pkgsrc/mk/check/check-portability.awk

89 lines
2.5 KiB
Awk

# $NetBSD: check-portability.awk,v 1.9 2016/02/24 08:54:23 jklos Exp $
#
# Checks a shell file for possible portability problems.
#
# ENVIRONMENT
# (See check-subr.awk)
#
BEGIN {
found_random = no;
found_test_eqeq = no;
}
# Check for $RANDOM, which is specific to ksh and bash.
function check_random(line) {
# $RANDOM together with the PID is often found in GNU-style
# configure scripts and is considered acceptable.
if (line ~ /\$\$-\$RANDOM/ || line ~ /\$RANDOM-\$\$/) {
# Assume that this is ok.
} else if (line ~ /\$RANDOM[A-Z_]+/) {
# That's ok, too.
} else if (line ~ /\$RANDOM/) {
found_random = yes;
cs_warning_heading("Found $RANDOM:");
cs_warning_msg(cs_fname ": " $0);
}
}
function check_test_eqeq(line, n, word, i) {
if (length(line) == 0)
return;
n = split(line, word);
for (i = 3; i < n; i++) {
if (word[i] == "==") {
if (word[i-2] == "test" || word[i-2] == "[") {
found_test_eqeq = yes;
cs_error_heading("Found test ... == ...:");
cs_error_msg(cs_fname ": " $0);
}
}
}
}
/./ {
# Note: This code does not find _all_ instances of
# unportable code. If a single line contains an unsafe and
# a safe usage of $RANDOM, it will pass the test.
# Strip comments
line = $0;
gsub(/^#.*/, "", line);
gsub(/[[:space:]]#.*/, "", line);
check_random(line);
check_test_eqeq(line);
}
END {
if (found_random) {
h = "The variable $RANDOM is not required for a POSIX-conforming shell, and\n";
h = h "many implementations of /bin/sh do not support it. It should therefore\n";
h = h "not be used in shell programs that are meant to be portable across a\n";
h = h "large number of POSIX-like systems.\n"
cs_explain(h);
}
if (found_test_eqeq) {
h = "The \"test\" command, as well as the \"[\" command, are not required to know\n";
h = h "the \"==\" operator. Only a few implementations like bash and some\n";
h = h "versions of ksh support it.\n";
h = h "\n";
h = h "When you run \"test foo == foo\" on a platform that does not support the\n";
h = h "\"==\" operator, the result will be \"false\" instead of \"true\". This can\n";
h = h "lead to unexpected behavior.\n";
h = h "\n";
h = h "There are two ways to fix this error message. If the file that contains\n";
h = h "the \"test ==\" is needed for building the package, you should create a\n";
h = h "patch for it, replacing the \"==\" operator with \"=\". If the file is not\n";
h = h "needed, add its name to the CHECK_PORTABILITY_SKIP variable in the\n";
h = h "package Makefile.\n";
cs_explain(h);
}
cs_exit();
}