[binutils-gdb] Use an std::vector for inline_states

[Simon Marchi <simark at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=b24531ed171b5751a3a64c461728c9ad62092c8a

commit b24531ed171b5751a3a64c461728c9ad62092c8a
Author: Simon Marchi <simon.marchi@polymtl.ca>
Date:   Mon Apr 9 15:40:45 2018 -0400

    Use an std::vector for inline_states
    
    This patch replaces VEC(inline_state) with std::vector<inline_state> and
    adjusts the code that uses it.
    
    gdb/ChangeLog:
    
    	* common/gdb_vecs.h (unordered_remove): Add overload that takes
    	an iterator.
    	* inline-frame.c: Include <algorithm>.
    	(struct inline_state): Add constructor.
    	(inline_state_s): Remove.
    	(DEF_VEC_O(inline_state_s)): Remove.
    	(inline_states): Change type to std::vector.
    	(find_inline_frame_state): Adjust to std::vector.
    	(allocate_inline_frame_state): Remove.
    	(clear_inline_frame_state): Adjust to std::vector.
    	(skip_inline_frames): Adjust to std::vector.

Diff:
---
 gdb/ChangeLog         |  14 +++++++
 gdb/common/gdb_vecs.h |  22 +++++++---
 gdb/inline-frame.c    | 113 +++++++++++++++++++++-----------------------------
 3 files changed, 79 insertions(+), 70 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index d1c4771..87b22e8 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,19 @@
 2018-04-09  Simon Marchi  <simon.marchi@polymtl.ca>
 
+	* common/gdb_vecs.h (unordered_remove): Add overload that takes
+	an iterator.
+	* inline-frame.c: Include <algorithm>.
+	(struct inline_state): Add constructor.
+	(inline_state_s): Remove.
+	(DEF_VEC_O(inline_state_s)): Remove.
+	(inline_states): Change type to std::vector.
+	(find_inline_frame_state): Adjust to std::vector.
+	(allocate_inline_frame_state): Remove.
+	(clear_inline_frame_state): Adjust to std::vector.
+	(skip_inline_frames): Adjust to std::vector.
+
+2018-04-09  Simon Marchi  <simon.marchi@polymtl.ca>
+
 	* tracepoint.h (struct trace_state_variable): Add constructor.
 	<name>: Change type to std::string.
 	* tracepoint.c (tsv_s): Remove.
diff --git a/gdb/common/gdb_vecs.h b/gdb/common/gdb_vecs.h
index 141d05e..3e461dc 100644
--- a/gdb/common/gdb_vecs.h
+++ b/gdb/common/gdb_vecs.h
@@ -47,6 +47,22 @@ extern void dirnames_to_char_ptr_vec_append
 extern std::vector<gdb::unique_xmalloc_ptr<char>>
   dirnames_to_char_ptr_vec (const char *dirnames);
 
+/* Remove the element pointed by iterator IT from VEC, not preserving the order
+   of the remaining elements.  Return the removed element.  */
+
+template <typename T>
+T
+unordered_remove (std::vector<T> &vec, typename std::vector<T>::iterator it)
+{
+  gdb_assert (it >= vec.begin () && it < vec.end ());
+
+  T removed = std::move (*it);
+  *it = std::move (vec.back ());
+  vec.pop_back ();
+
+  return removed;
+}
+
 /* Remove the element at position IX from VEC, not preserving the order of the
    remaining elements.  Return the removed element.  */
 
@@ -56,11 +72,7 @@ unordered_remove (std::vector<T> &vec, typename std::vector<T>::size_type ix)
 {
   gdb_assert (ix < vec.size ());
 
-  T removed = std::move (vec[ix]);
-  vec[ix] = std::move (vec.back ());
-  vec.pop_back ();
-
-  return removed;
+  return unordered_remove (vec, vec.begin () + ix);
 }
 
 /* Remove the element at position IX from VEC, preserving the order the
diff --git a/gdb/inline-frame.c b/gdb/inline-frame.c
index a019619..2f701e7 100644
--- a/gdb/inline-frame.c
+++ b/gdb/inline-frame.c
@@ -27,6 +27,7 @@
 #include "symtab.h"
 #include "vec.h"
 #include "frame.h"
+#include <algorithm>
 
 /* We need to save a few variables for every thread stopped at the
    virtual call site of an inlined function.  If there was always a
@@ -34,6 +35,12 @@
    keep our own list.  */
 struct inline_state
 {
+  inline_state (ptid_t ptid_, int skipped_frames_, CORE_ADDR saved_pc_,
+		symbol *skipped_symbol_)
+    : ptid (ptid_), skipped_frames (skipped_frames_), saved_pc (saved_pc_),
+      skipped_symbol (skipped_symbol_)
+  {}
+
   /* The thread this data relates to.  It should be a currently
      stopped thread; we assume thread IDs never change while the
      thread is stopped.  */
@@ -55,10 +62,7 @@ struct inline_state
   struct symbol *skipped_symbol;
 };
 
-typedef struct inline_state inline_state_s;
-DEF_VEC_O(inline_state_s);
-
-static VEC(inline_state_s) *inline_states;
+static std::vector<inline_state> inline_states;
 
