On Thu, Oct 18, 2012 at 2:17 PM, Jakub Jelinek <ja...@redhat.com> wrote: > 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?
Ok for the tree-sra.c parts, I'll appreciate another eye on the rest. Thanks, Richard. > 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