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/havege.c b/library/havege.c
index 4dcac02..54f897c 100644
--- a/library/havege.c
+++ b/library/havege.c
@@ -54,7 +54,7 @@
* ------------------------------------------------------------------------
*/
-#define SWAP(X,Y) { int *T = X; X = Y; Y = T; }
+#define SWAP(X,Y) { int *T = (X); (X) = (Y); (Y) = T; }
#define TST1_ENTER if( PTEST & 1 ) { PTEST ^= 3; PTEST >>= 1;
#define TST2_ENTER if( PTEST & 1 ) { PTEST ^= 3; PTEST >>= 1;