diff --git a/mlir/CMakeLists.txt b/mlir/CMakeLists.txt
--- a/mlir/CMakeLists.txt
+++ b/mlir/CMakeLists.txt
@@ -139,6 +139,16 @@
   mlir_configure_python_dev_packages()
 endif()
 
+# For upstream, we accumulate all libraries into the MLIR_CAPI_LIBRARIES
+# property via a custom wrapper function. This is then used to create an
+# aggregate below.
+set_property(GLOBAL APPEND PROPERTY MLIR_CAPI_LIBRARIES)
+function(add_mlir_upstream_c_api_library name)
+  add_mlir_public_c_api_library(${name} ${ARGN})
+  set_property(GLOBAL APPEND PROPERTY MLIR_CAPI_LIBRARIES ${name})
+endfunction()
+
+
 include_directories( "include")
 include_directories( ${MLIR_INCLUDE_DIR})
 
diff --git a/mlir/include/mlir-c/AffineExpr.h b/mlir/core/include/mlir-c/AffineExpr.h
rename from mlir/include/mlir-c/AffineExpr.h
rename to mlir/core/include/mlir-c/AffineExpr.h
diff --git a/mlir/include/mlir-c/AffineMap.h b/mlir/core/include/mlir-c/AffineMap.h
rename from mlir/include/mlir-c/AffineMap.h
rename to mlir/core/include/mlir-c/AffineMap.h
diff --git a/mlir/include/mlir-c/BuiltinAttributes.h b/mlir/core/include/mlir-c/BuiltinAttributes.h
rename from mlir/include/mlir-c/BuiltinAttributes.h
rename to mlir/core/include/mlir-c/BuiltinAttributes.h
diff --git a/mlir/include/mlir-c/BuiltinTypes.h b/mlir/core/include/mlir-c/BuiltinTypes.h
rename from mlir/include/mlir-c/BuiltinTypes.h
rename to mlir/core/include/mlir-c/BuiltinTypes.h
diff --git a/mlir/include/mlir-c/Debug.h b/mlir/core/include/mlir-c/Debug.h
rename from mlir/include/mlir-c/Debug.h
rename to mlir/core/include/mlir-c/Debug.h
diff --git a/mlir/include/mlir-c/Diagnostics.h b/mlir/core/include/mlir-c/Diagnostics.h
rename from mlir/include/mlir-c/Diagnostics.h
rename to mlir/core/include/mlir-c/Diagnostics.h
diff --git a/mlir/include/mlir-c/IR.h b/mlir/core/include/mlir-c/IR.h
rename from mlir/include/mlir-c/IR.h
rename to mlir/core/include/mlir-c/IR.h
diff --git a/mlir/include/mlir-c/IntegerSet.h b/mlir/core/include/mlir-c/IntegerSet.h
rename from mlir/include/mlir-c/IntegerSet.h
rename to mlir/core/include/mlir-c/IntegerSet.h
diff --git a/mlir/include/mlir-c/Interfaces.h b/mlir/core/include/mlir-c/Interfaces.h
rename from mlir/include/mlir-c/Interfaces.h
rename to mlir/core/include/mlir-c/Interfaces.h
diff --git a/mlir/include/mlir-c/Pass.h b/mlir/core/include/mlir-c/Pass.h
rename from mlir/include/mlir-c/Pass.h
rename to mlir/core/include/mlir-c/Pass.h
diff --git a/mlir/include/mlir-c/Registration.h b/mlir/core/include/mlir-c/Registration.h
rename from mlir/include/mlir-c/Registration.h
rename to mlir/core/include/mlir-c/Registration.h
diff --git a/mlir/include/mlir-c/Support.h b/mlir/core/include/mlir-c/Support.h
rename from mlir/include/mlir-c/Support.h
rename to mlir/core/include/mlir-c/Support.h
diff --git a/mlir/include/mlir/CAPI/AffineExpr.h b/mlir/core/include/mlir/CAPI/AffineExpr.h
rename from mlir/include/mlir/CAPI/AffineExpr.h
rename to mlir/core/include/mlir/CAPI/AffineExpr.h
