Replace if(NOT ${var}) by if(NOT var) (#41924)

Summary:
As explained in pytorch/pytorch#41922 using `if(NOT ${var})" is usually wrong and can lead to issues like pytorch/pytorch#41922 where the condition is wrongly evaluated to FALSE instead of TRUE. Instead the unevaluated variable name should be used in all cases, see the CMake docu for details.

This fixes the `NOT ${var}` cases by using a simple regexp replacement. It seems `pybind11_PREFER_third_party` is the only variable really prone to causing an issue as all others are set. However due to CMake evaluating unquoted strings in `if` conditions as variable names I recommend to never use unquoted `${var}` in an if condition. A similar regexp based replacement could be done on the whole codebase but as that does a lot of changes I didn't include this now. Also `if(${var})` will likely lead to a parser error if `var` is unset instead of a wrong result

Fixes pytorch/pytorch#41922

Pull Request resolved: pytorch/pytorch#41924

Reviewed By: seemethere

Differential Revision: D22700229

Pulled By: mrshenli

fbshipit-source-id: e2b3466039e4312887543c2e988270547a91c439

cmake/Dependencies.cmake

@@ -584,7 +584,7 @@ if(BUILD_TEST OR BUILD_MOBILE_BENCHMARK OR BUILD_MOBILE_TEST)
               "-P"
               "${CMAKE_CURRENT_LIST_DIR}/GoogleTestPatch.cmake"
       RESULT_VARIABLE _exitcode)
-    if(NOT ${_exitcode} EQUAL 0)
+    if(NOT _exitcode EQUAL 0)
       message(WARNING "Patching failed for Google Test. The build may fail.")
     endif()
   endif()
@@ -634,7 +634,7 @@ if(BUILD_TEST OR BUILD_MOBILE_BENCHMARK OR BUILD_MOBILE_TEST)
               "-P"
               "${CMAKE_CURRENT_LIST_DIR}/GoogleTestPatch.cmake"
       RESULT_VARIABLE _exitcode)
-    if(NOT ${_exitcode} EQUAL 0)
+    if(NOT _exitcode EQUAL 0)
       message(WARNING "Reverting changes failed for Google Test. The build may fail.")
     endif()
   endif()
@@ -877,7 +877,7 @@ if(BUILD_PYTHON)
     execute_process(
         COMMAND "${PYTHON_EXECUTABLE}" "--version"
         RESULT_VARIABLE _exitcode OUTPUT_VARIABLE PYTHON_VERSION)
-    if(NOT ${_exitcode} EQUAL 0)
+    if(NOT _exitcode EQUAL 0)
       message(FATAL_ERROR "The Python executable ${PYTHON_EXECUTABLE} cannot be run. Make sure that it is an absolute path.")
     endif()
     if(PYTHON_VERSION)
@@ -955,7 +955,7 @@ if(BUILD_PYTHON)
 endif()
 
 # ---[ pybind11
-if(NOT ${pybind11_PREFER_third_party})
+if(NOT pybind11_PREFER_third_party)
   find_package(pybind11 CONFIG)
   if(NOT pybind11_FOUND)
     find_package(pybind11)
@@ -1226,7 +1226,7 @@ if(USE_NCCL)
         "Not using CUDA/ROCM, so disabling USE_NCCL. Suppress this warning with "
         "-DUSE_NCCL=OFF.")
     caffe2_update_option(USE_NCCL OFF)
-  elseif(NOT ${CMAKE_SYSTEM_NAME} STREQUAL "Linux")
+  elseif(NOT CMAKE_SYSTEM_NAME STREQUAL "Linux")
     message(WARNING "NCCL is currently only supported under Linux.")
     caffe2_update_option(USE_NCCL OFF)
   elseif(USE_CUDA)

cmake/Modules_CUDA_fix/upstream/FindCUDA.cmake

@@ -1505,7 +1505,7 @@ macro(CUDA_WRAP_SRCS cuda_target format generated_files)
         set(_cuda_source_format ${format})
       endif()
       # If file isn't a .cu file, we need to tell nvcc to treat it as such.
-      if(NOT ${file} MATCHES "\\.cu$")
+      if(NOT file MATCHES "\\.cu$")
         set(cuda_language_flag -x=cu)
       else()
         set(cuda_language_flag)

cmake/ProtoBuf.cmake

@@ -85,7 +85,7 @@ endmacro()
 # coded BUILD_CUSTOM_PROTOBUF, we will hard code the use of custom protobuf
 # in the submodule.
 if(ANDROID OR IOS)
-  if(NOT ${BUILD_CUSTOM_PROTOBUF})
+  if(NOT BUILD_CUSTOM_PROTOBUF)
     message(WARNING
         "For Android and iOS cross compilation, I am automatically using "
         "custom protobuf under third party. Note that this behavior may "

cmake/Utils.cmake

@@ -154,7 +154,7 @@ function(dedent outvar text)
     INPUT_FILE "${CMAKE_BINARY_DIR}/indented.txt"
     RESULT_VARIABLE _dedent_exitcode
     OUTPUT_VARIABLE _dedent_text)
-  if(NOT ${_dedent_exitcode} EQUAL 0)
+  if(NOT _dedent_exitcode EQUAL 0)
     message(ERROR " Failed to remove indentation from: \n\"\"\"\n${text}\n\"\"\"
     Python dedent failed with error code: ${_dedent_exitcode}")
     message(FATAL_ERROR " Python dedent failed with error code: ${_dedent_exitcode}")
@@ -202,7 +202,7 @@ function(pycmd outvar cmd)
   dedent(_dedent_cmd "${cmd}")
   pycmd_no_exit(_output _exitcode "${_dedent_cmd}")
 
-  if(NOT ${_exitcode} EQUAL 0)
+  if(NOT _exitcode EQUAL 0)
     message(ERROR " Failed when running python code: \"\"\"\n${_dedent_cmd}\n\"\"\"")
     message(FATAL_ERROR " Python command failed with error code: ${_exitcode}")
   endif()

cmake/public/cuda.cmake

@@ -74,7 +74,7 @@ if(CUDA_FOUND)
     message(FATAL_ERROR "Caffe2: Couldn't determine version from header: " ${output_var})
   endif()
   message(STATUS "Caffe2: Header version is: " ${cuda_version_from_header})
-  if(NOT ${cuda_version_from_header} STREQUAL ${CUDA_VERSION_STRING})
+  if(NOT cuda_version_from_header STREQUAL ${CUDA_VERSION_STRING})
     # Force CUDA to be processed for again next time
     # TODO: I'm not sure if this counts as an implementation detail of
     # FindCUDA

torch/CMakeLists.txt

@@ -98,7 +98,7 @@ if(MSVC)
     if(BUILD_TEST)
       list(APPEND TORCH_PYTHON_LINK_LIBRARIES onnx_library)
     endif(BUILD_TEST)
-    if(NOT ${CMAKE_BUILD_TYPE} MATCHES "Release")
+    if(NOT CMAKE_BUILD_TYPE MATCHES "Release")
       string(APPEND TORCH_PYTHON_LINK_FLAGS " /DEBUG:FULL")
     endif()
 elseif(APPLE)