[Bug debug/36748] New: scev const-prop pass adds bad line numbers

["drow at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

I'm testing inlined function support for GCC.  When I compile the attached
testcase with GCC (Debian's 4.3 package or unmodified trunk) and -g -O2, "break
main" in the patched GDB puts a breakpoint at the start of main and again
inside the inlined copy of factorial.

This happens because there are several bits of code associated with the line
containing main's opening brace.

The bad line numbers are introduced by pass_scev_cprop (why is this dumped into
"sccp"; having a dump named sccp shortly after one named store_ccp is
confusing).  Here's the relevant piece of the diff between 096t.lim and
099t.sccp:

@@ -88,7 +100,11 @@

 <bb 8>:
   # mult_acc.12_13 = PHI <mult_acc.12_15(6)>
-  # value_16 = PHI <value_14(6)>
+  [../break.c : 13] D.2700_29 = value_11 + -1;
+  [../break.c : 13] D.2701_7 = (unsigned int) D.2633_10;
+  [../break.c : 13] D.2702_30 = 2 - D.2701_7;
+  [../break.c : 13] D.2703_31 = (int) D.2702_30;
+  value_16 = D.2700_29 + D.2703_31;

 <bb 9>:
   # mult_acc.12_19 = PHI <mult_acc.12_13(8), 1(4)>

There are no other lines associated with break.c:13 in the dump at this point.  

The location came from internal_get_tmp_var.

644       if (EXPR_HAS_LOCATION (val))
645         SET_EXPR_LOCUS (mod, EXPR_LOCUS (val));
646       else
647         SET_EXPR_LOCATION (mod, input_location);

input_location has nothing to do with anything at this point.


-- 
           Summary: scev const-prop pass adds bad line numbers
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: debug
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: drow at gcc dot gnu dot org
  GCC host triplet: x86_64-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36748