diff --git a/mlir/include/mlir/CAPI/AffineMap.h b/mlir/core/include/mlir/CAPI/AffineMap.h
rename from mlir/include/mlir/CAPI/AffineMap.h
rename to mlir/core/include/mlir/CAPI/AffineMap.h
diff --git a/mlir/include/mlir/CAPI/Diagnostics.h b/mlir/core/include/mlir/CAPI/Diagnostics.h
rename from mlir/include/mlir/CAPI/Diagnostics.h
rename to mlir/core/include/mlir/CAPI/Diagnostics.h
diff --git a/mlir/include/mlir/CAPI/IR.h b/mlir/core/include/mlir/CAPI/IR.h
rename from mlir/include/mlir/CAPI/IR.h
rename to mlir/core/include/mlir/CAPI/IR.h
diff --git a/mlir/include/mlir/CAPI/IntegerSet.h b/mlir/core/include/mlir/CAPI/IntegerSet.h
rename from mlir/include/mlir/CAPI/IntegerSet.h
rename to mlir/core/include/mlir/CAPI/IntegerSet.h
diff --git a/mlir/include/mlir/CAPI/Interfaces.h b/mlir/core/include/mlir/CAPI/Interfaces.h
rename from mlir/include/mlir/CAPI/Interfaces.h
rename to mlir/core/include/mlir/CAPI/Interfaces.h
diff --git a/mlir/include/mlir/CAPI/Pass.h b/mlir/core/include/mlir/CAPI/Pass.h
rename from mlir/include/mlir/CAPI/Pass.h
rename to mlir/core/include/mlir/CAPI/Pass.h
diff --git a/mlir/include/mlir/CAPI/Registration.h b/mlir/core/include/mlir/CAPI/Registration.h
rename from mlir/include/mlir/CAPI/Registration.h
rename to mlir/core/include/mlir/CAPI/Registration.h
diff --git a/mlir/include/mlir/CAPI/Support.h b/mlir/core/include/mlir/CAPI/Support.h
rename from mlir/include/mlir/CAPI/Support.h
rename to mlir/core/include/mlir/CAPI/Support.h
diff --git a/mlir/include/mlir/CAPI/Utils.h b/mlir/core/include/mlir/CAPI/Utils.h
rename from mlir/include/mlir/CAPI/Utils.h
rename to mlir/core/include/mlir/CAPI/Utils.h
diff --git a/mlir/include/mlir/CAPI/Wrap.h b/mlir/core/include/mlir/CAPI/Wrap.h
rename from mlir/include/mlir/CAPI/Wrap.h
rename to mlir/core/include/mlir/CAPI/Wrap.h
diff --git a/mlir/core/lib/CAPI/CMakeLists.txt b/mlir/core/lib/CAPI/CMakeLists.txt
new file mode 100644
--- /dev/null
+++ b/mlir/core/lib/CAPI/CMakeLists.txt
@@ -0,0 +1,4 @@
+add_subdirectory(Debug)
+add_subdirectory(Interfaces)
+add_subdirectory(IR)
+add_subdirectory(Registration)
diff --git a/mlir/lib/CAPI/Debug/CMakeLists.txt b/mlir/core/lib/CAPI/Debug/CMakeLists.txt
rename from mlir/lib/CAPI/Debug/CMakeLists.txt
rename to mlir/core/lib/CAPI/Debug/CMakeLists.txt
diff --git a/mlir/lib/CAPI/Debug/Debug.cpp b/mlir/core/lib/CAPI/Debug/Debug.cpp
rename from mlir/lib/CAPI/Debug/Debug.cpp
rename to mlir/core/lib/CAPI/Debug/Debug.cpp
diff --git a/mlir/lib/CAPI/IR/AffineExpr.cpp b/mlir/core/lib/CAPI/IR/AffineExpr.cpp
rename from mlir/lib/CAPI/IR/AffineExpr.cpp
rename to mlir/core/lib/CAPI/IR/AffineExpr.cpp
diff --git a/mlir/lib/CAPI/IR/AffineMap.cpp b/mlir/core/lib/CAPI/IR/AffineMap.cpp
rename from mlir/lib/CAPI/IR/AffineMap.cpp
rename to mlir/core/lib/CAPI/IR/AffineMap.cpp
diff --git a/mlir/lib/CAPI/IR/BuiltinAttributes.cpp b/mlir/core/lib/CAPI/IR/BuiltinAttributes.cpp
rename from mlir/lib/CAPI/IR/BuiltinAttributes.cpp
rename to mlir/core/lib/CAPI/IR/BuiltinAttributes.cpp
