[libcxxabi] Correctly export _Unwind_[GS]et(GR|IP) for EHABI.

[danalbert]

Summary

These need to have normal linkage instead of being static inline as
many libraries expect to be able to declare these and have the linker
find them rather than needing to include the header.

Also clean up some warnings while I'm here.

[jroelofs]

This is what I had in mind when we discussed this on irc this morning. Might want to add a link to http://mentorembedded.github.io/cxx-abi/abi-eh.html in the commit message, explaining why you're justified in doing this.

It looks OK to me, but I'll defer to @kledzik on the final go-ahead.

[kledzik]

LGTM

[danalbert]

Closed by commit rL219629 (authored by @danalbert).

include/unwind.h

 _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
 
-static inline 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;
-}
-
-static inline void _Unwind_SetGR(struct _Unwind_Context* context, int index,
-                                 uintptr_t new_value) {
-  _Unwind_VRS_Set(context, _UVRSC_CORE, (uint32_t)index,
-                  _UVRSD_UINT32, &new_value);
-}
-
-static inline uintptr_t _Unwind_GetIP(struct _Unwind_Context* context) {
-  // remove the thumb-bit before returning
-  return (_Unwind_GetGR(context, 15) & (~(uintptr_t)0x1));
-}
-
-static inline void _Unwind_SetIP(struct _Unwind_Context* context,
-                                 uintptr_t new_value) {
-  uintptr_t thumb_bit = _Unwind_GetGR(context, 15) & ((uintptr_t)0x1);
-  _Unwind_SetGR(context, 15, new_value | thumb_bit);
-}
-#else
 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);
-#endif
 
 extern uintptr_t _Unwind_GetRegionStart(struct _Unwind_Context *context);
 extern uintptr_t
     _Unwind_GetLanguageSpecificData(struct _Unwind_Context *context);
 #if __USING_SJLJ_EXCEPTIONS__
 extern _Unwind_Reason_Code
     _Unwind_SjLj_ForcedUnwind(_Unwind_Exception *exception_object,
                               _Unwind_Stop_Fn stop, void *stop_parameter);

src/Unwind/Unwind-EHABI.cpp

 // Generates mask discriminator for _Unwind_VRS_Pop, e.g. for _UVRSC_VFP /
 // _UVRSD_DOUBLE.
 uint32_t RegisterRange(uint8_t start, uint8_t count_minus_one) {
   return ((uint32_t)start << 16) | ((uint32_t)count_minus_one + 1);
 }
 
 } // end anonymous namespace
 
+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;
+}
+
+void _Unwind_SetGR(struct _Unwind_Context* context, int index, uintptr_t
+    new_value) {
+  _Unwind_VRS_Set(context, _UVRSC_CORE, (uint32_t)index,
+                  _UVRSD_UINT32, &new_value);
+}
+
+uintptr_t _Unwind_GetIP(struct _Unwind_Context* context) {
+  // remove the thumb-bit before returning
+  return (_Unwind_GetGR(context, 15) & (~(uintptr_t)0x1));
+}
+
+void _Unwind_SetIP(struct _Unwind_Context* context, uintptr_t new_value) {
+  uintptr_t thumb_bit = _Unwind_GetGR(context, 15) & ((uintptr_t)0x1);
+  _Unwind_SetGR(context, 15, new_value | thumb_bit);
+}
+
 /**
  * Decodes an EHT entry.
  *
  * @param data Pointer to EHT.
  * @param[out] off Offset from return value (in bytes) to begin interpretation.
  * @param[out] len Number of bytes in unwind code.
  * @return Pointer to beginning of unwind code.
  */

src/Unwind/UnwindCursor.hpp

struct EHABISectionIterator {
   static _Self begin(A& addressSpace, const UnwindInfoSections& sects) {
     return _Self(addressSpace, sects, 0);
   }
   static _Self end(A& addressSpace, const UnwindInfoSections& sects) {
     return _Self(addressSpace, sects, sects.arm_section_length);
   }
 
   EHABISectionIterator(A& addressSpace, const UnwindInfoSections& sects, size_t i)
-      : _addressSpace(&addressSpace), _sects(&sects), _i(i) {}
+      : _i(i), _addressSpace(&addressSpace), _sects(&sects) {}
 
   _Self& operator++() { ++_i; return *this; }
   _Self& operator+=(size_t a) { _i += a; return *this; }
   _Self& operator--() { assert(_i > 0); --_i; return *this; }
   _Self& operator-=(size_t a) { assert(_i >= a); _i -= a; return *this; }
 
   _Self operator+(size_t a) { _Self out = *this; out._i += a; return out; }
   _Self operator-(size_t a) { assert(_i >= a); _Self out = *this; out._i -= a; return out; }

src/Unwind/UnwindLevel1-gcc-ext.c

#if LIBCXXABI_ARM_EHABI
     unw_proc_info_t frameInfo;
     if (unw_get_proc_info(&cursor, &frameInfo) != UNW_ESUCCESS) {
       return _URC_END_OF_STACK;
     }
 
     struct _Unwind_Context *context = (struct _Unwind_Context *)&cursor;
     size_t off;
     size_t len;
-    uint32_t* unwindInfo = (uint32_t *) frameInfo.unwind_info;
+    const uint32_t* unwindInfo = (uint32_t *) frameInfo.unwind_info;
     unwindInfo = decode_eht_entry(unwindInfo, &off, &len);
     if (unwindInfo == NULL) {
       return _URC_FAILURE;
     }
 
     result = _Unwind_VRS_Interpret(context, unwindInfo, off, len);
     if (result != _URC_CONTINUE_UNWIND) {
       return _URC_END_OF_STACK;