[PATCH] D11897: [libunwind] Make it possible to use libunwind without heap.

[whitequark via llvm-commits]

whitequark updated the summary for this revision.
whitequark updated this revision to Diff 35212.
whitequark added a comment.

I've realized there is no need to disable any of the _unw_* functions now that DwarfFDECache::add() is a no-op on heapless systems, so I have simplified the patch.


http://reviews.llvm.org/D11897

Files:
  src/DwarfParser.hpp
  src/UnwindCursor.hpp

Index: src/UnwindCursor.hpp
===================================================================
--- src/UnwindCursor.hpp
+++ src/UnwindCursor.hpp
@@ -114,6 +114,7 @@
 template <typename A>
 void DwarfFDECache<A>::add(pint_t mh, pint_t ip_start, pint_t ip_end,
                            pint_t fde) {
+#ifndef _LIBUNWIND_NO_HEAP
   _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_wrlock(&_lock));
   if (_bufferUsed >= _bufferEnd) {
     size_t oldSize = (size_t)(_bufferEnd - _buffer);
@@ -139,6 +140,7 @@
   }
 #endif
   _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_unlock(&_lock));
+#endif
 }
 
 template <typename A>
Index: src/DwarfParser.hpp
===================================================================
--- src/DwarfParser.hpp
+++ src/DwarfParser.hpp
@@ -380,7 +380,9 @@
     uint64_t length;
     uint8_t opcode = addressSpace.get8(p);
     uint8_t operand;
+#ifndef _LIBUNWIND_NO_HEAP
     PrologInfoStackEntry *entry;
+#endif
     ++p;
     switch (opcode) {
     case DW_CFA_nop:
@@ -492,6 +494,7 @@
         fprintf(stderr, "DW_CFA_register(reg=%" PRIu64 ", reg2=%" PRIu64 ")\n",
                 reg, reg2);
       break;
+#ifndef _LIBUNWIND_NO_HEAP
     case DW_CFA_remember_state:
       // avoid operator new, because that would be an upward dependency
       entry = (PrologInfoStackEntry *)malloc(sizeof(PrologInfoStackEntry));
@@ -517,6 +520,7 @@
       if (logDwarf)
         fprintf(stderr, "DW_CFA_restore_state\n");
       break;
+#endif
     case DW_CFA_def_cfa:
       reg = addressSpace.getULEB128(p, instructionsEnd);
       offset = (int64_t)addressSpace.getULEB128(p, instructionsEnd);


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D11897.35212.patch
Type: text/x-patch
Size: 1611 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20150921/633c024f/attachment.bin>