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From: Tom Tromey <tom@tromey.com>
To: gdb-patches@sourceware.org
Cc: Tom Tromey <tom@tromey.com>
Subject: [PATCH 3/8] Change fde table to a vector
Date: Sat, 08 Feb 2020 15:28:00 -0000	[thread overview]
Message-ID: <20200208152758.29385-4-tom@tromey.com> (raw)
In-Reply-To: <20200208152758.29385-1-tom@tromey.com>

This removes struct dwarf2_fde_table, replacing it with a typedef of
std::vector.  This simplifies the code somewhat.

gdb/ChangeLog
2020-02-08  Tom Tromey  <tom@tromey.com>

	* dwarf2/frame.c (struct dwarf2_fde_table): Remove.
	(dwarf2_fde_table): Typedef for std::vector.
	(dwarf2_frame_objfile_data): Remove the deleter.
	(dwarf2_frame_find_fde, add_fde, decode_frame_entry_1)
	(decode_frame_entry): Update.
	(dwarf2_build_frame_info): Use "new".

Change-Id: Ie31c7413dce2865b76f5f70374ba7a559112ce5e
---
 gdb/ChangeLog      |   9 ++++
 gdb/dwarf2/frame.c | 102 ++++++++++++---------------------------------
 2 files changed, 35 insertions(+), 76 deletions(-)

diff --git a/gdb/dwarf2/frame.c b/gdb/dwarf2/frame.c
index db8e5cd25f3..6d87e598345 100644
--- a/gdb/dwarf2/frame.c
+++ b/gdb/dwarf2/frame.c
@@ -129,11 +129,7 @@ struct dwarf2_fde
   unsigned char eh_frame_p;
 };
 
-struct dwarf2_fde_table
-{
-  int num_entries;
-  struct dwarf2_fde **entries;
-};
+typedef std::vector<dwarf2_fde *> dwarf2_fde_table;
 
 /* A minimal decoding of DWARF2 compilation units.  We only decode
    what's needed to get to the call frame information.  */
@@ -1471,9 +1467,7 @@ dwarf2_frame_cfa (struct frame_info *this_frame)
   return get_frame_base (this_frame);
 }
 \f
-const struct objfile_key<dwarf2_fde_table,
-			 gdb::noop_deleter<dwarf2_fde_table>>
-  dwarf2_frame_objfile_data;
+const struct objfile_key<dwarf2_fde_table> dwarf2_frame_objfile_data;
 
 \f
 
@@ -1636,7 +1630,7 @@ dwarf2_frame_find_fde (CORE_ADDR *pc, CORE_ADDR *out_offset)
 {
   for (objfile *objfile : current_program_space->objfiles ())
     {
-      struct dwarf2_fde_table *fde_table;
+      dwarf2_fde_table *fde_table;
       CORE_ADDR offset;
       CORE_ADDR seek_pc;
 
@@ -1648,20 +1642,20 @@ dwarf2_frame_find_fde (CORE_ADDR *pc, CORE_ADDR *out_offset)
 	}
       gdb_assert (fde_table != NULL);
 
-      if (fde_table->num_entries == 0)
+      if (fde_table->empty ())
 	continue;
 
       gdb_assert (!objfile->section_offsets.empty ());
       offset = objfile->text_section_offset ();
 
-      gdb_assert (fde_table->num_entries > 0);
-      if (*pc < offset + fde_table->entries[0]->initial_location)
+      gdb_assert (!fde_table->empty ());
+      if (*pc < offset + (*fde_table)[0]->initial_location)
         continue;
 
       seek_pc = *pc - offset;
-      auto end = fde_table->entries + fde_table->num_entries;
-      auto it = gdb::binary_search (fde_table->entries, end, seek_pc, bsearch_fde_cmp);
-      if (it != end)
+      auto it = gdb::binary_search (fde_table->begin (), fde_table->end (),
+				    seek_pc, bsearch_fde_cmp);
+      if (it != fde_table->end ())
         {
           *pc = (*it)->initial_location + offset;
 	  if (out_offset)
@@ -1674,16 +1668,13 @@ dwarf2_frame_find_fde (CORE_ADDR *pc, CORE_ADDR *out_offset)
 
 /* Add a pointer to new FDE to the FDE_TABLE, allocating space for it.  */
 static void
-add_fde (struct dwarf2_fde_table *fde_table, struct dwarf2_fde *fde)
+add_fde (dwarf2_fde_table *fde_table, struct dwarf2_fde *fde)
 {
   if (fde->address_range == 0)
     /* Discard useless FDEs.  */
     return;
 
-  fde_table->num_entries += 1;
-  fde_table->entries = XRESIZEVEC (struct dwarf2_fde *, fde_table->entries,
-				   fde_table->num_entries);
-  fde_table->entries[fde_table->num_entries - 1] = fde;
+  fde_table->push_back (fde);
 }
 
