diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6fb0a9bf5a..7b75404958 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -105,18 +105,22 @@ option(DXC_DISABLE_ALLOCATOR_OVERRIDES "Disable usage of allocator overrides" OF
 mark_as_advanced(DXC_DISABLE_ALLOCATOR_OVERRIDES)
 
 # adjust link option to enable debugging from kernel mode; not compatible with incremental linking
-if(NOT CMAKE_VERSION VERSION_LESS "3.13" AND WIN32 AND NOT CMAKE_C_COMPILER_ARCHITECTURE_ID STREQUAL "ARM64EC")
+if(NOT CMAKE_VERSION VERSION_LESS "3.13" AND MSVC AND NOT CMAKE_C_COMPILER_ARCHITECTURE_ID STREQUAL "ARM64EC")
   add_link_options(/DEBUGTYPE:CV,FIXUP,PDATA /INCREMENTAL:NO)
 endif()
 
 # enable control flow guard
 if(WIN32)
-add_compile_options(/guard:cf)
-add_link_options(/guard:cf)
+  if(MSVC)
+    add_compile_options(/guard:cf)
+    add_link_options(/guard:cf)
+  else()
+    add_compile_options(-fcf-protection)
+  endif()
 endif(WIN32)
 
 # Enable CET Shadow Stack
-if(WIN32 AND NOT (CMAKE_C_COMPILER_ARCHITECTURE_ID MATCHES "ARM.*"))
+if(MSVC AND NOT (CMAKE_C_COMPILER_ARCHITECTURE_ID MATCHES "ARM.*"))
   add_link_options(/CETCOMPAT)
 endif()
 
@@ -646,9 +650,9 @@ endif( ${CMAKE_SYSTEM_NAME} MATCHES SunOS )
 set(CMAKE_SHARED_LIBRARY_LINK_CXX_FLAGS "")
 
 # enable warnings as errors for debug build
-if (WIN32)
+if (MSVC)
   SET(CMAKE_CXX_FLAGS_DEBUG  "${CMAKE_CXX_FLAGS_DEBUG} /WX")
-endif (WIN32)
+endif (MSVC)
 
 include(AddLLVM)
 include(TableGen)
@@ -761,7 +765,9 @@ if (LLVM_INCLUDE_DOCS)
   add_subdirectory(docs)
 endif()
 
-add_hlsl_hctgen(DxilDocs OUTPUT docs/DXIL.rst CODE_TAG) # HLSL Change
+if (LLVM_BUILD_DOCS)
+  add_hlsl_hctgen(DxilDocs OUTPUT docs/DXIL.rst CODE_TAG) # HLSL Change
+endif()
 
 add_subdirectory(cmake/modules)
 
diff --git a/cmake/modules/AddLLVM.cmake b/cmake/modules/AddLLVM.cmake
index b3c88ca65d..f25de66a32 100644
--- a/cmake/modules/AddLLVM.cmake
+++ b/cmake/modules/AddLLVM.cmake
@@ -245,14 +245,14 @@ endfunction()
 #
 function(add_windows_version_resource_file OUT_VAR)
   set(sources ${ARGN})
-  if (MSVC)
+  if (WIN32)
     set(resource_file ${LLVM_SOURCE_DIR}/resources/windows_version_resource.rc)
     if(EXISTS ${resource_file})
       set(sources ${sources} ${resource_file})
       source_group("Resource Files" ${resource_file})
       set(windows_resource_file ${resource_file} PARENT_SCOPE)
     endif()
-  endif(MSVC)
+  endif(WIN32)
 
   set(${OUT_VAR} ${sources} PARENT_SCOPE)
 endfunction(add_windows_version_resource_file)
@@ -296,8 +296,10 @@ function(set_windows_version_resource_properties name resource_file)
     set(ARG_PRODUCT_NAME "LLVM")
   endif()
 
