CVS commit: pkgsrc

["Roland Illig" <rillig%netbsd.org@localhost>]

Module Name:    pkgsrc
Committed By:   rillig
Date:           Wed May  6 06:14:56 UTC 2020

Modified Files:
        pkgsrc/mk/scripts: subst-identity.awk
        pkgsrc/regress/infra-unittests: subst.sh

Log Message:
mk/subst.mk: allow identity substitutions with escaped dots

This fixes the build of converters/help2man in SUBST_NOOP_OK=no mode.


To generate a diff of this commit:
cvs rdiff -u -r1.1 -r1.2 pkgsrc/mk/scripts/subst-identity.awk
cvs rdiff -u -r1.31 -r1.32 pkgsrc/regress/infra-unittests/subst.sh

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

Modified files:

Index: pkgsrc/mk/scripts/subst-identity.awk
diff -u pkgsrc/mk/scripts/subst-identity.awk:1.1 pkgsrc/mk/scripts/subst-identity.awk:1.2
--- pkgsrc/mk/scripts/subst-identity.awk:1.1    Wed Apr 29 18:33:57 2020
+++ pkgsrc/mk/scripts/subst-identity.awk        Wed May  6 06:14:56 2020
@@ -1,5 +1,5 @@
 #! /usr/bin/awk -f
-# $NetBSD: subst-identity.awk,v 1.1 2020/04/29 18:33:57 rillig Exp $
+# $NetBSD: subst-identity.awk,v 1.2 2020/05/06 06:14:56 rillig Exp $
 #
 # Tests whether a sed(1) command line consists of only identity substitutions
 # like s,id,id,.
@@ -7,23 +7,41 @@
 # See SUBST_NOOP_OK and regress/infra-unittests/subst.sh.
 #
 
-function is_safe_char(ch) {
-       return ch ~ /[\t -~]/ && ch !~ /[$&*.\[\\\]^]/;
+# Returns the first character of the given regular expression,
+# if it is a single-character regular expression.
+function identity_char(s) {
+       if (s ~ /^[\t -~]/ && s !~ /^[$&*.\[\\\]^]/)
+               return substr(s, 1, 1);
+       if (s ~ /^\\[$*.\[\]^]/)
+               return substr(s, 2, 1) "x";
+       if (s ~ /^\[[$*.]\]/)
+               return substr(s, 2, 1) "xx";
+       return "";
 }
 
-function is_identity_subst(s,   len, i, sep, pat) {
+# Tests whether a single "s,from,to," is an identity substitution.
+function is_identity_subst(s,   len, i, sep, pat_from, pat_to, ch, subst) {
        len = length(s);
        if (len < 6 || substr(s, 1, 1) != "s")
                return 0;
 
        sep = substr(s, 2, 1);
        i = 3;
-       while (i < len && substr(s, i, 1) != sep && is_safe_char(substr(s, i, 1)))
-               i++;
-       pat = substr(s, 3, i - 3);
+       pat_to = "";
+       while (i < len && substr(s, i, 1) != sep) {
+               ch = identity_char(substr(s, i));
+               if (ch == "")
+                       break;
+               pat_to = pat_to substr(ch, 1, 1);
+               i += length(ch);
+       }
+
+       if (pat_to == "")
+               return 0; # only for GNU Awk 5.0.1 in -Lfatal mode
+       pat_from = substr(s, 3, i - 3);
 
-       return (s == "s" sep pat sep pat sep ||
-               s == "s" sep pat sep pat sep "g");
+       subst = "s" sep pat_from sep pat_to sep;
+       return s == subst || s == subst "g";
 }
 
 function main(   i) {

Index: pkgsrc/regress/infra-unittests/subst.sh
diff -u pkgsrc/regress/infra-unittests/subst.sh:1.31 pkgsrc/regress/infra-unittests/subst.sh:1.32
--- pkgsrc/regress/infra-unittests/subst.sh:1.31        Sat May  2 06:48:59 2020
+++ pkgsrc/regress/infra-unittests/subst.sh     Wed May  6 06:14:56 2020
@@ -1,5 +1,5 @@
 #! /bin/sh
-# $NetBSD: subst.sh,v 1.31 2020/05/02 06:48:59 rillig Exp $
+# $NetBSD: subst.sh,v 1.32 2020/05/06 06:14:56 rillig Exp $
 #
 # Tests for mk/subst.mk.
 #
@@ -1189,6 +1189,29 @@ if test_case_begin "identity substitutio
        specials='!"%'\''()+,-/:;<=>@_`{|}~'
        assert_identity "yes"   -e "sX${specials}X${specials}X"
 
+       # Regular expression meta-characters may be escaped using a
+       # backslash or be enclosed in square brackets.
+       assert_identity 'yes'   -e 's,library\.so,library.so,g'
+       assert_identity 'yes'   -e 's,library[.]so,library.so,g'
+       assert_identity 'yes'   -e 's,[*],*,'
+       assert_identity 'yes'   -e 's,[$],$,'
+
+       # When this happens, it is probably a mistake.
+       assert_identity 'no'    -e 's,,,'
+
+       # Backslashes are not considered identity substitutions since
+       # there might be tricky corner cases.
+       assert_identity 'no'    -e 's,\\,\\,'
+
+       # Back-references are not considered identity substitutions.
+       assert_identity 'no'    -e 's,\1,\1,'
+
+       # The & is interpreted specially in the replacement string.
+       assert_identity 'no'    -e 's,&&&,&&&,'
+       assert_identity 'no'    -e 's,\&,&,'
+       assert_identity 'no'    -e 's,[&],&,'
+       assert_identity 'no'    -e 's,&,\&,' # this would be an identity
+
        test_case_end
 fi