[binutils-gdb] Don't call decode_line_with_current_source from select_source_symtab

[gdb-buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT 5c281dbb2458be9d58355e865f527e96b40bcd8c ***

commit 5c281dbb2458be9d58355e865f527e96b40bcd8c
Author:     Tom Tromey <tromey@adacore.com>
AuthorDate: Thu Aug 1 09:17:14 2019 -0600
Commit:     Tom Tromey <tromey@adacore.com>
CommitDate: Wed Oct 2 09:53:17 2019 -0600

    Don't call decode_line_with_current_source from select_source_symtab
    
    select_source_symtab currently calls decode_line_with_current_source.
    However, this function iterates over all program spaces, and so it is
    possible that it will return a "main" from some other program space.
    
    This patch changes select_source_symtab to simply use the symbol it
    already found in the current program space.
    
    gdb/ChangeLog
    2019-10-02  Tom Tromey  <tromey@adacore.com>
    
            * source.c (select_source_symtab): Don't call
            decode_line_with_current_source.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index c2417cfd37..d419fdfdae 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2019-10-02  Tom Tromey  <tromey@adacore.com>
+
+	* source.c (select_source_symtab): Don't call
+	decode_line_with_current_source.
+
 2019-10-02  Andrew Burgess  <andrew.burgess@embecosm.com>
 
 	* symtab.c (lookup_global_symbol): Search global block.
diff --git a/gdb/source.c b/gdb/source.c
index ff21818949..9222df1505 100644
--- a/gdb/source.c
+++ b/gdb/source.c
@@ -252,17 +252,14 @@ select_source_symtab (struct symtab *s)
 
   /* Make the default place to list be the function `main'
      if one exists.  */
-  if (lookup_symbol (main_name (), 0, VAR_DOMAIN, 0).symbol)
+  block_symbol bsym = lookup_symbol (main_name (), 0, VAR_DOMAIN, 0);
+  if (bsym.symbol != nullptr && SYMBOL_CLASS (bsym.symbol) == LOC_BLOCK)
     {
-      std::vector<symtab_and_line> sals
-	= decode_line_with_current_source (main_name (),
-					   DECODE_LINE_FUNFIRSTLINE);
-      const symtab_and_line &sal = sals[0];
+      symtab_and_line sal = find_function_start_sal (bsym.symbol, true);
       current_source_pspace = sal.pspace;
       current_source_symtab = sal.symtab;
       current_source_line = std::max (sal.line - (lines_to_list - 1), 1);
-      if (current_source_symtab)
-	return;
+      return;
     }
 
   /* Alright; find the last file in the symtab list (ignoring .h's