Move nested functions in frame_unwind.c.

* Nested functions 'pop' and 'push' in libdwfl/frame_unwind.c
  are moved to file scope. Used local variables are passed in
  struct eval_stack.

Signed-off-by: Chih-Hung Hsieh <chh@google.com>

2 files changed, 95 insertions, 73 deletions

diff --git a/libdwfl/ChangeLog b/libdwfl/ChangeLog
index d30fd3c4..e7c373e1 100644
--- a/libdwfl/ChangeLog
+++ b/libdwfl/ChangeLog
@@ -1,5 +1,10 @@
 2015-10-21  Chih-Hung Hsieh <chh@google.com>
 
+	* frame_unwind.c (expr_eval): Move nested function 'push' and 'pop'
+	to file scope. Pass used local variables in struct eval_stack.
+
+2015-10-21  Chih-Hung Hsieh <chh@google.com>
+
 	* dwfl_module.c (dwfl_report_module): Move nested function 'use' to
 	file scope.
 
diff --git a/libdwfl/frame_unwind.c b/libdwfl/frame_unwind.c
index bd100b8f..39509b70 100644
--- a/libdwfl/frame_unwind.c
+++ b/libdwfl/frame_unwind.c
@@ -101,6 +101,49 @@ bra_compar (const void *key_voidp, const void *elem_voidp)
   return (offset > op->offset) - (offset < op->offset);
 }
 
+struct eval_stack {
+  Dwarf_Addr *addrs;
+  size_t used;
+  size_t allocated;
+};
+
+static bool
+do_push (struct eval_stack *stack, Dwarf_Addr val)
+{
+  if (stack->used >= DWARF_EXPR_STACK_MAX)
+    {
+      __libdwfl_seterrno (DWFL_E_INVALID_DWARF);
+      return false;
+    }
+  if (stack->used == stack->allocated)
+    {
+      stack->allocated = MAX (stack->allocated * 2, 32);
+      Dwarf_Addr *new_addrs;
+      new_addrs = realloc (stack->addrs,
+			   stack->allocated * sizeof (*stack->addrs));
+      if (new_addrs == NULL)
+        {
+          __libdwfl_seterrno (DWFL_E_NOMEM);
+          return false;
+        }
+      stack->addrs = new_addrs;
+    }
+  stack->addrs[stack->used++] = val;
+  return true;
+}
+
+static bool
+do_pop (struct eval_stack *stack, Dwarf_Addr *val)
+{
+  if (stack->used == 0)
+    {
+      __libdwfl_seterrno (DWFL_E_INVALID_DWARF);
+      return false;
+    }
+  *val = stack->addrs[--stack->used];
+  return true;
+}
+
 /* If FRAME is NULL is are computing CFI frame base.  In such case another
    DW_OP_call_frame_cfa is no longer permitted.  */
 
@@ -114,43 +157,15 @@ expr_eval (Dwfl_Frame *state, Dwarf_Frame *frame, const Dwarf_Op *ops,
       __libdwfl_seterrno (DWFL_E_INVALID_DWARF);
       return false;
     }
-  Dwarf_Addr *stack = NULL;
-  size_t stack_used = 0, stack_allocated = 0;
+  struct eval_stack stack =
+    {
+      .addrs = NULL,
+      .used = 0,
+      .allocated = 0
+    };
 
-  bool
-  push (Dwarf_Addr val)
-  {
-    if (stack_used >= DWARF_EXPR_STACK_MAX)
-      {
-	__libdwfl_seterrno (DWFL_E_INVALID_DWARF);
-	return false;
-      }
-    if (stack_used == stack_allocated)
-      {
-	stack_allocated = MAX (stack_allocated * 2, 32);
-	Dwarf_Addr *stack_new = realloc (stack, stack_allocated * sizeof (*stack));
-	if (stack_new == NULL)
-	  {
-	    __libdwfl_seterrno (DWFL_E_NOMEM);
-	    return false;
-	  }
-	stack = stack_new;
-      }
-    stack[stack_used++] = val;
-    return true;
-  }
-
-  bool
-  pop (Dwarf_Addr *val)
-  {
-    if (stack_used == 0)
-      {
-	__libdwfl_seterrno (DWFL_E_INVALID_DWARF);
-	return false;
-      }
-    *val = stack[--stack_used];
-    return true;
-  }
+#define pop(x) do_pop(&stack, x)
+#define push(x) do_push(&stack, x)
 
