[compiler-rt] [llvm] [ctxprof] Capture sampling info for context roots (PR #131201)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-sie-win` running on `sie-win-worker` while building `compiler-rt,llvm` at step 7 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/46/builds/13613

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 7 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'LLVM :: Transforms/PGOProfile/ctx-instrumentation.ll' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 2
z:\b\llvm-clang-x86_64-sie-win\build\bin\opt.exe -passes=ctx-instr-gen -profile-context-root=an_entrypoint    -S < Z:\b\llvm-clang-x86_64-sie-win\llvm-project\llvm\test\Transforms\PGOProfile\ctx-instrumentation.ll | z:\b\llvm-clang-x86_64-sie-win\build\bin\filecheck.exe --check-prefix=INSTRUMENT Z:\b\llvm-clang-x86_64-sie-win\llvm-project\llvm\test\Transforms\PGOProfile\ctx-instrumentation.ll
# executed command: 'z:\b\llvm-clang-x86_64-sie-win\build\bin\opt.exe' -passes=ctx-instr-gen -profile-context-root=an_entrypoint -S
# executed command: 'z:\b\llvm-clang-x86_64-sie-win\build\bin\filecheck.exe' --check-prefix=INSTRUMENT 'Z:\b\llvm-clang-x86_64-sie-win\llvm-project\llvm\test\Transforms\PGOProfile\ctx-instrumentation.ll'
# RUN: at line 4
z:\b\llvm-clang-x86_64-sie-win\build\bin\opt.exe -passes=ctx-instr-gen,assign-guid,ctx-instr-lower -profile-context-root=an_entrypoint    -profile-context-root=another_entrypoint_no_callees    -S < Z:\b\llvm-clang-x86_64-sie-win\llvm-project\llvm\test\Transforms\PGOProfile\ctx-instrumentation.ll | z:\b\llvm-clang-x86_64-sie-win\build\bin\filecheck.exe --check-prefix=LOWERING Z:\b\llvm-clang-x86_64-sie-win\llvm-project\llvm\test\Transforms\PGOProfile\ctx-instrumentation.ll
# executed command: 'z:\b\llvm-clang-x86_64-sie-win\build\bin\opt.exe' -passes=ctx-instr-gen,assign-guid,ctx-instr-lower -profile-context-root=an_entrypoint -profile-context-root=another_entrypoint_no_callees -S
# executed command: 'z:\b\llvm-clang-x86_64-sie-win\build\bin\filecheck.exe' --check-prefix=LOWERING 'Z:\b\llvm-clang-x86_64-sie-win\llvm-project\llvm\test\Transforms\PGOProfile\ctx-instrumentation.ll'
# .---command stderr------------
# | Z:\b\llvm-clang-x86_64-sie-win\llvm-project\llvm\test\Transforms\PGOProfile\ctx-instrumentation.ll:12:13: error: LOWERING: expected string not found in input
# | ; LOWERING: @an_entrypoint_ctx_root = global { ptr, ptr, ptr, i8 } zeroinitializer
# |             ^
# | <stdin>:1:1: note: scanning from here
# | ; ModuleID = '<stdin>'
# | ^
# | <stdin>:4:1: note: possible intended match here
# |  at an_entrypoint_ctx_root = global { ptr, ptr, ptr, i64, i8 } zeroinitializer
# | ^
# | Z:\b\llvm-clang-x86_64-sie-win\llvm-project\llvm\test\Transforms\PGOProfile\ctx-instrumentation.ll:42:81: error: undefined variable: GLOB0
# | ; LOWERING-NEXT: [[TMP1:%.*]] = call ptr @__llvm_ctx_profile_get_context(ptr @[[GLOB0]], ptr @foo, i64 6699318081062747564, i32 2, i32 2)
# |                                                                                 ^
# | <stdin>:17:2: note: possible intended match here
# |  %1 = call ptr @__llvm_ctx_profile_get_context(ptr @0, ptr @foo, i64 6699318081062747564, i32 2, i32 2)
# |  ^
# | Z:\b\llvm-clang-x86_64-sie-win\llvm-project\llvm\test\Transforms\PGOProfile\ctx-instrumentation.ll:184:81: error: undefined variable: GLOB1
# | ; LOWERING-NEXT: [[TMP1:%.*]] = call ptr @__llvm_ctx_profile_get_context(ptr @[[GLOB1]], ptr @simple, i64 -3006003237940970099, i32 1, i32 0)
# |                                                                                 ^
# | <stdin>:103:2: note: possible intended match here
# |  %1 = call ptr @__llvm_ctx_profile_get_context(ptr @1, ptr @simple, i64 -3006003237940970099, i32 1, i32 0)
# |  ^
# | Z:\b\llvm-clang-x86_64-sie-win\llvm-project\llvm\test\Transforms\PGOProfile\ctx-instrumentation.ll:208:81: error: undefined variable: GLOB2
# | ; LOWERING-NEXT: [[TMP1:%.*]] = call ptr @__llvm_ctx_profile_get_context(ptr @[[GLOB2]], ptr @no_callsites, i64 5679753335911435902, i32 2, i32 0)
# |                                                                                 ^
# | <stdin>:111:2: note: possible intended match here
# |  %1 = call ptr @__llvm_ctx_profile_get_context(ptr @2, ptr @no_callsites, i64 5679753335911435902, i32 2, i32 0)
# |  ^
# | Z:\b\llvm-clang-x86_64-sie-win\llvm-project\llvm\test\Transforms\PGOProfile\ctx-instrumentation.ll:240:81: error: undefined variable: GLOB3
# | ; LOWERING-NEXT: [[TMP1:%.*]] = call ptr @__llvm_ctx_profile_get_context(ptr @[[GLOB3]], ptr @no_counters, i64 5458232184388660970, i32 1, i32 1)
# |                                                                                 ^
# | <stdin>:130:2: note: possible intended match here
# |  %1 = call ptr @__llvm_ctx_profile_get_context(ptr @3, ptr @no_counters, i64 5458232184388660970, i32 1, i32 1)
# |  ^
# | Z:\b\llvm-clang-x86_64-sie-win\llvm-project\llvm\test\Transforms\PGOProfile\ctx-instrumentation.ll:268:81: error: undefined variable: GLOB4
# | ; LOWERING-NEXT: [[TMP1:%.*]] = call ptr @__llvm_ctx_profile_get_context(ptr @[[GLOB4]], ptr @inlineasm, i64 -3771893999295659109, i32 1, i32 0)
# |                                                                                 ^
...

```

</details>

https://github.com/llvm/llvm-project/pull/131201