[PATCH v3] gdb/jit: add function symbols to global block

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

This v3 just fixes formatting (no opening parenthesis at the end of the line).

-- >8 --
While playing with JIT reader I realized that it is not possible to set
a breakpoint on jitted function:

    (gdb) b jit_function_stack_mangle
    Function "jit_function_stack_mangle" not defined.
    Make breakpoint pending on future shared library load? (y or [n])

The problem is that symbols for jitted functions (jit_function_stack_mangle
in the above example) are not added to jitted compunit's global block:

    (gdb) maint print symtabs
    ...
    Symtab for file  at 0x55d6f8c186c0
    Read from object file << JIT compiled code at 0x5555555592a0 >> (0x55d6f8cd4090)
    Language: unknown

    Line table:

     line 1 at 0x7ffff7fbc000	(stmt)
     line 0 at 0x7ffff7fbc001	(stmt)

    Blockvector:

    block #000, object at 0x55d6f8c188b0, 0 symbols in 0x7ffff7fbc000..0x7ffff7fbc011
      block #001, object at 0x55d6f8c18910 under 0x55d6f8c188b0, 0 symbols in 0x7ffff7fbc000..0x7ffff7fbc011
        block #002, object at 0x55d6f8c18730 under 0x55d6f8c18910, 0 symbols in 0x7ffff7fbc000..0x7ffff7fbc00a, function jit_function_stack_mangle
        block #003, object at 0x55d6f8c187f0 under 0x55d6f8c18910, 0 symbols in 0x7ffff7fbc00a..0x7ffff7fbc011, function jit_function_add

This commit changes JIT reader to add jitted functions to the global
block:

    ...
    Blockvector:

    block #000, object at 0x55ed6665b180, 2 symbols in 0x7ffff7fbc000..0x7ffff7fbc011
     void jit_function_stack_mangle(); block object 0x55ed6665b000, 0x7ffff7fbc000..0x7ffff7fbc00a
     void jit_function_add(); block object 0x55ed6665b0c0, 0x7ffff7fbc00a..0x7ffff7fbc011
      block #001, object at 0x55ed6665b230 under 0x55ed6665b180, 0 symbols in 0x7ffff7fbc000..0x7ffff7fbc011
        block #002, object at 0x55ed6665b000 under 0x55ed6665b230, 0 symbols in 0x7ffff7fbc000..0x7ffff7fbc00a, function jit_function_stack_mangle
        block #003, object at 0x55ed6665b0c0 under 0x55ed6665b230, 0 symbols in 0x7ffff7fbc00a..0x7ffff7fbc011, function jit_function_add
---
 gdb/jit.c                             | 16 ++++++++++++----
 gdb/testsuite/gdb.base/jit-reader.exp | 10 ++++++++++
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/gdb/jit.c b/gdb/jit.c
index 489386393a1..4add2fa4861 100644
--- a/gdb/jit.c
+++ b/gdb/jit.c
@@ -564,6 +564,7 @@ finalize_symtab (struct gdb_symtab *stab, struct objfile *objfile)
      object for each.  Simultaneously, keep setting the real_block
      fields.  */
   int block_idx = FIRST_LOCAL_BLOCK;
+  std::vector<symbol *> global_symbols;
   for (gdb_block &gdb_block_iter : stab->blocks)
     {
       struct block *new_block = new (&objfile->objfile_obstack) block;
@@ -585,6 +586,7 @@ finalize_symtab (struct gdb_symtab *stab, struct objfile *objfile)
 
       block_name->m_name = obstack_strdup (&objfile->objfile_obstack,
 					   gdb_block_iter.name.get ());
+      global_symbols.push_back (block_name);
 
       new_block->set_function (block_name);
 
@@ -606,12 +608,18 @@ finalize_symtab (struct gdb_symtab *stab, struct objfile *objfile)
       struct block *new_block;
 
       if (i == GLOBAL_BLOCK)
-	new_block = new (&objfile->objfile_obstack) global_block;
+	{
+	  new_block = new (&objfile->objfile_obstack) global_block;
+	  new_block->set_multidict
+	    (mdict_create_linear (&objfile->objfile_obstack, global_symbols));
+	}
       else
-	new_block = new (&objfile->objfile_obstack) block;
+	{
+	  new_block = new (&objfile->objfile_obstack) block;
+	  new_block->set_multidict
+	    (mdict_create_linear (&objfile->objfile_obstack, {}));
+	}
 
-      new_block->set_multidict
-	(mdict_create_linear (&objfile->objfile_obstack, {}));
       new_block->set_superblock (block_iter);
       block_iter = new_block;
 
diff --git a/gdb/testsuite/gdb.base/jit-reader.exp b/gdb/testsuite/gdb.base/jit-reader.exp
index 549859627f1..8b3f50d15b7 100644
--- a/gdb/testsuite/gdb.base/jit-reader.exp
+++ b/gdb/testsuite/gdb.base/jit-reader.exp
@@ -244,6 +244,16 @@ proc jit_reader_test {} {
 		    "<gdb.Objfile filename=<< JIT compiled code at $hex >>>" \
 		    "python gdb.Progspace.objfile_for_address"
 	    }
+
+	    # Check that jitted symbol completion works
+	    gdb_test "complete break jit_func" \
+		[multi_line "break jit_function_add" \
+		    "break jit_function_stack_mangle" ] \
+
+	    # Check that breakpoint can be set on jitted function
+	    gdb_test "break jit_function_add" \
+		"Breakpoint 1 at 0x\[0-9a-f\]+"
+	    gdb_test_no_output "del 1"
 	}
     }
 
-- 
2.51.0