Make LLVMInitializeAll* API have their symbols

[nagisa]

Summary

These functions were the only inline C API functions. This makes it impossible to bind these useful functions from non-C languages via FFI as they rely on symbols for these functions existing.

With this PR a new libLLVMAllTargets.a static library is built which contains the non-inline implementations for the functions. I manually confirmed that the bin directory does not increase much in size and that libLLVM-4.0svn.so contains the newly added symbols.

Resubmission of https://reviews.llvm.org/D22734.

[whitequark]

@echristo Assuming this works as one would expect, this is a massive improvement. However, I'm not completely certain of all subtle build system behavior. Do you see any potential downsides?

[nagisa]

@echristo I would really appreciate a review.

[nagisa]

This still wants a review, especially regarding the cmake particularities.

[mehdi_amini]

Isn't it exactly what was done in r192690 (and reverted later because it broke stuff)?

[whitequark]

@nagisa, please test your changes on Windows and OS X. (For reference the commit that introduced it can be seen at rL192690 and the revert at rL192697.)

[nagisa]

I built this on MSVC today (cmake $PATH_TO_LLVM && double-click LLVM.sln && initiate the build in MSVC) and it built (seemingly) whole of LLVM successfully, but ended failing at some ADT/ArrayRef tests due to missing declarations or definitions (something about .contains() not being present on some type etc), which seem to be unrelated to this patch.

[mehdi_amini]

The previous patch was reverted because of building with individual shared dylibs, might be worth trying it (whatever OS)

[whitequark]

@nagisa ping?

[nagisa]

No time/mood to pursue this further. Feel free to take over.

docs/ReleaseNotes.rst

 
 .. NOTE
    For small 1-3 sentence descriptions, just add an entry at the end of
    this list. If your description won't fit comfortably in one bullet
    point (e.g. maybe you would like to give an example of the
    functionality, or simply have a lot to talk about), see the `NOTE` below
    for adding a new subsection.
 
+* C APIs for ``LLVMInitializeAllTarget{s,Infos,MCs}`` and
+  ``LLVMInitializeAllAsm{Printers,Parsers}`` as well as their ``Native`` counterparts are not
+  ``static inline`` anymore allowing them to be used via FFI.
+
 * ... next change ...
 
 .. NOTE
    If you would like to document a larger change, then you can add a
    subsection about it right here. You can copy the following boilerplate
    and un-indent it (the indentation causes it to be inside this comment).
 
    Special New Feature

include/llvm-c/Target.h

 /* tools written in such languages.                                           */
 /*                                                                            */
 /*===----------------------------------------------------------------------===*/
 
 #ifndef LLVM_C_TARGET_H
 #define LLVM_C_TARGET_H
 
 #include "llvm-c/Types.h"
-#include "llvm/Config/llvm-config.h"
-
-#if defined(_MSC_VER) && !defined(inline)
-#define inline __inline
-#endif
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 /**
  * @defgroup LLVMCTarget Target information
  * @ingroup LLVMC
  *
  * @{
  */
 
 enum LLVMByteOrdering { LLVMBigEndian, LLVMLittleEndian };
 
 typedef struct LLVMOpaqueTargetData *LLVMTargetDataRef;
 typedef struct LLVMOpaqueTargetLibraryInfotData *LLVMTargetLibraryInfoRef;
 
 /* Declare all of the target-initialization functions that are available. */
 #define LLVM_TARGET(TargetName) \
   void LLVMInitialize##TargetName##TargetInfo(void);
 #include "llvm/Config/Targets.def"
 #undef LLVM_TARGET  /* Explicit undef to make SWIG happier */
 
-#define LLVM_TARGET(TargetName) void LLVMInitialize##TargetName##Target(void);
+#define LLVM_TARGET(TargetName) \
+  void LLVMInitialize##TargetName##Target(void);
 #include "llvm/Config/Targets.def"
 #undef LLVM_TARGET  /* Explicit undef to make SWIG happier */
 
 #define LLVM_TARGET(TargetName) \
   void LLVMInitialize##TargetName##TargetMC(void);
 #include "llvm/Config/Targets.def"
 #undef LLVM_TARGET  /* Explicit undef to make SWIG happier */
 

 #define LLVM_DISASSEMBLER(TargetName) \
   void LLVMInitialize##TargetName##Disassembler(void);
 #include "llvm/Config/Disassemblers.def"
 #undef LLVM_DISASSEMBLER  /* Explicit undef to make SWIG happier */
 
 /** LLVMInitializeAllTargetInfos - The main program should call this function if
     it wants access to all available targets that LLVM is configured to
     support. */
-static inline void LLVMInitializeAllTargetInfos(void) {
-#define LLVM_TARGET(TargetName) LLVMInitialize##TargetName##TargetInfo();
-#include "llvm/Config/Targets.def"
-#undef LLVM_TARGET  /* Explicit undef to make SWIG happier */
-}
+void LLVMInitializeAllTargetInfos(void);
 
