[PATCH] Rename -Wall to Wsparse-all, so it doesn't get turned on unintentionally

[PATCH] Rename -Wall to Wsparse-all, so it doesn't get turned on unintentionally

[Josh Triplett]

sparse's -Wall option turns on all sparse warnings, including those that
many projects will not want; for instance, warnings that enforce
particular stylistic choices, or behavior allowed by a standard but
considered questionable or error-prone.  Furthermore, using -Wall means
accepting all future warnings sparse may start issuing, not just those
intentionally turned on by default.

Other compilers like GCC also use -Wall, and interpret it to mean "turn
on a sensible set of warnings".  Since sparse exists to emit warnings,
it already defaults to emitting a sensible set of warnings.  Many
projects pass the same options to both sparse and the C compiler,
including warning options like -Wall; this results in turning on
excessive amounts of sparse warnings.

cgcc already filtered out -Wall, but many projects invoke sparse
directly rather than using cgcc.  Remove that filter, now that -Wall
does not change sparse's behavior.

Projects almost certainly don't want to use the new -Wsparse-all option;
they should choose the specific set of warnings they want, or just go
with sparse's defaults.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
---

This has come up for discussion numerous times before, and most people
seem to approve of renaming -Wall, but the change hasn't actually gone
into sparse yet.

 cgcc     |   15 +--------------
 lib.c    |    2 +-
 sparse.1 |    4 ++++
 3 files changed, 6 insertions(+), 15 deletions(-)

diff --git a/cgcc b/cgcc
index 995cc05..ff8c921 100755
--- a/cgcc
+++ b/cgcc
@@ -51,7 +51,7 @@ while (@ARGV) {
 
     my $this_arg = ' ' . &quote_arg ($_);
     $cc .= $this_arg unless &check_only_option ($_);
-    $check .= $this_arg unless &cc_only_option ($_);
+    $check .= $this_arg;
 }
 
 if ($gendeps) {
@@ -94,19 +94,6 @@ sub check_only_option {
 }
 
 # -----------------------------------------------------------------------------
-# Check if an option is for "cc" only.
-
-sub cc_only_option {
-    my ($arg) = @_;
-    # -Wall turns on all Sparse warnings, including experimental and noisy
-    # ones.  Don't include it just because a project wants to pass -Wall to cc.
-    # If you really want cgcc to run sparse with -Wall, use
-    # CHECK="sparse -Wall".
-    return 1 if $arg =~ /^-Wall$/;
-    return 0;
-}
-
-# -----------------------------------------------------------------------------
 # Simple arg-quoting function.  Just adds backslashes when needed.
 
 sub quote_arg {
diff --git a/lib.c b/lib.c
index 622b547..963be08 100644
--- a/lib.c
+++ b/lib.c
@@ -407,7 +407,7 @@ static char **handle_onoff_switch(char *arg, char **next, const struct warning w
 	char *p = arg + 1;
 	unsigned i;
 
-	if (!strcmp(p, "all")) {
+	if (!strcmp(p, "sparse-all")) {
 		for (i = 0; i < n; i++) {
 			if (*warnings[i].flag != WARNING_FORCE_OFF)
 				*warnings[i].flag = WARNING_ON;
diff --git a/sparse.1 b/sparse.1
index d7fe444..abc75a2 100644
--- a/sparse.1
+++ b/sparse.1
@@ -20,6 +20,10 @@ off those warnings, pass the negation of the associated warning option,
 .
 .SH WARNING OPTIONS
 .TP
+.B \-Wsparse\-all
+Turn on all sparse warnings, except for those explicitly disabled via
+\fB\-Wno\-something\fR.
+.TP
 .B \-Waddress\-space
 Warn about code which mixes pointers to different address spaces.
 
-- 
1.6.4.3