Hello,
I did a cleanup of the headers section of status.m4.
Advantages:
-- The code is more correct in a corner case: if you issue several
AC_DEFINEs, the last one is used, as a comment suggested.
-- I use ac_max_sed_lines, not ac_max_here_lines, as an old comment
suggested.
-- config.status is probably quicker now: I use one s/// command per
each define, which means that 97 defines are processed by one sed run.
I believe that the fact that less filtering rounds are needed overweights
any optimization inside the sed script. And even if I'm wrong, I don't
mind it, more projects have only one config header.
-- The generated configure script and config.status script are probably
a bit shorter now.
-- The code is shorter, and more readable, I hope.
Is the patch OK?
Can it be commited?
Have a nice day,
Stepan Kasal
2005-05-18 Stepan Kasal <[EMAIL PROTECTED]>
* lib/autoconf/general.m4 (_AC_INIT_DEFAULTS): Nuke ac_max_here_lines.
* lib/autoconf/status.m4 (_AC_OUTPUT_HEADERS): Simplify the sed
scripts created.
Index: lib/autoconf/general.m4
===================================================================
RCS file: /cvsroot/autoconf/autoconf/lib/autoconf/general.m4,v
retrieving revision 1.856
diff -u -r1.856 general.m4
--- lib/autoconf/general.m4 17 May 2005 09:29:05 -0000 1.856
+++ lib/autoconf/general.m4 18 May 2005 09:27:29 -0000
@@ -401,11 +401,6 @@
AC_SUBST([SHELL], [${CONFIG_SHELL-/bin/sh}])dnl
AC_SUBST([PATH_SEPARATOR])dnl
-# Maximum number of lines to put in a shell here document.
-# This variable seems obsolete. It should probably be removed, and
-# only ac_max_sed_lines should be used.
-: ${ac_max_here_lines=38}
-
# Identity of this package.
AC_SUBST([PACKAGE_NAME],
[m4_ifdef([AC_PACKAGE_NAME], ['AC_PACKAGE_NAME'])])dnl
Index: lib/autoconf/status.m4
===================================================================
RCS file: /cvsroot/autoconf/autoconf/lib/autoconf/status.m4,v
retrieving revision 1.56
diff -u -r1.56 status.m4
--- lib/autoconf/status.m4 17 May 2005 09:29:05 -0000 1.56
+++ lib/autoconf/status.m4 18 May 2005 09:27:29 -0000
@@ -482,40 +482,6 @@
# itself into $CONFIG_STATUS (eg, via here documents). Upon exit, no
# here document shall be opened.
#
-#
-# The code produced used to be extremely costly: there are was a
-# single sed script (n lines) handling both `#define' templates,
-# `#undef' templates with trailing space, and `#undef' templates
-# without trailing spaces. The full script was run on each of the m
-# lines of `config.h.in', i.e., about n x m.
-#
-# Now there are two scripts: `conftest.defines' for the `#define'
-# templates, and `conftest.undef' for the `#undef' templates.
-#
-# Optimization 1. It is incredibly costly to run two `#undef'
-# scripts, so just remove trailing spaces first. Removes about a
-# third of the cost.
-#
-# Optimization 2. Since `#define' are rare and obsoleted,
-# `conftest.defines' is built and run only if grep says there are
-# `#define'. Improves by at least a factor 2, since in addition we
-# avoid the cost of *producing* the sed script.
-#
-# Optimization 3. In each script, first check that the current input
-# line is a template. This avoids running the full sed script on
-# empty lines and comments (divides the cost by about 3 since each
-# template chunk is typically a comment, a template, an empty line).
-#
-# Optimization 4. Once a substitution performed, since there can be
-# only one per line, immediately restart the script on the next input
-# line (using the `t' sed instruction). Divides by about 2.
-# *Note:* In the case of the AC_SUBST sed script (_AC_OUTPUT_FILES)
-# this optimization cannot be applied as is, because there can be
-# several substitutions per line.
-#
-#
-# The result is about, hm, ... times blah... plus.... Ahem. The
-# result is about much faster.
m4_define([_AC_OUTPUT_HEADERS],
[cat >>$CONFIG_STATUS <<\_ACEOF
@@ -523,20 +489,22 @@
# CONFIG_HEADERS section.
#
-# These sed commands are passed to sed as "A NAME B NAME C VALUE D", where
-# NAME is the cpp macro being defined and VALUE is the value it is being given.
