[Unwind] Split unwind.h

[danielkiss]

Summary

Moving Itanium and ArmEHABI specific implementations to dedicated files.
This is a NFC patch.

[MaskRay]

Looks great!

[danielkiss]

as discussed here: D89570#2740272
Please comment on it.

libunwind/include/unwind.h

typedef enum {
   _UA_HANDLER_FRAME = 4,
   _UA_FORCE_UNWIND = 8,
   _UA_END_OF_STACK = 16 // gcc extension to C++ ABI
 } _Unwind_Action;
 
 typedef struct _Unwind_Context _Unwind_Context;   // opaque
 
 #if defined(_LIBUNWIND_ARM_EHABI)
-typedef uint32_t _Unwind_State;
-
-static const _Unwind_State _US_VIRTUAL_UNWIND_FRAME   = 0;
-static const _Unwind_State _US_UNWIND_FRAME_STARTING  = 1;
-static const _Unwind_State _US_UNWIND_FRAME_RESUME    = 2;
-static const _Unwind_State _US_ACTION_MASK            = 3;
-/* Undocumented flag for force unwinding. */
-static const _Unwind_State _US_FORCE_UNWIND           = 8;
-
-typedef uint32_t _Unwind_EHT_Header;
-
-struct _Unwind_Control_Block;
-typedef struct _Unwind_Control_Block _Unwind_Control_Block;
-typedef struct _Unwind_Control_Block _Unwind_Exception; /* Alias */
-
-struct _Unwind_Control_Block {
-  uint64_t exception_class;
-  void (*exception_cleanup)(_Unwind_Reason_Code, _Unwind_Control_Block*);
-
-  /* Unwinder cache, private fields for the unwinder's use */
-  struct {
-    uint32_t reserved1; /* init reserved1 to 0, then don't touch */
-    uint32_t reserved2;
-    uint32_t reserved3;
-    uint32_t reserved4;
-    uint32_t reserved5;
-  } unwinder_cache;
-
-  /* Propagation barrier cache (valid after phase 1): */
-  struct {
-    uint32_t sp;
-    uint32_t bitpattern[5];
-  } barrier_cache;
-
-  /* Cleanup cache (preserved over cleanup): */
-  struct {
-    uint32_t bitpattern[4];
-  } cleanup_cache;
-
-  /* Pr cache (for pr's benefit): */
-  struct {
-    uint32_t fnstart; /* function start address */
-    _Unwind_EHT_Header* ehtp; /* pointer to EHT entry header word */
-    uint32_t additional;
-    uint32_t reserved1;
-  } pr_cache;
-
-  long long int :0; /* Enforce the 8-byte alignment */
-} __attribute__((__aligned__(8)));
-
-typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn)
-      (_Unwind_State state,
-       _Unwind_Exception* exceptionObject,
-       struct _Unwind_Context* context);
-
-typedef _Unwind_Reason_Code (*_Unwind_Personality_Fn)(
-    _Unwind_State state, _Unwind_Exception *exceptionObject,
-    struct _Unwind_Context *context);
-#else
-struct _Unwind_Context;   // opaque
-struct _Unwind_Exception; // forward declaration
-typedef struct _Unwind_Exception _Unwind_Exception;
-
-struct _Unwind_Exception {
-  uint64_t exception_class;
-  void (*exception_cleanup)(_Unwind_Reason_Code reason,
-                            _Unwind_Exception *exc);
-#if defined(__SEH__) && !defined(__USING_SJLJ_EXCEPTIONS__)
-  uintptr_t private_[6];
+#include "unwind_arm_ehabi.h"
 #else
-  uintptr_t private_1; // non-zero means forced unwind
-  uintptr_t private_2; // holds sp that phase1 found for phase2 to use
-#endif
-#if __SIZEOF_POINTER__ == 4
-  // The implementation of _Unwind_Exception uses an attribute mode on the
-  // above fields which has the side effect of causing this whole struct to
-  // round up to 32 bytes in size (48 with SEH). To be more explicit, we add
-  // pad fields added for binary compatibility.
-  uint32_t reserved[3];
-#endif
-  // The Itanium ABI requires that _Unwind_Exception objects are "double-word
-  // aligned".  GCC has interpreted this to mean "use the maximum useful
-  // alignment for the target"; so do we.
-} __attribute__((__aligned__));
-
-typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn)
-    (int version,
-     _Unwind_Action actions,
-     uint64_t exceptionClass,
-     _Unwind_Exception* exceptionObject,
-     struct _Unwind_Context* context,
-     void* stop_parameter );
-
-typedef _Unwind_Reason_Code (*_Unwind_Personality_Fn)(
-    int version, _Unwind_Action actions, uint64_t exceptionClass,
-    _Unwind_Exception *exceptionObject, struct _Unwind_Context *context);
+#include "unwind_itanium.h"
 #endif
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-//
