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author | Zack Weinberg <zackw@panix.com> | 2020-07-10 14:16:18 -0400 |
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committer | Zack Weinberg <zackw@panix.com> | 2020-07-10 14:16:18 -0400 |
commit | 83798d2971a46fb0f49c020e3fdf0c0d43cfb63d (patch) | |
tree | 928070812028708eb8bd0f172acab1428eddc373 | |
parent | 5016cdc03a57c6ab9ea3e41e4457a77353d82d36 (diff) | |
download | autoconf-83798d2971a46fb0f49c020e3fdf0c0d43cfb63d.tar.gz |
NEWS: add notes about known breakage due to pickier macros.
These are all cases where the offending configure script or
third-party macro was always incorrect, but autoconf 2.69 let you get
away with it.
-rw-r--r-- | NEWS | 21 |
1 files changed, 21 insertions, 0 deletions
@@ -29,6 +29,27 @@ GNU Autoconf NEWS - User visible changes. account. This makes it possible to use AC_DEFINE for secondary headers without duplicating the template in the main config header. +** Many macros have been improved to expand their arguments + once and only once. This makes ‘autoconf’ run faster. However, it + may break configure scripts that did not quote all macro arguments + properly. The ‘M4 Quotation’ section of the manual explains how to + quote macro arguments properly. + +** Several macros that are commonly used early in a configure + script, such as AC_PROG_CC, have been optimized and no longer + invoke as many subroutine macros as they used to. This can expose + several classes of bugs: these are the ones we know about: + + - Make sure to explicitly invoke all of the macros that set result + variables used later in the configure script, or in generated + Makefiles. + + - AC_REQUIRE must not appear inside hand-written shell conditional + constructs. Use AS_IF, AS_FOR, etc. instead. + + - AC_REQUIRE cannot be applied to macros that need to be used with + arguments. Instead, invoke the macro normally, with its arguments. + ** Macros that take whitespace-separated lists as arguments now always expand macros within those arguments. (Formerly, these macros would *usually* expand those arguments, but the behavior was |