[build] Add build options to force-enable debug preconditions and to set a trap function in the stdlib

(The underlying functionality was added in #41445 and #41449, respectively.)

Author: lorentey

stdlib/cmake/modules/StdlibOptions.cmake

@@ -113,6 +113,9 @@ option(SWIFT_STDLIB_HAS_TYPE_PRINTING
        "Build stdlib with support for printing user-friendly type name as strings at runtime"
        TRUE)
 
+set(SWIFT_STDLIB_TRAP_FUNCTION "" CACHE STRING
+  "Name of function to call instead of emitting a trap instruction in the stdlib")
+
 option(SWIFT_STDLIB_BUILD_PRIVATE
        "Build private part of the Standard Library."
        TRUE)

stdlib/cmake/modules/SwiftSource.cmake

@@ -497,6 +497,10 @@ function(_compile_swift_files
     list(APPEND swift_flags "-D" "SWIFT_ENABLE_REFLECTION")
   endif()
 
+  if(NOT "${SWIFT_STDLIB_TRAP_FUNCTION}" STREQUAL "")
+    list(APPEND swift_flags "-Xfrontend" "-trap-function" "-Xfrontend" "${SWIFT_STDLIB_TRAP_FUNCTION}")
+  endif()
+
   # FIXME: Cleaner way to do this?
   if(SWIFTFILE_IS_STDLIB_CORE)
     list(APPEND swift_flags

utils/build-script-impl

@@ -191,6 +191,7 @@ KNOWN_SETTINGS=(
     swift-primary-variant-sdk                     ""                "default SDK for target binaries"
     swift-runtime-enable-leak-checker             "0"               "Enable leaks checking routines in the runtime"
     swift-stdlib-enable-assertions                "1"               "enable assertions in Swift"
+    swift-stdlib-enable-debug-preconditions-in-release "0"          "Enable _debugPrecondition checks in the stdlib in Release configurations"
     swift-tools-enable-lto                        ""                "enable LTO compilation of Swift tools. *NOTE* This does not include the swift standard library and runtime. Must be set to one of 'thin' or 'full'"
     extra-swift-args                              ""                "Extra arguments to pass to swift modules which match regex. Assumed to be a flattened cmake list consisting of [module_regexp, args, module_regexp, args, ...]"
     report-statistics                             "0"               "set to 1 to generate compilation statistics files for swift libraries"
@@ -223,6 +224,7 @@ KNOWN_SETTINGS=(
     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-stdlib-trap-function                    ""                "Name of function to call instead of emitting a trap instruction"
     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"
     swift-enable-experimental-string-processing   "1"               "whether to build experimental string processing feature"
@@ -2006,6 +2008,7 @@ for host in "${ALL_HOSTS[@]}"; do
                     -DSWIFT_ANALYZE_CODE_COVERAGE:STRING=$(toupper "${SWIFT_ANALYZE_CODE_COVERAGE}")
                     -DSWIFT_STDLIB_BUILD_TYPE:STRING="${SWIFT_STDLIB_BUILD_TYPE}"
                     -DSWIFT_STDLIB_ASSERTIONS:BOOL=$(true_false "${SWIFT_STDLIB_ENABLE_ASSERTIONS}")
+                    -DSWIFT_STDLIB_ENABLE_DEBUG_PRECONDITIONS_IN_RELEASE=$(true_false "${SWIFT_STDLIB_ENABLE_DEBUG_PRECONDITIONS_IN_RELEASE}")
                     -DSWIFT_ENABLE_DISPATCH:BOOL=$(true_false "${SWIFT_ENABLE_DISPATCH}")
                     -DSWIFT_IMPLICIT_CONCURRENCY_IMPORT:BOOL=$(true_false "${SWIFT_IMPLICIT_CONCURRENCY_IMPORT}")
                     -DSWIFT_STDLIB_SUPPORT_BACK_DEPLOYMENT:BOOL=$(true_false "${SWIFT_STDLIB_SUPPORT_BACK_DEPLOYMENT}")
@@ -2023,6 +2026,7 @@ for host in "${ALL_HOSTS[@]}"; do
                     -DSWIFT_STDLIB_SHORT_MANGLING_LOOKUPS:BOOL=$(true_false "${SWIFT_STDLIB_SHORT_MANGLING_LOOKUPS}")
                     -DSWIFT_STDLIB_ENABLE_VECTOR_TYPES:BOOL=$(true_false "${SWIFT_STDLIB_ENABLE_VECTOR_TYPES}")
                     -DSWIFT_STDLIB_HAS_TYPE_PRINTING:BOOL=$(true_false "${SWIFT_STDLIB_HAS_TYPE_PRINTING}")
+                    -DSWIFT_STDLIB_TRAP_FUNCTION:STRING="${SWIFT_STDLIB_TRAP_FUNCTION}"
                     -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}"