JLI_ReportErrorMessageSys has a number of issues, as listed below: - The windows variant prints message, then extra-info if available, but the Unix variant prints first extra-info, then message on a newline. Standardize both to print their system errors on newlines below the message.
- The Windows implementation intermingles GetLastError and errno, which is incorrect. Both can be set, from independent API calls, and without knowing which API was called we don't know which to display. There is no way for JLI_ReportErrorMessageSys to know which is the right code. As it is, in its current form, we may call JLI_ReportErrorMessageSys for a CRT error and it may accidentally display a Win32 API error lingering around from some earlier unrelated Win32 API call. Changing JLI_ReportErrorMessageSys to add Windows specific components is not desired, so as a compromise we can simply print both Win32 and C Runtime errors together, if both exist. - On macOS, we have two call sites of JLI_ReportErrorMessageSys where the errno text is already provided as part of the message by the caller, and therefore would be printed twice. - Visual separation of message and extra-message: the rule is apparently that the caller has to provide the separation formatting: "it's up to the calling routine to correctly format the separation of messages" (of message and extra info). This leads to very awkward call sites (see https://github.com/openjdk/jdk/pull/9749). The problem is that the extra info may not be available: errno or GetLastError may report 0. That cannot be predicted by the caller, therefore the caller should not have to think about it. The function should append the extra-info only if available, omit it if it is not available, and take care of separation itself. Side note: The javaw implementation in this patch for Windows is a bit of a mess, advice or improvements to it are appreciated ------------- Commit messages: - Whitespace in Unix variant - Improve null termination - Fix formatting issues - Initial change to JLI_ReportErrorMessageSys Changes: https://git.openjdk.org/jdk/pull/9793/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9793&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8292016 Stats: 66 lines in 4 files changed: 33 ins; 10 del; 23 mod Patch: https://git.openjdk.org/jdk/pull/9793.diff Fetch: git fetch https://git.openjdk.org/jdk pull/9793/head:pull/9793 PR: https://git.openjdk.org/jdk/pull/9793
