[Modules] Fix a layering issue that is actually impacting the modules

selfhost.

The 'Core.h' C-API header is part of the IR LLVM library. (One might
even argue it should be called IR.h, but that's a separate point.) We
can't include it into a Support header without violating the layering,
and in a way that breaks modules. MemoryBuffer's opaque C type was being
defined in the Core.h C-API header despite being in the Support library,
and thus we ended up with this weird issue.

It turns out that there were other constructs from the Support library
in the Core.h header. This patch lifts all of them into Support.h and
then includes that into Core.h.

The only possible fallout is if someone was including Support.h and
relying on Core.h to be visible for their own uses. Considering the
narrow interface actually provided by the C-API for the Support library,
this seems a very, very unlikely mistake.

llvm-svn: 203071

llvm/include/llvm-c/Core.h

@@ -15,7 +15,7 @@
 #ifndef LLVM_C_CORE_H
 #define LLVM_C_CORE_H
 
-#include "llvm/Support/DataTypes.h"
+#include "llvm-c/Support.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -62,8 +62,6 @@ extern "C" {
  * @{
  */
 
-typedef int LLVMBool;
-
 /* Opaque types. */
 
 /**
@@ -114,13 +112,6 @@ typedef struct LLVMOpaqueBuilder *LLVMBuilderRef;
  */
 typedef struct LLVMOpaqueModuleProvider *LLVMModuleProviderRef;
 
-/**
- * Used to provide a module to JIT or interpreter.
- *
- * @see llvm::MemoryBuffer
- */
-typedef struct LLVMOpaqueMemoryBuffer *LLVMMemoryBufferRef;
-
 /** @see llvm::PassManagerBase */
 typedef struct LLVMOpaquePassManager *LLVMPassManagerRef;
 

llvm/include/llvm-c/Support.h

@@ -14,12 +14,31 @@
 #ifndef LLVM_C_SUPPORT_H
 #define LLVM_C_SUPPORT_H
 
-#include "llvm-c/Core.h"
+#include "llvm/Support/DataTypes.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+/**
+ * @defgroup LLVMCSupportTypes Types and Enumerations
+ *
+ * @{
+ */
+
+typedef int LLVMBool;
+
+/**
+ * Used to pass regions of memory through LLVM interfaces.
+ *
+ * @see llvm::MemoryBuffer
+ */
+typedef struct LLVMOpaqueMemoryBuffer *LLVMMemoryBufferRef;
+
+/**
+ * @}
+ */
+
 /**
  * This function permanently loads the dynamic library at the given path.
  * It is safe to call this function multiple times for the same library.

llvm/include/llvm/Support/MemoryBuffer.h

@@ -14,7 +14,7 @@
 #ifndef LLVM_SUPPORT_MEMORYBUFFER_H
 #define LLVM_SUPPORT_MEMORYBUFFER_H
 
-#include "llvm-c/Core.h"
+#include "llvm-c/Support.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/Support/CBindingWrapping.h"
 #include "llvm/Support/Compiler.h"