-// The following are the base functions documented by the C++ ABI
-//
-#ifdef __USING_SJLJ_EXCEPTIONS__
-extern _Unwind_Reason_Code
-    _Unwind_SjLj_RaiseException(_Unwind_Exception *exception_object);
-extern void _Unwind_SjLj_Resume(_Unwind_Exception *exception_object);
-#else
-extern _Unwind_Reason_Code
-    _Unwind_RaiseException(_Unwind_Exception *exception_object);
-extern void _Unwind_Resume(_Unwind_Exception *exception_object);
-#endif
-extern void _Unwind_DeleteException(_Unwind_Exception *exception_object);
-
-#if defined(_LIBUNWIND_ARM_EHABI)
-typedef enum {
-  _UVRSC_CORE = 0, /* integer register */
-  _UVRSC_VFP = 1, /* vfp */
-  _UVRSC_WMMXD = 3, /* Intel WMMX data register */
-  _UVRSC_WMMXC = 4 /* Intel WMMX control register */
-} _Unwind_VRS_RegClass;
-
-typedef enum {
-  _UVRSD_UINT32 = 0,
-  _UVRSD_VFPX = 1,
-  _UVRSD_UINT64 = 3,
-  _UVRSD_FLOAT = 4,
-  _UVRSD_DOUBLE = 5
-} _Unwind_VRS_DataRepresentation;
-
-typedef enum {
-  _UVRSR_OK = 0,
-  _UVRSR_NOT_IMPLEMENTED = 1,
-  _UVRSR_FAILED = 2
-} _Unwind_VRS_Result;
-
-extern void _Unwind_Complete(_Unwind_Exception* exception_object);
-
-extern _Unwind_VRS_Result
-_Unwind_VRS_Get(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
-                uint32_t regno, _Unwind_VRS_DataRepresentation representation,
-                void *valuep);
-
-extern _Unwind_VRS_Result
-_Unwind_VRS_Set(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
-                uint32_t regno, _Unwind_VRS_DataRepresentation representation,
-                void *valuep);
-
-extern _Unwind_VRS_Result
-_Unwind_VRS_Pop(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
-                uint32_t discriminator,
-                _Unwind_VRS_DataRepresentation representation);
-#endif
-
-#if !defined(_LIBUNWIND_ARM_EHABI)
-
-extern uintptr_t _Unwind_GetGR(struct _Unwind_Context *context, int index);
-extern void _Unwind_SetGR(struct _Unwind_Context *context, int index,
-                          uintptr_t new_value);
-extern uintptr_t _Unwind_GetIP(struct _Unwind_Context *context);
-extern void _Unwind_SetIP(struct _Unwind_Context *, uintptr_t new_value);
-
-#else  // defined(_LIBUNWIND_ARM_EHABI)
-
-#if defined(_LIBUNWIND_UNWIND_LEVEL1_EXTERNAL_LINKAGE)
-#define _LIBUNWIND_EXPORT_UNWIND_LEVEL1 extern
-#else
-#define _LIBUNWIND_EXPORT_UNWIND_LEVEL1 static __inline__
-#endif
-
-// These are de facto helper functions for ARM, which delegate the function
-// calls to _Unwind_VRS_Get/Set().  These are not a part of ARM EHABI
-// specification, thus these function MUST be inlined.  Please don't replace
-// these with the "extern" function declaration; otherwise, the program
-// including this <unwind.h> header won't be ABI compatible and will result in
-// link error when we are linking the program with libgcc.
-
-_LIBUNWIND_EXPORT_UNWIND_LEVEL1
-uintptr_t _Unwind_GetGR(struct _Unwind_Context *context, int index) {
-  uintptr_t value = 0;
-  _Unwind_VRS_Get(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value);
-  return value;
-}
-
-_LIBUNWIND_EXPORT_UNWIND_LEVEL1
-void _Unwind_SetGR(struct _Unwind_Context *context, int index,
-                   uintptr_t value) {
-  _Unwind_VRS_Set(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value);
-}
-
-_LIBUNWIND_EXPORT_UNWIND_LEVEL1
-uintptr_t _Unwind_GetIP(struct _Unwind_Context *context) {
-  // remove the thumb-bit before returning
-  return _Unwind_GetGR(context, 15) & (~(uintptr_t)0x1);
-}
-
-_LIBUNWIND_EXPORT_UNWIND_LEVEL1
-void _Unwind_SetIP(struct _Unwind_Context *context, uintptr_t value) {
-  uintptr_t thumb_bit = _Unwind_GetGR(context, 15) & ((uintptr_t)0x1);
-  _Unwind_SetGR(context, 15, value | thumb_bit);
-}
-#endif  // defined(_LIBUNWIND_ARM_EHABI)
-
 extern uintptr_t _Unwind_GetRegionStart(struct _Unwind_Context *context);
 extern uintptr_t
     _Unwind_GetLanguageSpecificData(struct _Unwind_Context *context);
 #ifdef __USING_SJLJ_EXCEPTIONS__
 extern _Unwind_Reason_Code
     _Unwind_SjLj_ForcedUnwind(_Unwind_Exception *exception_object,
                               _Unwind_Stop_Fn stop, void *stop_parameter);
 #else

