tools/bpftool: Make skeleton code C++17-friendly by dropping typeof()

Seems like C++17 standard mode doesn't recognize typeof() anymore. This can
be tested by compiling test_cpp test with -std=c++17 or -std=c++1z options.
The use of typeof in skeleton generated code is unnecessary, all types are
well-known at the time of code generation, so remove all typeof()'s to make
skeleton code more future-proof when interacting with C++ compilers.

Fixes: 985ead416df3 ("bpftool: Add skeleton codegen command")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200812025907.1371956-1-andriin@fb.com

diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
index 8a4c2b3b0cd63ef13bec9cfb4f5573933788cc9b..db80e836816ee3ca6ba9c074618d5fdc4012c371 100644 (file)
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c
@@ -397,7 +397,7 @@ static int do_skeleton(int argc, char **argv)
                {                                                           \n\
                        struct %1$s *obj;                                   \n\
                                                                            \n\
-                       obj = (typeof(obj))calloc(1, sizeof(*obj));         \n\
+                       obj = (struct %1$s *)calloc(1, sizeof(*obj));       \n\
                        if (!obj)                                           \n\
                                return NULL;                                \n\
                        if (%1$s__create_skeleton(obj))                     \n\
@@ -461,7 +461,7 @@ static int do_skeleton(int argc, char **argv)
                {                                                           \n\
                        struct bpf_object_skeleton *s;                      \n\
                                                                            \n\
-                       s = (typeof(s))calloc(1, sizeof(*s));               \n\
+                       s = (struct bpf_object_skeleton *)calloc(1, sizeof(*s));\n\
                        if (!s)                                             \n\
                                return -1;                                  \n\
                        obj->skeleton = s;                                  \n\
@@ -479,7 +479,7 @@ static int do_skeleton(int argc, char **argv)
                                /* maps */                                  \n\
                                s->map_cnt = %zu;                           \n\
                                s->map_skel_sz = sizeof(*s->maps);          \n\
-                               s->maps = (typeof(s->maps))calloc(s->map_cnt, s->map_skel_sz);\n\
+                               s->maps = (struct bpf_map_skeleton *)calloc(s->map_cnt, s->map_skel_sz);\n\
                                if (!s->maps)                               \n\
                                        goto err;                           \n\
                        ",
@@ -515,7 +515,7 @@ static int do_skeleton(int argc, char **argv)
                                /* programs */                              \n\
                                s->prog_cnt = %zu;                          \n\
                                s->prog_skel_sz = sizeof(*s->progs);        \n\
-                               s->progs = (typeof(s->progs))calloc(s->prog_cnt, s->prog_skel_sz);\n\
+                               s->progs = (struct bpf_prog_skeleton *)calloc(s->prog_cnt, s->prog_skel_sz);\n\
                                if (!s->progs)                              \n\
                                        goto err;                           \n\
                        ",