[binutils-gdb] Adapt .gdb_index writer to new DWARF scanner

[binutils-gdb] Adapt .gdb_index writer to new DWARF scanner

[Tom Tromey]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=6dd7aa909b6f98202ebe995518613e565e11e1a5

commit 6dd7aa909b6f98202ebe995518613e565e11e1a5
Author: Tom Tromey <tom@tromey.com>
Date:   Sat May 29 08:57:16 2021 -0600

    Adapt .gdb_index writer to new DWARF scanner
    
    This updates the .gdb_index writer to work with the new DWARF scanner.
    The .debug_names writer is deferred to another patch, to make review
    simpler.
    
    This introduces a small hack to psyms_seen_size, but is
    inconsequential because this function will be deleted in a subsequent
    patch.

Diff:
---
 gdb/dwarf2/index-write.c               | 63 +++++++++++++++++++++++++++++-----
 gdb/testsuite/gdb.dwarf2/gdb-index.exp |  5 ++-
 2 files changed, 59 insertions(+), 9 deletions(-)

diff --git a/gdb/dwarf2/index-write.c b/gdb/dwarf2/index-write.c
index 9fe7724feea..4d9a9a18c95 100644
--- a/gdb/dwarf2/index-write.c
+++ b/gdb/dwarf2/index-write.c
@@ -189,7 +189,7 @@ struct mapped_symtab
   offset_type n_elements = 0;
   std::vector<symtab_index_entry> data;
 
-  /* Temporary storage for Ada names.  */
+  /* Temporary storage for names.  */
   auto_obstack m_string_obstack;
 };
 
@@ -1237,6 +1237,9 @@ check_dwarf64_offsets (dwarf2_per_objfile *per_objfile)
 static size_t
 psyms_seen_size (dwarf2_per_objfile *per_objfile)
 {
+  if (per_objfile->per_bfd->using_index)
+    return 0;
+
   size_t psyms_count = 0;
   for (const auto &per_cu : per_objfile->per_bfd->all_comp_units)
     {
@@ -1312,6 +1315,41 @@ write_gdbindex_1 (FILE *out_file,
   assert_file_size (out_file, total_len);
 }
 
+/* Write the contents of the internal "cooked" index.  */
+
+static void
+write_cooked_index (dwarf2_per_objfile *per_objfile,
+		    const cu_index_map &cu_index_htab,
+		    struct mapped_symtab *symtab)
+{
+  gdb_assert (per_objfile->per_bfd->using_index);
+
+  for (const cooked_index_entry *entry
+	 : per_objfile->per_bfd->cooked_index_table->all_entries ())
+    {
+      const auto it = cu_index_htab.find (entry->per_cu);
+      gdb_assert (it != cu_index_htab.cend ());
+
+      const char *name = entry->full_name (&symtab->m_string_obstack);
+
+      gdb_index_symbol_kind kind;
+      if (entry->tag == DW_TAG_subprogram)
+	kind = GDB_INDEX_SYMBOL_KIND_FUNCTION;
+      else if (entry->tag == DW_TAG_variable
+	       || entry->tag == DW_TAG_constant
+	       || entry->tag == DW_TAG_enumerator)
+	kind = GDB_INDEX_SYMBOL_KIND_VARIABLE;
+      else if (entry->tag == DW_TAG_module
+	       || entry->tag == DW_TAG_common_block)
+	kind = GDB_INDEX_SYMBOL_KIND_OTHER;
+      else
+	kind = GDB_INDEX_SYMBOL_KIND_TYPE;
+
+      add_index_entry (symtab, name, (entry->flags & IS_STATIC) != 0,
+		       kind, it->second);
+    }
+}
+
 /* Write contents of a .gdb_index section for OBJFILE into OUT_FILE.
    If OBJFILE has an associated dwz file, write contents of a .gdb_index
    section for that dwz file into DWZ_OUT_FILE.  If OBJFILE does not have an
@@ -1348,7 +1386,9 @@ write_gdbindex (dwarf2_per_objfile *per_objfile, FILE *out_file,
     {
       dwarf2_per_cu_data *per_cu
 	= per_objfile->per_bfd->all_comp_units[i].get ();
-      partial_symtab *psymtab = per_cu->v.psymtab;
+      partial_symtab *psymtab = (per_objfile->per_bfd->using_index
+				 ? nullptr
+				 : per_cu->v.psymtab);
 
       int &this_counter = per_cu->is_debug_types ? types_counter : counter;
 
