[llvm] [YAML] Make `std::array` available (PR #116059)

[NAKAMURA Takumi via llvm-commits]

https://github.com/chapuni updated https://github.com/llvm/llvm-project/pull/116059

>From f71a854f74fe69c5d8cbb1915e6acd660fcb79d7 Mon Sep 17 00:00:00 2001
From: NAKAMURA Takumi <geek4civic at gmail.com>
Date: Wed, 13 Nov 2024 22:55:31 +0900
Subject: [PATCH 1/2] Reformat

---
 llvm/unittests/Support/YAMLIOTest.cpp | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/llvm/unittests/Support/YAMLIOTest.cpp b/llvm/unittests/Support/YAMLIOTest.cpp
index e10fe099a30adb..2d76b1509840f1 100644
--- a/llvm/unittests/Support/YAMLIOTest.cpp
+++ b/llvm/unittests/Support/YAMLIOTest.cpp
@@ -3368,15 +3368,14 @@ struct FixedArray {
 
 namespace llvm {
 namespace yaml {
-  template <>
-  struct MappingTraits<FixedArray> {
-    static void mapping(IO &io, FixedArray& st) {
-      MutableArrayRef<int> array = st.values;
-      io.mapRequired("Values", array);
-    }
-  };
-}
-}
+template <> struct MappingTraits<FixedArray> {
+  static void mapping(IO &io, FixedArray &st) {
+    MutableArrayRef<int> array = st.values;
+    io.mapRequired("Values", array);
+  }
+};
+} // namespace yaml
+} // namespace llvm
 
 TEST(YAMLIO, FixedSizeArray) {
   FixedArray faval;
@@ -3423,5 +3422,4 @@ TEST(YAMLIO, FixedSizeArrayMismatch) {
     // Error for too many elements.
     EXPECT_TRUE(!!yin.error());
   }
-
 }

>From 9bb3a411692a7a09c06191e18923d75d544dc93e Mon Sep 17 00:00:00 2001
From: NAKAMURA Takumi <geek4civic at gmail.com>
Date: Wed, 13 Nov 2024 22:55:41 +0900
Subject: [PATCH 2/2] YAMLTraits.h: std::array

---
 llvm/include/llvm/Support/YAMLTraits.h |  5 +++++
 llvm/unittests/Support/YAMLIOTest.cpp  | 29 +++++++++++++++++++++-----
 2 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/llvm/include/llvm/Support/YAMLTraits.h b/llvm/include/llvm/Support/YAMLTraits.h
index 1d04783753d5cd..45d82f3ebefa9c 100644
--- a/llvm/include/llvm/Support/YAMLTraits.h
+++ b/llvm/include/llvm/Support/YAMLTraits.h
@@ -2006,6 +2006,11 @@ struct SequenceTraits<
     std::enable_if_t<CheckIsBool<SequenceElementTraits<T>::flow>::value>>
     : SequenceTraitsImpl<std::vector<T>, SequenceElementTraits<T>::flow> {};
 template <typename T, unsigned N>
+struct SequenceTraits<
+    std::array<T, N>,
+    std::enable_if_t<CheckIsBool<SequenceElementTraits<T>::flow>::value>>
+    : SequenceTraitsImpl<std::array<T, N>, SequenceElementTraits<T>::flow> {};
+template <typename T, unsigned N>
 struct SequenceTraits<
     SmallVector<T, N>,
     std::enable_if_t<CheckIsBool<SequenceElementTraits<T>::flow>::value>>
diff --git a/llvm/unittests/Support/YAMLIOTest.cpp b/llvm/unittests/Support/YAMLIOTest.cpp
index 2d76b1509840f1..a7d1b338719f3b 100644
--- a/llvm/unittests/Support/YAMLIOTest.cpp
+++ b/llvm/unittests/Support/YAMLIOTest.cpp
@@ -3366,6 +3366,15 @@ struct FixedArray {
   int values[4];
 };
 
+struct StdArray {
+  StdArray() {
+    // Initialize to int max as a sentinel value.
+    for (auto &v : values)
+      v = std::numeric_limits<int>::max();
+  }
+  std::array<int, 4> values;
+};
+
 namespace llvm {
 namespace yaml {
 template <> struct MappingTraits<FixedArray> {
@@ -3374,11 +3383,21 @@ template <> struct MappingTraits<FixedArray> {
     io.mapRequired("Values", array);
   }
 };
+template <> struct MappingTraits<StdArray> {
+  static void mapping(IO &io, StdArray &st) {
+    io.mapRequired("Values", st.values);
+  }
+};
 } // namespace yaml
 } // namespace llvm
 
-TEST(YAMLIO, FixedSizeArray) {
-  FixedArray faval;
+using TestTypes = ::testing::Types<FixedArray, StdArray>;
+
+template <typename T> class YAMLIO : public testing::Test {};
+TYPED_TEST_SUITE(YAMLIO, TestTypes, );
+
+TYPED_TEST(YAMLIO, FixedSizeArray) {
+  TypeParam faval;
   Input yin("---\nValues:  [ 1, 2, 3, 4 ]\n...\n");
   yin >> faval;
 
@@ -3400,9 +3419,9 @@ TEST(YAMLIO, FixedSizeArray) {
   ASSERT_EQ(serialized, expected);
 }
 
-TEST(YAMLIO, FixedSizeArrayMismatch) {
+TYPED_TEST(YAMLIO, FixedSizeArrayMismatch) {
   {
-    FixedArray faval;
+    TypeParam faval;
     Input yin("---\nValues:  [ 1, 2, 3 ]\n...\n");
     yin >> faval;
 
@@ -3415,7 +3434,7 @@ TEST(YAMLIO, FixedSizeArrayMismatch) {
   }
 
   {
-    FixedArray faval;
+    TypeParam faval;
     Input yin("---\nValues:  [ 1, 2, 3, 4, 5 ]\n...\n");
     yin >> faval;