On Fri, 22 Jan 2021 18:49:42 GMT, Anton Kozlov <akoz...@openjdk.org> wrote:
> Please review the implementation of JEP 391: macOS/AArch64 Port. > > It's heavily based on existing ports to linux/aarch64, macos/x86_64, and > windows/aarch64. > > Major changes are in: > * src/hotspot/cpu/aarch64: support of the new calling convention (subtasks > JDK-8253817, JDK-8253818) > * src/hotspot/os_cpu/bsd_aarch64: copy of os_cpu/linux_aarch64 with necessary > adjustments (JDK-8253819) > * src/hotspot/share, test/hotspot/gtest: support of write-xor-execute (W^X), > required on macOS/AArch64 platform. It's implemented with > pthread_jit_write_protect_np provided by Apple. The W^X mode is local to a > thread, so W^X mode change relates to the java thread state change (for java > threads). In most cases, JVM executes in write-only mode, except when calling > a generated stub like SafeFetch, which requires a temporary switch to > execute-only mode. The same execute-only mode is enabled when a java thread > executes in java or native states. This approach of managing W^X mode turned > out to be simple and efficient enough. > * src/jdk.hotspot.agent: serviceability agent implementation (JDK-8254941) Build changes in general look good. make/autoconf/flags-cflags.m4 line 169: > 167: WARNINGS_ENABLE_ALL="-Wall -Wextra -Wformat=2 > $WARNINGS_ENABLE_ADDITIONAL" > 168: > 169: DISABLED_WARNINGS="unknown-warning-option unused-parameter unused > format-nonliteral" Globally disabling a warning needs some motivation. Why is this needed? Does it really need to be applied everywhere or is there a specific binary or source file where this is triggered? ------------- PR: https://git.openjdk.java.net/jdk/pull/2200