+  if (MSVC)
   set_property(SOURCE ${resource_file}
                PROPERTY COMPILE_FLAGS /nologo)
+  endif()
   set_property(SOURCE ${resource_file}
                PROPERTY COMPILE_DEFINITIONS
                "RC_VERSION_FIELD_1=${ARG_VERSION_MAJOR}"
@@ -318,7 +320,7 @@ function(set_windows_version_resource_properties name resource_file)
                   "INCLUDE_HLSL_VERSION_FILE=1")
       set_property(SOURCE ${resource_file}
                   PROPERTY COMPILE_OPTIONS
-                  "/I" "${HLSL_VERSION_LOCATION}")
+                  "-I" "${HLSL_VERSION_LOCATION}")
     endif (DEFINED resource_file)
   endif(${HLSL_EMBED_VERSION})
   # HLSL change ends
diff --git a/cmake/modules/HandleLLVMOptions.cmake b/cmake/modules/HandleLLVMOptions.cmake
index 0ce75eeae8..7b8edecd3f 100644
--- a/cmake/modules/HandleLLVMOptions.cmake
+++ b/cmake/modules/HandleLLVMOptions.cmake
@@ -195,12 +195,13 @@ if( LLVM_ENABLE_PIC )
     # Xcode has -mdynamic-no-pic on by default, which overrides -fPIC. I don't
     # know how to disable this, so just force ENABLE_PIC off for now.
     message(WARNING "-fPIC not supported with Xcode.")
-  elseif( WIN32 OR CYGWIN)
-    # On Windows all code is PIC. MinGW warns if -fPIC is used.
   else()
-    add_flag_or_print_warning("-fPIC" FPIC)
+    if( NOT WIN32 AND NOT CYGWIN )
+      # On Windows all code is PIC. MinGW warns if -fPIC is used.
+      add_flag_or_print_warning("-fPIC" FPIC)
+    endif()
 
-    if( WIN32 OR CYGWIN)
+    if( (MINGW AND NOT CLANG) OR CYGWIN )
       # MinGW warns if -fvisibility-inlines-hidden is used.
     else()
       check_cxx_compiler_flag("-fvisibility-inlines-hidden" SUPPORTS_FVISIBILITY_INLINES_HIDDEN_FLAG)
@@ -407,6 +408,15 @@ elseif( LLVM_COMPILER_IS_GCC_COMPATIBLE )
     # Disable unknown pragma warnings because the output is just too long with them.
     append("-Wno-unknown-pragmas" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
 
+    if (MINGW)
+      append("-Wno-implicit-fallthrough" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
+      append("-Wno-missing-exception-spec" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
+      append("-Wno-reorder-ctor" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
+      append("-Wno-sign-compare" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
+      append("-Wno-unused-const-variable" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
+      append("-Wno-unused-function" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
+    endif()
+
     add_flag_if_supported("-Wno-unused-but-set-variable" UNUSED_BUT_SET_VARIABLE)
     add_flag_if_supported("-Wno-deprecated-copy" DEPRECATED_COPY)
 
@@ -614,6 +624,15 @@ 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()
 
+if (MINGW)
+  if (LLVM_ENABLE_EH)
+    append("-fexceptions" CMAKE_CXX_FLAGS)
+  endif()
+  if (LLVM_ENABLE_RTTI)
+    append("-frtti" CMAKE_CXX_FLAGS)
+  endif()
+endif()
+
 # HLSL Change Begin
 option(LLVM_ENABLE_LTO "Enable building with LTO" ${HLSL_OFFICIAL_BUILD})
 if (LLVM_ENABLE_LTO)
@@ -624,7 +643,7 @@ if (LLVM_ENABLE_LTO)
     append("/GL" CMAKE_C_FLAGS${_SUFFIX} CMAKE_CXX_FLAGS${_SUFFIX})
     append("/LTCG" CMAKE_MODULE_LINKER_FLAGS${_SUFFIX} CMAKE_MODULE_LINKER_FLAGS${_SUFFIX} CMAKE_EXE_LINKER_FLAGS${_SUFFIX})
   else()
-    add_flag_if_supported("-flto" SUPPORST_FLTO)
+    add_flag_if_supported("-flto" SUPPORTS_FLTO)
   endif()
 endif()
 # HLSL Change End
diff --git a/lib/DxilDia/CMakeLists.txt b/lib/DxilDia/CMakeLists.txt
index 2423d38740..fa47fa30bf 100644
--- a/lib/DxilDia/CMakeLists.txt
+++ b/lib/DxilDia/CMakeLists.txt
@@ -1,11 +1,11 @@
 # Copyright (C) Microsoft Corporation. All rights reserved.
 # This file is distributed under the University of Illinois Open Source License. See LICENSE.TXT for details.
 