diff --git a/mlir/lib/CAPI/IR/BuiltinTypes.cpp b/mlir/core/lib/CAPI/IR/BuiltinTypes.cpp
rename from mlir/lib/CAPI/IR/BuiltinTypes.cpp
rename to mlir/core/lib/CAPI/IR/BuiltinTypes.cpp
diff --git a/mlir/lib/CAPI/IR/CMakeLists.txt b/mlir/core/lib/CAPI/IR/CMakeLists.txt
rename from mlir/lib/CAPI/IR/CMakeLists.txt
rename to mlir/core/lib/CAPI/IR/CMakeLists.txt
diff --git a/mlir/lib/CAPI/IR/Diagnostics.cpp b/mlir/core/lib/CAPI/IR/Diagnostics.cpp
rename from mlir/lib/CAPI/IR/Diagnostics.cpp
rename to mlir/core/lib/CAPI/IR/Diagnostics.cpp
diff --git a/mlir/lib/CAPI/IR/DialectHandle.cpp b/mlir/core/lib/CAPI/IR/DialectHandle.cpp
rename from mlir/lib/CAPI/IR/DialectHandle.cpp
rename to mlir/core/lib/CAPI/IR/DialectHandle.cpp
diff --git a/mlir/lib/CAPI/IR/IR.cpp b/mlir/core/lib/CAPI/IR/IR.cpp
rename from mlir/lib/CAPI/IR/IR.cpp
rename to mlir/core/lib/CAPI/IR/IR.cpp
diff --git a/mlir/lib/CAPI/IR/IntegerSet.cpp b/mlir/core/lib/CAPI/IR/IntegerSet.cpp
rename from mlir/lib/CAPI/IR/IntegerSet.cpp
rename to mlir/core/lib/CAPI/IR/IntegerSet.cpp
diff --git a/mlir/lib/CAPI/IR/Pass.cpp b/mlir/core/lib/CAPI/IR/Pass.cpp
rename from mlir/lib/CAPI/IR/Pass.cpp
rename to mlir/core/lib/CAPI/IR/Pass.cpp
diff --git a/mlir/lib/CAPI/IR/Support.cpp b/mlir/core/lib/CAPI/IR/Support.cpp
rename from mlir/lib/CAPI/IR/Support.cpp
rename to mlir/core/lib/CAPI/IR/Support.cpp
diff --git a/mlir/lib/CAPI/Interfaces/CMakeLists.txt b/mlir/core/lib/CAPI/Interfaces/CMakeLists.txt
rename from mlir/lib/CAPI/Interfaces/CMakeLists.txt
rename to mlir/core/lib/CAPI/Interfaces/CMakeLists.txt
diff --git a/mlir/lib/CAPI/Interfaces/Interfaces.cpp b/mlir/core/lib/CAPI/Interfaces/Interfaces.cpp
rename from mlir/lib/CAPI/Interfaces/Interfaces.cpp
rename to mlir/core/lib/CAPI/Interfaces/Interfaces.cpp
diff --git a/mlir/core/lib/CAPI/Registration/CMakeLists.txt b/mlir/core/lib/CAPI/Registration/CMakeLists.txt
new file mode 100644
--- /dev/null
+++ b/mlir/core/lib/CAPI/Registration/CMakeLists.txt
@@ -0,0 +1,10 @@
+add_mlir_upstream_c_api_library(MLIRCAPIRegistration
+  Registration.cpp
+
+  LINK_LIBS PUBLIC
+  MLIRCAPIIR
+  MLIRLLVMToLLVMIRTranslation
+  MLIRAllDialects
+  MLIRAllConversions
+  MLIRAllTranslations
+  )
diff --git a/mlir/lib/CAPI/Registration/Registration.cpp b/mlir/core/lib/CAPI/Registration/Registration.cpp
rename from mlir/lib/CAPI/Registration/Registration.cpp
rename to mlir/core/lib/CAPI/Registration/Registration.cpp
diff --git a/mlir/core/lib/CMakeLists.txt b/mlir/core/lib/CMakeLists.txt
--- a/mlir/core/lib/CMakeLists.txt
+++ b/mlir/core/lib/CMakeLists.txt
@@ -1,2 +1,3 @@
+add_subdirectory(CAPI)
 add_subdirectory(Interfaces)
 add_subdirectory(IR)
diff --git a/mlir/lib/CAPI/CMakeLists.txt b/mlir/lib/CAPI/CMakeLists.txt
--- a/mlir/lib/CAPI/CMakeLists.txt
+++ b/mlir/lib/CAPI/CMakeLists.txt
@@ -1,18 +1,6 @@
-# For upstream, we accumulate all libraries into the MLIR_CAPI_LIBRARIES
-# property via a custom wrapper function. This is then used to create an
-# aggregate below.
