Hi!
This patch improves debug info quality in two small changes.
One is that for DEBUG stmts like DEBUG p => &MEM[&a, 8] for
a non-addressable we were giving up instead of creating DEBUG_IMPLICIT_PTR
(plus 8) for it. The reason is
if (GET_CODE (op0) == DEBUG_IMPLICIT_PTR
|| (GET_CODE (op0) == PLUS
&& GET_CODE (XEXP (op0, 0)) == DEBUG_IMPLICIT_PTR))
/* (mem (debug_implicit_ptr)) might confuse aliasing.
Instead just use get_inner_reference. */
goto component_ref;
hunk in expand_debug_expr MEM_REF handling which was added to avoid
crashes on some testcases. The above means unfortunately that while
&a expands into DEBUG_IMPLICIT_PTR, we later throw that away, for MEM_REF
return NULL and for the outer ADDR_EXPR, as what it points to is not
a handled component of non-addressable decl or non-addressable decl itself,
we give up. Fixed by special casing ADDR_EXPR of such MEM_REF.
The second change is to fix failures of the new testcase with -m32 -Os -
in that case tree-sra.c is considering adding DECL_DEBUG_EXPR, but doesn't,
because MEM_REF isn't handled component. Fixed by handling MEM_REF with
ADDR_EXPR in the first operand the same way as handled_component_p,
get_ref_base_and_extent handles that just fine.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2012-10-18 Jakub Jelinek <ja...@redhat.com>
PR debug/54970
* cfgexpand.c (expand_debug_expr): Expand &MEM_REF[&var, n]
as DEBUG_IMPLICIT_PTR + n if &var expands to DEBUG_IMPLICIT_PTR.
* tree-sra.c (create_access_replacement): Allow also MEM_REFs
with ADDR_EXPR first operand in DECL_DEBUG_EXPR expressions.
* var-tracking.c (track_expr_p): Handle MEM_REFs in DECL_DEBUG_EXPR
expressions.
* dwarf2out.c (add_var_loc_to_decl): Likewise.
* gcc.dg/guality/pr54970.c: New test.
--- gcc/cfgexpand.c.jj 2012-10-17 17:18:21.000000000 +0200
+++ gcc/cfgexpand.c 2012-10-18 10:06:35.058258719 +0200
@@ -3284,6 +3284,27 @@ expand_debug_expr (tree exp)
}
}
+ if (TREE_CODE (TREE_OPERAND (exp, 0)) == MEM_REF
+ && TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
+ == ADDR_EXPR)
+ {
+ op0 = expand_debug_expr (TREE_OPERAND (TREE_OPERAND (exp, 0),
+ 0));
+ if (op0 != NULL
+ && (GET_CODE (op0) == DEBUG_IMPLICIT_PTR
+ || (GET_CODE (op0) == PLUS
+ && GET_CODE (XEXP (op0, 0)) == DEBUG_IMPLICIT_PTR
+ && CONST_INT_P (XEXP (op0, 1)))))
+ {
+ op1 = expand_debug_expr (TREE_OPERAND (TREE_OPERAND (exp, 0),
+ 1));
+ if (!op1 || !CONST_INT_P (op1))
+ return NULL;
+
+ return plus_constant (mode, op0, INTVAL (op1));
+ }
+ }
+
return NULL;
}
--- gcc/tree-sra.c.jj 2012-09-21 15:04:35.000000000 +0200
+++ gcc/tree-sra.c 2012-10-18 11:09:26.310581459 +0200
@@ -1894,7 +1894,8 @@ create_access_replacement (struct access
and that get_ref_base_and_extent works properly on the
expression. It cannot handle accesses at a non-constant offset
though, so just give up in those cases. */
- for (d = debug_expr; !fail && handled_component_p (d);
+ for (d = debug_expr;
+ !fail && (handled_component_p (d) || TREE_CODE (d) == MEM_REF);
d = TREE_OPERAND (d, 0))
switch (TREE_CODE (d))
{
@@ -1912,6 +1913,12 @@ create_access_replacement (struct access
&& TREE_CODE (TREE_OPERAND (d, 2)) != INTEGER_CST)
fail = true;
break;
+ case MEM_REF:
+ if (TREE_CODE (TREE_OPERAND (d, 0)) != ADDR_EXPR)
+ fail = true;
+ else
+ d = TREE_OPERAND (d, 0);
+ break;
default:
break;
}
--- gcc/var-tracking.c.jj 2012-10-17 17:18:20.000000000 +0200
+++ gcc/var-tracking.c 2012-10-18 11:13:21.300327939 +0200
@@ -4921,7 +4921,9 @@ track_expr_p (tree expr, bool need_rtl)
realdecl = expr;
else if (!DECL_P (realdecl))
{
- if (handled_component_p (realdecl))
+ if (handled_component_p (realdecl)
+ || (TREE_CODE (realdecl) == MEM_REF
+ && TREE_CODE (TREE_OPERAND (realdecl, 0)) == ADDR_EXPR))
{
HOST_WIDE_INT bitsize, bitpos, maxsize;
tree innerdecl
--- gcc/dwarf2out.c.jj 2012-10-17 17:18:21.000000000 +0200
+++ gcc/dwarf2out.c 2012-10-18 11:16:45.504211284 +0200
@@ -4620,7 +4620,10 @@ add_var_loc_to_decl (tree decl, rtx loc_
if (DECL_DEBUG_EXPR_IS_FROM (decl))
{
tree realdecl = DECL_DEBUG_EXPR (decl);
- if (realdecl && handled_component_p (realdecl))
+ if (realdecl
+ && (handled_component_p (realdecl)
+ || (TREE_CODE (realdecl) == MEM_REF
+ && TREE_CODE (TREE_OPERAND (realdecl, 0)) == ADDR_EXPR)))
{
HOST_WIDE_INT maxsize;
tree innerdecl;
--- gcc/testsuite/gcc.dg/guality/pr54970.c.jj 2012-10-18 10:21:25.587109451
+0200
+++ gcc/testsuite/gcc.dg/guality/pr54970.c 2012-10-18 10:46:40.746395100
+0200
@@ -0,0 +1,23 @@
+/* PR debug/54970 */
+/* { dg-do run } */
+/* { dg-options "-g" } */
+
+#include "../nop.h"
+
+int
+main ()
+{
+ int a[] = { 1, 2, 3 }; /* { dg-final { gdb-test 13 "a\[1\]" "2" } } */
+ int *p = a + 2; /* { dg-final { gdb-test 13 "a\[2\]" "3" } } */
+ int *q = a + 1; /* { dg-final { gdb-test 13 "*p" "3" } } */
+ asm volatile ("NOP"); /* { dg-final { gdb-test 13 "*q" "2" }
} */
+ *p += 10; /* { dg-final { gdb-test 17 "a\[1\]" "2" } } */
+ /* { dg-final { gdb-test 17 "a\[2\]" "13" } } */
+ /* { dg-final { gdb-test 17 "*p" "13" } } */
+ asm volatile ("NOP"); /* { dg-final { gdb-test 17 "*q" "2" }
} */
+ *q += 10; /* { dg-final { gdb-test 21 "a\[1\]" "12" } } */
+ /* { dg-final { gdb-test 21 "a\[2\]" "13" } } */
+ /* { dg-final { gdb-test 21 "*p" "13" } } */
+ asm volatile ("NOP"); /* { dg-final { gdb-test 21 "*q" "12" }
} */
+ return 0;
+}
Jakub
