[binutils-gdb] [gdb/symtab] Find filename in shared psymtab

[Tom de Vries <vries@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=eea9e35758138f83e8c44e0e5a5e47e351f8f31a

commit eea9e35758138f83e8c44e0e5a5e47e351f8f31a
Author: Tom de Vries <tdevries@suse.de>
Date:   Wed Apr 22 08:24:11 2020 +0200

    [gdb/symtab] Find filename in shared psymtab
    
    When running test-case gdb.ada/dgopt.exp with target board
    unix/-flto/-O0/-flto-partition=none/-ffat-lto-objects and gcc-8, gcc-9 or
    gcc-10, and the fix for PR25700, we run into this regression:
    ...
    (gdb) list x.adb:16, 16^M
    No source file named x.adb.^M
    (gdb) FAIL: gdb.ada/dgopt.exp: list x.adb:16, 16
    ...
    
    The reason for the failure is that without the fix for PR25700, we
    have an unshared psymtab:
    ...
      { psymtab gdb.ada/dgopt/x.adb ((struct partial_symtab *) $hex)^M
        readin no^M
        fullname (null)^M
        text addresses 0x0 -- 0x0^M
        psymtabs_addrmap_supported yes^M
        globals (none)^M
        statics (none)^M
        dependencies (none)^M
      }^M
    ...
    and a shared psymtab (with user field set):
    ...
      { psymtab gdb.ada/dgopt/x.adb ((struct partial_symtab *) $hex)^M
        readin no^M
        fullname (null)^M
        text addresses 0x0 -- 0x0^M
        psymtabs_addrmap_supported yes^M
        globals (none)^M
        statics (none)^M
        user <artificial>@0x159a ((struct partial_symtab *) 0x37b57c0)^M
        dependencies (none)^M
      }^M
    ...
    
    The fix for PR25700 removes the unshared psymtab.
    
    Then when trying to find a psymtab matching x.adb in
    psym_map_symtabs_matching_filename, we run into this continue for the shared
    psymtab:
    ...
      for (partial_symtab *pst : require_partial_symbols (objfile, true))
        {
          /* We can skip shared psymtabs here, because any file name will be
            attached to the unshared psymtab.  */
          if (pst->user != NULL)
           continue;
    ...
    and consequently cannot find the file.
    
    Fix this by not skipping the shared symtab in
    psym_map_symtabs_matching_filename.
    
    Build and reg-tested on x86_64-linux.
    
    gdb/ChangeLog:
    
    2020-04-22  Tom de Vries  <tdevries@suse.de>
    
            PR symtab/25801
            * psymtab.c (psym_map_symtabs_matching_filename): Don't skip shared
            symtabs.
    
    gdb/testsuite/ChangeLog:
    
    2020-04-22  Tom de Vries  <tdevries@suse.de>
    
            PR symtab/25801
            * gdb.dwarf2/imported-unit.exp: Test that we can get imported_unit.c
            in "info source" output.

Diff:
---
 gdb/ChangeLog                              | 6 ++++++
 gdb/psymtab.c                              | 8 +++-----
 gdb/testsuite/ChangeLog                    | 6 ++++++
 gdb/testsuite/gdb.dwarf2/imported-unit.exp | 6 ++++++
 4 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 3f1cce59e7d..fdafdb99db4 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2020-04-22  Tom de Vries  <tdevries@suse.de>
+
+	PR symtab/25801
+	* psymtab.c (psym_map_symtabs_matching_filename): Don't skip shared
+	symtabs.
+
 2020-04-22  Tom de Vries  <tdevries@suse.de>
 
 	PR symtab/25700
diff --git a/gdb/psymtab.c b/gdb/psymtab.c
index b156aa0e228..376cbeedcdf 100644
--- a/gdb/psymtab.c
+++ b/gdb/psymtab.c
@@ -157,17 +157,15 @@ psym_map_symtabs_matching_filename
 
   for (partial_symtab *pst : require_partial_symbols (objfile, true))
     {
-      /* We can skip shared psymtabs here, because any file name will be
-	 attached to the unshared psymtab.  */
-      if (pst->user != NULL)
-	continue;
-
       /* Anonymous psymtabs don't have a file name.  */
       if (pst->anonymous)
 	continue;
 
       if (compare_filenames_for_search (pst->filename, name))
 	{
+	  while (pst->user)
+	    pst = pst->user;
+
 	  if (partial_map_expand_apply (objfile, name, real_path,
 					pst, callback))
 	    return true;
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index f6c52c8e425..1331fe5248b 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2020-04-22  Tom de Vries  <tdevries@suse.de>
+
+	PR symtab/25801
+	* gdb.dwarf2/imported-unit.exp: Test that we can get imported_unit.c
+	in "info source" output.
+
 2020-04-22  Tom de Vries  <tdevries@suse.de>
 
 	PR symtab/25700
diff --git a/gdb/testsuite/gdb.dwarf2/imported-unit.exp b/gdb/testsuite/gdb.dwarf2/imported-unit.exp
index d7b3d4c5398..32a9abf6204 100644
--- a/gdb/testsuite/gdb.dwarf2/imported-unit.exp
+++ b/gdb/testsuite/gdb.dwarf2/imported-unit.exp
@@ -186,6 +186,12 @@ if { $psymtabs_p } {
     unsupported $test
 }
 
+gdb_test "l imported_unit.c:1" \
+    "1\timported_unit.c: No such file or directory\."
+
+gdb_test "info source" "\r\nCurrent source file is imported_unit.c\r\n.*" \
+    "info source for imported_unit.c"
+
 # Sanity check
 gdb_test "ptype main" "= int \\(void\\)"