-set_property(GLOBAL APPEND PROPERTY MLIR_CAPI_LIBRARIES)
-function(add_mlir_upstream_c_api_library name)
-  add_mlir_public_c_api_library(${name} ${ARGN})
-  set_property(GLOBAL APPEND PROPERTY MLIR_CAPI_LIBRARIES ${name})
-endfunction()
 
-add_subdirectory(Debug)
 add_subdirectory(Dialect)
 add_subdirectory(Conversion)
-add_subdirectory(Interfaces)
-add_subdirectory(IR)
-add_subdirectory(Registration)
 add_subdirectory(Transforms)
 
 # Only enable the ExecutionEngine if the native target is configured in.
diff --git a/mlir/lib/CAPI/Registration/CMakeLists.txt b/mlir/lib/CAPI/Registration/CMakeLists.txt
deleted file mode 100644
--- a/mlir/lib/CAPI/Registration/CMakeLists.txt
+++ /dev/null
@@ -1,14 +0,0 @@
-# Dialect registration.
-get_property(dialect_libs GLOBAL PROPERTY MLIR_DIALECT_LIBS)
-get_property(translation_libs GLOBAL PROPERTY MLIR_TRANSLATION_LIBS)
-get_property(conversion_libs GLOBAL PROPERTY MLIR_CONVERSION_LIBS)
-add_mlir_upstream_c_api_library(MLIRCAPIRegistration
-  Registration.cpp
-
-  LINK_LIBS PUBLIC
-  MLIRCAPIIR
-  MLIRLLVMToLLVMIRTranslation
-  ${dialect_libs}
-  ${translation_libs}
-  ${conversion_libs}
-)
diff --git a/mlir/lib/CMakeLists.txt b/mlir/lib/CMakeLists.txt
--- a/mlir/lib/CMakeLists.txt
+++ b/mlir/lib/CMakeLists.txt
@@ -14,6 +14,19 @@
 add_subdirectory(Tools)
 add_subdirectory(Transforms)
 
+get_property(dialect_libs GLOBAL PROPERTY MLIR_DIALECT_LIBS)
+add_mlir_library(MLIRAllDialects empty.cpp)
+target_link_libraries(MLIRAllDialects INTERFACE ${dialect_libs})
+
+get_property(translation_libs GLOBAL PROPERTY MLIR_TRANSLATION_LIBS)
+add_mlir_library(MLIRAllTranslations empty.cpp)
+target_link_libraries(MLIRAllDialects INTERFACE ${translation_libs})
+
+get_property(conversion_libs GLOBAL PROPERTY MLIR_CONVERSION_LIBS)
+add_mlir_library(MLIRAllConversions empty.cpp)
+target_link_libraries(MLIRAllDialects INTERFACE ${conversion_libs})
+
+
 # Only enable the ExecutionEngine if the native target is configured in.
 if(TARGET ${LLVM_NATIVE_ARCH})
   add_subdirectory(ExecutionEngine)
diff --git a/mlir/lib/empty.cpp b/mlir/lib/empty.cpp
new file mode 100644