Commit Graph

2 Commits

Author SHA1 Message Date
Yonghong Song d82247cb80 [BPF] Do not generate BTF sections unnecessarily
If There is no types/non-empty strings, do not generate
.BTF section. If there is no func_info/line_info, do
not generate .BTF.ext section.

Signed-off-by: Yonghong Song <yhs@fb.com>

Differential Revision: https://reviews.llvm.org/D58936

llvm-svn: 355360
2019-03-05 01:01:21 +00:00
Yonghong Song 7b410ac352 [BPF] Generate BTF DebugInfo under BPF target
This patch implements BTF (BPF Type Format).
The BTF is the debug info format for BPF, introduced
in the below linux patch:
  69b693f0ae (diff-06fb1c8825f653d7e539058b72c83332)
and further extended several times, e.g.,
  https://www.spinics.net/lists/netdev/msg534640.html
  https://www.spinics.net/lists/netdev/msg538464.html
  https://www.spinics.net/lists/netdev/msg540246.html

The main advantage of implementing in LLVM is:
   . better integration/deployment as no extra tools are needed.
   . bpf JIT based compilation (like bcc, bpftrace, etc.) can get
     BTF without much extra effort.
   . BTF line_info needs selective source codes, which can be
     easily retrieved when inside the compiler.

This patch implemented BTF generation by registering a BPF
specific DebugHandler in BPFAsmPrinter.

Signed-off-by: Yonghong Song <yhs@fb.com>

Differential Revision: https://reviews.llvm.org/D55752

llvm-svn: 349640
2018-12-19 16:40:25 +00:00