[PATCH v2 01/13] gdb: reimplement readnow_functions::search

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

This commit reimplements readnow_functions::search without using DWARF
data structures. This will allow readnow_functions to be used in other
cases, for example in JIT reader.

I was bit surprised to realize that original code did not use lookup_name
to match symbols at all, and this calling listener with more CUs than
needed. I did try to use it as described in the comment  but run into
issues (test failures) when completing symbols so I decided not to.

With this change, running all tests with -readnow shown no regressions
(on my Debian, x86_64 machine).

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=33554
---
 gdb/dwarf2/read.c | 49 +++++++++++++++++++++++++++++++----------------
 1 file changed, 32 insertions(+), 17 deletions(-)

diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index b34c3463774..561e2dc2add 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -1546,26 +1546,41 @@ struct readnow_functions : public dwarf2_base_index_functions
 	       domain_search_flags domain,
 	       search_symtabs_lang_matcher lang_matcher) override
   {
-    dwarf2_per_objfile *per_objfile = get_dwarf2_per_objfile (objfile);
-    auto_bool_vector cus_to_skip;
-    dw_search_file_matcher (per_objfile, cus_to_skip, file_matcher);
+    /* This invariant is documented in quick-functions.h.  */
+    gdb_assert (lookup_name != nullptr || symbol_matcher == nullptr);
 
-    for (const auto &per_cu : per_objfile->per_bfd->all_units)
+    for (compunit_symtab &cu : objfile->compunits ())
       {
-	QUIT;
-
-	/* Skip various types of unit that should not be searched
-	   directly: partial units and dummy units.  */
-	if (/* Note that we request the non-strict unit type here.  If
-	       there was an error while reading, like in
-	       dw-form-strx-out-of-bounds.exp, then the unit type may
-	       not be set.  */
-	    per_cu->unit_type (false) == DW_UT_partial
-	    || per_cu->unit_type (false) == 0
-	    || per_objfile->get_symtab (per_cu.get ()) == nullptr)
+	if (lang_matcher != nullptr && !lang_matcher (cu.language ()))
 	  continue;
-	if (!dw2_search_one (per_cu.get (), per_objfile, cus_to_skip,
-			     file_matcher, listener, lang_matcher))
+
+	if (file_matcher != nullptr)
+	  {
+	    bool matched = false;
+	    for (auto st : cu.filetabs ())
+	      {
+		if (file_matcher (st->filename (), false))
+		  {
+		    matched = true;
+		    break;
+		  }
+		if ((basenames_may_differ
+		     || file_matcher (lbasename (st->filename ()), true))
+		    && file_matcher (symtab_to_fullname (st), false))
+		  {
+		    matched = true;
+		    break;
+		  }
+	      }
+	    if (!matched)
+	      continue;
+	  }
+
+	/* Here we simply call the listener (if any) without bothering to
+	   consult lookup_name and symbol_matcher (if any).  This should be
+	   okay since i) all symtabs are already expanded and ii) listeners
+	   iterate over matching symbols themselves.  */
+	if (listener != nullptr && !listener (&cu))
 	  return false;
       }
     return true;
-- 
2.51.0