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From:   =?utf-8?q?Thomas_Wei=C3=9Fschuh?= <linux@weissschuh.net>
Date:   Tue, 28 Mar 2023 21:07:35 +0000
Subject: [PATCH] tools/nolibc: validate C99 compatibility
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Message-Id: <20230328-nolibc-c99-v1-1-a8302fb19f19@weissschuh.net>
To:     Willy Tarreau <w@1wt.eu>, Shuah Khan <shuah@kernel.org>
Cc:     linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
        =?utf-8?q?Thomas_Wei=C3=9Fschuh?= <linux@weissschuh.net>
Precedence: bulk

Most of the code was migrated to C99-conformant __asm__ statements
before. It seems string.h was missed.

Fix string.h and also validate during build that nolibc stays within
C99.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---

This patch is based on the "dev" branch of the RCU tree.
---
 tools/include/nolibc/string.h                | 4 ++--
 tools/testing/selftests/nolibc/Makefile      | 2 +-
 tools/testing/selftests/nolibc/nolibc-test.c | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/include/nolibc/string.h b/tools/include/nolibc/string.h
index fffdaf6ff467..0c2e06c7c477 100644
--- a/tools/include/nolibc/string.h
+++ b/tools/include/nolibc/string.h
@@ -90,7 +90,7 @@ void *memset(void *dst, int b, size_t len)
 
 	while (len--) {
 		/* prevent gcc from recognizing memset() here */
-		asm volatile("");
+		__asm__ volatile("");
 		*(p++) = b;
 	}
 	return dst;
@@ -139,7 +139,7 @@ size_t strlen(const char *str)
 	size_t len;
 
 	for (len = 0; str[len]; len++)
-		asm("");
+		__asm__("");
 	return len;
 }
 
diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
index bbce57420465..55efcb1011cb 100644
--- a/tools/testing/selftests/nolibc/Makefile
+++ b/tools/testing/selftests/nolibc/Makefile
@@ -83,7 +83,7 @@ CFLAGS_STKP_i386 = $(CFLAGS_STACKPROTECTOR)
 CFLAGS_STKP_x86_64 = $(CFLAGS_STACKPROTECTOR)
 CFLAGS_STKP_x86 = $(CFLAGS_STACKPROTECTOR)
 CFLAGS_s390 = -m64
-CFLAGS  ?= -Os -fno-ident -fno-asynchronous-unwind-tables \
+CFLAGS  ?= -Os -fno-ident -fno-asynchronous-unwind-tables -std=c99 \
 		$(call cc-option,-fno-stack-protector) \
 		$(CFLAGS_STKP_$(ARCH)) $(CFLAGS_$(ARCH))
 LDFLAGS := -s
diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index 47013b78972e..932b2c7b0ce3 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -895,7 +895,7 @@ int main(int argc, char **argv, char **envp)
 #else
 		else if (ioperm(0x501, 1, 1) == 0)
 #endif
-			asm volatile ("outb %%al, %%dx" :: "d"(0x501), "a"(0));
+			__asm__ volatile ("outb %%al, %%dx" :: "d"(0x501), "a"(0));
 		/* if it does nothing, fall back to the regular panic */
 #endif
 	}

---
base-commit: a5333c037de823912dd20e933785c63de7679e64
change-id: 20230328-nolibc-c99-59f44ea45636

Best regards,
-- 
Thomas Weißschuh <linux@weissschuh.net>