libunwind/include/unwind_arm_ehabi.h

+//===------------------------------- unwind.h -----------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//
+// C++ ABI Level 1 ABI documented at:
+//   https://github.com/ARM-software/abi-aa/blob/main/ehabi32/ehabi32.rst
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef __ARM_EHABI_UNWIND_H__
+#define __ARM_EHABI_UNWIND_H__
+
+typedef uint32_t _Unwind_State;
+
+static const _Unwind_State _US_VIRTUAL_UNWIND_FRAME   = 0;
+static const _Unwind_State _US_UNWIND_FRAME_STARTING  = 1;
+static const _Unwind_State _US_UNWIND_FRAME_RESUME    = 2;
+static const _Unwind_State _US_ACTION_MASK            = 3;
+/* Undocumented flag for force unwinding. */
+static const _Unwind_State _US_FORCE_UNWIND           = 8;
+
+typedef uint32_t _Unwind_EHT_Header;
+
+struct _Unwind_Control_Block;
+typedef struct _Unwind_Control_Block _Unwind_Control_Block;
+typedef struct _Unwind_Control_Block _Unwind_Exception; /* Alias */
+
+struct _Unwind_Control_Block {
+  uint64_t exception_class;
+  void (*exception_cleanup)(_Unwind_Reason_Code, _Unwind_Control_Block*);
+
+  /* Unwinder cache, private fields for the unwinder's use */
+  struct {
+    uint32_t reserved1; /* init reserved1 to 0, then don't touch */
+    uint32_t reserved2;
+    uint32_t reserved3;
+    uint32_t reserved4;
+    uint32_t reserved5;
+  } unwinder_cache;
+
+  /* Propagation barrier cache (valid after phase 1): */
+  struct {
+    uint32_t sp;
+    uint32_t bitpattern[5];
+  } barrier_cache;
+
+  /* Cleanup cache (preserved over cleanup): */
+  struct {
+    uint32_t bitpattern[4];
+  } cleanup_cache;
+
+  /* Pr cache (for pr's benefit): */
+  struct {
+    uint32_t fnstart; /* function start address */
+    _Unwind_EHT_Header* ehtp; /* pointer to EHT entry header word */
+    uint32_t additional;
+    uint32_t reserved1;
+  } pr_cache;
+
+  long long int :0; /* Enforce the 8-byte alignment */
+} __attribute__((__aligned__(8)));
+
+typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn)
+      (_Unwind_State state,
+       _Unwind_Exception* exceptionObject,
+       struct _Unwind_Context* context);
+
+typedef _Unwind_Reason_Code (*_Unwind_Personality_Fn)(
+    _Unwind_State state, _Unwind_Exception *exceptionObject,
+    struct _Unwind_Context *context);
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+//
+// The following are the base functions documented by the C++ ABI
+//
+#ifdef __USING_SJLJ_EXCEPTIONS__
+extern _Unwind_Reason_Code
+    _Unwind_SjLj_RaiseException(_Unwind_Exception *exception_object);
+extern void _Unwind_SjLj_Resume(_Unwind_Exception *exception_object);
+#else
+extern _Unwind_Reason_Code
+    _Unwind_RaiseException(_Unwind_Exception *exception_object);
+extern void _Unwind_Resume(_Unwind_Exception *exception_object);
+#endif
