With MSVC, file needs to be compiled with /BIGOBJ

[amccarth]

Summary

MSVC, by default, limits the number of sections generated by a single translation unit to 2^16. In a debug build, each function or method can require 4 sections, so it's not uncommon to hit it. The cl.exe option /BIGOBJ raises the limit.

I saw the problem when building tests for LLDB (but, interestingly, not for LLDB itself).

[labath]

I saw the problem when building tests for LLDB (but, interestingly, not for LLDB itself).

My guess would be this is because this file does not actually get used in lldb. It is used in the clang driver though, which is a dependency for running lldb tests...

clang/lib/ARCMigrate/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
   Support
   )
 
+# By default MSVC has a 2^16 limit on the number of sections in an object
+# file, and Transforms.cpp needs more than that.
+if (MSVC)
+  set_source_files_properties(Transforms.cpp PROPERTIES COMPILE_FLAGS /bigobj)
+endif()
+
 add_clang_library(clangARCMigrate
   ARCMT.cpp
   ARCMTActions.cpp
   FileRemapper.cpp
   ObjCMT.cpp
   PlistReporter.cpp
   TransAPIUses.cpp
   TransARCAssign.cpp