[PATCH 11/11] UAPI: Check headers build for C++ [ver #2]

David Howells
2018-09-06T09:19:42Z

Check that all the headers can be included from one file and built for C++,
thereby catching the use of C++ reserved words and bits of unimplemented
C++ in the UAPI headers.

Note that certain headers are excluded from the build, including:

(1) Any header ending in "_32.h", "_64.h" or "_x32.h" as these are
expected to be multiarch variant headers.

(2) Endianness variant headers.

(3) asm-generic/ headers (they're used conditionally by the asm/ headers
and shouldn't be used directly).

(4) netfilter_ipv*/ip*t_LOG.h headers. They emit a warning indicating
they're going to be removed soon.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Masahiro Yamada <yamada.masahiro@socionext.com>
cc: Michal Marek <michal.lkml@markovi.net>
cc: linux-kbuild@vger.kernel.org
---

Makefile | 1
scripts/headers-c++.sh | 124 ++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 125 insertions(+)
create mode 100755 scripts/headers-c++.sh

diff --git a/Makefile b/Makefile
index 19948e556941..38d655cb4474 100644
--- a/Makefile
+++ b/Makefile
@@ -1186,6 +1186,7 @@ headers_install: __headers
$(error Headers not exportable for the $(SRCARCH) architecture))
$(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include
$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst)
+ $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers-c++.sh check

PHONY += headers_check_all
headers_check_all: headers_install_all
diff --git a/scripts/headers-c++.sh b/scripts/headers-c++.sh
new file mode 100755
index 000000000000..7e56913629f8
--- /dev/null
+++ b/scripts/headers-c++.sh
@@ -0,0 +1,124 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# Run headers_$1 command for all suitable architectures
+
+# Stop on error
+set -e
+
+if ! $CC -x c++ -c - -o /dev/null </dev/null 2>/dev/null
+then
+ echo " CHECK C++ HEADER COMPILATION [SKIPPED]"
+ exit 0
+fi
+
+echo " CHECK C++ HEADER COMPILATION"
+
+mkdir -p hdr-check
+cd hdr-check
+
+mkdir -p include/sys
+mkdir -p include/arpa
+mkdir -p include/xen/interface
+echo >include/endian.h
+echo >include/limits.h
+echo >include/stdint.h
+echo >include/stdlib.h
+echo >include/stdio.h
+echo >include/string.h
+echo >include/time.h
+echo >include/unistd.h
+echo >include/arpa/inet.h
+echo >include/sys/ioctl.h
+echo >include/sys/types.h
+echo >include/sys/time.h
+echo >include/sys/socket.h
+echo >include/xen/interface/xen.h
+
+cat >test.h <<EOF
+#ifdef __cplusplus
+#define NULL nullptr
+#define _Bool bool
+#else
+#define NULL ((void *)0)
+#define bool _Bool
+#endif
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/time.h>
+
+typedef __s8 int8_t;
+typedef __s16 int16_t;
+typedef __s32 int32_t;
+typedef __s64 int64_t;
+typedef __u8 uint8_t;
+typedef __u16 uint16_t;
+typedef __u32 uint32_t;
+typedef __u64 uint64_t;
+typedef long int intptr_t;
+typedef unsigned long int uintptr_t;
+typedef unsigned short u_short;
+typedef unsigned int u_int;
+typedef unsigned long u_long;
+typedef char *caddr_t;
+
+typedef __kernel_clockid_t clockid_t;
+typedef __kernel_ino_t ino_t;
+typedef __kernel_pid_t pid_t;
+typedef __kernel_sa_family_t sa_family_t;
+typedef __kernel_size_t size_t;
+typedef __kernel_uid_t uid_t;
+
+typedef unsigned long elf_greg_t;
+typedef elf_greg_t elf_gregset_t[1];
+typedef unsigned long long elf_fpregset_t[1];
+typedef unsigned long long elf_fpxregset_t[1];
+
+#define INT_MIN ((int)0x80000000)
+#define INT_MAX ((int)0x7fffffff)
+
+extern size_t strlen(const char *);
+extern void *memset(void *, int, size_t);
+extern void *memcpy(void *, const void *, size_t);
+extern __u16 ntohs(__u16);
+extern __u16 htons(__u16);
+extern __u32 ntohl(__u32);
+extern __u32 htonl(__u32);
+
+typedef uint32_t grant_ref_t;
+typedef uint16_t domid_t;
+typedef unsigned long xen_pfn_t;
+
+#define MSG_FIN 0x200
+
+typedef int SVGA3dMSPattern;
+typedef int SVGA3dMSQualityLevel;
+
+struct sockaddr
+{
+ sa_family_t sa_family;
+ char sa_data[14];
+};
+#define sockaddr_storage __kernel_sockaddr_storage
+
+#define _LINUX_PATCHKEY_H_INDIRECT
+
+EOF
+
+find ../usr/include -name '*.h' |
+ grep -v 'linux/byteorder/big_endian.h' |
+ grep -v 'linux/byteorder/little_endian.h' |
+ grep -v '_\(32\|64\|x32\)[.]h$' |
+ grep -v '/asm-generic/' |
+ # ip*t_LOG.h are deprecated
+ grep -v 'linux/netfilter_ipv4/ipt_LOG[.]h' |
+ grep -v 'linux/netfilter_ipv6/ip6t_LOG[.]h' |
+ sed -e 's!../usr/include/!#include <!' -e 's!$!>!' >>test.h
+
+echo '#include "test.h"' >test.cpp
+
+$CC -x c++ -o /dev/null -c test.cpp \
+ -nostdinc \
+ -isystem ./include \
+ -isystem ../usr/include \
+ -fpermissive \
+ -D PAGE_SIZE='#PAGE_SIZE_IS_NOT_VALID_OUTSIDE_OF_KERNEL'