-if (WIN32)
+if (MSVC)
   find_package(DiaSDK REQUIRED) # Used for constants and declarations.
-endif (WIN32)
+endif (MSVC)
 
-if (WIN32)
+if (MSVC)
   add_llvm_library(LLVMDxilDia
     DxcPixCompilationInfo.cpp
     DxcPixDxilDebugInfo.cpp
@@ -33,7 +33,7 @@ if (WIN32)
     ADDITIONAL_HEADER_DIRS
     ${LLVM_MAIN_INCLUDE_DIR}/llvm/IR
   )
-else(WIN32)
+else(MSVC)
   # DxcPixLiveVariables_FragmentIterator is not dependent on dia.
   # It is used by PixTest.
   set(HLSL_IGNORE_SOURCES
@@ -65,11 +65,11 @@ else(WIN32)
     ADDITIONAL_HEADER_DIRS
     ${LLVM_MAIN_INCLUDE_DIR}/llvm/IR
   )
-endif(WIN32)
+endif(MSVC)
 
-if (WIN32)
+if (MSVC)
   target_link_libraries(LLVMDxilDia PRIVATE ${LIBRARIES} ${DIASDK_LIBRARIES})
   include_directories(AFTER ${LLVM_INCLUDE_DIR}/dxc/Tracing ${DIASDK_INCLUDE_DIRS})
-endif (WIN32)
+endif (MSVC)
 
 add_dependencies(LLVMDxilDia LLVMDxilPIXPasses intrinsics_gen)
diff --git a/lib/Support/CMakeLists.txt b/lib/Support/CMakeLists.txt
index 396878aa2b..a1627a06c5 100644
--- a/lib/Support/CMakeLists.txt
+++ b/lib/Support/CMakeLists.txt
@@ -145,8 +145,8 @@ add_llvm_library(LLVMSupport
   )
 
 set_property(TARGET LLVMSupport PROPERTY LLVM_SYSTEM_LIBS "${system_libs}")
-if(WIN32)
+if(MSVC)
 set_property(TARGET LLVMSupport PROPERTY COMPILE_FLAGS /EHsc )
-endif(WIN32)
+endif(MSVC)
 
 target_link_libraries(LLVMSupport PUBLIC LLVMMSSupport) # HLSL Change
diff --git a/tools/CMakeLists.txt b/tools/CMakeLists.txt
index 2c96814c44..78f0f35f6d 100644
--- a/tools/CMakeLists.txt
+++ b/tools/CMakeLists.txt
@@ -21,10 +21,10 @@ add_llvm_tool_subdirectory(llvm-dis) # HLSL Change
 # add_llvm_tool_subdirectory(llvm-mc) # HLSL Change
 
 # HLSL Change Begins
-if (WIN32)
+if (MSVC)
 # This target can currently only be built on Windows.
 add_llvm_tool_subdirectory(dxexp)
-endif (WIN32)
+endif (MSVC)
 # HLSL Change ends
 