@@ -1357,7 +1397,10 @@ write_gdbindex (dwarf2_per_objfile *per_objfile, FILE *out_file,
 	  if (psymtab->user == NULL)
 	    recursively_write_psymbols (objfile, psymtab, &symtab,
 					psyms_seen, this_counter);
+	}
 
+      if (psymtab != NULL || per_objfile->per_bfd->using_index)
+	{
 	  const auto insertpair = cu_index_htab.emplace (per_cu,
 							 this_counter);
 	  gdb_assert (insertpair.second);
@@ -1385,6 +1428,9 @@ write_gdbindex (dwarf2_per_objfile *per_objfile, FILE *out_file,
       ++this_counter;
     }
 
+  if (per_objfile->per_bfd->using_index)
+    write_cooked_index (per_objfile, cu_index_htab, &symtab);
+
   /* Dump the address map.  */
   data_buf addr_vec;
   if (per_objfile->per_bfd->using_index)
@@ -1396,8 +1442,7 @@ write_gdbindex (dwarf2_per_objfile *per_objfile, FILE *out_file,
     }
   else
     write_address_map (per_objfile->per_bfd->partial_symtabs->psymtabs_addrmap,
-		       addr_vec, cu_index_htab,
-		       per_objfile->per_bfd->using_index);
+		       addr_vec, cu_index_htab, false);
 
   /* Now that we've processed all symbols we can shrink their cu_indices
      lists.  */
@@ -1603,15 +1648,17 @@ write_dwarf_index (dwarf2_per_objfile *per_objfile, const char *dir,
   dwarf2_per_bfd *per_bfd = per_objfile->per_bfd;
   struct objfile *objfile = per_objfile->objfile;
 
-  if (per_objfile->per_bfd->using_index)
+  if (per_objfile->per_bfd->using_index
+      && per_objfile->per_bfd->cooked_index_table == nullptr)
     error (_("Cannot use an index to create the index"));
 
   if (per_objfile->per_bfd->types.size () > 1)
     error (_("Cannot make an index when the file has multiple .debug_types sections"));
 
-  if (per_bfd->partial_symtabs == nullptr
-      || !per_bfd->partial_symtabs->psymtabs
-      || !per_bfd->partial_symtabs->psymtabs_addrmap)
+  if ((per_bfd->partial_symtabs == nullptr
+       || !per_bfd->partial_symtabs->psymtabs
+       || !per_bfd->partial_symtabs->psymtabs_addrmap)
+      && per_bfd->cooked_index_table == nullptr)
     return;
 
   struct stat st;
diff --git a/gdb/testsuite/gdb.dwarf2/gdb-index.exp b/gdb/testsuite/gdb.dwarf2/gdb-index.exp
index 587b034b28b..5badcaccb1b 100644
--- a/gdb/testsuite/gdb.dwarf2/gdb-index.exp
+++ b/gdb/testsuite/gdb.dwarf2/gdb-index.exp
@@ -90,12 +90,15 @@ gdb_test_multiple "mt print objfiles ${testfile}" $test {
     -re "debug_names.*${gdb_prompt} $" {
 	set binfile_with_index $binfile
     }
-    -re "Psymtabs.*${gdb_prompt} $" {
+    -re "(Psymtabs|Cooked).*${gdb_prompt} $" {
 	set binfile_with_index [local_add_gdb_index $binfile]
 	if { ${binfile_with_index} == "" } {
 	    return -1
 	}
     }
+    -re ".*${gdb_prompt} $" {
+	fail "unrecognized symbol reader"
+    }
 }
 
 # Ok, we have a copy of $binfile with an index.