* [PATCH] stdlib: Fix macro expansion producing 'defined' has undefined behavior
@ 2022-08-29 19:00 Adhemerval Zanella
2022-08-29 20:24 ` Paul Eggert
0 siblings, 1 reply; 2+ messages in thread
From: Adhemerval Zanella @ 2022-08-29 19:00 UTC (permalink / raw)
To: libc-alpha
The FPIOCONST_HAVE_EXTENDED_RANGE is defined as:
#define FPIOCONST_HAVE_EXTENDED_RANGE \
((!defined __NO_LONG_DOUBLE_MATH && __LDBL_MAX_EXP__ > 1024) \
|| __HAVE_DISTINCT_FLOAT128)
Which is undefined behavior accordingly to C Standard (Preprocessing
directives, p4).
Checked on x86_64-linux-gnu.
---
stdlib/fpioconst.h | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/stdlib/fpioconst.h b/stdlib/fpioconst.h
index 1e01999941..3e185f5751 100644
--- a/stdlib/fpioconst.h
+++ b/stdlib/fpioconst.h
@@ -52,9 +52,12 @@
- LDBL_MIN_EXP + 2)). When _Float128 is enabled in libm and it is
ABI-distinct from long double (e.g. on powerpc64le), we also need powers
of 10 up to floor (log_2 (FLT128_MANT_DIG - FLT128_MIN_EXP + 2)). */
-#define FPIOCONST_HAVE_EXTENDED_RANGE \
- ((!defined __NO_LONG_DOUBLE_MATH && __LDBL_MAX_EXP__ > 1024) \
- || __HAVE_DISTINCT_FLOAT128)
+#if (!defined __NO_LONG_DOUBLE_MATH && __LDBL_MAX_EXP__ > 1024) \
+ || __HAVE_DISTINCT_FLOAT128
+# define FPIOCONST_HAVE_EXTENDED_RANGE 1
+#else
+# define FPIOCONST_HAVE_EXTENDED_RANGE 0
+#endif
#if FPIOCONST_HAVE_EXTENDED_RANGE
# define FPIOCONST_POW10_ARRAY_SIZE 15
--
2.34.1
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] stdlib: Fix macro expansion producing 'defined' has undefined behavior
2022-08-29 19:00 [PATCH] stdlib: Fix macro expansion producing 'defined' has undefined behavior Adhemerval Zanella
@ 2022-08-29 20:24 ` Paul Eggert
0 siblings, 0 replies; 2+ messages in thread
From: Paul Eggert @ 2022-08-29 20:24 UTC (permalink / raw)
To: Adhemerval Zanella, libc-alpha
Thanks, this looks good too.
^ permalink raw reply [flat|nested] 2+ messages in thread
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2022-08-29 19:00 [PATCH] stdlib: Fix macro expansion producing 'defined' has undefined behavior Adhemerval Zanella
2022-08-29 20:24 ` Paul Eggert
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