r248773 - in /trunk/gcc: ChangeLog dwarf2out.c ...

[pmderodat at gcc dot gnu dot org]

Author: pmderodat
Date: Thu Jun  1 08:36:57 2017
New Revision: 248773

URL: https://gcc.gnu.org/viewcvs?rev=248773&root=gcc&view=rev
Log:
DWARF: for variants, produce unsigned discr. when debug type is unsigned

In Ada, the Character type is supposed to be unsigned.  However,
depending on the sign of C char types, GNAT can materialize it as a
signed type for code generation purposes.  When this is the case, GNAT
also attach a debug type to it so it is represented as an unsigned base
type in the debug information.

This change adapts record variant parts processing in the DWARF back-end
so that when the debug type of discriminant is unsigned while
discriminant values are signed themselves, we output unsigned
discriminant values in DWARF.

gcc/

	* dwarf2out.c (get_discr_value): Call the get_debug_type hook on
	the type of the input discriminant value.  Convert the
	discriminant value of signedness vary.

gcc/testsuite/

	* gnat.dg/debug11.adb: New testcase.

Added:
    trunk/gcc/testsuite/gnat.dg/debug11.adb
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/dwarf2out.c
    trunk/gcc/testsuite/ChangeLog