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authorMichael Gran <spk121@yahoo.com>2009-08-01 10:15:20 -0700
committerMichael Gran <spk121@yahoo.com>2009-08-01 10:15:20 -0700
commit4c402b889eecaa7ffc61da6656f415c8c983507a (patch)
tree3f2abeffb8a43afce6e04fcdeebfa0ce007edfb2
parent64bad3f5a8d7351a41a5b9ccb1df5c393a48b4a9 (diff)
downloadguile-4c402b889eecaa7ffc61da6656f415c8c983507a.tar.gz
Don't use GNU extensions for SCM_MAKE_CHAR macro
Since the contents of SCM_MAKE_CHAR are evaluated more than once, don't use it in situations where this could cause side-effects. * libguile/vm-i-system.c (make-char8): avoid side-effects with SCM_MAKE_CHAR call * libguile/chars.h (SCM_MAKE_CHAR): modified
-rw-r--r--libguile/chars.h8
-rw-r--r--libguile/vm-i-system.c8
2 files changed, 11 insertions, 5 deletions
diff --git a/libguile/chars.h b/libguile/chars.h
index e68f06d21..8e1bc64b4 100644
--- a/libguile/chars.h
+++ b/libguile/chars.h
@@ -37,10 +37,10 @@ typedef scm_t_int32 scm_t_wchar;
#define SCM_CHARP(x) (SCM_ITAG8(x) == scm_tc8_char)
#define SCM_CHAR(x) ((scm_t_wchar)SCM_ITAG8_DATA(x))
-#define SCM_MAKE_CHAR(x) ({scm_t_int32 _x = (x); \
- _x < 0 \
- ? SCM_MAKE_ITAG8((scm_t_bits)(unsigned char)_x, scm_tc8_char) \
- : SCM_MAKE_ITAG8((scm_t_bits)_x, scm_tc8_char);})
+#define SCM_MAKE_CHAR(x) \
+ (x < 0 \
+ ? SCM_MAKE_ITAG8 ((scm_t_bits) (unsigned char) x, scm_tc8_char) \
+ : SCM_MAKE_ITAG8 ((scm_t_bits) x, scm_tc8_char))
#define SCM_CODEPOINT_MAX (0x10ffff)
#define SCM_IS_UNICODE_CHAR(c) \
diff --git a/libguile/vm-i-system.c b/libguile/vm-i-system.c
index ecafbebdd..4536b91da 100644
--- a/libguile/vm-i-system.c
+++ b/libguile/vm-i-system.c
@@ -171,7 +171,13 @@ VM_DEFINE_INSTRUCTION (15, make_uint64, "make-uint64", 8, 0, 1)
VM_DEFINE_INSTRUCTION (16, make_char8, "make-char8", 1, 0, 1)
{
- PUSH (SCM_MAKE_CHAR (FETCH ()));
+ scm_t_uint8 v = 0;
+ v = FETCH ();
+
+ PUSH (SCM_MAKE_CHAR (v));
+ /* Don't simplify this to PUSH (SCM_MAKE_CHAR (FETCH ())). The
+ contents of SCM_MAKE_CHAR may be evaluated more than once,
+ resulting in a double fetch. */
NEXT;
}