Index: tools/llvm-shlib/CMakeLists.txt
===================================================================
--- tools/llvm-shlib/CMakeLists.txt
+++ tools/llvm-shlib/CMakeLists.txt
@@ -164,8 +164,21 @@
 
   set(LLVM_EXPORTED_SYMBOL_FILE ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/libllvm-c.exports)
 
+  # If we are crosscompiling with clang-cl MSVC reports as true yet the llvm-nm
+  # in the build directory can not run on the host. If so, default to the nm
+  # found by cmake.
+  if (CMAKE_CROSSCOMPILING)
+    if (CMAKE_NM)
+      set(GEN_NM ${CMAKE_NM})
+    else()
+      message(FATAL_ERROR "Building LLVM-C requires the nm tool. Either disable it or set -DCMAKE_NM=/path/to/nm")
+    endif()
+  else()
+    set(GEN_NM ${LLVM_TOOLS_BINARY_DIR}/llvm-nm)
+  endif()
+
   add_custom_command(OUTPUT ${LLVM_EXPORTED_SYMBOL_FILE}
-    COMMAND ${PYTHON_EXECUTABLE} ${GEN_SCRIPT} --libsfile ${LIBSFILE} ${GEN_UNDERSCORE} --nm ${LLVM_TOOLS_BINARY_DIR}/llvm-nm -o ${LLVM_EXPORTED_SYMBOL_FILE}
+    COMMAND ${PYTHON_EXECUTABLE} ${GEN_SCRIPT} --libsfile ${LIBSFILE} ${GEN_UNDERSCORE} --nm ${GEN_NM} -o ${LLVM_EXPORTED_SYMBOL_FILE}
     DEPENDS ${LIB_NAMES} llvm-nm
     COMMENT "Generating export list for LLVM-C"
     VERBATIM )