llvm-mirror/test/TableGen/unsetop.td
Simon Tatham 66c63456e2 [TableGen] Permit dag operators to be unset.
This is not a new semantic feature. The syntax `(? 1, 2, 3)` was
disallowed by the parser in a dag //expression//, but there were
already ways to sneak a `?` into the operator field of a dag
//value//, e.g. by initializing it from a class template parameter
which is then set to `?` by the instantiating `def`.

This patch makes `?` in the operator slot syntactically legal, so it's
now easy to construct dags with an unset operator. Also, the semantics
of `!con` are relaxed so that it will allow a combination of set and
unset operator fields in the dag nodes it's concatenating, with the
restriction that all the operators that are //not// unset still have
to agree with each other.

Reviewers: hfinkel, nhaehnle

Reviewed By: hfinkel, nhaehnle

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71195
2019-12-10 11:09:40 +00:00

25 lines
703 B
TableGen

// RUN: llvm-tblgen %s | FileCheck %s
// RUN: not llvm-tblgen -DERROR %s 2>&1 | FileCheck --check-prefix=ERROR %s
def op;
def otherop;
def test {
// CHECK: dag d = (? "hello":$world);
dag d = (? "hello":$world);
// CHECK: dag undefNeither = (op 1, 2);
dag undefNeither = !con((op 1), (op 2));
// CHECK: dag undefFirst = (op 1, 2);
dag undefFirst = !con((? 1), (op 2));
// CHECK: dag undefSecond = (op 1, 2);
dag undefSecond = !con((op 1), (? 2));
// CHECK: dag undefBoth = (? 1, 2);
dag undefBoth = !con((? 1), (? 2));
#ifdef ERROR
// ERROR: Concatenated Dag operators do not match: '(op 1)' vs. '(otherop 2)'
dag mismatch = !con((op 1), (otherop 2));
#endif
}