[cxx-interop][stdlib] windows - use new hash inline functions like other platforms

The PR #77857 added windows-specific workaround for #77856, that happened after #77843. Unfortunately this caused a new issue on windows - #78119. It looks like windows is suffering from a similar serialization issue as libstdc++, although its even more complex as the callAsFunction is not only a derived function from a base class, the base class although has a static call operator. In any case, the libstdc++ callAsFunction deserialization fix should align with the static operator () deserialization too, so for now make windows use the same workaround as other platforms to avoid the deserialization crash (77856).

This change was tested on i686 windows too, ensuring that IR verifier crash no longer happens

Author: hyp

stdlib/public/Cxx/cxxshim/libcxxstdlibshim.h

@@ -4,19 +4,19 @@
 
 /// Used for std::string conformance to Swift.Hashable
 typedef std::hash<std::string> __swift_interopHashOfString;
-inline std::size_t __swift_interopComputeHashOfString(std::string str) {
+inline std::size_t __swift_interopComputeHashOfString(const std::string &str) {
   return __swift_interopHashOfString()(str);
 }
 
 /// Used for std::u16string conformance to Swift.Hashable
 typedef std::hash<std::u16string> __swift_interopHashOfU16String;
-inline std::size_t __swift_interopComputeHashOfU16String(std::u16string str) {
+inline std::size_t __swift_interopComputeHashOfU16String(const std::u16string &str) {
   return __swift_interopHashOfU16String()(str);
 }
 
 /// Used for std::u32string conformance to Swift.Hashable
 typedef std::hash<std::u32string> __swift_interopHashOfU32String;
-inline std::size_t __swift_interopComputeHashOfU32String(std::u32string str) {
+inline std::size_t __swift_interopComputeHashOfU32String(const std::u32string &str) {
   return __swift_interopHashOfU32String()(str);
 }
 

stdlib/public/Cxx/std/String.swift

@@ -198,11 +198,7 @@ extension std.string: Hashable {
   @_alwaysEmitIntoClient
   public func hash(into hasher: inout Hasher) {
     // Call std::hash<std::string>::operator()
-#if os(Windows) // FIXME: https://github.com/swiftlang/swift/issues/77856
-    let cxxHash = __swift_interopHashOfString().callAsFunction(self)
-#else
     let cxxHash = __swift_interopComputeHashOfString(self)
-#endif
     hasher.combine(cxxHash)
   }
 }
@@ -211,11 +207,7 @@ extension std.u16string: Hashable {
   @_alwaysEmitIntoClient
   public func hash(into hasher: inout Hasher) {
     // Call std::hash<std::u16string>::operator()
-#if os(Windows) // FIXME: https://github.com/swiftlang/swift/issues/77856
-    let cxxHash = __swift_interopHashOfU16String().callAsFunction(self)
-#else
     let cxxHash = __swift_interopComputeHashOfU16String(self)
-#endif
     hasher.combine(cxxHash)
   }
 }
@@ -224,11 +216,7 @@ extension std.u32string: Hashable {
   @_alwaysEmitIntoClient
   public func hash(into hasher: inout Hasher) {
     // Call std::hash<std::u32string>::operator()
-#if os(Windows) // FIXME: https://github.com/swiftlang/swift/issues/77856
-    let cxxHash = __swift_interopHashOfU32String().callAsFunction(self)
-#else
     let cxxHash = __swift_interopComputeHashOfU32String(self)
-#endif
     hasher.combine(cxxHash)
   }
 }

test/Interop/Cxx/stdlib/Inputs/module.modulemap

@@ -40,6 +40,12 @@ module StdString {
   export *
 }
 
+module StdStringAndVector {
+  header "std-string-and-vector.h"
+  requires cplusplus
+  export *
+}
+
 module StdStringView {
   header "std-string-view.h"
   requires cplusplus

test/Interop/Cxx/stdlib/Inputs/std-string-and-vector.h

@@ -0,0 +1,11 @@
+#include <string>
+#include <vector>
+
+struct Item {
+  std::vector<std::string> keys;
+  std::vector<std::string> values;
+};
+
+inline Item get_item() {
+  return {};
+}

test/Interop/Cxx/stdlib/use-std-string-with-opts.swift

@@ -0,0 +1,20 @@
+// RUN: %target-run-simple-swift(-I %S/Inputs -cxx-interoperability-mode=default -Xcc -std=c++20 -O)
+//
+// REQUIRES: executable_test
+
+// Tests optimizations related to CxxStdlib.
+
+import StdlibUnittest
+import CxxStdlib
+import StdStringAndVector
+
+var StdStringOptTestSuite = TestSuite("StdStringWithOpts")
+
+StdStringOptTestSuite.test("std::string with Hashable conformance optimized") {
+    let item = get_item()
+    let dict = Dictionary(uniqueKeysWithValues: zip(item.keys, item.values).lazy)
+
+    expectEqual(dict.count, 0)
+}
+
+runAllTests()