Use Frame*.

stepmania/src/archutils/Darwin/DarwinThreadHelpers.cpp

@@ -35,7 +35,7 @@ bool GetThreadBacktraceContext( uint64_t iID, BacktraceContext *ctx )
 	
 	if( thread_get_state(thread, PPC_THREAD_STATE, thread_state_t(&state), &count) )
 		return false;
-	ctx->FramePtr = (void *)state.r1;
+	ctx->FramePtr = (const Frame *)state.r1;
 	ctx->PC = (void *)state.srr0;
 	return true;
 #elif defined(__i386__)

stepmania/src/archutils/Unix/Backtrace.cpp

@@ -421,17 +421,17 @@ void GetBacktrace( const void **buf, size_t size, const BacktraceContext *ctx )
 }
 
 #elif defined(BACKTRACE_METHOD_POWERPC_DARWIN)
-typedef struct Frame
+struct Frame
 {
     Frame *stackPointer;
     long conditionReg;
     void *linkReg;
-} *FramePtr;
+};
 
 void GetSignalBacktraceContext( BacktraceContext *ctx, const ucontext_t *uc )
 {
-	ctx->PC = (void *) uc->uc_mcontext->ss.srr0;
-	ctx->FramePtr = (void *) uc->uc_mcontext->ss.r1;
+	ctx->PC = (const void *) uc->uc_mcontext->ss.srr0;
+	ctx->FramePtr = (const Frame *) uc->uc_mcontext->ss.r1;
 }
 
 void InitializeBacktrace() { }
@@ -445,11 +445,11 @@ void GetBacktrace( const void **buf, size_t size, const BacktraceContext *ctx )
 
 		/* __builtin_frame_address is broken on OS X; it sometimes returns bogus results. */
 		register void *r1 __asm__ ("r1");
-		CurrentCtx.FramePtr = (void *) r1;
+		CurrentCtx.FramePtr = (const Frame *) r1;
 		CurrentCtx.PC = NULL;
 	}
 	
-	const Frame *frame = (Frame *) ctx->FramePtr;
+	const Frame *frame = ctx->FramePtr;
 
 	unsigned i = 0;
 	if( ctx->PC && i < size-1 )

stepmania/src/archutils/Unix/Backtrace.h

@@ -3,6 +3,9 @@
 
 /* This API works like backtrace_pointers(), to retrieve a stack trace. */
 
+#if defined(CPU_PPC)
+struct Frame;
+#endif
 /* This contains the information necessary to backtrace a thread. */
 struct BacktraceContext
 {
@@ -15,7 +18,8 @@ struct BacktraceContext
 #endif
 
 #if defined(CPU_PPC)
-	void *FramePtr, *PC;
+	const Frame *FramePtr;
+	const void *PC;
 #endif
 };