[PATCH v2 4/5] [gdb/symtab] Improve invalid range check in create_addrmap_from_gdb_index

[Tom de Vries <tdevries@suse.de>]

When running test-case gdb.tui/tui-missing-src.exp with target board
gold-gdb-index (and likewise fission and fission-dwp) on aarch64-linux, I run
into:
...
FAIL: gdb.tui/tui-missing-src.exp: checking if inside f2 ()
...

Looking at the gold-gdb-index case, the problem is caused by the address table
of the .gdb_index section:
...
Address table:
000000000040066c 0000000000400694 0
000000000040053f 0000000000400563 1
...

The address range for f2 is [0x400694, 0x4006b8), but the address table says
it's [0x40053f, 0x400563).

The address 0x40053f is not even in a section:
...
  [Nr] Name    Type            Address          Off    Size   ES Flg Lk Inf Al
  ...
  [12] .plt    PROGBITS        00000000004004b8 0004b8 000050 10  AX  0   0  8
  [13] .text   PROGBITS        0000000000400540 000540 000178 00  AX  0   0 64
...
but part of the hole [0x400508, 0x400540) in between .plt and .text.

Detect this in the invalid range check in create_addrmap_from_gdb_index.

Tested on aarch64-linux.
---
 gdb/dwarf2/read-gdb-index.c | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/gdb/dwarf2/read-gdb-index.c b/gdb/dwarf2/read-gdb-index.c
index 79d19a3abaa..df20b20e081 100644
--- a/gdb/dwarf2/read-gdb-index.c
+++ b/gdb/dwarf2/read-gdb-index.c
@@ -1420,14 +1420,33 @@ create_addrmap_from_gdb_index (dwarf2_per_objfile *per_objfile,
       cu_index = extract_unsigned_integer (iter, 4, BFD_ENDIAN_LITTLE);
       iter += 4;
 
-      if (lo >= hi)
+      bool valid_range_p = lo < hi;
+      bool valid_index_p = cu_index < index->units.size ();
+
+      /* Variable hi is the exclusive upper bound, get the inclusive one.  */
+      CORE_ADDR hi_m1 = (valid_range_p
+			 ? hi - 1
+			 : 0);
+
+      if (valid_range_p)
+	{
+	  CORE_ADDR relocated_lo
+	    = per_objfile->relocate (unrelocated_addr (lo));
+	  CORE_ADDR relocated_hi_m1
+	    = per_objfile->relocate (unrelocated_addr (hi_m1));
+	  struct obj_section *lo_sect = find_pc_section (relocated_lo);
+	  struct obj_section *hi_sect = find_pc_section (relocated_hi_m1);
+	  valid_range_p = lo_sect != nullptr && hi_sect != nullptr;
+	}
+
+      if (!valid_range_p)
 	{
 	  complaint (_(".gdb_index address table has invalid range (%s - %s)"),
 		     hex_string (lo), hex_string (hi));
 	  return false;
 	}
 
-      if (cu_index >= index->units.size ())
+      if (!valid_index_p)
 	{
 	  complaint (_(".gdb_index address table has invalid CU number %u"),
 		     (unsigned) cu_index);
@@ -1435,7 +1454,7 @@ create_addrmap_from_gdb_index (dwarf2_per_objfile *per_objfile,
 	}
 
       bool full_range_p
-	= mutable_map.set_empty (lo, hi - 1, index->units[cu_index]);
+	= mutable_map.set_empty (lo, hi_m1, index->units[cu_index]);
       if (!full_range_p)
 	{
 	  complaint (_(".gdb_index address table has a range (%s - %s) that"
-- 
2.43.0