-#
-# ac_d sets the value in "#define NAME VALUE" lines.
-dnl Double quote for the `[ ]' and `define'.
-[ac_dA='s,^\([ ]*\)#\([ ]*define[ ][ ]*\)'
-ac_dB='[ ].*$,\1#\2'
+# These sed commands are passed to sed as "A NAME B PARAMS C VALUE D", where
+# NAME is the cpp macro being defined, VALUE is the value it is being given.
+# PARAMS is the parameter list in the macro definition--in most cases, it's
+# just an empty string.
+#
+dnl Quote, for the `[ ]' and `define'.
+[ac_dA='s,^\([ ]*#[ ]*\)[^ ]*\([ ][ ]*'
+ac_dB='\)\([ (].*\)*$,\1define\2'
ac_dC=' '
-ac_dD=',;t'
-# ac_u turns "#undef NAME" without trailing blanks into "#define NAME VALUE".
-ac_uA='s,^\([ ]*\)#\([ ]*\)undef\([ ][ ]*\)'
-ac_uB='$,\1#\2define\3'
-ac_uC=' '
-ac_uD=',;t']
+ac_dD=',']
+dnl ac_dD used to contain `;t' at the end.
+dnl This was an optimization which was making the code both slow and incorrect.
+dnl 1) Since the script has to be broken to chunks containing 100 commands,
+dnl this extra command means we have to call sed more times.
+dnl 2) The code was incorrect: in the strange case that a sumbol has multiple
+dnl different AC_DEFINEs, we want to honour the *last* one.
for ac_file in : $CONFIG_HEADERS; do test "x$ac_file" = x: && continue
# Support "outfile[:infile[:infile...]]", defaulting infile="outfile.in".
@@ -585,91 +553,60 @@
# config.status. Protect against being in an unquoted here document
# in config.status.
rm -f conftest.defines conftest.undefs
-# Using a here document instead of a string reduces the quoting nightmare.
# Putting comments in sed scripts is not portable.
#
-# `end' is used to avoid that the second main sed command (meant for
+# Command `t' is used to avoid that the second main sed command (meant for
# 0-ary CPP macros) applies to n-ary macro definitions.
# See the Autoconf documentation for `clear'.
-cat >confdef2sed.sed <<\_ACEOF
-dnl Double quote for `[ ]' and `define'.
-[s/[\\&,]/\\&/g
+dnl
+dnl Quote, for `[ ]' and `define'.
+echo '[s/[\\&,]/\\&/g
s,[\\$`],\\&,g
t clear
: clear
-s,^[ ]*#[ ]*define[ ][ ]*\([^ (][^ (]*\)\(([^)]*)\)[
]*\(.*\)$,${ac_dA}\1${ac_dB}\1\2${ac_dC}\3${ac_dD},gp
-t end
-s,^[ ]*#[ ]*define[ ][ ]*\([^ ][^ ]*\)[
]*\(.*\)$,${ac_dA}\1${ac_dB}\1${ac_dC}\2${ac_dD},gp
-: end]
-_ACEOF
+s,^[ ]*#[ ]*define[ ][ ]*\([^ (][^ (]*\)\(([^)]*)\)[
]*\(.*\)$,${ac_dA}\1${ac_dB}\2${ac_dC}\3${ac_dD},gp
+t
+s,^[ ]*#[ ]*define[ ][ ]*\([^ ][^ ]*\)[
]*\(.*\)$,${ac_dA}\1${ac_dB}${ac_dC}\2${ac_dD},gp]' \
+ >confdef2sed.sed
+
# If some macros were called several times there might be several times
# the same #defines, which is useless. Nevertheless, we may not want to
-# sort them, since we want the *last* AC-DEFINE to be honored.
+# sort them, since we want the *last* AC_DEFINE to be honored.
uniq confdefs.h | sed -n -f confdef2sed.sed >conftest.defines
-sed 's/ac_d/ac_u/g' conftest.defines >conftest.undefs
rm -f confdef2sed.sed
# This sed command replaces #undef with comments. This is necessary, for
# example, in the case of _POSIX_SOURCE, which is predefined and required
# on some systems where configure will not decide to define it.
-cat >>conftest.undefs <<\_ACEOF
-[s,^[ ]*#[ ]*undef[ ][ ]*[a-zA-Z_][a-zA-Z_0-9]*,/* & */,]
-_ACEOF
+echo '[s,^[ ]*#[ ]*undef[ ][ ]*[a-zA-Z_][a-zA-Z_0-9]*,/* &
*/,]' >>conftest.defines
+
+# Break up conftest.defines because some old seds have a limit on number
+# of cmds (HP-UX can take 100 cmds). Subtract the
+# Here, there are 2 cmd per line, and three cmds at the beginning.
