[musl] [C23 stdckdint.h 1/1] C23: add the stdckdint.h header for checked integer operations

[musl] [C23 stdckdint.h 1/1] C23: add the stdckdint.h header for checked integer operations

[Jens Gustedt]

These macros have a direct correspondence with gcc builtins, so the
implementation for musl is trivial. Note that this only intefaces the
type-generic features, so no function symbol is added to the
library. Since also this is a new header that only exposes its
contents when it is explicitly included, no feature test macros are
needed.
---
 include/stdckdint.h | 8 ++++++++
 1 file changed, 8 insertions(+)
 create mode 100644 include/stdckdint.h

diff --git a/include/stdckdint.h b/include/stdckdint.h
new file mode 100644
index 00000000..893126dc
--- /dev/null
+++ b/include/stdckdint.h
@@ -0,0 +1,8 @@
+#ifndef __STDC_VERSION_STDCKDINT_H__
+#define __STDC_VERSION_STDCKDINT_H__ 202311L
+
+#define ckd_add(R, A, B) __builtin_add_overflow ((A), (B), (R))
+#define ckd_sub(R, A, B) __builtin_sub_overflow ((A), (B), (R))
+#define ckd_mul(R, A, B) __builtin_mul_overflow ((A), (B), (R))
+
+#endif
-- 
2.34.1

[musl] [C23 stdckdint.h 1/1] C23: add the stdckdint.h header for checked integer operations

[Jens Gustedt]

These macros have a direct correspondence to gcc builtins, so the
implementation is trivial for compilers that have this.

Note that this only intefaces the type-generic features, so no
function symbol is added to the library. Since also this is a new
header that only exposes its contents when it is explicitly included,
no feature test macros are needed.

As there are no function symbols added, for the compilation of musl
itself this header makes no change. If on the other hand a user uses a
macro from this header with a compiler that does not support that
functionality, the compilation will fail.
---
 include/stdckdint.h | 8 ++++++++
 1 file changed, 8 insertions(+)
 create mode 100644 include/stdckdint.h

diff --git a/include/stdckdint.h b/include/stdckdint.h
new file mode 100644
index 00000000..893126dc
--- /dev/null
+++ b/include/stdckdint.h
@@ -0,0 +1,8 @@
+#ifndef __STDC_VERSION_STDCKDINT_H__
+#define __STDC_VERSION_STDCKDINT_H__ 202311L
+
+#define ckd_add(R, A, B) __builtin_add_overflow ((A), (B), (R))
+#define ckd_sub(R, A, B) __builtin_sub_overflow ((A), (B), (R))
+#define ckd_mul(R, A, B) __builtin_mul_overflow ((A), (B), (R))
+
+#endif
-- 
2.34.1