This is the mail archive of the
gdb-cvs@sourceware.org
mailing list for the GDB project.
[binutils-gdb] compile-loc2c: Fix uninitialized variable error
- From: Simon Marchi <simark at sourceware dot org>
- To: gdb-cvs at sourceware dot org
- Date: 9 Jul 2017 18:28:16 -0000
- Subject: [binutils-gdb] compile-loc2c: Fix uninitialized variable error
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=266934d1ad029100f4073f9e351f8685ea175b83
commit 266934d1ad029100f4073f9e351f8685ea175b83
Author: Simon Marchi <simon.marchi@ericsson.com>
Date: Sun Jul 9 20:25:38 2017 +0200
compile-loc2c: Fix uninitialized variable error
Compiling with clang gives this warning/error:
/home/emaisin/src/binutils-gdb/gdb/compile/compile-loc2c.c:731:6: error: variable 'uoffset' is uninitialized when used here [-Werror,-Wuninitialized]
uoffset += dwarf2_per_cu_text_offset (per_cu);
^~~~~~~
/home/emaisin/src/binutils-gdb/gdb/compile/compile-loc2c.c:669:23: note: initialize the variable 'uoffset' to silence this warning
uint64_t uoffset, reg;
^
= 0
I am really not sure if what this patch does is good, but it is my best
guess. DW_OP_addr means that there's an constant address provided by
the DWARF bytecode that should be pushed on the stack. That address is
considered skipped by the "op_ptr += addr_size", but it is never read.
uoffset is indeed read just after, without having been assigned first.
So I think the intent is to read the address, it was just omitted.
gdb/ChangeLog:
* compile/compile-loc2c.c (do_compile_dwarf_expr_to_c): Read
address when op is DW_OP_addr.
Diff:
---
gdb/ChangeLog | 5 +++++
gdb/compile/compile-loc2c.c | 1 +
2 files changed, 6 insertions(+)
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 86a41b6..8ccd7a4 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2017-07-09 Simon Marchi <simon.marchi@ericsson.com>
+
+ * compile/compile-loc2c.c (do_compile_dwarf_expr_to_c): Read
+ address when op is DW_OP_addr.
+
2017-07-09 Tom Tromey <tom@tromey.com>
* dwarf2loc.c (dwarf2_evaluate_loc_desc_full): Reverse size
diff --git a/gdb/compile/compile-loc2c.c b/gdb/compile/compile-loc2c.c
index a53214f..ead1003 100644
--- a/gdb/compile/compile-loc2c.c
+++ b/gdb/compile/compile-loc2c.c
@@ -722,6 +722,7 @@ do_compile_dwarf_expr_to_c (int indent, string_file &stream,
break;
case DW_OP_addr:
+ uoffset = extract_unsigned_integer (op_ptr, addr_size, byte_order);
op_ptr += addr_size;
/* Some versions of GCC emit DW_OP_addr before
DW_OP_GNU_push_tls_address. In this case the value is an