 #define DW64_CIE_ID 0xffffffffffffffffULL
@@ -1702,7 +1693,7 @@ static const gdb_byte *decode_frame_entry (struct comp_unit *unit,
 					   const gdb_byte *start,
 					   int eh_frame_p,
 					   dwarf2_cie_table &cie_table,
-					   struct dwarf2_fde_table *fde_table,
+					   dwarf2_fde_table *fde_table,
 					   enum eh_frame_type entry_type);
 
 /* Decode the next CIE or FDE, entry_type specifies the expected type.
@@ -1712,7 +1703,7 @@ static const gdb_byte *
 decode_frame_entry_1 (struct comp_unit *unit, const gdb_byte *start,
 		      int eh_frame_p,
                       dwarf2_cie_table &cie_table,
-                      struct dwarf2_fde_table *fde_table,
+                      dwarf2_fde_table *fde_table,
                       enum eh_frame_type entry_type)
 {
   struct gdbarch *gdbarch = get_objfile_arch (unit->objfile);
@@ -2014,7 +2005,7 @@ static const gdb_byte *
 decode_frame_entry (struct comp_unit *unit, const gdb_byte *start,
 		    int eh_frame_p,
 		    dwarf2_cie_table &cie_table,
-                    struct dwarf2_fde_table *fde_table,
+                    dwarf2_fde_table *fde_table,
                     enum eh_frame_type entry_type)
 {
   enum { NONE, ALIGN4, ALIGN8, FAIL } workaround = NONE;
@@ -2128,11 +2119,8 @@ dwarf2_build_frame_info (struct objfile *objfile)
   struct comp_unit *unit;
   const gdb_byte *frame_ptr;
   dwarf2_cie_table cie_table;
-  struct dwarf2_fde_table fde_table;
-  struct dwarf2_fde_table *fde_table2;
-
-  fde_table.num_entries = 0;
-  fde_table.entries = NULL;
+  dwarf2_fde_table fde_table;
+  dwarf2_fde_table *fde_table2;
 
   /* Build a minimal decoding of the DWARF2 compilation unit.  */
   unit = XOBNEW (&objfile->objfile_obstack, comp_unit);
@@ -2181,12 +2169,7 @@ dwarf2_build_frame_info (struct objfile *objfile)
 	      warning (_("skipping .eh_frame info of %s: %s"),
 		       objfile_name (objfile), e.what ());
 
-	      if (fde_table.num_entries != 0)
-		{
-                  xfree (fde_table.entries);
-		  fde_table.entries = NULL;
-		  fde_table.num_entries = 0;
-		}
+	      fde_table.clear ();
 	      /* The cie_table is discarded below.  */
 	    }
 
@@ -2200,7 +2183,7 @@ dwarf2_build_frame_info (struct objfile *objfile)
                            &unit->dwarf_frame_size);
   if (unit->dwarf_frame_size)
     {
-      int num_old_fde_entries = fde_table.num_entries;
+      size_t num_old_fde_entries = fde_table.size ();
 
       try
 	{
@@ -2215,42 +2198,20 @@ dwarf2_build_frame_info (struct objfile *objfile)
 	  warning (_("skipping .debug_frame info of %s: %s"),
 		   objfile_name (objfile), e.what ());
 
-	  if (fde_table.num_entries != 0)
-	    {
-	      fde_table.num_entries = num_old_fde_entries;
-	      if (num_old_fde_entries == 0)
-		{
-		  xfree (fde_table.entries);
-		  fde_table.entries = NULL;
-		}
-	      else
-		{
-		  fde_table.entries
-		    = XRESIZEVEC (struct dwarf2_fde *, fde_table.entries,
-				  fde_table.num_entries);
-		}
-	    }
-	  fde_table.num_entries = num_old_fde_entries;
+	  fde_table.resize (num_old_fde_entries);
 	}
     }
 
   /* Copy fde_table to obstack: it is needed at runtime.  */
-  fde_table2 = XOBNEW (&objfile->objfile_obstack, struct dwarf2_fde_table);
+  fde_table2 = new dwarf2_fde_table;
 
-  if (fde_table.num_entries == 0)
-    {
-      fde_table2->entries = NULL;
-      fde_table2->num_entries = 0;
-    }
-  else
+  if (!fde_table.empty ())
     {
       struct dwarf2_fde *fde_prev = NULL;
       struct dwarf2_fde *first_non_zero_fde = NULL;
-      int i;
 
       /* Prepare FDE table for lookups.  */
-      std::sort (fde_table.entries, fde_table.entries + fde_table.num_entries,
-		 fde_is_less_than);
+      std::sort (fde_table.begin (), fde_table.end (), fde_is_less_than);
 
