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

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3 messages, 2 authors, 2016-08-11 · open the first message on its own page

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

From: Junio C Hamano <hidden>
Date: 2016-08-11 19:46:43

"Shawn O. Pearce" [off-list ref] 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.

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.

In other words, how about this patch instead?

-- >8 --
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>...";
 

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

From: Shawn O. Pearce <hidden>
Date: 2016-08-11 19:42:24

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 <redacted>
---
 This is a resend of my earlier patch in in this same thread...

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

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

From: Shawn Pearce <hidden>
Date: 2016-08-11 19:48:57

Junio C Hamano [off-list ref] wrote:
"Shawn O. Pearce" [off-list ref] writes:
quoted
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.

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