Re: [PATCH] ewah/bitmap: silence warning about MASK macro redefinition
On Tue, Jun 02, 2015 at 03:15:09PM -0700, Junio C Hamano wrote:
Show 12 quoted lines
> > The alternative is to rename MASK in ewah/bitmap.c to something less
> > generic, resulting in a slightly more noisy patch. I chose the #undef
> > approach since it's a relatively common idiom to #undef a macro before
> > #defining it in order to avoid exactly this sort of redefinition
> > problem.
>
> I agree that there is nothing controversial against this use of
> #undef; I however wonder if we are stomping on _their_ use of MASK
> and breaking whatever Mac OS X wants to express with that macro,
> though (in which case, hiding collision like this may not be
> sufficient and we have to live with the poor implementation choice
> made by the header file and change the macro _we_ use).
Yeah. It looks like we only use the macros a few times. I would not be opposed to s/(BLOCK|MASK)/EWAH_&/. We also use BITS_IN_WORD, which is rather generic, and is actually defined in a header file (so it affects the rest of git). Probably BITS_IN_EWORD would be better.
The resulting patch is rather noisy, but I don't think there's any ongoing work in that area (actually, I have a few things that need cleaned up and submitted, but the conflicts are not a big deal).
-- >8 --
Subject: [PATCH] ewah: use less generic macro names
The ewah/ewok.h header pollutes the global namespace with "BITS_IN_WORD", without any specific notion that we are talking about the bits in an eword_t. We can give this the more specific name "BITS_IN_EWORD".
Likewise, ewah/bitmap.c uses the generic MASK and BLOCK macro names. These are local to the .c file, but we have the opposite problem: on PowerPC Mac OS X (10.5.8 "Leopard" with Xcode 3.1), system header /usr/include/ppc/param.h[1] pollutes the preprocessor namespace with a macro generically named MASK. We can give these macros more specific names, as well, to avoid this conflict.
Reported-and-analyzed-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Jeff King <peff@peff.net>
---
I'm also happy to split it into two patches, and make Eric the author on
the MASK part.
ewah/bitmap.c | 24 ++++++++++++------------
ewah/ewah_bitmap.c | 22 +++++++++++-----------
ewah/ewok.h | 2 +-
pack-bitmap.c | 10 +++++-----
4 files changed, 29 insertions(+), 29 deletions(-)
Show changes to 4 files +29 −29
ewah/bitmap.c, ewah/ewah_bitmap.c, ewah/ewok.h, pack-bitmap.c
diff --git a/ewah/bitmap.c b/ewah/bitmap.c
index 710e58c..47ad674 100644
--- a/ewah/bitmap.c
+++ b/ewah/bitmap.c
@@ -20,8 +20,8 @@
#include "git-compat-util.h"
#include "ewok.h"
-#define MASK(x) ((eword_t)1 << (x % BITS_IN_WORD))
-#define BLOCK(x) (x / BITS_IN_WORD)
+#define EWAH_MASK(x) ((eword_t)1 << (x % BITS_IN_EWORD))
+#define EWAH_BLOCK(x) (x / BITS_IN_EWORD)
struct bitmap *bitmap_new(void)
{
@@ -33,7 +33,7 @@ struct bitmap *bitmap_new(void)
void bitmap_set(struct bitmap *self, size_t pos)
{
- size_t block = BLOCK(pos);
+ size_t block = EWAH_BLOCK(pos);
