Fixed #define style.

We had a mix of styles for declaring function-like macros:

Style A:
 #define                    \
 foo()                      \
     do {                   \
         ...                \
     } while (0)

Style B:
 #define foo()              \
     do {                   \
         ...                \
     } while (0)

We had a similar number of occurences of each style:

 $ grep -rnI '^\w*(.*\\' | wc -l
 244
 $ grep -rn 'define.*(.*)' | wc -l
 239

(Those regexes aren't perfect, but a very decent approximation.)

Real examples:

 $ find src -type f | xargs sed -n '/^nxt_double_is_zero/,/^$/p'
 nxt_double_is_zero(f)                                                         \
     (fabs(f) <= FLT_EPSILON)

 $ find src -type f | xargs sed -n '/define nxt_http_field_set/,/^$/p'
 #define nxt_http_field_set(_field, _name, _value)                             \
     do {                                                                      \
         (_field)->name_length = nxt_length(_name);                            \
         (_field)->value_length = nxt_length(_value);                          \
         (_field)->name = (u_char *) _name;                                    \
         (_field)->value = (u_char *) _value;                                  \
     } while (0)

I'd like to standardize on a single style for them, and IMO,
having the identifier in the same line as #define is a better
option for the following reasons:

- Programmers are used to `#define foo() ...` (readability).
- One less line of code.
- The program for finding them is really simple (see below).

 function grep_ngx_func()
 {
     if (($# != 1)); then
         >&2 echo "Usage: ${FUNCNAME[0]} <func>";
         return 1;
     fi;

     find src -type f \
     | grep '\.[ch]$' \
     | xargs grep -l "$1" \
     | sort \
     | xargs pcregrep -Mn "(?s)^\$[\w\s*]+?^$1\(.*?^}";

     find src -type f \
     | grep '\.[ch]$' \
     | xargs grep -l "$1" \
     | sort \
     | xargs pcregrep -Mn "(?s)define $1\(.*?^$" \
     | sed -E '1s/^[^:]+:[0-9]+:/&\n\n/';
 }

 $ grep_ngx_func
 Usage: grep_ngx_func <func>

 $ grep_ngx_func nxt_http_field_set
 src/nxt_http.h:98:

 #define nxt_http_field_set(_field, _name, _value)                             \
     do {                                                                      \
         (_field)->name_length = nxt_length(_name);                            \
         (_field)->value_length = nxt_length(_value);                          \
         (_field)->name = (u_char *) _name;                                    \
         (_field)->value = (u_char *) _value;                                  \
     } while (0)

 $ grep_ngx_func nxt_sprintf
 src/nxt_sprintf.c:56:

 u_char * nxt_cdecl
 nxt_sprintf(u_char *buf, u_char *end, const char *fmt, ...)
 {
     u_char   *p;
     va_list  args;

     va_start(args, fmt);
     p = nxt_vsprintf(buf, end, fmt, args);
     va_end(args);

     return p;
 }

................
Scripted change:
................

$ find src -type f \
  | grep '\.[ch]$' \
  | xargs sed -i '/define *\\$/{N;s/ *\\\n/ /;s/        //}'

1 files changed, 22 insertions, 44 deletions

diff --git a/src/nxt_clang.h b/src/nxt_clang.h
index 26afba7a..94638346 100644
--- a/src/nxt_clang.h
+++ b/src/nxt_clang.h
@@ -16,45 +16,37 @@
 #if (NXT_CLANG)
 
 /* Any __asm__ directive disables loop vectorization in GCC and Clang. */
-#define                                                                       \
-nxt_pragma_loop_disable_vectorization                                         \
+#define nxt_pragma_loop_disable_vectorization                                 \
     __asm__("")
 
 #else
 
-#define                                                                       \
-nxt_pragma_loop_disable_vectorization
+#define nxt_pragma_loop_disable_vectorization
 
 #endif
 
 
 #if (NXT_HAVE_BUILTIN_EXPECT)
 
-#define                                                                       \
-nxt_expect(c, x)                                                              \
+#define nxt_expect(c, x)                                                      \
     __builtin_expect((long) (x), (c))
 
