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From: Andrii Nakryiko <andriin@fb.com>
To: <bpf@vger.kernel.org>, <netdev@vger.kernel.org>, <ast@fb.com>,
	<daniel@iogearbox.net>
Cc: <andrii.nakryiko@gmail.com>, <kernel-team@fb.com>,
	Andrii Nakryiko <andriin@fb.com>
Subject: [PATCH v3 bpf-next 05/17] libbpf: extract common user-facing helpers
Date: Fri, 13 Dec 2019 14:32:02 -0800	[thread overview]
Message-ID: <20191213223214.2791885-6-andriin@fb.com> (raw)
In-Reply-To: <20191213223214.2791885-1-andriin@fb.com>

LIBBPF_API and DECLARE_LIBBPF_OPTS are needed in many public libbpf API
headers. Extract them into libbpf_common.h to avoid unnecessary
interdependency between btf.h, libbpf.h, and bpf.h or code duplication.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
---
 tools/lib/bpf/bpf.h           |  6 ++----
 tools/lib/bpf/btf.h           |  6 ++----
 tools/lib/bpf/libbpf.h        | 28 ++------------------------
 tools/lib/bpf/libbpf_common.h | 38 +++++++++++++++++++++++++++++++++++
 4 files changed, 44 insertions(+), 34 deletions(-)
 create mode 100644 tools/lib/bpf/libbpf_common.h

diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 3c791fa8e68e..269807ce9ef5 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -28,14 +28,12 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#include "libbpf_common.h"
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-#ifndef LIBBPF_API
-#define LIBBPF_API __attribute__((visibility("default")))
-#endif
-
 struct bpf_create_map_attr {
 	const char *name;
 	enum bpf_map_type map_type;
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index d9ac73a02cde..5fc23b988deb 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -8,14 +8,12 @@
 #include <linux/btf.h>
 #include <linux/types.h>
 
+#include "libbpf_common.h"
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-#ifndef LIBBPF_API
-#define LIBBPF_API __attribute__((visibility("default")))
-#endif
-
 #define BTF_ELF_SEC ".BTF"
 #define BTF_EXT_ELF_SEC ".BTF.ext"
 #define MAPS_ELF_SEC ".maps"
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index fa803dde1f46..49e6fa01024b 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -17,14 +17,12 @@
 #include <sys/types.h>  // for size_t
 #include <linux/bpf.h>
 
+#include "libbpf_common.h"
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-#ifndef LIBBPF_API
-#define LIBBPF_API __attribute__((visibility("default")))
-#endif
-
 enum libbpf_errno {
 	__LIBBPF_ERRNO__START = 4000,
 
@@ -67,28 +65,6 @@ struct bpf_object_open_attr {
 	enum bpf_prog_type prog_type;
 };
 
-/* Helper macro to declare and initialize libbpf options struct
- *
- * This dance with uninitialized declaration, followed by memset to zero,
- * followed by assignment using compound literal syntax is done to preserve
- * ability to use a nice struct field initialization syntax and **hopefully**
- * have all the padding bytes initialized to zero. It's not guaranteed though,
- * when copying literal, that compiler won't copy garbage in literal's padding
- * bytes, but that's the best way I've found and it seems to work in practice.
- *
- * Macro declares opts struct of given type and name, zero-initializes,
- * including any extra padding, it with memset() and then assigns initial
- * values provided by users in struct initializer-syntax as varargs.
- */
-#define DECLARE_LIBBPF_OPTS(TYPE, NAME, ...)				    \
-	struct TYPE NAME = ({ 						    \
-		memset(&NAME, 0, sizeof(struct TYPE));			    \
-		(struct TYPE) {						    \
-			.sz = sizeof(struct TYPE),			    \
-			__VA_ARGS__					    \
-		};							    \
-	})
-
 struct bpf_object_open_opts {
 	/* size of this struct, for forward/backward compatiblity */
 	size_t sz;
diff --git a/tools/lib/bpf/libbpf_common.h b/tools/lib/bpf/libbpf_common.h
new file mode 100644
index 000000000000..4fb833840961
--- /dev/null
+++ b/tools/lib/bpf/libbpf_common.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+
+/*
+ * Common user-facing libbpf helpers.
+ *
+ * Copyright (c) 2019 Facebook
+ */
+
+#ifndef __LIBBPF_LIBBPF_COMMON_H
+#define __LIBBPF_LIBBPF_COMMON_H
+
+#ifndef LIBBPF_API
+#define LIBBPF_API __attribute__((visibility("default")))
+#endif
+
+/* Helper macro to declare and initialize libbpf options struct
+ *
+ * This dance with uninitialized declaration, followed by memset to zero,
+ * followed by assignment using compound literal syntax is done to preserve
+ * ability to use a nice struct field initialization syntax and **hopefully**
+ * have all the padding bytes initialized to zero. It's not guaranteed though,
+ * when copying literal, that compiler won't copy garbage in literal's padding
+ * bytes, but that's the best way I've found and it seems to work in practice.
+ *
+ * Macro declares opts struct of given type and name, zero-initializes,
+ * including any extra padding, it with memset() and then assigns initial
+ * values provided by users in struct initializer-syntax as varargs.
+ */
+#define DECLARE_LIBBPF_OPTS(TYPE, NAME, ...)				    \
+	struct TYPE NAME = ({ 						    \
+		memset(&NAME, 0, sizeof(struct TYPE));			    \
+		(struct TYPE) {						    \
+			.sz = sizeof(struct TYPE),			    \
+			__VA_ARGS__					    \
+		};							    \
+	})
+
+#endif /* __LIBBPF_LIBBPF_COMMON_H */
-- 
2.17.1


