[PATCH v2 3/3] xen/types: Rework stdint vs __{u,s}$N types

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

Xen uses the stdint types.  Rearrange the types headers to define the
compatibility __{u,s}$N types in terms of the stdint types, not the other way
around.

All all supported compilers on architectures other than x86 support the stdint
__*_TYPE__ macros.  Move these into a new xen/stdint.h to avoid them being
duplicated in each architecture.

For the compilers which don't support the __*_TYPE__ macros, synthesize
appropriate alternatives.

This cleanup has the side effect of removing all use of the undocumented
__signed__ GCC keyword.  This is a vestigial remnant of `gcc -traditional`
mode for dialetcs of C prior to the introduction of the signed keyword.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
CC: Wei Liu <wl@xxxxxxx>
CC: Stefano Stabellini <sstabellini@xxxxxxxxxx>
CC: Julien Grall <julien@xxxxxxx>
CC: Volodymyr Babchuk <Volodymyr_Babchuk@xxxxxxxx>
CC: Bertrand Marquis <bertrand.marquis@xxxxxxx>
CC: Bob Eshleman <bobbyeshleman@xxxxxxxxx>
CC: Alistair Francis <alistair.francis@xxxxxxx>
CC: Connor Davis <connojdavis@xxxxxxxxx>
CC: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
CC: Shawn Anastasio <sanastasio@xxxxxxxxxxxxxxxxxxxxx>
CC: Timothy Pearson <tpearson@xxxxxxxxxxxxxxxxxxxxx>
CC: Roberto Bagnara <roberto.bagnara@xxxxxxxxxxx>

v2:
 * Introduce xen/stdint.h as discussed at XenSummit
---
 xen/arch/arm/include/asm/types.h   | 19 -----------------
 xen/arch/riscv/include/asm/types.h | 19 -----------------
 xen/arch/x86/include/asm/types.h   | 14 -------------
 xen/include/xen/stdint.h           | 33 ++++++++++++++++++++++++++++++
 xen/include/xen/types.h            | 20 ++++++++----------
 5 files changed, 42 insertions(+), 63 deletions(-)
 create mode 100644 xen/include/xen/stdint.h

diff --git a/xen/arch/arm/include/asm/types.h b/xen/arch/arm/include/asm/types.h
index fb6618ef247f..545a5e9d1175 100644
--- a/xen/arch/arm/include/asm/types.h
+++ b/xen/arch/arm/include/asm/types.h
@@ -1,25 +1,6 @@
 #ifndef __ARM_TYPES_H__
 #define __ARM_TYPES_H__
 
-typedef __signed__ char __s8;
-typedef unsigned char __u8;
-
-typedef __signed__ short __s16;
-typedef unsigned short __u16;
-
-typedef __signed__ int __s32;
-typedef unsigned int __u32;
-
-#if defined(__GNUC__) && !defined(__STRICT_ANSI__)
-#if defined(CONFIG_ARM_32)
-typedef __signed__ long long __s64;
-typedef unsigned long long __u64;
-#elif defined (CONFIG_ARM_64)
-typedef __signed__ long __s64;
-typedef unsigned long __u64;
-#endif
-#endif
-
 typedef signed char s8;
 typedef unsigned char u8;
 
diff --git a/xen/arch/riscv/include/asm/types.h 
b/xen/arch/riscv/include/asm/types.h
index 0c0ce78c8f6e..93a680a8f323 100644
--- a/xen/arch/riscv/include/asm/types.h
+++ b/xen/arch/riscv/include/asm/types.h
@@ -1,25 +1,6 @@
 #ifndef __RISCV_TYPES_H__
 #define __RISCV_TYPES_H__
 
