From: Ulya Trofimovich <skvadrik@gmail.com>
Date: Thu, 17 Sep 2015 14:03:24 +0000 (+0100)
Subject: Documentation: added warning descriptions to '-h, -?, --help' option.
X-Git-Tag: 0.15~52
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=0837ad250c27fa64412e08a7e8995a5df0570ac7;p=re2c

Documentation: added warning descriptions to '-h, -?, --help' option.
---

diff --git a/re2c/src/conf/msg.cc b/re2c/src/conf/msg.cc
index 6b5fe03e..6a94b266 100644
--- a/re2c/src/conf/msg.cc
+++ b/re2c/src/conf/msg.cc
@@ -151,9 +151,59 @@ void usage ()
 	"                        e.g: [], [^\\x00-\\xFF], [\\x00-\\xFF]\\[\\x00-\\xFF].\n"
 	"\n"
 	"-1     --single-pass    Deprecated and does nothing (single pass is by default now).\n"
+	"\n"
+	"-W                      Turn on all warnings.\n"
+	"\n"
+	"-Werror                 Turn warnings into errors. Note that this option along doesn't\n"
+	"                        turn on any warnings, it only affects those warnings that have\n"
+	"                        been turned on so far or will be turned on later.\n"
+	"\n"
+	"-W<warning>             Turn on individual warning.\n"
+	"\n"
+	"-Wno-<warning>          Turn off individual warning.\n"
+	"\n"
+	"-Werror-<warning>       Turn on individual warning and treat it as error (this implies\n"
+	"                        '-W<warning>').\n"
+	"\n"
+	"-Wno-error-<warning>    Don't treat this particular warning as error. This doesn't turn\n"
+	"                        off the warning itself.\n"
+	"\n"
+	"Warnings:\n"
+	"\n"
+	"-Wcondition-order       Warn if the generated program makes implicit assumptions about\n"
+	"                        condition numbering. One should use either '-t, --type-header'\n"
+	"                        option or '/*!types:re2c*/' directive to generate mapping of\n"
+	"                        condition names to numbers and use autogenerated condition names.\n"
+	"\n"
+	"-Wempty-character-class Warn if regular expression contains empty character class. From\n"
+	"                        the rational point of view trying to match empty character class\n"
+	"                        makes no sense: it should always fail. However, for backwards\n"
+	"                        compatibility reasons re2c allows empty character class and treats\n"
+	"                        it as empty string. Use '--empty-class' option to change default\n"
+	"                        behaviour.\n"
+	"\n"
+	"-Wmatch-empty-string    Warn if regular expression in a rule is nullable (matches empty\n"
+	"                        string). If DFA runs in a loop and empty match is unintentional\n"
+	"                        (input position in not advanced manually), lexer may get stuck\n"
+	"                        in eternal loop.\n"
+	"\n"
+	"-Wswapped-range         Warn if range lower bound is greater that upper bound. Default\n"
+	"                        re2c behaviour is to silently swap range bounds.\n"
+	"\n"
+	"-Wundefined-control-flow\n"
+	"                        Warn if some input strings cause undefined control flow in lexer\n"
+	"                        (the faulty patterns are reported). This is the most dangerous\n"
+	"                        and common mistake. It can be easily fixed by adding default rule\n"
+	"                        '*' (this rule has the lowest priority, matches any code unit\n"
+	"                        and consumes exactly one code unit).\n"
+	"\n"
+	"-Wuseless-escape        Warn if a symbol is escaped when it shouldn't be. By default re2c\n"
+	"                        silently ignores escape, but this may as well indicate a typo\n"
+	"                        or an error in escape sequence.\n"
+	"\n"
 	);
 }
- 
+
 void vernum ()
 {
 	std::string vernum (PACKAGE_VERSION);