[Debuginfod][CMake] Don't build a defunct llvm-debuginfod

[mysterymath]

Summary

llvm-debuginfod intrinsically requires cpp-httplib to operate, so
exclude the target if it's unavailable. Right now the tool walks off an
llvm_unreachable.

[phosek]

LGTM

llvm/test/CMakeLists.txt

set(LLVM_TEST_DEPENDS
           llvm-cfi-verify
           llvm-config
           llvm-cov
           llvm-cvtres
           llvm-cxxdump
           llvm-cxxfilt
           llvm-cxxmap
           llvm-debuginfo-analyzer
-          llvm-debuginfod
           llvm-debuginfod-find
           llvm-diff
           llvm-dis
           llvm-dlltool
           dsymutil
           llvm-dwarfdump
           llvm-dwarfutil
           llvm-dwp
set(LLVM_TEST_DEPENDS ${LLVM_TEST_DEPENDS}
           ocaml_llvm_transform_utils
         )
 endif()
 
 if (LLVM_INCLUDE_DXIL_TESTS)
   list(APPEND LLVM_TEST_DEPENDS dxil-dis)
 endif()
 
+if(LLVM_ENABLE_HTTPLIB)
+  list(APPEND LLVM_TEST_DEPENDS llvm-debuginfod)
+endif()
+
 add_custom_target(llvm-test-depends DEPENDS ${LLVM_TEST_DEPENDS})
 set_target_properties(llvm-test-depends PROPERTIES FOLDER "Tests")
 
 if(LLVM_BUILD_TOOLS)
   set(exclude_from_check_all "")
 else()
   set(exclude_from_check_all "EXCLUDE_FROM_CHECK_ALL")
 endif()

llvm/test/lit.cfg.py

tools = [
     ToolSubst('%llvm-bitcode-strip', FindTool('llvm-bitcode-strip')),
     ToolSubst('%split-file', FindTool('split-file')),
 ]
 
 # FIXME: Why do we have both `lli` and `%lli` that do slightly different things?
 tools.extend([
     'dsymutil', 'lli', 'lli-child-target', 'llvm-ar', 'llvm-as',
     'llvm-addr2line', 'llvm-bcanalyzer', 'llvm-bitcode-strip', 'llvm-config',
-    'llvm-cov', 'llvm-cxxdump', 'llvm-cvtres', 'llvm-debuginfod-find', 'llvm-debuginfod',
+    'llvm-cov', 'llvm-cxxdump', 'llvm-cvtres', 'llvm-debuginfod-find',
     'llvm-debuginfo-analyzer',
     'llvm-diff', 'llvm-dis', 'llvm-dwarfdump', 'llvm-dwarfutil', 'llvm-dlltool',
     'llvm-exegesis', 'llvm-extract', 'llvm-isel-fuzzer', 'llvm-ifs',
     'llvm-install-name-tool', 'llvm-jitlink', 'llvm-opt-fuzzer', 'llvm-lib',
     'llvm-link', 'llvm-lto', 'llvm-lto2', 'llvm-mc', 'llvm-mca',
     'llvm-modextract', 'llvm-nm', 'llvm-objcopy', 'llvm-objdump', 'llvm-otool',
     'llvm-pdbutil', 'llvm-profdata', 'llvm-profgen', 'llvm-ranlib', 'llvm-rc', 'llvm-readelf',
     'llvm-readobj', 'llvm-remark-size-diff', 'llvm-rtdyld', 'llvm-sim',
     'llvm-size', 'llvm-split', 'llvm-stress', 'llvm-strings', 'llvm-strip',
     'llvm-tblgen', 'llvm-tapi-diff', 'llvm-undname', 'llvm-windres',
     'llvm-c-test', 'llvm-cxxfilt', 'llvm-xray', 'yaml2obj', 'obj2yaml',
     'yaml-bench', 'verify-uselistorder', 'bugpoint', 'llc', 'llvm-symbolizer',
     'opt', 'sancov', 'sanstats', 'llvm-remarkutil'])
 
 # The following tools are optional
 tools.extend([
     ToolSubst('llvm-mt', unresolved='ignore'),
+    ToolSubst('llvm-debuginfod', unresolved='ignore'),
     ToolSubst('Kaleidoscope-Ch3', unresolved='ignore'),
     ToolSubst('Kaleidoscope-Ch4', unresolved='ignore'),
     ToolSubst('Kaleidoscope-Ch5', unresolved='ignore'),
     ToolSubst('Kaleidoscope-Ch6', unresolved='ignore'),
     ToolSubst('Kaleidoscope-Ch7', unresolved='ignore'),
     ToolSubst('Kaleidoscope-Ch8', unresolved='ignore'),
     ToolSubst('LLJITWithThinLTOSummaries', unresolved='ignore'),
     ToolSubst('LLJITWithRemoteDebugging', unresolved='ignore'),

llvm/tools/CMakeLists.txt

 if(NOT LLVM_USE_INTEL_JITEVENTS )
   set(LLVM_TOOL_LLVM_JITLISTENER_BUILD Off)
 endif()
 
 if(CYGWIN OR NOT LLVM_ENABLE_PIC)
   set(LLVM_TOOL_LTO_BUILD Off)
 endif()
 
+if(NOT LLVM_ENABLE_HTTPLIB)
+  set(LLVM_TOOL_LLVM_DEBUGINFOD_BUILD Off)
+endif()
+
 if (LLVM_TOOL_LLVM_DRIVER_BUILD)
   add_llvm_tool(llvm-driver)
 endif()
 
 # Add LTO, llvm-ar, llvm-config, and llvm-profdata before clang, ExternalProject
 # requires targets specified in DEPENDS to exist before the call to
 # ExternalProject_Add.
 add_llvm_tool_subdirectory(lto)