[llvm] [llvm][cmake] Add clang if not already present when building lldb (PR #149055)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-aarch64-sve2-vla` running on `linaro-g4-02` while building `llvm` at step 7 "ninja check 1".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/198/builds/6231

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

```
Step 7 (ninja check 1) failure: stage 1 checked (failure)
******************** TEST 'HWAddressSanitizer-aarch64 :: TestCases/hwasan_symbolize_stack_overflow.cpp' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
rm -rf /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp; mkdir /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp # RUN: at line 1
+ rm -rf /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp
+ mkdir /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp
/home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/./bin/clang    -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta   -gline-tables-only -fsanitize=hwaddress -fuse-ld=lld -mllvm -hwasan-globals -mllvm -hwasan-use-short-granules -mllvm -hwasan-instrument-landing-pads=0 -mllvm -hwasan-instrument-personality-functions -Wl,--build-id -g /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/llvm/compiler-rt/test/hwasan/TestCases/hwasan_symbolize_stack_overflow.cpp -o /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp/hwasan_overflow # RUN: at line 2
+ /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/./bin/clang -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta -gline-tables-only -fsanitize=hwaddress -fuse-ld=lld -mllvm -hwasan-globals -mllvm -hwasan-use-short-granules -mllvm -hwasan-instrument-landing-pads=0 -mllvm -hwasan-instrument-personality-functions -Wl,--build-id -g /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/llvm/compiler-rt/test/hwasan/TestCases/hwasan_symbolize_stack_overflow.cpp -o /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp/hwasan_overflow
env HWASAN_OPTIONS=disable_allocator_tagging=1:random_tags=0:fail_without_syscall_abi=0:symbolize=0 not  /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp/hwasan_overflow 16 2>&1 | /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/bin/hwasan_symbolize --symbols /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp --index | FileCheck /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/llvm/compiler-rt/test/hwasan/TestCases/hwasan_symbolize_stack_overflow.cpp --check-prefixes=CHECK,AFTER0 # RUN: at line 3
+ env HWASAN_OPTIONS=disable_allocator_tagging=1:random_tags=0:fail_without_syscall_abi=0:symbolize=0 not /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp/hwasan_overflow 16
+ /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/bin/hwasan_symbolize --symbols /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp --index
+ FileCheck /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/llvm/compiler-rt/test/hwasan/TestCases/hwasan_symbolize_stack_overflow.cpp --check-prefixes=CHECK,AFTER0
Could not find symbols for lib/aarch64-linux-gnu/libc.so.6 (Build ID: 2a450fe74d1b79a321cc1b12337fc31a2c3fb834)
env HWASAN_OPTIONS=disable_allocator_tagging=1:random_tags=0:fail_without_syscall_abi=0:symbolize=0 not  /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp/hwasan_overflow 17 2>&1 | /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/bin/hwasan_symbolize --symbols /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp --index | FileCheck /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/llvm/compiler-rt/test/hwasan/TestCases/hwasan_symbolize_stack_overflow.cpp --check-prefixes=CHECK,AFTER1 # RUN: at line 4
+ env HWASAN_OPTIONS=disable_allocator_tagging=1:random_tags=0:fail_without_syscall_abi=0:symbolize=0 not /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp/hwasan_overflow 17
+ /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/bin/hwasan_symbolize --symbols /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp --index
+ FileCheck /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/llvm/compiler-rt/test/hwasan/TestCases/hwasan_symbolize_stack_overflow.cpp --check-prefixes=CHECK,AFTER1
Could not find symbols for lib/aarch64-linux-gnu/libc.so.6 (Build ID: 2a450fe74d1b79a321cc1b12337fc31a2c3fb834)
