build: fix mac build on xcode 12

[ramaraochavali]

Commit Message: fix mac build on xcode 12
Additional Description:
Build with Xcode 12 on Mac fails with the following error as abseil while constructing map uses non reference range loop.

source/extensions/filters/network/postgres_proxy/postgres_decoder.cc:502:19: error: loop variable 'sp' of type 'const absl::string_view' creates a copy from type 'const absl::string_view' [-Werror,-Wrange-loop-analysis]
  for (const auto sp : splitter) {
                  ^
source/extensions/filters/network/postgres_proxy/postgres_decoder.cc:502:8: note: use reference type 'const absl::string_view &' to prevent copying
  for (const auto sp : splitter) {
       ^~~~~~~~~~~~~~~

Risk Level: Low
Testing: N/A
Docs Changes: N/A
Release Notes: N/A
Platform Specific Features:
[Optional Runtime guard:]
[Optional Fixes #Issue]
[Optional Deprecated:]
[Optional API Considerations:]

[PiotrSikora]

FWIW, I believe this is a false-positive (see: https://reviews.llvm.org/D73007), so adding -Wno-range-loop-analysis on macOS might be better than this expensive fix.

[codefromthecrypt]

see also #13184 as it is similar

[codefromthecrypt]

Homebrew/homebrew-core#81490 will try to work around this until merged as currently homebrew is busted

[htuch]

@ramaraochavali what is the status of this? Should we close or revise as per comments?

[ramaraochavali]

I am fine with the workaround of removing -Wrange-loop-analysis for mac. Is this the right place to disable

envoy/bazel/envoy_internal.bzl

Line 69 in a12869f

"-Wrange-loop-analysis",

?

Is that fine with every one @rebello95 ?

[codefromthecrypt]

project team: (for lack of knowing how escalations work @mattklein123 )

I don't know how severity works here, but this should be a dev 1. only thing worse would be all platforms unable to build (dev 0). That os/x doesn't build due to this means no one can upgrade homebrew to envoy 1.19. To understand the full context is basically knowing that many projects rely on github actions, who have finally stopped installing ancient xcode.

Note: this is also hurting the homebrew project as it is causing broken builds on the existing versions. In other words envoy's config is causing stalls on unrelated forumulas such as go. Can someone with deep knowledge on the build please pitch in and resolve this!

[mattklein123]

@ramaraochavali yes let's just disable range-loop-analysis on macOS. cc @keith or @lizan for help on how to do that or just ask them in the #bazel slack room. Thank you!

/wait

[keith]

#17428

[mattklein123]

Thanks Keith! Closing this one.

[ramaraochavali]

makes sense. Will look forward for the other PR getting merged :-)