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| author | Joel Fernandes (Google) <joel@joelfernandes.org> | 2022-08-14 23:15:51 -0400 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2022-09-08 18:10:27 -0400 |
| commit | 5c375b0d061174c597748c058e60670adac67232 (patch) | |
| tree | a7953231a1d949fcb98ca1f3baf3526bc772fa42 | |
| parent | 7839fc2ac1af0a0e341edb5ca8fc223c9043d1a7 (diff) | |
| download | libtraceevent-5c375b0d061174c597748c058e60670adac67232.tar.gz | |
libtraceevent: Fixing linking to C++ code
Linking in C++ compilers (including g++) causes references to be created
with their arguments. Due to this, trace library headers included into
C++ code base will cause their objects to built with symbols with
arguments. Apparently this is to support operator overloading in C++.
This causes linker errors. For example, here's what I get when I try to
link libtraceevent with a main.o built from a C++ main.cc source file.
main.cc:(.text+0x90):
undefined reference to `trace_seq_init(trace_seq*)'
undefined reference to `trace_seq_do_printf(trace_seq*)'
undefined reference to `tep_event_fields(tep_event*)'
The standard fix for this is to wrap the C project's header in
extern "C".
With this patch, I am able to link libtraceevent into a C++
code base.
Link: https://lore.kernel.org/linux-trace-devel/20220815031551.775444-1-joel@joelfernandes.org
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| -rw-r--r-- | include/traceevent/event-parse.h | 8 | ||||
| -rw-r--r-- | include/traceevent/trace-seq.h | 8 |
2 files changed, 16 insertions, 0 deletions
diff --git a/include/traceevent/event-parse.h b/include/traceevent/event-parse.h index 0b911e1..9d7634e 100644 --- a/include/traceevent/event-parse.h +++ b/include/traceevent/event-parse.h @@ -14,6 +14,10 @@ #include "trace-seq.h" +#ifdef __cplusplus +extern "C" { +#endif + #ifndef __maybe_unused #define __maybe_unused __attribute__((unused)) #endif @@ -778,4 +782,8 @@ void tep_set_loglevel(enum tep_loglevel level); void tep_print_field(struct trace_seq *s, void *data, struct tep_format_field *field); +#ifdef __cplusplus +} +#endif + #endif /* _PARSE_EVENTS_H */ diff --git a/include/traceevent/trace-seq.h b/include/traceevent/trace-seq.h index d68ec69..217492f 100644 --- a/include/traceevent/trace-seq.h +++ b/include/traceevent/trace-seq.h @@ -10,6 +10,10 @@ #include <stdarg.h> #include <stdio.h> +#ifdef __cplusplus +extern "C" { +#endif + /* ----------------------- trace_seq ----------------------- */ #ifndef TRACE_SEQ_BUF_SIZE @@ -52,4 +56,8 @@ extern void trace_seq_terminate(struct trace_seq *s); extern int trace_seq_do_fprintf(struct trace_seq *s, FILE *fp); extern int trace_seq_do_printf(struct trace_seq *s); +#ifdef __cplusplus +} +#endif + #endif /* _TRACE_SEQ_H */ |