if (block >= self->word_alloc) {
size_t old_size = self->word_alloc;
@@ -45,22 +45,22 @@ void bitmap_set(struct bitmap *self, size_t pos)
(self->word_alloc - old_size) * sizeof(eword_t));
}
- self->words[block] |= MASK(pos);
+ self->words[block] |= EWAH_MASK(pos);
}
void bitmap_clear(struct bitmap *self, size_t pos)
{
- size_t block = BLOCK(pos);
+ size_t block = EWAH_BLOCK(pos);
if (block < self->word_alloc)
- self->words[block] &= ~MASK(pos);
+ self->words[block] &= ~EWAH_MASK(pos);
}
int bitmap_get(struct bitmap *self, size_t pos)
{
- size_t block = BLOCK(pos);
+ size_t block = EWAH_BLOCK(pos);
return block < self->word_alloc &&
- (self->words[block] & MASK(pos)) != 0;
+ (self->words[block] & EWAH_MASK(pos)) != 0;
}
struct ewah_bitmap *bitmap_to_ewah(struct bitmap *bitmap)
@@ -127,7 +127,7 @@ void bitmap_and_not(struct bitmap *self, struct bitmap *other)
void bitmap_or_ewah(struct bitmap *self, struct ewah_bitmap *other)
{
size_t original_size = self->word_alloc;
- size_t other_final = (other->bit_size / BITS_IN_WORD) + 1;
+ size_t other_final = (other->bit_size / BITS_IN_EWORD) + 1;
size_t i = 0;
struct ewah_iterator it;
eword_t word;
@@ -155,17 +155,17 @@ void bitmap_each_bit(struct bitmap *self, ewah_callback callback, void *data)
uint32_t offset;
if (word == (eword_t)~0) {
- for (offset = 0; offset < BITS_IN_WORD; ++offset)
+ for (offset = 0; offset < BITS_IN_EWORD; ++offset)
callback(pos++, data);
} else {
- for (offset = 0; offset < BITS_IN_WORD; ++offset) {
+ for (offset = 0; offset < BITS_IN_EWORD; ++offset) {
if ((word >> offset) == 0)
break;
offset += ewah_bit_ctz64(word >> offset);
callback(pos + offset, data);
}
- pos += BITS_IN_WORD;
+ pos += BITS_IN_EWORD;
}
}
}
diff --git a/ewah/ewah_bitmap.c b/ewah/ewah_bitmap.c
index fccb42b..b522437 100644
--- a/ewah/ewah_bitmap.c
+++ b/ewah/ewah_bitmap.c
@@ -102,7 +102,7 @@ size_t ewah_add_empty_words(struct ewah_bitmap *self, int v, size_t number)
if (number == 0)
return 0;
- self->bit_size += number * BITS_IN_WORD;
+ self->bit_size += number * BITS_IN_EWORD;
return add_empty_words(self, v, number);
}
@@ -152,7 +152,7 @@ void ewah_add_dirty_words(
self->buffer_size += can_add;
}
- self->bit_size += can_add * BITS_IN_WORD;
+ self->bit_size += can_add * BITS_IN_EWORD;
if (number - can_add == 0)
break;
@@ -197,7 +197,7 @@ static size_t add_empty_word(struct ewah_bitmap *self, int v)
size_t ewah_add(struct ewah_bitmap *self, eword_t word)
{
- self->bit_size += BITS_IN_WORD;
+ self->bit_size += BITS_IN_EWORD;
if (word == 0)
return add_empty_word(self, 0);
@@ -211,8 +211,8 @@ size_t ewah_add(struct ewah_bitmap *self, eword_t word)
void ewah_set(struct ewah_bitmap *self, size_t i)
{
const size_t dist =
- (i + BITS_IN_WORD) / BITS_IN_WORD -
- (self->bit_size + BITS_IN_WORD - 1) / BITS_IN_WORD;
+ (i + BITS_IN_EWORD) / BITS_IN_EWORD -
+ (self->bit_size + BITS_IN_EWORD - 1) / BITS_IN_EWORD;
assert(i >= self->bit_size);
@@ -222,19 +222,19 @@ void ewah_set(struct ewah_bitmap *self, size_t i)
if (dist > 1)
