bfd: Improve lookup of file / line information for errors

When looking up file and line information (used from the linker to
report error messages) if no symbol is passed in, then use the symbol
list to look for a matching symbol.

If a matching symbol is found then use this to look up the file / line
information.

This should improve errors when looking up file / line information for
data sections.  Hopefully we should find a matching data symbol, which
should, in turn (we hope) match a DW_TAG_variable in the DWARF, this
should allow us to give accurate file / line errors for data symbols.

As the hope is to find a matching DW_TAG_variable in the DWARF then we
ignore section symbols, and prefer global symbols to locals.

bfd/ChangeLog:

	* dwarf2.c (_bfd_dwarf2_find_nearest_line): Perform symbol lookup
	before trying to fine matching file and line information.

ld/ChangeLog:

	* testsuite/ld-elf/shared.exp: Update expected results.
	* testsuite/ld-elf/dwarf2.err: Likewise

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 01314bda146263b08391c0143a6bbad7b3aca8c5..40edca71ff455469669ad1977a0bd99d0b0b5907 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,8 @@
+2017-02-16  Andrew Burgess  <andrew.burgess@embecosm.com>
+
+       * dwarf2.c (_bfd_dwarf2_find_nearest_line): Perform symbol lookup
+       before trying to fine matching file and line information.
+
 2017-02-16  Andrew Burgess  <andrew.burgess@embecosm.com>
 
        * dwarf2.c (struct dwarf2_debug): Add orig_bfd member.

diff --git a/bfd/dwarf2.c b/bfd/dwarf2.c
index 03447a908a5337b543c64849ffb086183ba0ae6d..9bb81264872554d766a47bc1fdf38cb97358d847 100644 (file)
--- a/bfd/dwarf2.c
+++ b/bfd/dwarf2.c
@@ -4155,6 +4155,38 @@ _bfd_dwarf2_find_nearest_line (bfd *abfd,
     {
       BFD_ASSERT (section != NULL && functionname_ptr != NULL);
       addr = offset;
+
+      /* If we have no SYMBOL but the section we're looking at is not a
+         code section, then take a look through the list of symbols to see
+         if we have a symbol at the address we're looking for.  If we do
+         then use this to look up line information.  This will allow us to
+         give file and line results for data symbols.  We exclude code
+         symbols here, if we look up a function symbol and then look up the
+         line information we'll actually return the line number for the
+         opening '{' rather than the function definition line.  This is
+         because looking up by symbol uses the line table, in which the
+         first line for a function is usually the opening '{', while
+         looking up the function by section + offset uses the
+         DW_AT_decl_line from the function DW_TAG_subprogram for the line,
+         which will be the line of the function name.  */
+      if ((section->flags & SEC_CODE) == 0)
+       {
+         asymbol **tmp;
+
+         for (tmp = symbols; (*tmp) != NULL; ++tmp)
+           if ((*tmp)->the_bfd == abfd
+               && (*tmp)->section == section
+               && (*tmp)->value == offset
+               && ((*tmp)->flags & BSF_SECTION_SYM) == 0)
+             {
+               symbol = *tmp;
+               do_line = TRUE;
+                /* For local symbols, keep going in the hope we find a
+                   global.  */
+                if ((symbol->flags & BSF_GLOBAL) != 0)
+                  break;
+             }
+       }
     }
 
   if (section->output_section)

diff --git a/ld/ChangeLog b/ld/ChangeLog
index 696e08afffb5e1bcfa847e91e19fce01c4c63837..7d4739756a399effdd6efd18295adf15e8236220 100644 (file)
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,8 @@
+2017-02-16  Andrew Burgess  <andrew.burgess@embecosm.com>
+
+       * testsuite/ld-elf/shared.exp: Update expected results.
+       * testsuite/ld-elf/dwarf2.err: Likewise
+
 2017-02-16  Andrew Burgess  <andrew.burgess@embecosm.com>
 
        * testsuite/ld-elf/dwarf.exp (build_tests): Add new tests.

diff --git a/ld/testsuite/ld-elf/dwarf2.err b/ld/testsuite/ld-elf/dwarf2.err
index 872d282363543c796ef6aa0a14324673d61c34d4..b4ea67fc1959b6847884c22d14e0b6e5599fd808 100644 (file)
--- a/ld/testsuite/ld-elf/dwarf2.err
+++ b/ld/testsuite/ld-elf/dwarf2.err
@@ -1,4 +1,5 @@
-tmpdir/dwarf2b\.o:\(\.data\+0x0\): multiple definition of `global_var'
-tmpdir/dwarf2a\.o:\(\.data\+0x0\): first defined here
-tmpdir/dwarf2b\.o:\(\.data\+0x4\): multiple definition of `other_var'
-tmpdir/dwarf2a\.o:\(\.data\+0x4\): first defined here
+tmpdir/dwarf2b\.o:.*dwarf2b\.c:1: multiple definition of `global_var'
+tmpdir/dwarf2a\.o:.*dwarf2a\.c:1: first defined here
+tmpdir/dwarf2b\.o:.*dwarf2b\.c:2: multiple definition of `other_var'
+tmpdir/dwarf2a\.o:.*dwarf2a\.c:2: first defined here
+#...
\ No newline at end of file

diff --git a/ld/testsuite/ld-elf/shared.exp b/ld/testsuite/ld-elf/shared.exp
index 9d5a9d9fe904f28b9468d66217615ea7908d9767..3b8ab181d1f98144f3493440a34c06ff20aa04e1 100644 (file)
--- a/ld/testsuite/ld-elf/shared.exp
+++ b/ld/testsuite/ld-elf/shared.exp
@@ -105,7 +105,7 @@ set build_tests {
    "-shared" "-fPIC"
   {beginwarn.c end.c}
   {{readelf {-S --wide} libbarw.rd}
-   {warning "^.*\\): warning: function foo is deprecated$"}}
+   {warning "^.*beginwarn.c:7: warning: function foo is deprecated$"}}
   "libbarw.so" "c"}
   {"Build hidden libbar.so"
    "-shared" "-fPIC"
@@ -350,7 +350,7 @@ set run_tests [list \
     [list "Run warn with versioned libfoo.so" \
      "-Wl,--no-as-needed tmpdir/beginwarn.o tmpdir/libfoov.so" "" \
      {main.c} "warn" "warn.out" \
-     "" "c" {^.*\): warning: function foo is deprecated$} ] \
+     "" "c" {^.*beginwarn.c:7: warning: function foo is deprecated$} ] \
     [list "Run protected with versioned libfoo.so" \
      "-Wl,--no-as-needed tmpdir/begin.o tmpdir/libfoov.so tmpdir/endprotected.o" "" \
      {main.c} "protected" "normal.out" ] \