threads / patch / 43507

patch, 2 partsUse ULONG_MAX rather than implicit cast of -1.

Subject: [PATCH 1/2] Use ULONG_MAX rather than implicit cast of -1.

## tl;dr

2 messages between Nov 5, 2006 and Nov 5, 2006. Diffs are folded; open one to read it.

replies: 1people: 1as markdown or json

Shawn Pearce· Nov 5, 2006, 07:18 UTC · lore

Re: [PATCH 1/3] Apply obvious numerical cast for stupid C compilers.

Junio C Hamano <junkio@cox.net> wrote:

Show 10 quoted lines

> "Shawn O. Pearce" <spearce@spearce.org> writes:
> 
> > At least one (older) version of the Solaris C compiler won't allow
> > 'unsigned long x = -1' without explicitly casting -1 to a type of
> > unsigned long.  As annoying as it may be to explicitly perform the
> > cast the compiler is right; -1 is not an unsigned value.
> 
> Is the compiler really _right_?  The usual integral promotion
> rules should apply if it claims to be a C compiler, I would
> think.

I'm rusty on my C; but I would expect an error if I tried to assign
a clearly negative value into an unsigned value, especially in a
case like this.  It could be compiler is wrong, but as a programmer
I'd want to know I wrote something stupid like that, because maybe
the variable should have been signed.  :-)

> But I think the code actually wants ULONG_MAX there.  Is that
> symbolic constant available at the point of offending
> initialization with the header files we already include, I
> wonder.

Yes, I agree. I almost changed it to ULONG_MAX but didn't since the original author felt -1 was the better choice here. *shrug*

For what its worth ULONG_MAX works on my Mac OS X system.

Tomorrow when I have access to that "broken" platform again I'll try ULONG_MAX and see if it compiles there.

Shawn O. Pearce· Nov 5, 2006, 07:27 UTC · re: Shawn Pearce · lore

At least one (older) version of the Solaris C compiler won't allow 'unsigned long x = -1' without explicitly casting -1 to a type of unsigned long. So instead use ULONG_MAX, which is really the correct constant anyway.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 This is a resend of my earlier patch in in this same thread...

 builtin-apply.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

Show changes to builtin-apply.c +1 −1

diff --git a/builtin-apply.c b/builtin-apply.c
index db7cdce..aad5526 100644
--- a/builtin-apply.c
+++ b/builtin-apply.c
@@ -43,7 +43,7 @@ static int apply_verbosely;
 static int no_add;
 static int show_index_info;
 static int line_termination = '\n';
-static unsigned long p_context = -1;
+static unsigned long p_context = ULONG_MAX;
 static const char apply_usage[] =
 "git-apply [--stat] [--numstat] [--summary] [--check] [--index] [--cached] [--apply] [--no-add] [--index-info] [--allow-binary-replacement] [--reverse] [--reject] [--verbose] [-z] [-pNUM] [-CNUM] [--whitespace=<nowarn|warn|error|error-all|strip>] <patch>...";

-- 
1.4.3.3.g9621