-#define                                                                       \
-nxt_fast_path(x)                                                              \
+#define nxt_fast_path(x)                                                      \
     nxt_expect(1, x)
 
-#define                                                                       \
-nxt_slow_path(x)                                                              \
+#define nxt_slow_path(x)                                                      \
     nxt_expect(0, x)
 
 
 #else
 
-#define                                                                       \
-nxt_expect(c, x)                                                              \
+#define nxt_expect(c, x)                                                      \
     (x)
 
-#define                                                                       \
-nxt_fast_path(x)                                                              \
+#define nxt_fast_path(x)                                                      \
     (x)
 
-#define                                                                       \
-nxt_slow_path(x)                                                              \
+#define nxt_slow_path(x)                                                      \
     (x)
 
 #endif
@@ -62,28 +54,24 @@ nxt_slow_path(x)                                                              \
 
 #if (NXT_HAVE_BUILTIN_UNREACHABLE)
 
-#define                                                                       \
-nxt_unreachable()                                                             \
+#define nxt_unreachable()                                                     \
     __builtin_unreachable()
 
 #else
 
-#define                                                                       \
-nxt_unreachable()
+#define nxt_unreachable()
 
 #endif
 
 
 #if (NXT_HAVE_BUILTIN_PREFETCH)
 
-#define                                                                       \
-nxt_prefetch(a)                                                               \
+#define nxt_prefetch(a)                                                       \
     __builtin_prefetch(a)
 
 #else
 
-#define                                                                       \
-nxt_prefetch(a)
+#define nxt_prefetch(a)
 
 #endif
 
@@ -206,13 +194,11 @@ nxt_popcount(unsigned int x)
 #endif
 
 
-#define                                                                       \
-nxt_alloca(size)                                                              \
+#define nxt_alloca(size)                                                      \
     alloca(size)
 
 
-#define                                                                       \
-nxt_container_of(p, type, field)                                              \
+#define nxt_container_of(p, type, field)                                      \
     (type *) ((u_char *) (p) - offsetof(type, field))
 
 
@@ -224,30 +210,25 @@ nxt_container_of(p, type, field)                                              \
     *(type *) ((u_char *) p + offset)
 
 
-#define                                                                       \
-nxt_nitems(x)                                                                 \
+#define nxt_nitems(x)                                                         \
     (sizeof(x) / sizeof((x)[0]))
 
 
 /* GCC and Clang use __builtin_abs() instead of libc abs(). */
 
-#define                                                                       \
-nxt_abs(val)                                                                  \
+#define nxt_abs(val)                                                          \
     abs(val)
 
 
-#define                                                                       \
-nxt_max(val1, val2)                                                           \
+#define nxt_max(val1, val2)                                                   \
     ((val1 < val2) ? (val2) : (val1))
 
 
-#define                                                                       \
-nxt_min(val1, val2)                                                           \
+#define nxt_min(val1, val2)                                                   \
     ((val1 > val2) ? (val2) : (val1))
 
 
-#define                                                                       \
-nxt_bswap32(val)                                                              \
+#define nxt_bswap32(val)                                                      \
     (   ((val)               >> 24)                                           \
      | (((val) & 0x00FF0000) >>  8)                                           \
      | (((val) & 0x0000FF00) <<  8)                                           \
@@ -258,18 +239,15 @@ nxt_bswap32(val)                                                              \
     ((((value) - 1) & (value)) == 0)
 
 
-#define                                                                       \
-nxt_align_size(d, a)                                                          \
+#define nxt_align_size(d, a)                                                  \
     (((d) + ((size_t) (a) - 1)) & ~((size_t) (a) - 1))
 
 
-#define                                                                       \
-nxt_align_ptr(p, a)                                                           \
+#define nxt_align_ptr(p, a)                                                   \
     (u_char *) (((uintptr_t) (p) + ((uintptr_t) (a) - 1))                     \
                   & ~((uintptr_t) (a) - 1))
 
-#define                                                                       \
-nxt_trunc_ptr(p, a)                                                           \
+#define nxt_trunc_ptr(p, a)                                                   \
     (u_char *) ((uintptr_t) (p) & ~((uintptr_t) (a) - 1))