 # add_llvm_tool_subdirectory(llc) # HLSL Change
diff --git a/tools/clang/lib/Basic/CMakeLists.txt b/tools/clang/lib/Basic/CMakeLists.txt
index 2b2af8af26..243a017489 100644
--- a/tools/clang/lib/Basic/CMakeLists.txt
+++ b/tools/clang/lib/Basic/CMakeLists.txt
@@ -35,7 +35,7 @@ set(get_svn_script "${LLVM_MAIN_SRC_DIR}/cmake/modules/GetSVN.cmake")
 if (HLSL_ENABLE_FIXED_VER)
   # Actual version string is no longer specified here, but instead derived from
   # the defines in the generated or copied dxcversion.inc
-  add_definitions(/DHLSL_FIXED_VER)
+  add_definitions(-DHLSL_FIXED_VER)
 endif (HLSL_ENABLE_FIXED_VER)
 # HLSL Change Ends
 
diff --git a/tools/clang/lib/Sema/CMakeLists.txt b/tools/clang/lib/Sema/CMakeLists.txt
index 92cfcf3772..a4c51fa17c 100644
--- a/tools/clang/lib/Sema/CMakeLists.txt
+++ b/tools/clang/lib/Sema/CMakeLists.txt
@@ -72,6 +72,10 @@ add_clang_library(clangSema
 # Sema got too big for debug builds on arm64ec, which means it will hit
 # other targets too eventually.
 if(WIN32)
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /bigobj")
+  if(MSVC)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /bigobj")
+  else()
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wa,-mbig-obj")
+  endif()
 endif(WIN32)
 # HLSL Change End
diff --git a/tools/clang/tools/CMakeLists.txt b/tools/clang/tools/CMakeLists.txt
index 144135db49..ee7e404014 100644
--- a/tools/clang/tools/CMakeLists.txt
+++ b/tools/clang/tools/CMakeLists.txt
@@ -33,11 +33,11 @@ add_subdirectory(dxr)
 add_subdirectory(dxv)
 
 # These targets can currently only be built on Windows.
-if (WIN32)
+if (MSVC)
 add_subdirectory(d3dcomp)
 add_subdirectory(dxrfallbackcompiler)
 add_subdirectory(dxlib-sample)
 # UI powered by .NET.
 add_subdirectory(dotnetc)
-endif (WIN32)
+endif (MSVC)
 # HLSL Change Ends
diff --git a/tools/clang/tools/dxa/CMakeLists.txt b/tools/clang/tools/dxa/CMakeLists.txt
index 33e61ca121..6f12425939 100644
--- a/tools/clang/tools/dxa/CMakeLists.txt
+++ b/tools/clang/tools/dxa/CMakeLists.txt
@@ -2,9 +2,9 @@
 # This file is distributed under the University of Illinois Open Source License. See LICENSE.TXT for details.
 # Builds dxa.exe
 
-if (WIN32)
+if (MSVC)
   find_package(DiaSDK REQUIRED) # Used for constants and declarations.
-endif (WIN32)
+endif (MSVC)
 
 set( LLVM_LINK_COMPONENTS
   ${LLVM_TARGETS_TO_BUILD}
@@ -27,9 +27,9 @@ target_link_libraries(dxa
 
 set_target_properties(dxa PROPERTIES VERSION ${CLANG_EXECUTABLE_VERSION})
 
-if (WIN32)
+if (MSVC)
   include_directories(AFTER ${DIASDK_INCLUDE_DIRS})
-endif (WIN32)
+endif (MSVC)
 
 add_dependencies(dxa dxcompiler)
 
diff --git a/tools/clang/tools/dxc/CMakeLists.txt b/tools/clang/tools/dxc/CMakeLists.txt
index 882629c871..9df8da3463 100644
--- a/tools/clang/tools/dxc/CMakeLists.txt
+++ b/tools/clang/tools/dxc/CMakeLists.txt
@@ -2,9 +2,9 @@
 # This file is distributed under the University of Illinois Open Source License. See LICENSE.TXT for details.
 # Builds dxc.exe
 
-if (WIN32)
+if (MSVC)
   find_package(DiaSDK REQUIRED) # Used for constants and declarations.
-endif (WIN32)
+endif (MSVC)
 
 set( LLVM_LINK_COMPONENTS
   ${LLVM_TARGETS_TO_BUILD}
@@ -33,9 +33,9 @@ endif()
 
 set_target_properties(dxc PROPERTIES VERSION ${CLANG_EXECUTABLE_VERSION})
 