 /* Locate saved inlined frame state for PTID, if it exists
    and is valid.  */
@@ -66,43 +70,29 @@ static VEC(inline_state_s) *inline_states;
 static struct inline_state *
 find_inline_frame_state (ptid_t ptid)
 {
-  struct inline_state *state;
-  int ix;
-
-  for (ix = 0; VEC_iterate (inline_state_s, inline_states, ix, state); ix++)
-    {
-      if (ptid_equal (state->ptid, ptid))
-	{
-	  struct regcache *regcache = get_thread_regcache (ptid);
-	  CORE_ADDR current_pc = regcache_read_pc (regcache);
-
-	  if (current_pc != state->saved_pc)
-	    {
-	      /* PC has changed - this context is invalid.  Use the
-		 default behavior.  */
-	      VEC_unordered_remove (inline_state_s, inline_states, ix);
-	      return NULL;
-	    }
-	  else
-	    return state;
-	}
-    }
+  auto state_it = std::find_if (inline_states.begin (), inline_states.end (),
+				[&ptid] (const inline_state &state)
+				  {
+				    return ptid == state.ptid;
+				  });
 
-  return NULL;
-}
+  if (state_it == inline_states.end ())
+    return nullptr;
 
-/* Allocate saved inlined frame state for PTID.  */
+  inline_state &state = *state_it;
+  struct regcache *regcache = get_thread_regcache (ptid);
+  CORE_ADDR current_pc = regcache_read_pc (regcache);
 
-static struct inline_state *
-allocate_inline_frame_state (ptid_t ptid)
-{
-  struct inline_state *state;
+  if (current_pc != state.saved_pc)
+    {
+      /* PC has changed - this context is invalid.  Use the
+	 default behavior.  */
 
-  state = VEC_safe_push (inline_state_s, inline_states, NULL);
-  memset (state, 0, sizeof (*state));
-  state->ptid = ptid;
+      unordered_remove (inline_states, state_it);
+      return nullptr;
+    }
 
-  return state;
+  return &state;
 }
 
 /* Forget about any hidden inlined functions in PTID, which is new or
@@ -112,36 +102,34 @@ allocate_inline_frame_state (ptid_t ptid)
 void
 clear_inline_frame_state (ptid_t ptid)
 {
-  struct inline_state *state;
-  int ix;
-
-  if (ptid_equal (ptid, minus_one_ptid))
+  if (ptid == minus_one_ptid)
     {
-      VEC_free (inline_state_s, inline_states);
+      inline_states.clear ();
       return;
     }
 
-  if (ptid_is_pid (ptid))
+  if (ptid.is_pid ())
     {
-      VEC (inline_state_s) *new_states = NULL;
-      int pid = ptid_get_pid (ptid);
-
-      for (ix = 0;
-	   VEC_iterate (inline_state_s, inline_states, ix, state);
-	   ix++)
-	if (pid != ptid_get_pid (state->ptid))
-	  VEC_safe_push (inline_state_s, new_states, state);
-      VEC_free (inline_state_s, inline_states);
-      inline_states = new_states;
+      int pid = ptid.pid ();
+      auto it = std::remove_if (inline_states.begin (), inline_states.end (),
+				[pid] (const inline_state &state)
+				  {
+				    return pid == state.ptid.pid ();
+				  });
+
+      inline_states.erase (it, inline_states.end ());
+
       return;
     }
 
-  for (ix = 0; VEC_iterate (inline_state_s, inline_states, ix, state); ix++)
-    if (ptid_equal (state->ptid, ptid))
-      {
-	VEC_unordered_remove (inline_state_s, inline_states, ix);
-	return;
-      }
+  auto it = std::find_if (inline_states.begin (), inline_states.end (),
+			  [&ptid] (const inline_state &state)
+			    {
+			      return ptid == state.ptid;
+			    });
+
+  if (it != inline_states.end ())
+    unordered_remove (inline_states, it);
 }
 
 static void
@@ -303,16 +291,14 @@ block_starting_point_at (CORE_ADDR pc, const struct block *block)
 void
 skip_inline_frames (ptid_t ptid)
 {
-  CORE_ADDR this_pc;
   const struct block *frame_block, *cur_block;
   struct symbol *last_sym = NULL;
   int skip_count = 0;
-  struct inline_state *state;
 
   /* This function is called right after reinitializing the frame
      cache.  We try not to do more unwinding than absolutely
      necessary, for performance.  */
-  this_pc = get_frame_pc (get_current_frame ());
+  CORE_ADDR this_pc = get_frame_pc (get_current_frame ());
   frame_block = block_for_pc (this_pc);
 
   if (frame_block != NULL)
@@ -341,10 +327,7 @@ skip_inline_frames (ptid_t ptid)
     }
 
   gdb_assert (find_inline_frame_state (ptid) == NULL);
-  state = allocate_inline_frame_state (ptid);
-  state->skipped_frames = skip_count;
-  state->saved_pc = this_pc;
-  state->skipped_symbol = last_sym;
+  inline_states.emplace_back (ptid, skip_count, this_pc, last_sym);
 
   if (skip_count != 0)
     reinit_frame_cache ();