3 Commits

Author SHA1 Message Date
Fangrui Song
c5037db4ac [BPF,test] Change llc -march= to -mtriple=
Similar to 806761a7629df268c8aed49657aeccffa6bca449

-mtriple= specifies the full target triple while -march= merely sets the
architecture part of the default target triple (e.g. Windows, macOS),
leaving a target triple which may not make sense.

Therefore, -march= is error-prone and not recommended for tests without
a target triple. The issue has been benign as we recognize
bpf*-apple-darwin as ELF instead of rejecting it outrightly.
2024-12-15 11:04:24 -08:00
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