+extern void _Unwind_DeleteException(_Unwind_Exception *exception_object);
+
+typedef enum {
+  _UVRSC_CORE = 0, /* integer register */
+  _UVRSC_VFP = 1, /* vfp */
+  _UVRSC_WMMXD = 3, /* Intel WMMX data register */
+  _UVRSC_WMMXC = 4 /* Intel WMMX control register */
+} _Unwind_VRS_RegClass;
+
+typedef enum {
+  _UVRSD_UINT32 = 0,
+  _UVRSD_VFPX = 1,
+  _UVRSD_UINT64 = 3,
+  _UVRSD_FLOAT = 4,
+  _UVRSD_DOUBLE = 5
+} _Unwind_VRS_DataRepresentation;
+
+typedef enum {
+  _UVRSR_OK = 0,
+  _UVRSR_NOT_IMPLEMENTED = 1,
+  _UVRSR_FAILED = 2
+} _Unwind_VRS_Result;
+
+extern void _Unwind_Complete(_Unwind_Exception* exception_object);
+
+extern _Unwind_VRS_Result
+_Unwind_VRS_Get(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
+                uint32_t regno, _Unwind_VRS_DataRepresentation representation,
+                void *valuep);
+
+extern _Unwind_VRS_Result
+_Unwind_VRS_Set(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
+                uint32_t regno, _Unwind_VRS_DataRepresentation representation,
+                void *valuep);
+
+extern _Unwind_VRS_Result
+_Unwind_VRS_Pop(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
+                uint32_t discriminator,
+                _Unwind_VRS_DataRepresentation representation);
+
+#if defined(_LIBUNWIND_UNWIND_LEVEL1_EXTERNAL_LINKAGE)
+#define _LIBUNWIND_EXPORT_UNWIND_LEVEL1 extern
+#else
+#define _LIBUNWIND_EXPORT_UNWIND_LEVEL1 static __inline__
+#endif
+
+// These are de facto helper functions for ARM, which delegate the function
+// calls to _Unwind_VRS_Get/Set().  These are not a part of ARM EHABI
+// specification, thus these function MUST be inlined.  Please don't replace
+// these with the "extern" function declaration; otherwise, the program
+// including this <unwind.h> header won't be ABI compatible and will result in
+// link error when we are linking the program with libgcc.
+
+_LIBUNWIND_EXPORT_UNWIND_LEVEL1
+uintptr_t _Unwind_GetGR(struct _Unwind_Context *context, int index) {
+  uintptr_t value = 0;
+  _Unwind_VRS_Get(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value);
+  return value;
+}
+
+_LIBUNWIND_EXPORT_UNWIND_LEVEL1
+void _Unwind_SetGR(struct _Unwind_Context *context, int index,
+                   uintptr_t value) {
+  _Unwind_VRS_Set(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value);
+}
+
+_LIBUNWIND_EXPORT_UNWIND_LEVEL1
+uintptr_t _Unwind_GetIP(struct _Unwind_Context *context) {
+  // remove the thumb-bit before returning
+  return _Unwind_GetGR(context, 15) & (~(uintptr_t)0x1);
+}
+
+_LIBUNWIND_EXPORT_UNWIND_LEVEL1
+void _Unwind_SetIP(struct _Unwind_Context *context, uintptr_t value) {
+  uintptr_t thumb_bit = _Unwind_GetGR(context, 15) & ((uintptr_t)0x1);
+  _Unwind_SetGR(context, 15, value | thumb_bit);
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // __ARM_EHABI_UNWIND_H__

