[src/trunk]: src/etc Instead of stupid postprocessor tricks, use redirect tricks

[apb <apb%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/6077521506da
branches:  trunk
changeset: 791007:6077521506da
user:      apb <apb%NetBSD.org@localhost>
date:      Wed Oct 30 15:15:12 2013 +0000

description:
Instead of stupid postprocessor tricks, use redirect tricks
to ensure that the output from ${PRINT_PARAMS} contains only
the desired information without any debugging noise.

diffstat:

 etc/Makefile.params |  90 ++++++++++++++++------------------------------------
 1 files changed, 28 insertions(+), 62 deletions(-)

diffs (151 lines):

diff -r 277d505e39a3 -r 6077521506da etc/Makefile.params
--- a/etc/Makefile.params       Wed Oct 30 14:25:47 2013 +0000
+++ b/etc/Makefile.params       Wed Oct 30 15:15:12 2013 +0000
@@ -1,4 +1,4 @@
-#      $NetBSD: Makefile.params,v 1.3 2013/10/18 11:42:59 njoly Exp $
+#      $NetBSD: Makefile.params,v 1.4 2013/10/30 15:15:12 apb Exp $
 #
 # Makefile fragment for printing build parameters.
 #
@@ -7,7 +7,8 @@
 #              List of variables whose value should be printed.
 #
 #      PRINT_PARAMS
-#              A command to print the desired variables and values.
+#              A command to print the desired variables and values
+#              to stdout, without any additional debugging information.
 #              Values are printed as single-quoted strings, with
 #              embedded quotes and newlines escaped in a way that's
 #              acceptable to sh(1).  Undefined values are printed
@@ -15,15 +16,18 @@
 #
 # Internal targets:
 #      _params:
-#              Prints the names and values of all the variables
-#              listed in ${RELEASEVARS}.  The output may be intermixed
-#              with debugging information, which can be removed by the
-#              ${_PARAMS_POSTPROCESS} command.
+#              Prints the names and values of all the variables
+#              listed in ${RELEASEVARS}.  The desired results may be
+#              redirected somewhere other than stdout, for example by
+#              setting _params_redirect='>&3'.  stdout and stderr may
+#              contain unwanted debugging information, from make and
+#              the shell.
 #
 # Internal variables:
-#      _PARAMS_POSTPROCESS
-#              A command to postprocess the output from "make _params",
-#              to remove debugging information and other noise.
+#      _params_redirect:
+#              If set, this should be a shell redirection specification, such
+#              as '>&3', controlling where the output from "make _params" will
+#              be sent.
 #
 # Example:
 #      . ${NETBSDSRCDIR}/etc/Makefile.params
@@ -31,8 +35,6 @@
 #              @${PRINT_PARAMS}
 #
 
-.include <bsd.sys.mk>          # for TOOL_AWK, ...
-
 RELEASEVARS=   BSDOBJDIR BSDSRCDIR BUILDID \
                DESTDIR DISTRIBVER EXTERNAL_TOOLCHAIN HAVE_GCC HAVE_GDB \
                HAVE_LLVM HAVE_PCC INSTALLWORLDDIR \
@@ -59,23 +61,25 @@
                USETOOLS USR_OBJMACHINE \
                X11SRCDIR X11FLAVOUR
 
-PRINT_PARAMS= (cd ${.CURDIR}; ${MAKE} _params) | ${_PARAMS_POSTPROCESS}
+_params_redirect?= # empty
 
 _params: .PHONY
 .for var in ${RELEASEVARS}
 .if defined(${var})
-       @printf "%20s = '%-s'\n" ${var} ${${var}:C/'/'\\\\''/gW:Q}
+       @printf "%20s = '%-s'\n" ${var} ${${var}:C/'/'\\\\''/gW:Q} \
+           ${_params_redirect}
 .else
-       @printf "%20s = (undefined)\n" ${var}
+       @printf >&3 "%20s = (undefined)\n" ${var} \
+           ${_params_redirect}
 .endif
 .endfor
 
-# _PARAMS_POSTPROCESS:
+# PRINT_PARAMS:
 #
 # The output from the "make _params" can include the following types of
 # unwanted lines:
 #
-#     make -j prints "--- params ---";
+#     make -j prints "--- _params ---";
 #
 #     if MAKEVERBOSE is set to 3 or more then make prints each "printf"
 #     command in addition to executing it;
@@ -85,7 +89,7 @@
 #
 # So the resulting output can look like this:
 #
-#      --- params ---
+#      --- _params ---
 #      + echo 'printf "%20s = '\''%-s'\''\n" BSDOBJDIR /usr/obj'
 #      printf "%20s = '%-s'\n" BSDOBJDIR /usr/obj
 #      + printf '%20s = '\''%-s'\''\n' BSDOBJDIR /usr/obj
@@ -102,49 +106,11 @@
 #                 BSDSRCDIR = '/usr/src'
 #                 [...]
 #
-# The awk program in ${PARAMS_POSTPROCESS} removes the unwanted noise,
-# taking care with variables whose values contain embedded newlines
-# (assuming that embedded newlines appear only inside single quotes).
+# The shell redirections in ${PRINT_PARAMS} ensure that the unwanted
+# noise is discarded (via ">/dev/null"), while the desired information
+# ends up on the subshell's stdout (via ">&3" and "3>&1").  The value
+# of _params_redirect is passed in the environment instead of on the
+# command line, to prevent it from appearing in MAKEFLAGS (which would
+# appear in the output).
 #
-_PARAMS_POSTPROCESS= ${TOOL_AWK} '\
-       BEGIN { single_quote = "'\''"; \
-               NORMAL = 0; \
-               SKIP_HEADING = 1; \
-               SKIP_MULTILINE = 2; \
-               PRINT_MULTILINE = 3; \
-               state = SKIP_HEADING; \
-       } \
-       function quotes_balanced_p(line) { \
-               return (line ~ /^([^\\"'\'']|\\.|'\''[^'\'']*'\''|"(\\.|[^\\"])*")*$$/); \
-       } \
-       state == SKIP_MULTILINE { \
-               if (quotes_balanced_p(single_quote $$0)) { \
-                       state = NORMAL; \
-               } \
-               next; \
-       } \
-       state == PRINT_MULTILINE { \
-               if (quotes_balanced_p(single_quote $$0)) { \
-                       state = NORMAL; \
-               } \
-               print; next; \
-       } \
-       state == SKIP_HEADING && $$0 ~ /^--- .* ---$$/ { next; } \
-       state == SKIP_HEADING && $$0 ~ / ===> / { next; } \
-       /^(\+ )?(echo ["'\''])?printf.* = / { \
-               if (quotes_balanced_p($$0)) { \
-                       state = NORMAL; \
-               } else { \
-                       state = SKIP_MULTILINE; \
-               } \
-               next; \
-       } \
-       // { \
-               if (quotes_balanced_p($$0)) { \
-                       state = NORMAL; \
-               } else { \
-                       state = PRINT_MULTILINE; \
-               } \
-               print; next; \
-       } \
-       '
+PRINT_PARAMS:= (_params_redirect='>&3' ${MAKE} -f ${.PARSEDIR:Q}/${.PARSEFILE:Q} _params 3>&1 >/dev/null)