[cmake] Allow LLVM_BUILD_INSTRUMENTED to be set to IR or Frontend

- This deprecates LLVM_ENABLE_IR_PGO but keeps it around for now.
- Errors out when LLVM_BUILD_INSTRUMENTED and LLVM_BUILD_INSTRUMENTED_COVERAGE
  are both set.

Motivated by bogner's post-commit review of r313770.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@317725 91177308-0d34-0410-b5e6-96231b3b80d8

cmake/modules/HandleLLVMOptions.cmake

@@ -738,14 +738,15 @@ if(LLVM_ENABLE_EH AND NOT LLVM_ENABLE_RTTI)
   message(FATAL_ERROR "Exception handling requires RTTI. You must set LLVM_ENABLE_RTTI to ON")
 endif()
 
-option(LLVM_ENABLE_IR_PGO "Build LLVM and tools with IR PGO instrumentation (experimental)" Off)
+option(LLVM_ENABLE_IR_PGO "Build LLVM and tools with IR PGO instrumentation (deprecated)" Off)
 mark_as_advanced(LLVM_ENABLE_IR_PGO)
 
-option(LLVM_BUILD_INSTRUMENTED "Build LLVM and tools with PGO instrumentation" Off)
+set(LLVM_BUILD_INSTRUMENTED OFF CACHE STRING "Build LLVM and tools with PGO instrumentation. May be specified as IR or Frontend")
 mark_as_advanced(LLVM_BUILD_INSTRUMENTED)
+string(TOUPPER "${LLVM_BUILD_INSTRUMENTED}" uppercase_LLVM_BUILD_INSTRUMENTED)
 
 if (LLVM_BUILD_INSTRUMENTED)
-  if (LLVM_ENABLE_IR_PGO)
+  if (LLVM_ENABLE_IR_PGO OR uppercase_LLVM_BUILD_INSTRUMENTED STREQUAL "IR")
     append("-fprofile-generate='${LLVM_PROFILE_DATA_DIR}'"
       CMAKE_CXX_FLAGS
       CMAKE_C_FLAGS
@@ -768,6 +769,10 @@ append_if(LLVM_BUILD_INSTRUMENTED_COVERAGE "-fprofile-instr-generate='${LLVM_PRO
   CMAKE_EXE_LINKER_FLAGS
   CMAKE_SHARED_LINKER_FLAGS)
 
+if (LLVM_BUILD_INSTRUMENTED AND LLVM_BUILD_INSTRUMENTED_COVERAGE)
+  message(FATAL_ERROR "LLVM_BUILD_INSTRUMENTED and LLVM_BUILD_INSTRUMENTED_COVERAGE cannot both be specified")
+endif()
+
 if(LLVM_ENABLE_LTO AND LLVM_ON_WIN32 AND NOT LINKER_IS_LLD_LINK)
   message(FATAL_ERROR "When compiling for Windows, LLVM_ENABLE_LTO requires using lld as the linker (point CMAKE_LINKER at lld-link.exe)")
 endif()