libunwind/include/unwind_itanium.h

+//===------------------------------- unwind.h -----------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//
+// C++ ABI Level 1 ABI documented at:
+//   https://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef __ITANIUM_UNWIND_H__
+#define __ITANIUM_UNWIND_H__
+
+struct _Unwind_Context;   // opaque
+struct _Unwind_Exception; // forward declaration
+typedef struct _Unwind_Exception _Unwind_Exception;
+
+struct _Unwind_Exception {
+  uint64_t exception_class;
+  void (*exception_cleanup)(_Unwind_Reason_Code reason,
+                            _Unwind_Exception *exc);
+#if defined(__SEH__) && !defined(__USING_SJLJ_EXCEPTIONS__)
+  uintptr_t private_[6];
+#else
+  uintptr_t private_1; // non-zero means forced unwind
+  uintptr_t private_2; // holds sp that phase1 found for phase2 to use
+#endif
+#if __SIZEOF_POINTER__ == 4
+  // The implementation of _Unwind_Exception uses an attribute mode on the
+  // above fields which has the side effect of causing this whole struct to
+  // round up to 32 bytes in size (48 with SEH). To be more explicit, we add
+  // pad fields added for binary compatibility.
+  uint32_t reserved[3];
+#endif
+  // The Itanium ABI requires that _Unwind_Exception objects are "double-word
+  // aligned".  GCC has interpreted this to mean "use the maximum useful
+  // alignment for the target"; so do we.
+} __attribute__((__aligned__));
+
+typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn)
+    (int version,
+     _Unwind_Action actions,
+     uint64_t exceptionClass,
+     _Unwind_Exception* exceptionObject,
+     struct _Unwind_Context* context,
+     void* stop_parameter );
+
+typedef _Unwind_Reason_Code (*_Unwind_Personality_Fn)(
+    int version, _Unwind_Action actions, uint64_t exceptionClass,
+    _Unwind_Exception *exceptionObject, struct _Unwind_Context *context);
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+//
+// The following are the base functions documented by the C++ ABI
+//
+#ifdef __USING_SJLJ_EXCEPTIONS__
+extern _Unwind_Reason_Code
+    _Unwind_SjLj_RaiseException(_Unwind_Exception *exception_object);
+extern void _Unwind_SjLj_Resume(_Unwind_Exception *exception_object);
+#else
+extern _Unwind_Reason_Code
+    _Unwind_RaiseException(_Unwind_Exception *exception_object);
+extern void _Unwind_Resume(_Unwind_Exception *exception_object);
+#endif
+extern void _Unwind_DeleteException(_Unwind_Exception *exception_object);
+
+
+extern uintptr_t _Unwind_GetGR(struct _Unwind_Context *context, int index);
+extern void _Unwind_SetGR(struct _Unwind_Context *context, int index,
+                          uintptr_t new_value);
+extern uintptr_t _Unwind_GetIP(struct _Unwind_Context *context);
+extern void _Unwind_SetIP(struct _Unwind_Context *, uintptr_t new_value);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // __ITANIUM_UNWIND_H__

libunwind/src/CMakeLists.txt

set(LIBUNWIND_HEADERS
     FrameHeaderCache.hpp
     libunwind_ext.h
     Registers.hpp
     RWMutex.hpp
     Unwind-EHABI.h
     UnwindCursor.hpp
     ../include/libunwind.h
     ../include/unwind.h
+    ../include/unwind_itanium.h
+    ../include/unwind_arm_ehabi.h
     )
 if(APPLE)
   list(APPEND LIBUNWIND_HEADERS
     ../include/mach-o/compact_unwind_encoding.h
     )
 endif()
 
 if (MSVC_IDE)