* Update runner to Go 1.22,1.23 (two most recent releases).

* Update runner to Go 1.22,1.23 (two most recent releases).

* Update Go mod to 1.22 as well.

* Update staticcheck to 0.5.1 so it works with 1.23 code

* Update golangci-lint to 1.60.3.

v1.51 fails with errors related to old slices package.

* Require Go 1.22 for bootstrapping Go tip

* Github actions do not support else statements

* Another attempt at Workflow syntax

* Another attempt at Workflow syntax

* Fix caching for Go bootstrap compiler

* Fix caching for Go bootstrap compiler

* Fix caching for Go bootstrap compiler

* Fix caching for Go bootstrap compiler

* Fix caching for Go bootstrap compiler

* Fix caching for Go bootstrap compiler

* Fix caching for Go bootstrap compiler

* Add comments saying why we need cache directives

* Add doc URL to profile format and use it display help link.

* Add test for Report.DocURL

* Update new proto field comment

Output looks something like:

```
% pprof -top ...
File: ...
Build ID: ...
Type: cpu
Doc: http://example.com/cpuprofile
Duration: 6.71s, Total samples = 5.72s (85.30%)
Showing nodes accounting for 5.17s, 90.38% of 5.72s total
Dropped 326 nodes (cum <= 0.03s)
...
```

Signed-off-by: cuishuang <imcusg@gmail.com>

Display the details (name + samples) of the currently hovered box
above the flame graph. If no box is currently being hovered
over, we display the total samples in the flame graph.

Co-authored-by: Alexey Alexandrov <aalexand@users.noreply.github.com>

* Support different display granularities in flame graph view.

Previously, flame-graph view could only display filefunctions
granularity. We can now support all the available granularities.

This allows the user to supply a granularity either via a command-line
flag (e.g., --files), or as a URL parameter (e.g., ?g=files).

Details
* Made the default initial granularity "" so that we can stick with
  the default flame-graph granularity of "filefunctions" while also
  allowing overrides.
* Use different computation of the list of shorter display names
  for file names (strip off leading path components instead of package
  prefixes).
* Similarly compute color based on directory name instead of package name.
* Include line number and column number in displayed names if the
  granularity includes line numbers.

* Improve granularity entry for options command

---------

Co-authored-by: Alexey Alexandrov <aalexand@users.noreply.github.com>

- `http://HOST/profilez` -> `http://HOST/symbolz`
- `http://HOST/some/deeper/path/profilez` -> `http://HOST/some/deeper/path/symbolz`

Co-authored-by: Alexey Alexandrov <aalexand@users.noreply.github.com>

* Use llvm-symbolizer's JSON output to provide function start lines

When analyzing a perf.data profile converted automatically via perf_to_profile via pprof -raw perf.data, no function start lines (s=0) are present in any of the locations. With 813a5fb, this can be easily solved by using the same JSON frame data from llvm-symbolizer to provide StartLine for Function.start_line. This solves #823.

* Fixed TestPEFile windows test

* Fixed TestMachoFiles mac tests

* Fix making sure llvm-symbolizer is available in the CI env for Linux tests

Modify the `Fetch dependencies` step in `test-linux` job to include the installation of llvm. Add `Verify llvm-symbolizer installation` step to ensure that llvm-symbolizer is available in the CI environment for the Linux tests. This should resolve the test failures related to the missing llvm-symbolizer tool.

* ci: Improve LLVM installation for Ubuntu 20.04 and 22.04

Enhances the CI workflow to ensure proper installation of LLVM and the `llvm-symbolizer` across both Ubuntu 20.04 and 22.04 environments. These changes address the issue of an outdated llvm-symbolizer on Ubuntu 20.04, while maintaining compatibility with Ubuntu 22.04.

- Add LLVM official repository for Ubuntu 20.04
- Install LLVM 14 on Ubuntu 20.04 to ensure a recent version
- Use update-alternatives to manage llvm-symbolizer versions
- Maintain existing LLVM 14 for Ubuntu 22.04

* ci: Make it clear that our goal is to install llvm-symbolizer

---------

Co-authored-by: Alexey Alexandrov <aalexand@users.noreply.github.com>

Bumps [actions/checkout](https://github.com/actions/checkout) from 4.1.7 to 4.2.0.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@692973e...d632683)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Bumps [actions/checkout](https://github.com/actions/checkout) from 4.2.0 to 4.2.1.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@d632683...eef6144)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Bumps [codecov/codecov-action](https://github.com/codecov/codecov-action) from 4.5.0 to 4.6.0.
- [Release notes](https://github.com/codecov/codecov-action/releases)
- [Changelog](https://github.com/codecov/codecov-action/blob/main/CHANGELOG.md)
- [Commits](codecov/codecov-action@e28ff12...b9fd7d1)

---
updated-dependencies:
- dependency-name: codecov/codecov-action
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Alexey Alexandrov <aalexand@users.noreply.github.com>

The current time format (Jan 2, 2006 at 3:04pm (MST)) has a few issues:

 - It displays time at minute granularity, while profiles usually have
   have second-level (and more[^go]) granularity.
 - It uses a 12-hour clock, which is tricky to handle at AM/PM
   switchovers, for people (like myself) who are not used to it. By
   contrast, a 24-hour clock is unambiguous.
 - Minor: using names for months makes it more difficult to calculate
   with time differences.

Hence, I propose replacing it with an RFC3339-alike format, with spaces
between elements for better readability.

[^go]: https://github.com/golang/go/blob/3aa71c12eacd68ec16e7172d92aa5c6af32f0c3b/src/runtime/pprof/proto.go#L351

Replace an existing check for "start >= loadSegment.Vaddr" with
"start >= 0x8000000000000000".

The old condition was checking for the mapping start address to be greater
or equal to the program segment Vaddr. However, for kernels without KASLR,
the mapping start address (start) is less or equal the program header Vaddr.
If the program header that includes the '.text' section is not the first
segment, then the mapping start is strictly less than loadSegment.Vaddr.

Instead of removing the condition, we replace it with a check that start is
in the kernel address space, so we don't take this path for user space
binaries.

Adjusted the test case for PIE kernels to match actual addresses seen for
a non-KASLR kernel. The new test fails with the old code and succeeds now.

We added skipping unsymbolizable mappings in symbolz long time ago in
PR #368 to address #339 where we saw error like "unexpected negative
adjusted address".

But that error was fixed in a more proper way in subsequent #397 to fix
another reported issue #280 (and internal b/32020573). So skipping
unsymbolized mappings shouldn't be needed anymore.

I tested this by verifying that the test case from #339 still works fine
with the proposed change. And that it does fail if I roll back #397
locally.

This change is useful as we experiment with using symbolz to symbolize
JIT locations from //anon (which is unsymbolizable per current terminology).

Co-authored-by: Maggie Nolan Edmonds <nolanmar@google.com>

Bumps [actions/setup-go](https://github.com/actions/setup-go) from 5.0.2 to 5.1.0.
- [Release notes](https://github.com/actions/setup-go/releases)
- [Commits](actions/setup-go@0a12ed9...41dfa10)

---
updated-dependencies:
- dependency-name: actions/setup-go
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Bumps [actions/checkout](https://github.com/actions/checkout) from 4.2.1 to 4.2.2.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@eef6144...11bd719)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Alexey Alexandrov <aalexand@users.noreply.github.com>