-if (WIN32)
+if (MSVC)
   include_directories(AFTER ${DIASDK_INCLUDE_DIRS})
-endif (WIN32)
+endif (MSVC)
 
 include_directories(${LLVM_SOURCE_DIR}/tools/clang/tools)
 
diff --git a/tools/clang/tools/dxclib/CMakeLists.txt b/tools/clang/tools/dxclib/CMakeLists.txt
index 830dedfcfa..e853eb56e0 100644
--- a/tools/clang/tools/dxclib/CMakeLists.txt
+++ b/tools/clang/tools/dxclib/CMakeLists.txt
@@ -2,9 +2,9 @@
 # This file is distributed under the University of Illinois Open Source License. See LICENSE.TXT for details.
 # Builds dxclib
 
-if (WIN32)
+if (MSVC)
   find_package(DiaSDK REQUIRED) # Used for constants and declarations.
-endif (WIN32)
+endif (MSVC)
 
 set( LLVM_LINK_COMPONENTS
   ${LLVM_TARGETS_TO_BUILD}
@@ -25,9 +25,13 @@ if(ENABLE_SPIRV_CODEGEN)
   target_link_libraries(dxclib PRIVATE clangSPIRV)
 endif()
 
-if (WIN32)
+if (MINGW)
+  target_link_libraries(dxclib PRIVATE version)
+endif()
+
+if (MSVC)
   include_directories(AFTER ${DIASDK_INCLUDE_DIRS})
-endif (WIN32)
+endif (MSVC)
 
 target_compile_definitions(dxclib
     PRIVATE VERSION_STRING_SUFFIX=" for ${CMAKE_SYSTEM_NAME}")
diff --git a/tools/clang/tools/dxcompiler/CMakeLists.txt b/tools/clang/tools/dxcompiler/CMakeLists.txt
index 8cddfcc941..d7aec3276e 100644
--- a/tools/clang/tools/dxcompiler/CMakeLists.txt
+++ b/tools/clang/tools/dxcompiler/CMakeLists.txt
@@ -121,13 +121,13 @@ set(GENERATED_HEADERS
   ClangStmtNodes
   )
 
-if (WIN32)
+if (MSVC)
   find_package(DiaSDK REQUIRED) # Used for constants and declarations.
-endif (WIN32)
+endif (MSVC)
 
 add_clang_library(dxcompiler SHARED ${SOURCES})
 add_dependencies(dxcompiler TablegenHLSLOptions) 
-if (WIN32)
+if (MSVC)
   # No DxcEtw on non-Windows platforms.
   add_dependencies(dxcompiler DxcEtw)
 endif()
diff --git a/tools/clang/tools/dxl/CMakeLists.txt b/tools/clang/tools/dxl/CMakeLists.txt
index 230140cff0..d3f123aad3 100644
--- a/tools/clang/tools/dxl/CMakeLists.txt
+++ b/tools/clang/tools/dxl/CMakeLists.txt
@@ -2,9 +2,9 @@
 # This file is distributed under the University of Illinois Open Source License. See LICENSE.TXT for details.
 # Builds dxl.exe
 
-if (WIN32)
+if (MSVC)
   find_package(DiaSDK REQUIRED) # Used for constants and declarations.
-endif (WIN32)
+endif (MSVC)
 
 set( LLVM_LINK_COMPONENTS
   ${LLVM_TARGETS_TO_BUILD}
@@ -26,9 +26,9 @@ target_link_libraries(dxl
 
 set_target_properties(dxl PROPERTIES VERSION ${CLANG_EXECUTABLE_VERSION})
 
-if (WIN32)
+if (MSVC)
   include_directories(AFTER ${DIASDK_INCLUDE_DIRS})
-endif (WIN32)
+endif (MSVC)
 
 include_directories(${LLVM_SOURCE_DIR}/tools/clang/tools)