  parent reply	other threads:[~2019-12-13 22:32 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-13 22:31 [PATCH v3 bpf-next 00/17] Add code-generated BPF object skeleton support Andrii Nakryiko
2019-12-13 22:31 ` [PATCH v3 bpf-next 01/17] libbpf: don't require root for bpf_object__open() Andrii Nakryiko
2019-12-13 22:31 ` [PATCH v3 bpf-next 02/17] libbpf: add generic bpf_program__attach() Andrii Nakryiko
2019-12-13 22:32 ` [PATCH v3 bpf-next 03/17] libbpf: move non-public APIs from libbpf.h to libbpf_internal.h Andrii Nakryiko
2019-12-13 22:32 ` [PATCH v3 bpf-next 04/17] libbpf: add BPF_EMBED_OBJ macro for embedding BPF .o files Andrii Nakryiko
2019-12-13 22:32 ` Andrii Nakryiko [this message]
2019-12-13 22:32 ` [PATCH v3 bpf-next 06/17] libbpf: expose btf__align_of() API Andrii Nakryiko
2019-12-13 22:32 ` [PATCH v3 bpf-next 07/17] libbpf: expose BTF-to-C type declaration emitting API Andrii Nakryiko
2019-12-13 23:50   ` Alexei Starovoitov
2019-12-14  1:06     ` Andrii Nakryiko
2019-12-13 22:32 ` [PATCH v3 bpf-next 08/17] libbpf: expose BPF program's function name Andrii Nakryiko
2019-12-13 22:32 ` [PATCH v3 bpf-next 09/17] libbpf: refactor global data map initialization Andrii Nakryiko
2019-12-13 22:32 ` [PATCH v3 bpf-next 10/17] libbpf: postpone BTF ID finding for TRACING programs to load phase Andrii Nakryiko
2019-12-13 22:32 ` [PATCH v3 bpf-next 11/17] libbpf: reduce log level of supported section names dump Andrii Nakryiko
2019-12-13 22:32 ` [PATCH v3 bpf-next 12/17] libbpf: add BPF object skeleton support Andrii Nakryiko
2019-12-13 23:59   ` Alexei Starovoitov
2019-12-14  1:07     ` Andrii Nakryiko
2019-12-13 22:32 ` [PATCH v3 bpf-next 13/17] bpftool: add skeleton codegen command Andrii Nakryiko
2019-12-13 22:32 ` [PATCH v3 bpf-next 14/17] selftests/bpf: add BPF skeletons selftests and convert attach_probe.c Andrii Nakryiko
2019-12-14  0:00   ` Alexei Starovoitov
2019-12-13 22:32 ` [PATCH v3 bpf-next 15/17] selftests/bpf: convert few more selftest to skeletons Andrii Nakryiko
2019-12-14  0:01   ` Alexei Starovoitov
2019-12-13 22:32 ` [PATCH v3 bpf-next 16/17] selftests/bpf: add test validating data section to struct convertion layout Andrii Nakryiko
2019-12-13 22:32 ` [PATCH v3 bpf-next 17/17] bpftool: add `gen skeleton` BASH completions Andrii Nakryiko

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