib-passthrough-metadata-allocator   "0"               "whether stdlib should be built without a custom implementation of MetadataAllocator, relying on malloc+free instead"
     swift-stdlib-short-mangling-lookups           "1"               "whether to build stdlib with fast-path context descriptor lookups based on well-known short manglings"
     swift-stdlib-experimental-hermetic-seal-at-link     "0"         "whether stdlib should be built with -experimental-hermetic-seal-at-link"
+    swift-stdlib-disable-instantiation-caches     "0"               "whether to build stdlib with -disable-preallocated-instantiation-caches"
     swift-stdlib-has-type-printing                "1"               "whether stdlib should support printing user-friendly type name as strings at runtime"
     swift-disable-dead-stripping                  "0"               "turns off Darwin-specific dead stripping for Swift host tools"
     common-swift-flags                            ""                "Flags used for Swift targets other than the stdlib, like the corelibs"
@@ -2010,6 +2011,7 @@ for host in "${ALL_HOSTS[@]}"; do
                     -DSWIFT_STDLIB_SHORT_MANGLING_LOOKUPS:BOOL=$(true_false "${SWIFT_STDLIB_SHORT_MANGLING_LOOKUPS}")
                     -DSWIFT_STDLIB_HAS_TYPE_PRINTING:BOOL=$(true_false "${SWIFT_STDLIB_HAS_TYPE_PRINTING}")
                     -DSWIFT_STDLIB_EXPERIMENTAL_HERMETIC_SEAL_AT_LINK:BOOL=$(true_false "${SWIFT_STDLIB_EXPERIMENTAL_HERMETIC_SEAL_AT_LINK}")
+                    -DSWIFT_STDLIB_DISABLE_INSTANTIATION_CACHES:BOOL=$(true_false "${SWIFT_STDLIB_DISABLE_INSTANTIATION_CACHES}")
                     -DSWIFT_NATIVE_LLVM_TOOLS_PATH:STRING="${native_llvm_tools_path}"
                     -DSWIFT_NATIVE_CLANG_TOOLS_PATH:STRING="${native_clang_tools_path}"
                     -DSWIFT_NATIVE_SWIFT_TOOLS_PATH:STRING="${native_swift_tools_path}"