 /** LLVMInitializeAllTargets - The main program should call this function if it
     wants to link in all available targets that LLVM is configured to
     support. */
-static inline void LLVMInitializeAllTargets(void) {
-#define LLVM_TARGET(TargetName) LLVMInitialize##TargetName##Target();
-#include "llvm/Config/Targets.def"
-#undef LLVM_TARGET  /* Explicit undef to make SWIG happier */
-}
+void LLVMInitializeAllTargets(void);
 
 /** LLVMInitializeAllTargetMCs - The main program should call this function if
     it wants access to all available target MC that LLVM is configured to
     support. */
-static inline void LLVMInitializeAllTargetMCs(void) {
-#define LLVM_TARGET(TargetName) LLVMInitialize##TargetName##TargetMC();
-#include "llvm/Config/Targets.def"
-#undef LLVM_TARGET  /* Explicit undef to make SWIG happier */
-}
+void LLVMInitializeAllTargetMCs(void);
 
 /** LLVMInitializeAllAsmPrinters - The main program should call this function if
     it wants all asm printers that LLVM is configured to support, to make them
     available via the TargetRegistry. */
-static inline void LLVMInitializeAllAsmPrinters(void) {
-#define LLVM_ASM_PRINTER(TargetName) LLVMInitialize##TargetName##AsmPrinter();
-#include "llvm/Config/AsmPrinters.def"
-#undef LLVM_ASM_PRINTER  /* Explicit undef to make SWIG happier */
-}
+void LLVMInitializeAllAsmPrinters(void);
 
 /** LLVMInitializeAllAsmParsers - The main program should call this function if
     it wants all asm parsers that LLVM is configured to support, to make them
     available via the TargetRegistry. */
-static inline void LLVMInitializeAllAsmParsers(void) {
-#define LLVM_ASM_PARSER(TargetName) LLVMInitialize##TargetName##AsmParser();
-#include "llvm/Config/AsmParsers.def"
-#undef LLVM_ASM_PARSER  /* Explicit undef to make SWIG happier */
-}
+void LLVMInitializeAllAsmParsers(void);
 
 /** LLVMInitializeAllDisassemblers - The main program should call this function
     if it wants all disassemblers that LLVM is configured to support, to make
     them available via the TargetRegistry. */
-static inline void LLVMInitializeAllDisassemblers(void) {
-#define LLVM_DISASSEMBLER(TargetName) \
-  LLVMInitialize##TargetName##Disassembler();
-#include "llvm/Config/Disassemblers.def"
-#undef LLVM_DISASSEMBLER  /* Explicit undef to make SWIG happier */
-}
+void LLVMInitializeAllDisassemblers(void);
 
 /** LLVMInitializeNativeTarget - The main program should call this function to
     initialize the native target corresponding to the host.  This is useful
     for JIT applications to ensure that the target gets linked in correctly. */
-static inline LLVMBool LLVMInitializeNativeTarget(void) {
-  /* If we have a native target, initialize it to ensure it is linked in. */
-#ifdef LLVM_NATIVE_TARGET
-  LLVM_NATIVE_TARGETINFO();
-  LLVM_NATIVE_TARGET();
-  LLVM_NATIVE_TARGETMC();
-  return 0;
-#else
-  return 1;
-#endif
-}
+LLVMBool LLVMInitializeNativeTarget(void);
 
 /** LLVMInitializeNativeTargetAsmParser - The main program should call this
     function to initialize the parser for the native target corresponding to the
     host. */
-static inline LLVMBool LLVMInitializeNativeAsmParser(void) {
-#ifdef LLVM_NATIVE_ASMPARSER
-  LLVM_NATIVE_ASMPARSER();
-  return 0;
-#else
-  return 1;
-#endif
-}
+LLVMBool LLVMInitializeNativeAsmParser(void);
 
 /** LLVMInitializeNativeTargetAsmPrinter - The main program should call this
     function to initialize the printer for the native target corresponding to
     the host. */
-static inline LLVMBool LLVMInitializeNativeAsmPrinter(void) {
-#ifdef LLVM_NATIVE_ASMPRINTER
-  LLVM_NATIVE_ASMPRINTER();
-  return 0;
-#else
-  return 1;
-#endif
-}
+LLVMBool LLVMInitializeNativeAsmPrinter(void);
 
 /** LLVMInitializeNativeTargetDisassembler - The main program should call this
     function to initialize the disassembler for the native target corresponding
     to the host. */
-static inline LLVMBool LLVMInitializeNativeDisassembler(void) {
-#ifdef LLVM_NATIVE_DISASSEMBLER
-  LLVM_NATIVE_DISASSEMBLER();
-  return 0;
-#else
-  return 1;
-#endif
-}
+LLVMBool LLVMInitializeNativeDisassembler(void);
 
