tools/nolibc: include nolibc.h early from all header files

Inclusion of any nolibc header file should also bring all other headers.
On the other hand it should also be possible to include any nolibc header
files
in any order.

Currently this is implemented by including the catch-all nolibc.h after the
headers own definitions.
This is problematic if one nolibc header depends on another one.
The first header has to include the other one before defining any symbols.
That in turn will include the rest of nolibc while the current header has
not defined anything yet. If any other part of nolibc depends on
definitions from the current header, errors are encountered.
This is already the case today. Effectively nolibc can only be included in
the order of nolibc.h.

Restructure the way "nolibc.h" is included.
Move it to the beginning of the header files and before the include guards.
Now any header will behave exactly like "nolibc.h" while the include
guards prevent any duplicate definitions.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250424-nolibc-header-check-v1-2-011576b6ed6f@linutronix.de

20 files changed, 60 insertions, 63 deletions

diff --git a/tools/include/nolibc/ctype.h b/tools/include/nolibc/ctype.h
index 6f90706d0644..470fdf34394a 100644
--- a/tools/include/nolibc/ctype.h
+++ b/tools/include/nolibc/ctype.h
@@ -4,6 +4,9 @@
  * Copyright (C) 2017-2021 Willy Tarreau <w@1wt.eu>
  */
 
+/* make sure to include all global symbols */
+#include "nolibc.h"
+
 #ifndef _NOLIBC_CTYPE_H
 #define _NOLIBC_CTYPE_H
 
@@ -96,7 +99,4 @@ int ispunct(int c)
 	return isgraph(c) && !isalnum(c);
 }
 
-/* make sure to include all global symbols */
-#include "nolibc.h"
-
 #endif /* _NOLIBC_CTYPE_H */
diff --git a/tools/include/nolibc/dirent.h b/tools/include/nolibc/dirent.h
index 6c60ec4ba27b..758b95c48e7a 100644
--- a/tools/include/nolibc/dirent.h
+++ b/tools/include/nolibc/dirent.h
@@ -4,6 +4,9 @@
  * Copyright (C) 2025 Thomas Weißschuh <linux@weissschuh.net>
  */
 
+/* make sure to include all global symbols */
+#include "nolibc.h"
+
 #ifndef _NOLIBC_DIRENT_H
 #define _NOLIBC_DIRENT_H
 
@@ -94,7 +97,4 @@ int readdir_r(DIR *dirp, struct dirent *entry, struct dirent **result)
 	return 0;
 }
 
-/* make sure to include all global symbols */
-#include "nolibc.h"
-
 #endif /* _NOLIBC_DIRENT_H */
diff --git a/tools/include/nolibc/elf.h b/tools/include/nolibc/elf.h
index beb0b3a87569..3e2c5228bf3d 100644
--- a/tools/include/nolibc/elf.h
+++ b/tools/include/nolibc/elf.h
@@ -4,12 +4,12 @@
  * Copyright (C) 2025 Thomas Weißschuh <thomas.weissschuh@linutronix.de>
  */
 
+/* make sure to include all global symbols */
+#include "nolibc.h"
+
 #ifndef _NOLIBC_SYS_ELF_H
 #define _NOLIBC_SYS_ELF_H
 
 #include <linux/elf.h>
 
-/* make sure to include all global symbols */
-#include "nolibc.h"
-
 #endif /* _NOLIBC_SYS_ELF_H */
diff --git a/tools/include/nolibc/errno.h b/tools/include/nolibc/errno.h
index 1d8d8033e8ff..08a33c40ec0c 100644
--- a/tools/include/nolibc/errno.h
+++ b/tools/include/nolibc/errno.h
@@ -4,6 +4,9 @@
  * Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu>
  */
 
+/* make sure to include all global symbols */
+#include "nolibc.h"
+
 #ifndef _NOLIBC_ERRNO_H
 #define _NOLIBC_ERRNO_H
 
@@ -22,7 +25,4 @@ int errno __attribute__((weak));
  */
 #define MAX_ERRNO 4095
 
-/* make sure to include all global symbols */
-#include "nolibc.h"
-
 #endif /* _NOLIBC_ERRNO_H */
diff --git a/tools/include/nolibc/fcntl.h b/tools/include/nolibc/fcntl.h
index 5feb08ad54a7..bff2e542f20f 100644
--- a/tools/include/nolibc/fcntl.h
+++ b/tools/include/nolibc/fcntl.h
@@ -4,6 +4,9 @@
  * Copyright (C) 2017-2021 Willy Tarreau <w@1wt.eu>
  */
 
