PR c/68162 reports a spurious warning about incompatible types
involving arrays of const double, constructed in one place using a
typedef for const double and in another place literally using const
double.
The problem is that the array of the typedef was incorrectly
constructed without a TYPE_MAIN_VARIANT being an array of unqualified
elements as it should be (though it seems some more recent change
resulted in this producing incorrect diagnostics, likely the support
for C++-style handling of arrays of qualified type). This patch fixes
the logic in grokdeclarator to determine first_non_attr_kind, which is
used to determine whether it is necessary to use the TYPE_MAIN_VARIANT
of the type in the declaration specifiers.
However, fixing that logic introduces a failure of
gcc.dg/debug/dwarf2/pr47939-4.c, a test introduced along with
first_non_attr_kind. Thus, it is necessary to track the original
qualified typedef when qualifying an array type, to use it rather than
a newly-constructed type, to avoid regressing regarding typedef names
in debug info. This is done along lines I suggested in
<https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47939#c6>: track the
original type and the number of levels of array indirection at which
it appears, and, in possibly affected cases, pass extra arguments to
c_build_qualified_type (with default arguments to avoid needing to
pass those extra arguments explicitly everywhere). Given Richard's
recent fix to dwarf2out.c, this allows the C bug to be fixed without
causing debug information regressions.
Bootstrapped with no regressions on x86_64-pc-linux-gnu.
gcc/c:
PR c/68162
* c-decl.c (grokdeclarator): Set first_non_attr_kind before
following link from declarator to next declarator. Track original
qualified type and pass it to c_build_qualified_type.
* c-typeck.c (c_build_qualified_type): Add arguments
orig_qual_type and orig_qual_indirect.
gcc/c-family:
PR c/68162
* c-common.h (c_build_qualified_type): Add extra default
arguments.
gcc/cp:
PR c/68162
* tree.c (c_build_qualified_type): Add extra arguments.
gcc/testsuite:
PR c/68162
* gcc.dg/pr68162-1.c: New test.
From-SVN: r231194
