diff mbox series

[02/14] libdw: Handle split DWARF in dwarf_entrypc

Message ID 4d980efe1a90d50a4aae2758bbed21c05b664ee4.1695837512.git.osandov@fb.com
State Committed
Headers
Series elfutils: DWARF package (.dwp) file support |

Commit Message

Omar Sandoval Sept. 27, 2023, 6:20 p.m. UTC 
  From: Omar Sandoval <osandov@fb.com>

If a DIE has no DW_AT_entry_pc attribute, dwarf_entrypc looks for
DW_AT_low_pc in that DIE.  But for a split compilation unit DIE,
DW_AT_low_pc is in the corresponding skeleton DIE, so this fails.
dwarf_lowpc already handles this fallback, so use it instead.

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 libdw/ChangeLog       |  1 +
 libdw/dwarf_entrypc.c | 12 +++++-------
 tests/ChangeLog       |  4 ++++
 tests/run-varlocs.sh  | 14 +++++++-------
 4 files changed, 17 insertions(+), 14 deletions(-)

Comments

Mark Wielaard Oct. 3, 2023, 4:10 p.m. UTC | #1 
Hi Omar,

On Wed, 2023-09-27 at 11:20 -0700, Omar Sandoval wrote:
> From: Omar Sandoval <osandov@fb.com>
> 
> If a DIE has no DW_AT_entry_pc attribute, dwarf_entrypc looks for
> DW_AT_low_pc in that DIE.  But for a split compilation unit DIE,
> DW_AT_low_pc is in the corresponding skeleton DIE, so this fails.
> dwarf_lowpc already handles this fallback, so use it instead.

Nice find. Also interesting varlocs already "tested" for that and we
hadn't noticed before. Applied.

Thanks,

Mark
diff mbox series

Patch

diff --git a/libdw/ChangeLog b/libdw/ChangeLog
index 0014aeb1..af74ce0d 100644
--- a/libdw/ChangeLog
+++ b/libdw/ChangeLog
@@ -1,6 +1,7 @@ 
 2023-09-27  Omar Sandoval  <osandov@fb.com>
 
 	* libdw_find_split_unit.c (try_split_file): Make static.
+	* dwarf_entrypc.c (dwarf_entrypc): Call dwarf_lowpc.
 
 2023-02-22  Mark Wielaard  <mark@klomp.org>
 
diff --git a/libdw/dwarf_entrypc.c b/libdw/dwarf_entrypc.c
index 0ef3b0ea..543567d4 100644
--- a/libdw/dwarf_entrypc.c
+++ b/libdw/dwarf_entrypc.c
@@ -37,12 +37,10 @@ 
 int
 dwarf_entrypc (Dwarf_Die *die, Dwarf_Addr *return_addr)
 {
-  Dwarf_Attribute attr_mem;
-
-  return INTUSE(dwarf_formaddr) (INTUSE(dwarf_attr) (die, DW_AT_entry_pc,
-						     &attr_mem)
-				 ?: INTUSE(dwarf_attr) (die, DW_AT_low_pc,
-							&attr_mem),
-				 return_addr);
+  Dwarf_Attribute attr_mem, *attr;
+  if ((attr = INTUSE(dwarf_attr) (die, DW_AT_entry_pc, &attr_mem)) != NULL)
+    return INTUSE(dwarf_formaddr) (attr, return_addr);
+  else
+    return INTUSE(dwarf_lowpc) (die, return_addr);
 }
 INTDEF(dwarf_entrypc)
diff --git a/tests/ChangeLog b/tests/ChangeLog
index d816873c..f934c114 100644
--- a/tests/ChangeLog
+++ b/tests/ChangeLog
@@ -1,3 +1,7 @@ 
+2023-09-27  Omar Sandoval  <osandov@fb.com>
+
+	* run-varlocs.sh: Add entry PC to split units.
+
 2023-04-21  Frank Ch. Eigler <fche@redhat.com>
 
 	* run-debuginfod-IXr.sh: New test.
diff --git a/tests/run-varlocs.sh b/tests/run-varlocs.sh
index b2621776..cbbcf6c7 100755
--- a/tests/run-varlocs.sh
+++ b/tests/run-varlocs.sh
@@ -206,7 +206,7 @@  testfiles testfilesplitranges5.debug
 testfiles testfile-ranges-hello5.dwo testfile-ranges-world5.dwo
 testrun_compare ${abs_top_builddir}/tests/varlocs --debug -e testfilesplitranges5.debug <<\EOF
 module 'testfilesplitranges5.debug'
-[14] CU 'hello.c'
+[14] CU 'hello.c'@0
   [1d] function 'no_say'@401160
     frame_base: {call_frame_cfa {...}}
     [33] parameter 'prefix'
@@ -236,7 +236,7 @@  module 'testfilesplitranges5.debug'
     [111] parameter 'count'
       [401150,401160) {reg4}
 module 'testfilesplitranges5.debug'
-[14] CU 'world.c'
+[14] CU 'world.c'@401180
   [1d] function 'no_main'@4011d0
     frame_base: {call_frame_cfa {...}}
     [35] parameter 'argc'
@@ -282,7 +282,7 @@  testfiles testfilesplitranges4.debug
 testfiles testfile-ranges-hello.dwo testfile-ranges-world.dwo
 testrun_compare ${abs_top_builddir}/tests/varlocs --debug -e testfilesplitranges4.debug <<\EOF
 module 'testfilesplitranges4.debug'
-[b] CU 'hello.c'
+[b] CU 'hello.c'@0
   [18] function 'no_say'@4004f0
     frame_base: {call_frame_cfa {...}}
     [2f] parameter 'prefix'
@@ -310,7 +310,7 @@  module 'testfilesplitranges4.debug'
     [102] parameter 'count'
       [4004e0,4004f0) {reg4}
 module 'testfilesplitranges4.debug'
-[b] CU 'world.c'
+[b] CU 'world.c'@400500
   [18] function 'no_main'@400550
     frame_base: {call_frame_cfa {...}}
     [2f] parameter 'argc'
@@ -373,7 +373,7 @@  EOF
 testfiles testfile-addrx_constx-5 addrx_constx-5.dwo
 testrun_compare ${abs_top_builddir}/tests/varlocs --exprlocs -e testfile-addrx_constx-5 <<\EOF
 module 'testfile-addrx_constx-5'
-[14] CU 'addrx_constx.c'
+[14] CU 'addrx_constx.c'@0
   producer (strx)
   language (data1)
   name (strx)
@@ -467,7 +467,7 @@  EOF
 testfiles testfile-addrx_constx-4 addrx_constx-4.dwo
 testrun_compare ${abs_top_builddir}/tests/varlocs --exprlocs -e testfile-addrx_constx-4 <<\EOF
 module 'testfile-addrx_constx-4'
-[b] CU 'addrx_constx.c'
+[b] CU 'addrx_constx.c'@0
   producer (GNU_str_index)
   language (data1)
   name (GNU_str_index)
@@ -565,7 +565,7 @@  testfiles splitdwarf4-not-split4.dwo
 
 testrun_compare ${abs_top_builddir}/tests/varlocs --debug -e testfile-splitdwarf4-not-split4.debug <<\EOF
 module 'testfile-splitdwarf4-not-split4.debug'
-[b] CU 'splitdwarf4-not-split4.c'
+[b] CU 'splitdwarf4-not-split4.c'@0
   [18] function 'main'@401050
     frame_base: {call_frame_cfa {...}}
     [30] parameter 'argc'