+/* make sure to include all global symbols */
+#include "nolibc.h"
+
 #ifndef _NOLIBC_FCNTL_H
 #define _NOLIBC_FCNTL_H
 
@@ -63,7 +66,4 @@ int open(const char *path, int flags, ...)
 	return __sysret(sys_open(path, flags, mode));
 }
 
-/* make sure to include all global symbols */
-#include "nolibc.h"
-
 #endif /* _NOLIBC_FCNTL_H */
diff --git a/tools/include/nolibc/getopt.h b/tools/include/nolibc/getopt.h
index 5fd06c9702e9..217abb95264b 100644
--- a/tools/include/nolibc/getopt.h
+++ b/tools/include/nolibc/getopt.h
@@ -5,6 +5,9 @@
  * Copyright (C) 2025 Thomas Weißschuh <linux@weissschuh.net>
  */
 
+/* make sure to include all global symbols */
+#include "nolibc.h"
+
 #ifndef _NOLIBC_GETOPT_H
 #define _NOLIBC_GETOPT_H
 
@@ -95,7 +98,4 @@ int getopt(int argc, char * const argv[], const char *optstring)
 	return c;
 }
 
-/* make sure to include all global symbols */
-#include "nolibc.h"
-
 #endif /* _NOLIBC_GETOPT_H */
diff --git a/tools/include/nolibc/signal.h b/tools/include/nolibc/signal.h
index cdcc5904c51e..ac13e53ac31d 100644
--- a/tools/include/nolibc/signal.h
+++ b/tools/include/nolibc/signal.h
@@ -4,6 +4,9 @@
  * Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu>
  */
 
+/* make sure to include all global symbols */
+#include "nolibc.h"
+
 #ifndef _NOLIBC_SIGNAL_H
 #define _NOLIBC_SIGNAL_H
 
@@ -20,7 +23,4 @@ int raise(int signal)
 	return sys_kill(sys_getpid(), signal);
 }
 
-/* make sure to include all global symbols */
-#include "nolibc.h"
-
 #endif /* _NOLIBC_SIGNAL_H */
diff --git a/tools/include/nolibc/stdio.h b/tools/include/nolibc/stdio.h
index fb0417477759..8fa98abab212 100644
--- a/tools/include/nolibc/stdio.h
+++ b/tools/include/nolibc/stdio.h
@@ -4,6 +4,9 @@
  * Copyright (C) 2017-2021 Willy Tarreau <w@1wt.eu>
  */
 
+/* make sure to include all global symbols */
+#include "nolibc.h"
+
 #ifndef _NOLIBC_STDIO_H
 #define _NOLIBC_STDIO_H
 
@@ -598,7 +601,4 @@ const char *strerror(int errno)
 	return buf;
 }
 
-/* make sure to include all global symbols */
-#include "nolibc.h"
-
 #endif /* _NOLIBC_STDIO_H */
diff --git a/tools/include/nolibc/stdlib.h b/tools/include/nolibc/stdlib.h
index 69cf1d4418f1..4790298f985c 100644
--- a/tools/include/nolibc/stdlib.h
+++ b/tools/include/nolibc/stdlib.h
@@ -4,6 +4,9 @@
  * Copyright (C) 2017-2021 Willy Tarreau <w@1wt.eu>
  */
 
+/* make sure to include all global symbols */
+#include "nolibc.h"
+
 #ifndef _NOLIBC_STDLIB_H
 #define _NOLIBC_STDLIB_H
 
@@ -522,7 +525,4 @@ uintmax_t strtoumax(const char *nptr, char **endptr, int base)
 	return __strtox(nptr, endptr, base, 0, UINTMAX_MAX);
 }
 
-/* make sure to include all global symbols */
-#include "nolibc.h"
-
 #endif /* _NOLIBC_STDLIB_H */
diff --git a/tools/include/nolibc/string.h b/tools/include/nolibc/string.h
index f0d335f0e467..febfd6978966 100644
--- a/tools/include/nolibc/string.h
+++ b/tools/include/nolibc/string.h
@@ -4,6 +4,9 @@
  * Copyright (C) 2017-2021 Willy Tarreau <w@1wt.eu>
  */
 
+/* make sure to include all global symbols */
+#include "nolibc.h"
+
 #ifndef _NOLIBC_STRING_H
 #define _NOLIBC_STRING_H
 
