Am 06.12.23 um 14:08 schrieb Patrick Steinhardt:

On Wed, Dec 06, 2023 at 12:51:57PM +0100, René Scharfe wrote:

quoted

The revision options --reverse is incompatibel with --walk-reflogs and
--graph is incompatible with both --reverse and --walk-reflogs.  So they
are all incompatible with each other.

Use the function for checking three mutually incompatible options,
die_for_incompatible_opt3(), to perform this check in one place and
without repetition.  This is shorter and clearer.

Signed-off-by: René Scharfe <redacted>
---
 revision.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/revision.c b/revision.c
index b2861474b1..1b7e1af6c6 100644
--- a/revision.c
+++ b/revision.c

@@ -3036,8 +3036,6 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct s
 		revs->grep_filter.ignore_locale = 1;
 	compile_grep_patterns(&revs->grep_filter);

-	if (revs->reverse && revs->reflog_info)
-		die(_("options '%s' and '%s' cannot be used together"), "--reverse", "--walk-reflogs");
 	if (revs->reflog_info && revs->limited)
 		die("cannot combine --walk-reflogs with history-limiting options");
 	if (revs->rewrite_parents && revs->children.name)

@@ -3048,11 +3046,10 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct s
 	/*
 	 * Limitations on the graph functionality
 	 */
-	if (revs->reverse && revs->graph)
-		die(_("options '%s' and '%s' cannot be used together"), "--reverse", "--graph");
+	die_for_incompatible_opt3(!!revs->graph, "--graph",
+				  !!revs->reverse, "--reverse",
+				  !!revs->reflog_info, "--walk-reflogs");

I've been wondering why we use `!!` here, as `die_for_incompatible_*()`
doesn't care for the actual value but only checks that it is non-zero.
Is it because of the type mismatch, where these flags here use unsigned
ints whereas `die_for_incompatible_*()` expect ints?

->graph and ->reflog_info are pointers and clang reports an int-conversion
warning without the double negation.  ->reverse is an unsigned:1 and so
doesn't need it, but I gave it one anyway for aesthetic reasons.

René