-typedef __signed__ char __s8;
-typedef unsigned char __u8;
-
-typedef __signed__ short __s16;
-typedef unsigned short __u16;
-
-typedef __signed__ int __s32;
-typedef unsigned int __u32;
-
-#if defined(__GNUC__) && !defined(__STRICT_ANSI__)
-#if defined(CONFIG_RISCV_32)
-typedef __signed__ long long __s64;
-typedef unsigned long long __u64;
-#elif defined (CONFIG_RISCV_64)
-typedef __signed__ long __s64;
-typedef unsigned long __u64;
-#endif
-#endif
-
 typedef signed char s8;
 typedef unsigned char u8;
 
diff --git a/xen/arch/x86/include/asm/types.h b/xen/arch/x86/include/asm/types.h
index 2d56aed66782..c9d257716551 100644
--- a/xen/arch/x86/include/asm/types.h
+++ b/xen/arch/x86/include/asm/types.h
@@ -1,20 +1,6 @@
 #ifndef __X86_TYPES_H__
 #define __X86_TYPES_H__
 
-typedef __signed__ char __s8;
-typedef unsigned char __u8;
-
-typedef __signed__ short __s16;
-typedef unsigned short __u16;
-
-typedef __signed__ int __s32;
-typedef unsigned int __u32;
-
-#if defined(__GNUC__) && !defined(__STRICT_ANSI__)
-typedef __signed__ long __s64;
-typedef unsigned long __u64;
-#endif
-
 typedef signed char s8;
 typedef unsigned char u8;
 
diff --git a/xen/include/xen/stdint.h b/xen/include/xen/stdint.h
new file mode 100644
index 000000000000..4cf82790f196
--- /dev/null
+++ b/xen/include/xen/stdint.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __XEN_STDINT_H__
+#define __XEN_STDINT_H__
+
+#ifndef __INT8_TYPE__ /* GCC <= 4.4 */
+
+typedef __INT8_TYPE__        int8_t;
+typedef __UINT8_TYPE__      uint8_t;
+typedef __INT16_TYPE__      int16_t;
+typedef __UINT16_TYPE__    uint16_t;
+typedef __INT32_TYPE__      int32_t;
+typedef __UINT32_TYPE__    uint32_t;
+typedef __INT64_TYPE__      int64_t;
+typedef __UINT64_TYPE__    uint64_t;
+
+#else
+
+/*
+ * Define the types using GCC internal notation.  Clang understands this too.
+ * https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html
+ */
+typedef   signed __attribute__((__mode__(QI)))     int8_t;
+typedef unsigned __attribute__((__mode__(QI)))    uint8_t;
+typedef   signed __attribute__((__mode__(HI)))    int16_t;
+typedef unsigned __attribute__((__mode__(HI)))   uint16_t;
+typedef   signed __attribute__((__mode__(SI)))    int32_t;
+typedef unsigned __attribute__((__mode__(SI)))   uint32_t;
+typedef   signed __attribute__((__mode__(DI)))    int64_t;
+typedef unsigned __attribute__((__mode__(DI)))   uint64_t;
+
+#endif
+
+#endif /* __XEN_STDINT_H__ */
diff --git a/xen/include/xen/types.h b/xen/include/xen/types.h
index 8b22a02eeaa4..c873c81ccf06 100644
--- a/xen/include/xen/types.h
+++ b/xen/include/xen/types.h
@@ -2,6 +2,7 @@
 #define __TYPES_H__
 
 #include <xen/stdbool.h>
+#include <xen/stdint.h>
 
 #include <asm/types.h>
 
@@ -39,17 +40,14 @@ typedef __PTRDIFF_TYPE__ ptrdiff_t;
 #define LONG_MIN        (-LONG_MAX - 1)
 #define ULONG_MAX       (~0UL)
 
-typedef         __u8            uint8_t;
-typedef         __s8            int8_t;
-
-typedef         __u16           uint16_t;
-typedef         __s16           int16_t;
-
-typedef         __u32           uint32_t;
-typedef         __s32           int32_t;
-
-typedef         __u64           uint64_t;
-typedef         __s64           int64_t;
+typedef uint8_t         __u8;
+typedef int8_t          __s8;
+typedef uint16_t        __u16;
+typedef int16_t         __s16;
+typedef uint32_t        __u32;
+typedef int32_t         __s32;
+typedef uint64_t        __u64;
+typedef int64_t         __s64;
 
 typedef __u16 __le16;
 typedef __u16 __be16;
-- 
2.30.2