+ac_max_sed_lines=97
-# Break up conftest.defines because some shells have a limit on the size
-# of here documents, and old seds have small limits too (100 cmds).
-echo ' # Handle all the #define templates only if necessary.' >>$CONFIG_STATUS
-echo ' if grep ["^[ ]*#[ ]*define"] "$tmp/in" >/dev/null; then'
>>$CONFIG_STATUS
-echo ' # If there are no defines, we may have an empty if/fi' >>$CONFIG_STATUS
-echo ' :' >>$CONFIG_STATUS
rm -f conftest.tail
-while grep . conftest.defines >/dev/null
+while :
do
- # Write a limited-size here document to $tmp/defines.sed.
- echo ' cat >"$tmp/defines.sed" <<CEOF' >>$CONFIG_STATUS
- # Speed up: don't consider the non `#define' lines.
- echo ['/^[ ]*#[ ]*define/!b'] >>$CONFIG_STATUS
- # Work around the forget-to-reset-the-flag bug.
- echo 't clr' >>$CONFIG_STATUS
- echo ': clr' >>$CONFIG_STATUS
- sed ${ac_max_here_lines}q conftest.defines >>$CONFIG_STATUS
+ # Write a here document:
+ dnl Quote, for the `[ ]' and `define'.
+ echo [' # First, check the format of the line:
+ cat >"$tmp/defines.sed" <<CEOF
+/^[ ]*#[ ]*undef[ ][ ]*[a-zA-Z_][a-zA-Z_0-9]*[ ]*$/!{
+/^[ ]*#[ ]*define[ ][ ]*[a-zA-Z_][a-zA-Z_0-9]*[( ]/!b
+}'] >>$CONFIG_STATUS
+ sed ${ac_max_sed_lines}q conftest.defines >>$CONFIG_STATUS
echo 'CEOF
- sed -f "$tmp/defines.sed" "$tmp/in" >"$tmp/out"
- rm -f "$tmp/in"
- mv "$tmp/out" "$tmp/in"
+ sed -f "$tmp/defines.sed" "$tmp/in" >"$tmp/out"
+ rm -f "$tmp/in"
+ mv "$tmp/out" "$tmp/in"
' >>$CONFIG_STATUS
- sed 1,${ac_max_here_lines}d conftest.defines >conftest.tail
+ sed 1,${ac_max_sed_lines}d conftest.defines >conftest.tail
+ grep . conftest.tail >/dev/null || break
rm -f conftest.defines
mv conftest.tail conftest.defines
done
-rm -f conftest.defines
-echo ' fi # grep' >>$CONFIG_STATUS
-echo >>$CONFIG_STATUS
-
-# Break up conftest.undefs because some shells have a limit on the size
-# of here documents, and old seds have small limits too (100 cmds).
-echo ' # Handle all the #undef templates' >>$CONFIG_STATUS
-rm -f conftest.tail
-while grep . conftest.undefs >/dev/null
-do
- # Write a limited-size here document to $tmp/undefs.sed.
- echo ' cat >"$tmp/undefs.sed" <<CEOF' >>$CONFIG_STATUS
- # Speed up: don't consider the non `#undef'
- echo ['/^[ ]*#[ ]*undef/!b'] >>$CONFIG_STATUS
- # Work around the forget-to-reset-the-flag bug.
- echo 't clr' >>$CONFIG_STATUS
- echo ': clr' >>$CONFIG_STATUS
- sed ${ac_max_here_lines}q conftest.undefs >>$CONFIG_STATUS
- echo 'CEOF
- sed -f "$tmp/undefs.sed" "$tmp/in" >"$tmp/out"
- rm -f "$tmp/in"
- mv "$tmp/out" "$tmp/in"
-' >>$CONFIG_STATUS
- sed 1,${ac_max_here_lines}d conftest.undefs >conftest.tail
- rm -f conftest.undefs
- mv conftest.tail conftest.undefs
-done
-rm -f conftest.undefs
+rm -f conftest.defines conftest.tail
dnl Now back to your regularly scheduled config.status.
cat >>$CONFIG_STATUS <<\_ACEOF
