Improve macro hygiene
This commit improves hygiene and formatting of macro definitions
throughout the library. Specifically:
- It adds brackets around parameters to avoid unintended
interpretation of arguments, e.g. due to operator precedence.
- It adds uses of the `do { ... } while( 0 )` idiom for macros that
can be used as commands.
diff --git a/library/ecp_curves.c b/library/ecp_curves.c
index 731621d..282481d 100644
--- a/library/ecp_curves.c
+++ b/library/ecp_curves.c
@@ -51,11 +51,11 @@
*/
#if defined(MBEDTLS_HAVE_INT32)
-#define BYTES_TO_T_UINT_4( a, b, c, d ) \
- ( (mbedtls_mpi_uint) a << 0 ) | \
- ( (mbedtls_mpi_uint) b << 8 ) | \
- ( (mbedtls_mpi_uint) c << 16 ) | \
- ( (mbedtls_mpi_uint) d << 24 )
+#define BYTES_TO_T_UINT_4( a, b, c, d ) \
+ ( (mbedtls_mpi_uint) (a) << 0 ) | \
+ ( (mbedtls_mpi_uint) (b) << 8 ) | \
+ ( (mbedtls_mpi_uint) (c) << 16 ) | \
+ ( (mbedtls_mpi_uint) (d) << 24 )
#define BYTES_TO_T_UINT_2( a, b ) \
BYTES_TO_T_UINT_4( a, b, 0, 0 )
@@ -67,14 +67,14 @@
#else /* 64-bits */
#define BYTES_TO_T_UINT_8( a, b, c, d, e, f, g, h ) \
- ( (mbedtls_mpi_uint) a << 0 ) | \
- ( (mbedtls_mpi_uint) b << 8 ) | \
- ( (mbedtls_mpi_uint) c << 16 ) | \
- ( (mbedtls_mpi_uint) d << 24 ) | \
- ( (mbedtls_mpi_uint) e << 32 ) | \
- ( (mbedtls_mpi_uint) f << 40 ) | \
- ( (mbedtls_mpi_uint) g << 48 ) | \
- ( (mbedtls_mpi_uint) h << 56 )
+ ( (mbedtls_mpi_uint) (a) << 0 ) | \
+ ( (mbedtls_mpi_uint) (b) << 8 ) | \
+ ( (mbedtls_mpi_uint) (c) << 16 ) | \
+ ( (mbedtls_mpi_uint) (d) << 24 ) | \
+ ( (mbedtls_mpi_uint) (e) << 32 ) | \
+ ( (mbedtls_mpi_uint) (f) << 40 ) | \
+ ( (mbedtls_mpi_uint) (g) << 48 ) | \
+ ( (mbedtls_mpi_uint) (h) << 56 )
#define BYTES_TO_T_UINT_4( a, b, c, d ) \
BYTES_TO_T_UINT_8( a, b, c, d, 0, 0, 0, 0 )
@@ -890,7 +890,7 @@
}
#define WIDTH 8 / sizeof( mbedtls_mpi_uint )
-#define A( i ) N->p + i * WIDTH
+#define A( i ) N->p + (i) * WIDTH
#define ADD( i ) add64( p, A( i ), &c )
#define NEXT p += WIDTH; carry64( p, &c )
#define LAST p += WIDTH; *p = c; while( ++p < end ) *p = 0
@@ -955,7 +955,8 @@
#else /* 64-bit */
#define MAX32 N->n * 2
-#define A( j ) j % 2 ? (uint32_t)( N->p[j/2] >> 32 ) : (uint32_t)( N->p[j/2] )
+#define A( j ) (j) % 2 ? (uint32_t)( N->p[(j)/2] >> 32 ) : \
+ (uint32_t)( N->p[(j)/2] )
#define STORE32 \
if( i % 2 ) { \
N->p[i/2] &= 0x00000000FFFFFFFF; \
@@ -989,20 +990,21 @@
* Helpers for the main 'loop'
* (see fix_negative for the motivation of C)
*/
-#define INIT( b ) \
- int ret; \
- signed char c = 0, cc; \
- uint32_t cur; \
- size_t i = 0, bits = b; \
- mbedtls_mpi C; \
- mbedtls_mpi_uint Cp[ b / 8 / sizeof( mbedtls_mpi_uint) + 1 ]; \
- \
- C.s = 1; \
- C.n = b / 8 / sizeof( mbedtls_mpi_uint) + 1; \
- C.p = Cp; \
- memset( Cp, 0, C.n * sizeof( mbedtls_mpi_uint ) ); \
- \
- MBEDTLS_MPI_CHK( mbedtls_mpi_grow( N, b * 2 / 8 / sizeof( mbedtls_mpi_uint ) ) ); \
+#define INIT( b ) \
+ int ret; \
+ signed char c = 0, cc; \
+ uint32_t cur; \
+ size_t i = 0, bits = (b); \
+ mbedtls_mpi C; \
+ mbedtls_mpi_uint Cp[ (b) / 8 / sizeof( mbedtls_mpi_uint) + 1 ]; \
+ \
+ C.s = 1; \
+ C.n = (b) / 8 / sizeof( mbedtls_mpi_uint) + 1; \
+ C.p = Cp; \
+ memset( Cp, 0, C.n * sizeof( mbedtls_mpi_uint ) ); \
+ \
+ MBEDTLS_MPI_CHK( mbedtls_mpi_grow( N, (b) * 2 / 8 / \
+ sizeof( mbedtls_mpi_uint ) ) ); \
LOAD32;
#define NEXT \