   Dwarf_Addr val1, val2;
   bool is_location = false;
@@ -168,14 +183,14 @@ expr_eval (Dwfl_Frame *state, Dwarf_Frame *frame, const Dwarf_Op *ops,
 	case DW_OP_lit0 ... DW_OP_lit31:
 	  if (! push (op->atom - DW_OP_lit0))
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      return false;
 	    }
 	  break;
 	case DW_OP_addr:
 	  if (! push (op->number + bias))
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      return false;
 	    }
 	  break;
@@ -195,7 +210,7 @@ expr_eval (Dwfl_Frame *state, Dwarf_Frame *frame, const Dwarf_Op *ops,
 	case DW_OP_consts:
 	  if (! push (op->number))
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      return false;
 	    }
 	  break;
@@ -203,67 +218,67 @@ expr_eval (Dwfl_Frame *state, Dwarf_Frame *frame, const Dwarf_Op *ops,
 	  if (! state_get_reg (state, op->atom - DW_OP_reg0, &val1)
 	      || ! push (val1))
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      return false;
 	    }
 	  break;
 	case DW_OP_regx:
 	  if (! state_get_reg (state, op->number, &val1) || ! push (val1))
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      return false;
 	    }
 	  break;
 	case DW_OP_breg0 ... DW_OP_breg31:
 	  if (! state_get_reg (state, op->atom - DW_OP_breg0, &val1))
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      return false;
 	    }
 	  val1 += op->number;
 	  if (! push (val1))
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      return false;
 	    }
 	  break;
 	case DW_OP_bregx:
 	  if (! state_get_reg (state, op->number, &val1))
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      return false;
 	    }
 	  val1 += op->number2;
 	  if (! push (val1))
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      return false;
 	    }
 	  break;
 	case DW_OP_dup:
 	  if (! pop (&val1) || ! push (val1) || ! push (val1))
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      return false;
 	    }
 	  break;
 	case DW_OP_drop:
 	  if (! pop (&val1))
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      return false;
 	    }
 	  break;
 	case DW_OP_pick:
-	  if (stack_used <= op->number)
+	  if (stack.used <= op->number)
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      __libdwfl_seterrno (DWFL_E_INVALID_DWARF);
 	      return false;
 	    }
-	  if (! push (stack[stack_used - 1 - op->number]))
+	  if (! push (stack.addrs[stack.used - 1 - op->number]))
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      return false;
 	    }
 	  break;
@@ -271,14 +286,14 @@ expr_eval (Dwfl_Frame *state, Dwarf_Frame *frame, const Dwarf_Op *ops,
 	  if (! pop (&val1) || ! pop (&val2)
 	      || ! push (val2) || ! push (val1) || ! push (val2))
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      return false;
 	    }
 	  break;
 	case DW_OP_swap:
 	  if (! pop (&val1) || ! pop (&val2) || ! push (val1) || ! push (val2))
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      return false;
 	    }
 	  break;
@@ -288,7 +303,7 @@ expr_eval (Dwfl_Frame *state, Dwarf_Frame *frame, const Dwarf_Op *ops,
 	    if (! pop (&val1) || ! pop (&val2) || ! pop (&val3)
 		|| ! push (val1) || ! push (val3) || ! push (val2))
 	      {
-		free (stack);
+		free (stack.addrs);
 		return false;
 	      }
 	  }
@@ -297,7 +312,7 @@ expr_eval (Dwfl_Frame *state, Dwarf_Frame *frame, const Dwarf_Op *ops,
 	case DW_OP_deref_size:
 	  if (process->callbacks->memory_read == NULL)
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      __libdwfl_seterrno (DWFL_E_INVALID_ARGUMENT);
 	      return false;
 	    }
@@ -305,7 +320,7 @@ expr_eval (Dwfl_Frame *state, Dwarf_Frame *frame, const Dwarf_Op *ops,
 	      || ! process->callbacks->memory_read (process->dwfl, val1, &val1,
 						    process->callbacks_arg))
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      return false;
 	    }
 	  if (op->atom == DW_OP_deref_size)
@@ -314,7 +329,7 @@ expr_eval (Dwfl_Frame *state, Dwarf_Frame *frame, const Dwarf_Op *ops,
