summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorPaul Eggert <eggert@cs.ucla.edu>2019-08-24 17:17:39 -0700
committerPaul Eggert <eggert@cs.ucla.edu>2019-08-24 17:18:22 -0700
commit77daeef875821f8a00bafc752a5cfc95f3e11e40 (patch)
treefb68e149f8fe4289e54cfc66c28c4c71b6ef8c66
parent36b7459cf39ae8ced25a239bcf7c9a275f219f31 (diff)
downloadgnulib-77daeef875821f8a00bafc752a5cfc95f3e11e40.tar.gz
intprops: say why not Clang __builtin_add_overflow
* lib/intprops.h (_GL_HAS_BUILTIN_OVERFLOW): Mention Clang in comment, responding to a query from Mattias EngdegÄrd.
-rw-r--r--ChangeLog7
-rw-r--r--lib/intprops.h4
2 files changed, 10 insertions, 1 deletions
diff --git a/ChangeLog b/ChangeLog
index 2a458f077f..f7fbcf4135 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2019-08-24 Paul Eggert <eggert@cs.ucla.edu>
+
+ intprops: say why not Clang __builtin_add_overflow
+ * lib/intprops.h (_GL_HAS_BUILTIN_OVERFLOW):
+ Mention Clang in comment, responding to a query from
+ Mattias EngdegÄrd.
+
2019-08-24 Bruno Haible <bruno@clisp.org>
doc: Document most of the files outside of modules.
diff --git a/lib/intprops.h b/lib/intprops.h
index 2c02568834..fbbc3cffe0 100644
--- a/lib/intprops.h
+++ b/lib/intprops.h
@@ -220,7 +220,9 @@
? (a) < (min) >> (b) \
: (max) >> (b) < (a))
-/* True if __builtin_add_overflow (A, B, P) works when P is non-null. */
+/* True if __builtin_add_overflow (A, B, P) works when P is non-null.
+ See <https://bugs.llvm.org/show_bug.cgi?id=16404> for why this is
+ false for Clang. */
#if 5 <= __GNUC__ && !defined __ICC
# define _GL_HAS_BUILTIN_OVERFLOW 1
#else