@@ -305,8 +308,4 @@ int toupper(int c)
 	return c;
 }
 
-
-/* make sure to include all global symbols */
-#include "nolibc.h"
-
 #endif /* _NOLIBC_STRING_H */
diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
index bc47007f0442..68e60e674211 100644
--- a/tools/include/nolibc/sys.h
+++ b/tools/include/nolibc/sys.h
@@ -4,6 +4,9 @@
  * Copyright (C) 2017-2021 Willy Tarreau <w@1wt.eu>
  */
 
+/* make sure to include all global symbols */
+#include "nolibc.h"
+
 #ifndef _NOLIBC_SYS_H
 #define _NOLIBC_SYS_H
 
@@ -1119,7 +1122,4 @@ int memfd_create(const char *name, unsigned int flags)
 	return __sysret(sys_memfd_create(name, flags));
 }
 
-/* make sure to include all global symbols */
-#include "nolibc.h"
-
 #endif /* _NOLIBC_SYS_H */
diff --git a/tools/include/nolibc/sys/auxv.h b/tools/include/nolibc/sys/auxv.h
index 04c2b9cbe51a..c52463d6c18d 100644
--- a/tools/include/nolibc/sys/auxv.h
+++ b/tools/include/nolibc/sys/auxv.h
@@ -4,6 +4,9 @@
  * Copyright (C) 2017-2021 Willy Tarreau <w@1wt.eu>
  */
 
+/* make sure to include all global symbols */
+#include "../nolibc.h"
+
 #ifndef _NOLIBC_SYS_AUXV_H
 #define _NOLIBC_SYS_AUXV_H
 
@@ -35,7 +38,4 @@ unsigned long getauxval(unsigned long type)
 	return ret;
 }
 
-/* make sure to include all global symbols */
-#include "../nolibc.h"
-
 #endif /* _NOLIBC_SYS_AUXV_H */
diff --git a/tools/include/nolibc/sys/mman.h b/tools/include/nolibc/sys/mman.h
index ad9d06b6b791..41c7bf45e427 100644
--- a/tools/include/nolibc/sys/mman.h
+++ b/tools/include/nolibc/sys/mman.h
@@ -4,6 +4,9 @@
  * Copyright (C) 2017-2021 Willy Tarreau <w@1wt.eu>
  */
 
+/* make sure to include all global symbols */
+#include "../nolibc.h"
+
 #ifndef _NOLIBC_SYS_MMAN_H
 #define _NOLIBC_SYS_MMAN_H
 
@@ -57,7 +60,4 @@ int munmap(void *addr, size_t length)
 	return __sysret(sys_munmap(addr, length));
 }
 
-/* make sure to include all global symbols */
-#include "../nolibc.h"
-
 #endif /* _NOLIBC_SYS_MMAN_H */
diff --git a/tools/include/nolibc/sys/stat.h b/tools/include/nolibc/sys/stat.h
index 0eaf5496ce23..987c8bb52502 100644
--- a/tools/include/nolibc/sys/stat.h
+++ b/tools/include/nolibc/sys/stat.h
@@ -4,6 +4,9 @@
  * Copyright (C) 2017-2021 Willy Tarreau <w@1wt.eu>
  */
 
+/* make sure to include all global symbols */
+#include "../nolibc.h"
+
 #ifndef _NOLIBC_SYS_STAT_H
 #define _NOLIBC_SYS_STAT_H
 
@@ -67,8 +70,4 @@ int stat(const char *path, struct stat *buf)
 	return 0;
 }
 
-
-/* make sure to include all global symbols */
-#include "../nolibc.h"
-
 #endif /* _NOLIBC_SYS_STAT_H */
diff --git a/tools/include/nolibc/sys/syscall.h b/tools/include/nolibc/sys/syscall.h
index 59efdec8fd1c..4bf97f1386a0 100644
--- a/tools/include/nolibc/sys/syscall.h
+++ b/tools/include/nolibc/sys/syscall.h
@@ -4,6 +4,9 @@
  * Copyright (C) 2024 Thomas Weißschuh <linux@weissschuh.net>
  */
 
+/* make sure to include all global symbols */
+#include "../nolibc.h"
+
 #ifndef _NOLIBC_SYS_SYSCALL_H
 #define _NOLIBC_SYS_SYSCALL_H
 