 	      const unsigned addr_bytes = elfclass == ELFCLASS32 ? 4 : 8;
 	      if (op->number > addr_bytes)
 		{
-		  free (stack);
+		  free (stack.addrs);
 		  __libdwfl_seterrno (DWFL_E_INVALID_DWARF);
 		  return false;
 		}
@@ -330,7 +345,7 @@ expr_eval (Dwfl_Frame *state, Dwarf_Frame *frame, const Dwarf_Op *ops,
 	    }
 	  if (! push (val1))
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      return false;
 	    }
 	  break;
@@ -338,7 +353,7 @@ expr_eval (Dwfl_Frame *state, Dwarf_Frame *frame, const Dwarf_Op *ops,
 	case atom:							\
 	  if (! pop (&val1) || ! push (expr))				\
 	    {								\
-	      free (stack);						\
+	      free (stack.addrs);					\
 	      return false;						\
 	    }								\
 	  break;
@@ -349,7 +364,7 @@ expr_eval (Dwfl_Frame *state, Dwarf_Frame *frame, const Dwarf_Op *ops,
 	case DW_OP_plus_uconst:
 	  if (! pop (&val1) || ! push (val1 + op->number))
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      return false;
 	    }
 	  break;
@@ -357,7 +372,7 @@ expr_eval (Dwfl_Frame *state, Dwarf_Frame *frame, const Dwarf_Op *ops,
 	case atom:							\
 	  if (! pop (&val2) || ! pop (&val1) || ! push (val1 op val2))	\
 	    {								\
-	      free (stack);						\
+	      free (stack.addrs);					\
 	      return false;						\
 	    }								\
 	  break;
@@ -366,7 +381,7 @@ expr_eval (Dwfl_Frame *state, Dwarf_Frame *frame, const Dwarf_Op *ops,
 	  if (! pop (&val2) || ! pop (&val1)				\
 	      || ! push ((int64_t) val1 op (int64_t) val2))		\
 	    {								\
-	      free (stack);						\
+	      free (stack.addrs);					\
 	      return false;						\
 	    }								\
 	  break;
@@ -374,18 +389,18 @@ expr_eval (Dwfl_Frame *state, Dwarf_Frame *frame, const Dwarf_Op *ops,
 	case DW_OP_div:
 	  if (! pop (&val2) || ! pop (&val1))
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      return false;
 	    }
 	  if (val2 == 0)
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      __libdwfl_seterrno (DWFL_E_INVALID_DWARF);
 	      return false;
 	    }
 	  if (! push ((int64_t) val1 / (int64_t) val2))
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      return false;
 	    }
 	  break;
@@ -393,18 +408,18 @@ expr_eval (Dwfl_Frame *state, Dwarf_Frame *frame, const Dwarf_Op *ops,
 	case DW_OP_mod:
 	  if (! pop (&val2) || ! pop (&val1))
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      return false;
 	    }
 	  if (val2 == 0)
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      __libdwfl_seterrno (DWFL_E_INVALID_DWARF);
 	      return false;
 	    }
 	  if (! push (val1 % val2))
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      return false;
 	    }
 	  break;
@@ -426,7 +441,7 @@ expr_eval (Dwfl_Frame *state, Dwarf_Frame *frame, const Dwarf_Op *ops,
 	case DW_OP_bra:
 	  if (! pop (&val1))
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      return false;
 	    }
 	  if (val1 == 0)
@@ -438,7 +453,7 @@ expr_eval (Dwfl_Frame *state, Dwarf_Frame *frame, const Dwarf_Op *ops,
 					   sizeof (*ops), bra_compar);
 	  if (found == NULL)
 	    {
-	      free (stack);
+	      free (stack.addrs);
 	      /* PPC32 vDSO has such invalid operations.  */
 	      __libdwfl_seterrno (DWFL_E_INVALID_DWARF);
 	      return false;
@@ -460,7 +475,7 @@ expr_eval (Dwfl_Frame *state, Dwarf_Frame *frame, const Dwarf_Op *ops,
 	      || ! push (cfa))
 	    {
 	      __libdwfl_seterrno (DWFL_E_LIBDW);
-	      free (stack);
+	      free (stack.addrs);
 	      return false;
 	    }
 	  is_location = true;
@@ -476,10 +491,10 @@ expr_eval (Dwfl_Frame *state, Dwarf_Frame *frame, const Dwarf_Op *ops,
     }
   if (! pop (result))
     {
-      free (stack);
+      free (stack.addrs);
       return false;
     }
-  free (stack);
+  free (stack.addrs);
   if (is_location)
     {
       if (process->callbacks->memory_read == NULL)
@@ -492,6 +507,8 @@ expr_eval (Dwfl_Frame *state, Dwarf_Frame *frame, const Dwarf_Op *ops,
 	return false;
     }
   return true;
+#undef push
+#undef pop
 }
 
 static void