env HWASAN_OPTIONS=disable_allocator_tagging=1:random_tags=0:fail_without_syscall_abi=0:symbolize=0 not  /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp/hwasan_overflow -1 2>&1 | /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/bin/hwasan_symbolize --symbols /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp --index | FileCheck /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/llvm/compiler-rt/test/hwasan/TestCases/hwasan_symbolize_stack_overflow.cpp --check-prefixes=CHECK,BEFORE1 # RUN: at line 5
+ env HWASAN_OPTIONS=disable_allocator_tagging=1:random_tags=0:fail_without_syscall_abi=0:symbolize=0 not /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp/hwasan_overflow -1
+ /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/bin/hwasan_symbolize --symbols /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp --index
+ FileCheck /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/llvm/compiler-rt/test/hwasan/TestCases/hwasan_symbolize_stack_overflow.cpp --check-prefixes=CHECK,BEFORE1
Could not find symbols for lib/aarch64-linux-gnu/libc.so.6 (Build ID: 2a450fe74d1b79a321cc1b12337fc31a2c3fb834)
env HWASAN_OPTIONS=disable_allocator_tagging=1:random_tags=0:fail_without_syscall_abi=0:symbolize=0 not  /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp/hwasan_overflow -17 2>&1 | /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/bin/hwasan_symbolize --symbols /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp --index | FileCheck /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/llvm/compiler-rt/test/hwasan/TestCases/hwasan_symbolize_stack_overflow.cpp --check-prefixes=CHECK,BEFORE17 # RUN: at line 6
+ /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/bin/hwasan_symbolize --symbols /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp --index
+ env HWASAN_OPTIONS=disable_allocator_tagging=1:random_tags=0:fail_without_syscall_abi=0:symbolize=0 not /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp/hwasan_overflow -17
+ FileCheck /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/llvm/compiler-rt/test/hwasan/TestCases/hwasan_symbolize_stack_overflow.cpp --check-prefixes=CHECK,BEFORE17
Could not find symbols for lib/aarch64-linux-gnu/libc.so.6 (Build ID: 2a450fe74d1b79a321cc1b12337fc31a2c3fb834)
env HWASAN_OPTIONS=disable_allocator_tagging=1:random_tags=0:fail_without_syscall_abi=0:symbolize=0 not  /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp/hwasan_overflow 1016 2>&1 | /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/bin/hwasan_symbolize --symbols /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp --index | FileCheck /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/llvm/compiler-rt/test/hwasan/TestCases/hwasan_symbolize_stack_overflow.cpp --check-prefixes=CHECK,AFTER1000 # RUN: at line 7
+ env HWASAN_OPTIONS=disable_allocator_tagging=1:random_tags=0:fail_without_syscall_abi=0:symbolize=0 not /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp/hwasan_overflow 1016
+ /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/bin/hwasan_symbolize --symbols /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/hwasan/AARCH64/TestCases/Output/hwasan_symbolize_stack_overflow.cpp.tmp --index
+ FileCheck /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/llvm/compiler-rt/test/hwasan/TestCases/hwasan_symbolize_stack_overflow.cpp --check-prefixes=CHECK,AFTER1000
Could not find symbols for lib/aarch64-linux-gnu/libc.so.6 (Build ID: 2a450fe74d1b79a321cc1b12337fc31a2c3fb834)
/home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/llvm/compiler-rt/test/hwasan/TestCases/hwasan_symbolize_stack_overflow.cpp:21:12: error: CHECK: expected string not found in input
 // CHECK: Potentially referenced stack object:
           ^
<stdin>:1:1: note: scanning from here
==2208131==ERROR: HWAddressSanitizer: tag-mismatch on address 0xffffd8d003b8 at pc 0xafe189fdbab8
^
<stdin>:10:15: note: possible intended match here
Address 0xffffd8d003b8 is located in stack of thread T0
              ^

Input file: <stdin>
Check file: /home/tcwg-buildbot/worker/clang-aarch64-sve2-vla/llvm/compiler-rt/test/hwasan/TestCases/hwasan_symbolize_stack_overflow.cpp

-dump-input=help explains the following input dump.

...

```

</details>

https://github.com/llvm/llvm-project/pull/149055