[PATCH 5/7] gdb: update blockvector::lookup to handle non-contiguous blocks

[Jan Vrany <jan.vrany@labware.com>]

This commit updates blockvector::lookup to handle non-contiguous without
help of addrmap. It introduces a new method, block::contains(CORE_ADDR),
to check whether given block contains given address. This new method is
then used in blockvector::lookup instead of simply using block's
start and end addresses.

A unit test for non-contiguous blocks will come later in this series.

On Debian x86_64 I see no regressions except

    FAIL: gdb.dwarf2/debug-names.exp: print _start

This is caused by discrepancy between the debug info and the debug names
and will be eventually fixed in a separate patch.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=33829
---
 gdb/block.c | 24 +++++++++++++++++++++++-
 gdb/block.h |  4 ++++
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/gdb/block.c b/gdb/block.c
index 730e4580a5b..b964674865b 100644
--- a/gdb/block.c
+++ b/gdb/block.c
@@ -85,6 +85,25 @@ block::contains (const struct block *a, bool allow_nested) const
 
 /* See block.h.  */
 
+bool
+block::contains (const CORE_ADDR addr) const
+{
+  if (addr >= start () && addr < end ())
+    {
+      if (is_contiguous ())
+	return true;
+
+      for (auto range : ranges ())
+	{
+	  if (range.start () <= addr && addr < range.end ())
+	    return true;
+	}
+    }
+  return false;
+}
+
+/* See block.h.  */
+
 struct symbol *
 block::linkage_function () const
 {
@@ -857,7 +876,10 @@ blockvector::lookup (CORE_ADDR addr) const
       if (b->start () > addr)
 	return nullptr;
       if (b->end () > addr)
-	return b;
+	{
+	  if (b->contains (addr))
+	    return b;
+	}
       bot--;
     }
 
diff --git a/gdb/block.h b/gdb/block.h
index b84ca12c35a..f65546792ca 100644
--- a/gdb/block.h
+++ b/gdb/block.h
@@ -315,6 +315,10 @@ struct block : public allocate_on_obstack<block>
 
   bool contains (const struct block *a, bool allow_nested = false) const;
 
+  /* FIXME!!! */
+
+  bool contains (const CORE_ADDR addr) const;
+
   /* Relocate this block and all contained blocks.  OBJFILE is the
      objfile holding this block, and OFFSETS is the relocation offsets
      to use.  */
-- 
2.51.0