Rewrite float in structured annotations

Summary:
Currently in metadata.thrift, float is always stored as double, but in schema.thrift we will convert it to float.

This conversion created a small discrepancy between metadata.thrift and schema.thrift.

This diff changed the structured annotations to have the same logic as schema.thrift.

Without this change, equality comparison will fail for annotations that contains float.

Reviewed By: sadroeck

Differential Revision: D86642320

fbshipit-source-id: 65c95a6e1be0bcdc736f2408102044d3c879b244

Author: Mizuchi

third-party/thrift/src/thrift/compiler/sema/sema.cc

@@ -270,6 +270,15 @@ void match_type_with_const_value(
     value->assign(t_const_value(*constant->value()));
   }
 
+  if (value && type->is_float() && value->kind() == t_const_value::CV_DOUBLE) {
+    // Check whether double is in float range.
+    // If it is out of range, it will fail the validation later.
+    if (std::numeric_limits<float>::lowest() <= value->get_double() &&
+        value->get_double() <= std::numeric_limits<float>::max()) {
+      value->set_double(static_cast<float>(value->get_double()));
+    }
+  }
+
   if (const t_list* list = type->try_as<t_list>()) {
     if (value->kind() == t_const_value::CV_LIST) {
       for (auto list_val : value->get_list()) {

third-party/thrift/src/thrift/compiler/test/fixtures/mcpp2-compare/out/cpp2/gen-cpp2/module_constants.h

@@ -50,7 +50,7 @@ namespace module_constants {
   }
 
   /** Glean {"constant": "aFloat"} */
-  constexpr float const aFloat_ = static_cast<float>(0.1);
+  constexpr float const aFloat_ = static_cast<float>(0.10000000149011612);
   /** Glean {"constant": "aFloat"} */
   constexpr float aFloat() {
     return aFloat_;

third-party/thrift/src/thrift/compiler/test/fixtures/mcpp2-compare/out/py3/gen-py3/module/constants_FBTHRIFT_ONLY_DO_NOT_USE.py

@@ -71,7 +71,7 @@
 a16BitInt = 12
 a32BitInt = 123
 a64BitInt = 1234
-aFloat = 0.1
+aFloat = 0.10000000149011612
 aDouble = 0.12
 aString = "Joe Doe"
 aList = List__bool((True, False, ))

third-party/thrift/src/thrift/compiler/test/fixtures/mcpp2-compare/out/py3/gen-py3/module/types.pyx

@@ -4822,7 +4822,7 @@ aByte = 1
 a16BitInt = 12
 a32BitInt = 123
 a64BitInt = 1234
-aFloat = 0.1
+aFloat = 0.10000000149011612
 aDouble = 0.12
 aString = "Joe Doe"
 aList = List__bool__from_cpp(_module_cbindings.caList())

third-party/thrift/src/thrift/compiler/test/json_test.cc

@@ -60,7 +60,7 @@ TEST(JsonTest, to_json_t_const_value) {
       my_int = 1,
       my_string = "hello",
       my_double = 9.9,
-      my_list = [0.1, -0.2],
+      my_list = [0.125, -0.25],
       my_nested = Nested{
         nested_int = 0,
         nested_enum = MyEnum.SECOND,
@@ -81,7 +81,7 @@ TEST(JsonTest, to_json_t_const_value) {
   std::string to_json_result = to_json(annotations.at(0).value());
   EXPECT_EQ(
       "{\"my_bool\": true, \"my_int\": 1, \"my_string\": \"hello\", "
-      "\"my_double\": 9.9, \"my_list\": [0.1, -0.2], "
+      "\"my_double\": 9.9, \"my_list\": [0.125, -0.25], "
       "\"my_nested\": {\"nested_int\": 0, \"nested_enum\": 2}}",
       to_json_result);
 }

third-party/thrift/src/thrift/lib/cpp2/test/metadata/annotations.thrift

@@ -146,3 +146,13 @@ service TestService {
     1: TestException ex,
   );
 }
+
+@Annotation{floatField = 1.0}
+struct TestFloat1 {}
+
+// Delta < (1 / (2^26)), which can't be stored in float that only has 24 bits precision.
+@Annotation{floatField = 1.00000001}
+struct TestFloat2 {}
+
+@Annotation{floatField = 1.0000001}
+struct TestFloat3 {}

third-party/thrift/src/thrift/lib/cpp2/test/metadata/annotations_test.cpp

@@ -185,6 +185,15 @@ TEST(Annotations, Normalization) {
   }
 }
 
+TEST(Annotations, TestFloat) {
+  metadata::ThriftMetadata md1, md2, md3;
+  const auto& t1 = detail::md::StructMetadata<TestFloat1>::gen(md1);
+  const auto& t2 = detail::md::StructMetadata<TestFloat2>::gen(md2);
+  const auto& t3 = detail::md::StructMetadata<TestFloat3>::gen(md3);
+  EXPECT_EQ(t1.structured_annotations(), t2.structured_annotations());
+  EXPECT_NE(t1.structured_annotations(), t3.structured_annotations());
+}
+
 metadata::ThriftStruct expectedStruct() {
   metadata::ThriftStruct ret;
   ret.name() = "annotations.TestStruct";