       /* Check for leftovers from --gc-sections.  The GNU linker sets
 	 the relevant symbols to zero, but doesn't zero the FDE *end*
@@ -2264,10 +2225,8 @@ dwarf2_build_frame_info (struct objfile *objfile)
 	 Start by finding the first FDE with non-zero start.  Below
 	 we'll discard all FDEs that start at zero and overlap this
 	 one.  */
-      for (i = 0; i < fde_table.num_entries; i++)
+      for (struct dwarf2_fde *fde : fde_table)
 	{
-	  struct dwarf2_fde *fde = fde_table.entries[i];
-
 	  if (fde->initial_location != 0)
 	    {
 	      first_non_zero_fde = fde;
@@ -2278,11 +2237,8 @@ dwarf2_build_frame_info (struct objfile *objfile)
       /* Since we'll be doing bsearch, squeeze out identical (except
 	 for eh_frame_p) fde entries so bsearch result is predictable.
 	 Also discard leftovers from --gc-sections.  */
-      fde_table2->num_entries = 0;
-      for (i = 0; i < fde_table.num_entries; i++)
+      for (struct dwarf2_fde *fde : fde_table)
 	{
-	  struct dwarf2_fde *fde = fde_table.entries[i];
-
 	  if (fde->initial_location == 0
 	      && first_non_zero_fde != NULL
 	      && (first_non_zero_fde->initial_location
@@ -2293,16 +2249,10 @@ dwarf2_build_frame_info (struct objfile *objfile)
 	      && fde_prev->initial_location == fde->initial_location)
 	    continue;
 
-	  obstack_grow (&objfile->objfile_obstack, &fde_table.entries[i],
-			sizeof (fde_table.entries[0]));
-	  ++fde_table2->num_entries;
+	  fde_table2->push_back (fde);
 	  fde_prev = fde;
 	}
-      fde_table2->entries
-	= (struct dwarf2_fde **) obstack_finish (&objfile->objfile_obstack);
-
-      /* Discard the original fde_table.  */
-      xfree (fde_table.entries);
+      fde_table2->shrink_to_fit ();
     }
 
   dwarf2_frame_objfile_data.set (objfile, fde_table2);
-- 
2.17.2


  parent reply	other threads:[~2020-02-08 15:28 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-08 15:28 [PATCH 0/8] Share DWARF frame information across inferiors Tom Tromey
2020-02-08 15:28 ` [PATCH 6/8] Remove a use of the comp_unit backlink Tom Tromey
2020-02-08 15:28 ` [PATCH 2/8] Dont' allow copying of auto_obstack Tom Tromey
2020-02-09 23:56   ` Christian Biesinger via gdb-patches
2020-02-12  0:16     ` Tom Tromey
2020-02-12  0:53       ` Simon Marchi
2020-02-12  1:01         ` Tom Tromey
2020-02-08 15:28 ` [PATCH 5/8] Add per-unit obstack Tom Tromey
2020-02-11 10:34   ` Luis Machado
2020-02-12  3:53   ` Simon Marchi
2020-02-12 22:41     ` Tom Tromey
2020-02-12 22:48       ` Simon Marchi
2020-02-12 22:51         ` Tom Tromey
2020-02-08 15:28 ` [PATCH 1/8] Don't forward-declare struct objfile in frame.h Tom Tromey
2020-02-12  0:51   ` Simon Marchi
2020-02-12  1:59     ` Tom Tromey
2020-02-08 15:28 ` [PATCH 8/8] Move the frame data to the BFD when possible Tom Tromey
2020-02-11 10:45   ` Luis Machado
2020-02-12  0:31     ` Tom Tromey
2020-11-14  3:31   ` Simon Marchi
2020-02-08 15:28 ` [PATCH 4/8] Store the comp_unit instead of the FDE table Tom Tromey
2020-02-09 23:56   ` Christian Biesinger via gdb-patches
2020-02-12  0:19     ` Tom Tromey
2020-02-11 10:32   ` Luis Machado
2020-02-12  0:20     ` Tom Tromey
2020-02-12  3:36   ` Simon Marchi
2020-02-12 22:20     ` Tom Tromey
2020-02-08 15:28 ` Tom Tromey [this message]
     [not found]   ` <5a373a74-9283-5d82-a22d-7a2606a4d3f5@linaro.org>
2020-02-12  0:29     ` [PATCH 3/8] Change fde table to a vector Tom Tromey
2020-02-12  3:28   ` Simon Marchi
2020-02-12  3:33     ` Simon Marchi
2020-02-12 22:36     ` Tom Tromey
2020-02-12 22:47       ` Simon Marchi
2020-02-08 15:28 ` [PATCH 7/8] Remove the objfile backlink from comp_unit Tom Tromey
2020-02-09 23:56   ` Christian Biesinger via gdb-patches
2020-02-12  0:26     ` Tom Tromey
2020-02-11 10:40   ` Luis Machado
2020-02-08 15:29 ` [PATCH 0/8] Share DWARF frame information across inferiors Tom Tromey

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