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| author | Eric Blake <eblake@redhat.com> | 2010-08-25 16:56:37 -0600 |
|---|---|---|
| committer | Eric Blake <eblake@redhat.com> | 2010-08-27 10:05:10 -0600 |
| commit | d1bea5123b8ecb406fbeabbe70552271f60de8e7 (patch) | |
| tree | 1bd6b9693167b66344a4a54c22aefb86acbe32b9 /lib/m4sugar | |
| parent | 270b8340863c11c5e51bb2841a58974edf52e0db (diff) | |
| download | autoconf-d1bea5123b8ecb406fbeabbe70552271f60de8e7.tar.gz | |
m4sh: assume ${a:-b} support
* tests/m4sh.at (Null variable substitution): New test.
* doc/autoconf.texi (Shell Substitutions) <${var:-value}>: Mention
that m4sh guarantees support.
(Limitations of Usual Tools) <mktemp>: Use it.
* lib/m4sugar/m4sh.m4 (AS_LINENO_POP, AS_VAR_IF, AS_TMPDIR):
Exploit use of colon for smaller files.
Signed-off-by: Eric Blake <eblake@redhat.com>
Diffstat (limited to 'lib/m4sugar')
| -rw-r--r-- | lib/m4sugar/m4sh.m4 | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/lib/m4sugar/m4sh.m4 b/lib/m4sugar/m4sh.m4 index 2f8baec1..8343b259 100644 --- a/lib/m4sugar/m4sh.m4 +++ b/lib/m4sugar/m4sh.m4 @@ -859,8 +859,10 @@ m4_defun([AS_LINENO_PUSH], # ----------------------- # If this is call balances the outermost call to AS_LINENO_PUSH, # AS_MESSAGE will restart printing $LINENO as the line number. +# +# No need to use AS_UNSET, since as_lineno is necessarily set. m4_defun([AS_LINENO_POP], -[eval $as_lineno_stack; test "x$as_lineno_stack" = x && AS_UNSET([as_lineno])]) +[eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno]) @@ -1620,7 +1622,7 @@ m4_define([_AS_LITERAL_HEREDOC_IF_NO], [$2]) # it is a documented part of the public API and must not be changed. m4_define([AS_TMPDIR], [# Create a (secure) tmp directory for tmp files. -m4_if([$2], [], [: "${TMPDIR=/tmp}"]) +m4_if([$2], [], [: "${TMPDIR:=/tmp}"]) { tmp=`(umask 077 && mktemp -d "m4_default([$2], [$TMPDIR])/$1XXXXXX") 2>/dev/null` && @@ -1984,10 +1986,12 @@ m4_define([AS_VAR_GET], # Polymorphic, and avoids sh expansion error upon interrupt or term signal. m4_define([AS_VAR_IF], [AS_LITERAL_WORD_IF([$1], - [AS_IF([test "x$$1" = x""$2]], + [AS_IF(m4_ifval([$2], [[test "x$$1" = x[]$2]], [[${$1:+false} :]])], [AS_VAR_COPY([as_val], [$1]) - AS_IF([test "x$as_val" = x""$2]], - [AS_IF([eval test \"x\$"$1"\" = x"_AS_ESCAPE([$2], [`], [\"$])"]]), + AS_IF(m4_ifval([$2], [[test "x$as_val" = x[]$2]], [[${as_val:+false} :]])], + [AS_IF(m4_ifval([$2], + [[eval test \"x\$"$1"\" = x"_AS_ESCAPE([$2], [`], [\"$])"]], + [[eval \${$1:+false} :]])]), [$3], [$4])]) |