libdwfl: Move dwz alt multi file searching to find_debuginfo callback.

Don't hard code the Dwarf dwz alt multi file search but allow the user
to override it through the standard Dwfl_Callbacks. Also move ownership
completely to the user of dwarf_setalt by removing free_alt from Dwarf
and adding alt, fd and elf fields to Dwfl_Module. Add a relative .dwz
file test case.

Signed-off-by: Mark Wielaard <mjw@redhat.com>

1 files changed, 105 insertions, 0 deletions

diff --git a/tests/run-readelf-dwz-multi.sh b/tests/run-readelf-dwz-multi.sh
index 44d24758..27e0f38c 100755
--- a/tests/run-readelf-dwz-multi.sh
+++ b/tests/run-readelf-dwz-multi.sh
@@ -136,6 +136,109 @@ DWARF section [28] '.debug_info' at offset 0x1078:
              type                 (ref_udata) [    2b]
 EOF
 
+# Same as above, but find alt debug file in a .dwz subdir.
+mkdir .dwz
+mv testfile_multi.dwz .dwz
+testrun_compare ${abs_top_builddir}/src/readelf --debug-dump=info testfile_multi_main <<\EOF
+
+DWARF section [28] '.debug_info' at offset 0x1078:
+ [Offset]
+ Compilation unit at offset 0:
+ Version: 4, Abbreviation section offset: 0, Address size: 8, Offset size: 4
+ [     b]  compile_unit
+           producer             (strp) "GNU C 4.7.0 20120507 (Red Hat 4.7.0-5) -mtune=generic -march=x86-64 -g"
+           language             (data1) C89 (1)
+           name                 (strp) "main.c"
+           comp_dir             (GNU_strp_alt) "/home/mark/src/tests/dwz"
+           low_pc               (addr) 0x00000000004006ac <main>
+           high_pc              (udata) 44 (0x00000000004006d8)
+           stmt_list            (sec_offset) 0
+ [    26]    imported_unit
+             import               (GNU_ref_alt) [     b]
+ [    2b]    pointer_type
+             byte_size            (data1) 8
+             type                 (GNU_ref_alt) [    53]
+ [    31]    subprogram
+             external             (flag_present) 
+             name                 (strp) "main"
+             decl_file            (data1) 1
+             decl_line            (data1) 3
+             prototyped           (flag_present) 
+             type                 (GNU_ref_alt) [    3e]
+             low_pc               (addr) 0x00000000004006ac <main>
+             high_pc              (udata) 44 (0x00000000004006d8)
+             frame_base           (exprloc) 
+              [   0] call_frame_cfa
+             GNU_all_tail_call_sites (flag_present) 
+             sibling              (ref_udata) [    6e]
+ [    48]      formal_parameter
+               name                 (strp) "argc"
+               decl_file            (data1) 1
+               decl_line            (data1) 3
+               type                 (GNU_ref_alt) [    3e]
+               location             (exprloc) 
+                [   0] fbreg -36
+ [    56]      formal_parameter
+               name                 (strp) "argv"
+               decl_file            (data1) 1
+               decl_line            (data1) 3
+               type                 (ref_udata) [    6e]
+               location             (exprloc) 
+                [   0] fbreg -48
+ [    61]      variable
+               name                 (string) "b"
+               decl_file            (data1) 1
+               decl_line            (data1) 5
+               type                 (GNU_ref_alt) [    5a]
+               location             (exprloc) 
+                [   0] fbreg -32
+ [    6e]    pointer_type
+             byte_size            (data1) 8
+             type                 (ref_udata) [    2b]
+EOF
+mv .dwz/testfile_multi.dwz .
+rmdir .dwz
+
+testrun_compare ${abs_top_builddir}/src/readelf --debug-dump=info libtestfile_multi_shared.so <<\EOF
+
+DWARF section [25] '.debug_info' at offset 0x106c:
+ [Offset]
+ Compilation unit at offset 0:
+ Version: 4, Abbreviation section offset: 0, Address size: 8, Offset size: 4
+ [     b]  compile_unit
+           producer             (strp) "GNU C 4.7.0 20120507 (Red Hat 4.7.0-5) -fpreprocessed -mtune=generic -march=x86-64 -g -fPIC"
+           language             (data1) C89 (1)
+           name                 (strp) "shared.c"
+           comp_dir             (GNU_strp_alt) "/home/mark/src/tests/dwz"
+           low_pc               (addr) +0x0000000000000670 <call_foo>
+           high_pc              (udata) 23 (+0x0000000000000687)
+           stmt_list            (sec_offset) 0
+ [    26]    imported_unit
+             import               (GNU_ref_alt) [     b]
+ [    2b]    subprogram
+             external             (flag_present) 
+             name                 (strp) "call_foo"
+             decl_file            (data1) 1
+             decl_line            (data1) 3
+             prototyped           (flag_present) 
+             type                 (GNU_ref_alt) [    3e]
+             low_pc               (addr) +0x0000000000000670 <call_foo>
+             high_pc              (udata) 23 (+0x0000000000000687)
+             frame_base           (exprloc) 
+              [   0] call_frame_cfa
+             GNU_all_call_sites   (flag_present) 
+ [    41]      formal_parameter
+               name                 (string) "fb"
+               decl_file            (data1) 1
+               decl_line            (data1) 3
+               type                 (GNU_ref_alt) [    76]
+               location             (exprloc) 
+                [   0] fbreg -24
+EOF
+
+# Same as above, but find alt debug file in a .dwz subdir.
+mkdir .dwz
+mv testfile_multi.dwz .dwz
 testrun_compare ${abs_top_builddir}/src/readelf --debug-dump=info libtestfile_multi_shared.so <<\EOF
 
 DWARF section [25] '.debug_info' at offset 0x106c:
@@ -172,6 +275,8 @@ DWARF section [25] '.debug_info' at offset 0x106c:
                location             (exprloc) 
                 [   0] fbreg -24
 EOF
+mv .dwz/testfile_multi.dwz .
+rmdir .dwz
 
 testrun_compare ${abs_top_builddir}/src/readelf --debug-dump=info testfile-dwzstr <<\EOF