@@ -13,7 +16,4 @@
 #define _syscall_n(N, ...) _syscall(N, __VA_ARGS__)
 #define syscall(...) _syscall_n(_syscall_narg(__VA_ARGS__), ##__VA_ARGS__)
 
-/* make sure to include all global symbols */
-#include "../nolibc.h"
-
 #endif /* _NOLIBC_SYS_SYSCALL_H */
diff --git a/tools/include/nolibc/sys/time.h b/tools/include/nolibc/sys/time.h
index 1d326c05ee62..785961c52fa3 100644
--- a/tools/include/nolibc/sys/time.h
+++ b/tools/include/nolibc/sys/time.h
@@ -4,6 +4,9 @@
  * Copyright (C) 2017-2021 Willy Tarreau <w@1wt.eu>
  */
 
+/* make sure to include all global symbols */
+#include "../nolibc.h"
+
 #ifndef _NOLIBC_SYS_TIME_H
 #define _NOLIBC_SYS_TIME_H
 
@@ -30,7 +33,4 @@ int gettimeofday(struct timeval *tv, struct timezone *tz)
 	return __sysret(sys_gettimeofday(tv, tz));
 }
 
-/* make sure to include all global symbols */
-#include "../nolibc.h"
-
 #endif /* _NOLIBC_SYS_TIME_H */
diff --git a/tools/include/nolibc/sys/wait.h b/tools/include/nolibc/sys/wait.h
index 9a68e6a6b1df..f27be86ad5e4 100644
--- a/tools/include/nolibc/sys/wait.h
+++ b/tools/include/nolibc/sys/wait.h
@@ -4,6 +4,9 @@
  * Copyright (C) 2017-2021 Willy Tarreau <w@1wt.eu>
  */
 
+/* make sure to include all global symbols */
+#include "../nolibc.h"
+
 #ifndef _NOLIBC_SYS_WAIT_H
 #define _NOLIBC_SYS_WAIT_H
 
@@ -110,8 +113,4 @@ pid_t waitpid(pid_t pid, int *status, int options)
 	return info.si_pid;
 }
 
-
-/* make sure to include all global symbols */
-#include "../nolibc.h"
-
 #endif /* _NOLIBC_SYS_WAIT_H */
diff --git a/tools/include/nolibc/time.h b/tools/include/nolibc/time.h
index 84655361b9ad..9502f9aaf621 100644
--- a/tools/include/nolibc/time.h
+++ b/tools/include/nolibc/time.h
@@ -4,6 +4,9 @@
  * Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu>
  */
 
+/* make sure to include all global symbols */
+#include "nolibc.h"
+
 #ifndef _NOLIBC_TIME_H
 #define _NOLIBC_TIME_H
 
@@ -25,7 +28,4 @@ time_t time(time_t *tptr)
 	return tv.tv_sec;
 }
 
-/* make sure to include all global symbols */
-#include "nolibc.h"
-
 #endif /* _NOLIBC_TIME_H */
diff --git a/tools/include/nolibc/types.h b/tools/include/nolibc/types.h
index 32d0929c633b..fe97953d1657 100644
--- a/tools/include/nolibc/types.h
+++ b/tools/include/nolibc/types.h
@@ -4,6 +4,9 @@
  * Copyright (C) 2017-2021 Willy Tarreau <w@1wt.eu>
  */
 
+/* make sure to include all global symbols */
+#include "nolibc.h"
+
 #ifndef _NOLIBC_TYPES_H
 #define _NOLIBC_TYPES_H
 
@@ -214,7 +217,4 @@ struct stat {
 })
 #endif
 
-/* make sure to include all global symbols */
-#include "nolibc.h"
-
 #endif /* _NOLIBC_TYPES_H */
diff --git a/tools/include/nolibc/unistd.h b/tools/include/nolibc/unistd.h
index ac7d53d986cd..ed253305fdba 100644
--- a/tools/include/nolibc/unistd.h
+++ b/tools/include/nolibc/unistd.h
@@ -4,6 +4,9 @@
  * Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu>
  */
 
+/* make sure to include all global symbols */
+#include "nolibc.h"
+
 #ifndef _NOLIBC_UNISTD_H
 #define _NOLIBC_UNISTD_H
 
@@ -56,7 +59,4 @@ int tcsetpgrp(int fd, pid_t pid)
 	return ioctl(fd, TIOCSPGRP, &pid);
 }
 
-/* make sure to include all global symbols */
-#include "nolibc.h"
-
 #endif /* _NOLIBC_UNISTD_H */