btf: Fix building with system libbpf

Where we may not have newer things, like BTF_KIND_ENUM64.

So we're now again building with -DLIBBPF_EMBEDDED=Off.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

3 files changed, 36 insertions, 2 deletions

diff --git a/btf_encoder.c b/btf_encoder.c
index daa8e3b5..51d9897f 100644
--- a/btf_encoder.c
+++ b/btf_encoder.c
@@ -9,12 +9,12 @@
   Copyright (C) Red Hat Inc
  */
 
+#include <linux/btf.h>
 #include "dwarves.h"
 #include "elf_symtab.h"
 #include "btf_encoder.h"
 #include "gobuffer.h"
 
-#include <linux/btf.h>
 #include <bpf/btf.h>
 #include <bpf/libbpf.h>
 #include <ctype.h> /* for isalpha() and isalnum() */
@@ -124,7 +124,7 @@ static int btf_var_secinfo_cmp(const void *a, const void *b)
 #define BITS_ROUNDDOWN_BYTES(bits) ((bits) >> 3)
 #define BITS_ROUNDUP_BYTES(bits) (BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits))
 
-static const char * const btf_kind_str[NR_BTF_KINDS] = {
+static const char * const btf_kind_str[] = {
 	[BTF_KIND_UNKN]		= "UNKNOWN",
 	[BTF_KIND_INT]		= "INT",
 	[BTF_KIND_PTR]		= "PTR",
@@ -491,6 +491,29 @@ static int32_t btf_encoder__add_struct(struct btf_encoder *encoder, uint8_t kind
 	return id;
 }
 
+#if LIBBPF_MAJOR_VERSION < 1
+static inline int libbpf_err(int ret)
+{
+        if (ret < 0)
+                errno = -ret;
+        return ret;
+}
+
+static
+int btf__add_enum64(struct btf *btf __maybe_unused, const char *name __maybe_unused,
+		    __u32 byte_sz __maybe_unused, bool is_signed __maybe_unused)
+{
+	return  libbpf_err(-ENOTSUP);
+}
+
+static
+int btf__add_enum64_value(struct btf *btf __maybe_unused, const char *name __maybe_unused,
+			  __u64 value __maybe_unused)
+{
+	return  libbpf_err(-ENOTSUP);
+}
+#endif
+
 static int32_t btf_encoder__add_enum(struct btf_encoder *encoder, const char *name, struct type *etype,
 				     struct conf_load *conf_load)
 {
diff --git a/btf_loader.c b/btf_loader.c
index 406a007b..69b63a52 100644
--- a/btf_loader.c
+++ b/btf_loader.c
@@ -312,6 +312,7 @@ out_free:
 	return -ENOMEM;
 }
 
+#if LIBBPF_MAJOR_VERSION >= 1
 static struct enumerator *enumerator__new64(const char *name, uint64_t value)
 {
 	struct enumerator *en = tag__alloc(sizeof(*en));
@@ -354,6 +355,12 @@ out_free:
 	enumeration__delete(enumeration);
 	return -ENOMEM;
 }
+#else
+static int create_new_enumeration64(struct cu *cu __maybe_unused, const struct btf_type *tp __maybe_unused, uint32_t id __maybe_unused)
+{
+	return -ENOTSUP;
+}
+#endif
 
 static int create_new_subroutine_type(struct cu *cu, const struct btf_type *tp, uint32_t id)
 {
diff --git a/dutil.h b/dutil.h
index e45bba05..335a17c0 100644
--- a/dutil.h
+++ b/dutil.h
@@ -344,4 +344,8 @@ void __zfree(void **ptr);
 
 #define zfree(ptr) __zfree((void **)(ptr))
 
+#ifndef BTF_KIND_ENUM64
+#define BTF_KIND_ENUM64 19
+#endif
+
 #endif /* _DUTIL_H_ */