add_empty_words(self, 0, dist - 1);
- add_literal(self, (eword_t)1 << (i % BITS_IN_WORD));
+ add_literal(self, (eword_t)1 << (i % BITS_IN_EWORD));
return;
}
if (rlw_get_literal_words(self->rlw) == 0) {
rlw_set_running_len(self->rlw,
rlw_get_running_len(self->rlw) - 1);
- add_literal(self, (eword_t)1 << (i % BITS_IN_WORD));
+ add_literal(self, (eword_t)1 << (i % BITS_IN_EWORD));
return;
}
self->buffer[self->buffer_size - 1] |=
- ((eword_t)1 << (i % BITS_IN_WORD));
+ ((eword_t)1 << (i % BITS_IN_EWORD));
/* check if we just completed a stream of 1s */
if (self->buffer[self->buffer_size - 1] == (eword_t)(~0)) {
@@ -255,11 +255,11 @@ void ewah_each_bit(struct ewah_bitmap *self, void (*callback)(size_t, void*), vo
eword_t *word = &self->buffer[pointer];
if (rlw_get_run_bit(word)) {
- size_t len = rlw_get_running_len(word) * BITS_IN_WORD;
+ size_t len = rlw_get_running_len(word) * BITS_IN_EWORD;
for (k = 0; k < len; ++k, ++pos)
callback(pos, payload);
} else {
- pos += rlw_get_running_len(word) * BITS_IN_WORD;
+ pos += rlw_get_running_len(word) * BITS_IN_EWORD;
}
++pointer;
@@ -268,7 +268,7 @@ void ewah_each_bit(struct ewah_bitmap *self, void (*callback)(size_t, void*), vo
int c;
/* todo: zero count optimization */
- for (c = 0; c < BITS_IN_WORD; ++c, ++pos) {
+ for (c = 0; c < BITS_IN_EWORD; ++c, ++pos) {
if ((self->buffer[pointer] & ((eword_t)1 << c)) != 0)
callback(pos, payload);
}
diff --git a/ewah/ewok.h b/ewah/ewok.h
index e732525..6e2c5e1 100644
--- a/ewah/ewok.h
+++ b/ewah/ewok.h
@@ -32,7 +32,7 @@
struct strbuf;
typedef uint64_t eword_t;
-#define BITS_IN_WORD (sizeof(eword_t) * 8)
+#define BITS_IN_EWORD (sizeof(eword_t) * 8)
/**
* Do not use __builtin_popcountll. The GCC implementation
diff --git a/pack-bitmap.c b/pack-bitmap.c
index 2b3ff23..637770a 100644
--- a/pack-bitmap.c
+++ b/pack-bitmap.c
@@ -622,7 +622,7 @@ static void show_objects_for_type(
while (i < objects->word_alloc && ewah_iterator_next(&filter, &it)) {
eword_t word = objects->words[i] & filter;
- for (offset = 0; offset < BITS_IN_WORD; ++offset) {
+ for (offset = 0; offset < BITS_IN_EWORD; ++offset) {
const unsigned char *sha1;
struct revindex_entry *entry;
uint32_t hash = 0;
@@ -644,7 +644,7 @@ static void show_objects_for_type(
show_reach(sha1, object_type, 0, hash, bitmap_git.pack, entry->offset);
}
- pos += BITS_IN_WORD;
+ pos += BITS_IN_EWORD;
i++;
}
}
@@ -776,7 +776,7 @@ int reuse_partial_packfile_from_bitmap(struct packed_git **packfile,
break;
}
- reuse_objects += BITS_IN_WORD;
+ reuse_objects += BITS_IN_EWORD;
}
#ifdef GIT_BITMAP_DEBUG
@@ -1001,7 +1001,7 @@ static int rebuild_bitmap(uint32_t *reposition,
while (ewah_iterator_next(&word, &it)) {
uint32_t offset, bit_pos;
- for (offset = 0; offset < BITS_IN_WORD; ++offset) {
+ for (offset = 0; offset < BITS_IN_EWORD; ++offset) {
if ((word >> offset) == 0)
break;
@@ -1014,7 +1014,7 @@ static int rebuild_bitmap(uint32_t *reposition,
return -1;
}
- pos += BITS_IN_WORD;
+ pos += BITS_IN_EWORD;
}
return 0;
}
--
2.4.2.745.g0aa058d
Eric Sunshine
