A NOTE has been added to this issue. ====================================================================== https://www.austingroupbugs.net/view.php?id=1422 ====================================================================== Reported By: joerg Assigned To: ====================================================================== Project: Issue 8 drafts Issue ID: 1422 Category: Shell and Utilities Type: Error Severity: Objection Priority: normal Status: New Name: Jörg Schilling Organization: User Reference: Section: Page Number: 2894-2895 Line Number: 97277-97282 Final Accepted Text: ====================================================================== Date Submitted: 2020-11-18 13:49 UTC Last Modified: 2021-03-05 19:18 UTC ====================================================================== Summary: The current definition for the += assingment is in conflict with existing behavior of make and unpredictable/error-prone ======================================================================
---------------------------------------------------------------------- (0005260) psmith (developer) - 2021-03-05 19:18 https://www.austingroupbugs.net/view.php?id=1422#c5260 ---------------------------------------------------------------------- The behavior of += with respect to = (delayed) assignment is as you describe it: it appends the new text to the end of the existing text without any expansion and expansion happens when the variable is used. Regarding "macro :sh=command", that is not part of the POSIX standard so you can decide how it works with respect to += as you like, I suppose. Regarding the ::= assignment: this is intended to work (as I understand it) the same way that ":=" works in GNU make. That is, when the variable assignment is made the RHS is expanded immediately, and after that the value is treated as a static string and is no longer expanded when the variable is used. If a "+=" is made to a variable that was created with "::=", the RHS is expanded first, then the result of that expansion is appended to the variable. I think it's misleading to consider "::=" to be related to Sun's ":sh="; they are different and unrelated to each other. The goal of introducing a new operator like "::=" is exactly because the behavior we want there is not like existing make behavior; so it is not an inconsistency that they are different. Allowing the value of a ":=" assignment to be re-expanded again when the variable is used would be quite confusing. For example: foo := $$hello all: ; @echo '$(foo)' would print 'ello', instead of the desired '$hello'. Issue History Date Modified Username Field Change ====================================================================== 2020-11-18 13:49 joerg New Issue 2020-11-18 13:49 joerg Name => Jörg Schilling 2020-11-18 13:49 joerg Page Number => 2894-2895 2020-11-18 13:49 joerg Line Number => 97277-97282 2021-03-05 16:11 geoffclare Note Added: 0005257 2021-03-05 17:07 psmith Note Added: 0005258 2021-03-05 17:10 psmith Note Edited: 0005258 2021-03-05 17:11 psmith Note Edited: 0005258 2021-03-05 17:17 psmith Note Edited: 0005258 2021-03-05 18:30 joerg Note Added: 0005259 2021-03-05 19:18 psmith Note Added: 0005260 ======================================================================
