Commit Graph

4 Commits

Author SHA1 Message Date
Aaron Ballman ed509fe296 Use functions with prototypes when appropriate; NFC
A significant number of our tests in C accidentally use functions
without prototypes. This patch converts the function signatures to have
a prototype for the situations where the test is not specific to K&R C
declarations. e.g.,

  void func();

becomes

  void func(void);

This is the tenth batch of tests being updated (there are a
significant number of other tests left to be updated).
2022-02-15 09:28:02 -05:00
Yonghong Song e3d8ee35e4 reland "[DebugInfo] Support to emit debugInfo for extern variables"
Commit d77ae1552f
("[DebugInfo] Support to emit debugInfo for extern variables")
added deebugInfo for extern variables for BPF target.
The commit is reverted by 891e25b02d
as the committed tests using %clang instead of %clang_cc1 causing
test failed in certain scenarios as reported by Reid Kleckner.

This patch fixed the tests by using %clang_cc1.

Differential Revision: https://reviews.llvm.org/D71818
2019-12-22 18:28:50 -08:00
Reid Kleckner 891e25b02d Revert "[DebugInfo] Support to emit debugInfo for extern variables"
This reverts commit d77ae1552f.

The tests committed along with this change do not pass, and should be
changed to use %clang_cc1.
2019-12-22 12:54:06 -08:00
Yonghong Song d77ae1552f [DebugInfo] Support to emit debugInfo for extern variables
Extern variable usage in BPF is different from traditional
pure user space application. Recent discussion in linux bpf
mailing list has two use cases where debug info types are
required to use extern variables:
  - extern types are required to have a suitable interface
    in libbpf (bpf loader) to provide kernel config parameters
    to bpf programs.
    https://lore.kernel.org/bpf/CAEf4BzYCNo5GeVGMhp3fhysQ=_axAf=23PtwaZs-yAyafmXC9g@mail.gmail.com/T/#t
  - extern types are required so kernel bpf verifier can
    verify program which uses external functions more precisely.
    This will make later link with actual external function no
    need to reverify.
    https://lore.kernel.org/bpf/87eez4odqp.fsf@toke.dk/T/#m8d5c3e87ffe7f2764e02d722cb0d8cbc136880ed

This patch added clang support to emit debuginfo for extern variables
with a TargetInfo hook to enable it. The debuginfo for the
extern variable is emitted only if that extern variable is
referenced in the current compilation unit.

Currently, only BPF target enables to generate debug info for
extern variables. The emission of such debuginfo is disabled for C++
 at this moment since BPF only supports a subset of C language.
Emission with C++ can be enabled later if an appropriate use case
is identified.

-fstandalone-debug permits us to see more debuginfo with the cost
of bloated binary size. This patch did not add emission of extern
variable debug info with -fstandalone-debug. This can be
re-evaluated if there is a real need.

Differential Revision: https://reviews.llvm.org/D70696
2019-12-10 08:09:51 -08:00