tint: Rework sem::Constant to be variant-of-vector
Instead of vector-of-variant.
This:
• Makes it impossible to produce a mix of scalar variant types, which
would make no sense.
• Reduces the size of a Constant, by removing the union-tag from each
element.
Also clean up terminology. Rename 'Constant::Scalar' to
'Constant::Element'. Scalars are well-defined in WGSL, and with the
introduction of abstract-numerics, this no longer makes sense.
Bug: tint:1504
Change-Id: I599aa97ad1ea798b7db8e512a5990ba75827faad
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/91304
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ben Clayton <bclayton@chromium.org>
Commit-Queue: Ben Clayton <bclayton@google.com>
diff --git a/src/tint/utils/compiler_macros.h b/src/tint/utils/compiler_macros.h
new file mode 100644
index 0000000..8b360ff
--- /dev/null
+++ b/src/tint/utils/compiler_macros.h
@@ -0,0 +1,39 @@
+// Copyright 2022 The Tint Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef SRC_TINT_UTILS_COMPILER_MACROS_H_
+#define SRC_TINT_UTILS_COMPILER_MACROS_H_
+
+#define TINT_REQUIRE_SEMICOLON \
+ do { \
+ } while (false)
+
+#if defined(_MSC_VER)
+// clang-format off
+#define TINT_BEGIN_DISABLE_WARNING_UNREACHABLE_CODE() \
+ __pragma(warning(push)) \
+ __pragma(warning(disable:4702)) \
+ TINT_REQUIRE_SEMICOLON
+#define TINT_END_DISABLE_WARNING_UNREACHABLE_CODE() \
+ __pragma(warning(pop)) \
+ TINT_REQUIRE_SEMICOLON
+// clang-format on
+#else
+// clang-format off
+#define TINT_BEGIN_DISABLE_WARNING_UNREACHABLE_CODE() TINT_REQUIRE_SEMICOLON
+#define TINT_END_DISABLE_WARNING_UNREACHABLE_CODE() TINT_REQUIRE_SEMICOLON
+// clang-format on
+#endif // defined(_MSC_VER)
+
+#endif // SRC_TINT_UTILS_COMPILER_MACROS_H_
