[llvm-dev] Testing LLVM XRay

[buddhika chamith via llvm-dev]

Hi All,

I am trying to test run clang XRay tool. I was following the steps at [1]. But the log file does not seem to get generated. According to the instructions I used 'fxray-instrument' switch when compiling and then specified 'patch_premain=true' at XRAY_OPTIONS. Is there anything else that I need to do? I am on a trunk build of clang. Could that be it? I am on clang version 8.0.0 (trunk 340502).

Regards

Buddhika

[1] https://llvm.org/docs/XRayExample.html#id9 

--

Research Assistant
Indiana University
Web: http://homes.soic.indiana.edu/budkahaw/

[buddhika chamith via llvm-dev]

The link should be 

[1] https://llvm.org/docs/XRayExample.html#further-exploration

[Dean Michael Berris via llvm-dev]

Hi Buddhika,

On Tue, 28 Aug 2018 at 3:36 am, buddhika chamith via llvm-dev <llvm...@lists.llvm.org> wrote:

The link should be 

[1] https://llvm.org/docs/XRayExample.html#further-exploration

On Mon, Aug 27, 2018 at 1:33 PM, buddhika chamith <chamib...@gmail.com> wrote:

Hi All,

I am trying to test run clang XRay tool. I was following the steps at [1]. But the log file does not seem to get generated. According to the instructions I used 'fxray-instrument' switch when compiling and then specified 'patch_premain=true' at XRAY_OPTIONS. Is there anything else that I need to do? I am on a trunk build of clang. Could that be it? I am on clang version 8.0.0 (trunk 340502).

Apologies for that, it seems the documentation is out of date. You need to add `xray_mode=xray-basic` to the options. That should look like:

XRAY_OPTIONS="patch_premain=true:xray_mode=xray-basic"

We should update the documentation with that. Note that llvm.org/docs/XRay.html should already have the updated instructions.

Cheers

--

Dean

[buddhika chamith via llvm-dev]

Great! Now it works.

Thanks