 /*===-- Target Data -------------------------------------------------------===*/
 
 /**
  * Obtain the data layout for a module.
  *
  * @see Module::getDataLayout()
  */

lib/Target/AllTargets/AllTargets.cpp

+//===-- AllTargets.cpp --------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the C FFI bindings to utility functions which initialize
+// all targets and utility functions which initialize “native” targets. This is
+// a separate library from libLLVMTarget.a, so dependents on libLLVMTarget woudln’t
+// pull in all the available backends.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Config/llvm-config.h"
+#include "llvm-c/Target.h"
+#include "llvm-c/Initialization.h"
+
+void LLVMInitializeAllTargets(void) {
+#define LLVM_TARGET(TargetName) LLVMInitialize##TargetName##Target();
+#include "llvm/Config/Targets.def"
+#undef LLVM_TARGET  /* Explicit undef to make SWIG happier */
+}
+
+void LLVMInitializeAllTargetInfos(void) {
+#define LLVM_TARGET(TargetName) LLVMInitialize##TargetName##TargetInfo();
+#include "llvm/Config/Targets.def"
+#undef LLVM_TARGET  /* Explicit undef to make SWIG happier */
+}
+
+void LLVMInitializeAllTargetMCs(void) {
+#define LLVM_TARGET(TargetName) LLVMInitialize##TargetName##TargetMC();
+#include "llvm/Config/Targets.def"
+#undef LLVM_TARGET  /* Explicit undef to make SWIG happier */
+}
+
+void LLVMInitializeAllAsmPrinters(void) {
+#define LLVM_ASM_PRINTER(TargetName) LLVMInitialize##TargetName##AsmPrinter();
+#include "llvm/Config/AsmPrinters.def"
+#undef LLVM_ASM_PRINTER  /* Explicit undef to make SWIG happier */
+}
+
+void LLVMInitializeAllAsmParsers(void) {
+#define LLVM_ASM_PARSER(TargetName) LLVMInitialize##TargetName##AsmParser();
+#include "llvm/Config/AsmParsers.def"
+#undef LLVM_ASM_PARSER  /* Explicit undef to make SWIG happier */
+}
+
+void LLVMInitializeAllDisassemblers(void) {
+#define LLVM_DISASSEMBLER(TargetName) \
+  LLVMInitialize##TargetName##Disassembler();
+#include "llvm/Config/Disassemblers.def"
+#undef LLVM_DISASSEMBLER  /* Explicit undef to make SWIG happier */
+}
+
+LLVMBool LLVMInitializeNativeTarget(void) {
+  /* If we have a native target, initialize it to ensure it is linked in. */
+#ifdef LLVM_NATIVE_TARGET
+  LLVM_NATIVE_TARGETINFO();
+  LLVM_NATIVE_TARGET();
+  LLVM_NATIVE_TARGETMC();
+  return 0;
+#else
+  return 1;
+#endif
+}
+
+LLVMBool LLVMInitializeNativeAsmParser(void) {
+#ifdef LLVM_NATIVE_ASMPARSER
+  LLVM_NATIVE_ASMPARSER();
+  return 0;
+#else
+  return 1;
+#endif
+}
+
+LLVMBool LLVMInitializeNativeAsmPrinter(void) {
+#ifdef LLVM_NATIVE_ASMPRINTER
+  LLVM_NATIVE_ASMPRINTER();
+  return 0;
+#else
+  return 1;
+#endif
+}
+
+LLVMBool LLVMInitializeNativeDisassembler(void) {
+#ifdef LLVM_NATIVE_DISASSEMBLER
+  LLVM_NATIVE_DISASSEMBLER();
+  return 0;
+#else
+  return 1;
+#endif
+}

lib/Target/AllTargets/CMakeLists.txt

+add_llvm_library(LLVMAllTargets
+  AllTargets.cpp
+
+  ADDITIONAL_HEADER_DIRS
+  ${LLVM_MAIN_INCLUDE_DIR}/llvm/Target
+  ${LLVM_MAIN_INCLUDE_DIR}/llvm-c/
+
+  LINK_COMPONENTS ${LLVM_TARGETS_TO_BUILD}
+  )

lib/Target/CMakeLists.txt

add_llvm_library(LLVMTarget
   ADDITIONAL_HEADER_DIRS
   ${LLVM_MAIN_INCLUDE_DIR}/llvm/Target
   )
 
 foreach(t ${LLVM_TARGETS_TO_BUILD})
   message(STATUS "Targeting ${t}")
   add_subdirectory(${t})
 endforeach()
+
+add_subdirectory(AllTargets)

lib/Target/Target.cpp

 //===-- Target.cpp --------------------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
-// This file implements the common infrastructure (including C bindings) for 
+// This file implements the common infrastructure (including C bindings) for
 // libLLVMTarget.a, which implements target information.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm-c/Target.h"
 #include "llvm-c/Initialization.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/LLVMContext.h"

tools/llvm-c-test/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
+  AllTargets
   ${LLVM_TARGETS_TO_BUILD}
   BitReader
   Core
   MCDisassembler
   Object
   Support
   Target
   )