[clang][SYCL] Fix field/base builtins for PCH support (#20560)

We have added several builtins for device copyability checking a while
back. These are implemented via new AST nodes, so they require
implementation of ASTReaderStmt's and ASTWriterStmt's methods. The
implementation was in place but it was untested so we never saw that it
is missing writing/reading of the builtin expression's type which
resulted in crashes during PCH reading.

Author: Fznamznon

clang/lib/Serialization/ASTReaderStmt.cpp

@@ -1866,22 +1866,26 @@ void ASTStmtReader::VisitBuiltinBitCastExpr(BuiltinBitCastExpr *E) {
 }
 
 void ASTStmtReader::VisitSYCLBuiltinNumFieldsExpr(SYCLBuiltinNumFieldsExpr *E) {
+  VisitExpr(E);
   E->setLocation(readSourceLocation());
   E->SourceTy = Record.readType();
 }
 
 void ASTStmtReader::VisitSYCLBuiltinFieldTypeExpr(SYCLBuiltinFieldTypeExpr *E) {
+  VisitExpr(E);
   E->setLocation(readSourceLocation());
   E->SourceTy = Record.readType();
   E->Index = Record.readExpr();
 }
 
 void ASTStmtReader::VisitSYCLBuiltinNumBasesExpr(SYCLBuiltinNumBasesExpr *E) {
+  VisitExpr(E);
   E->setLocation(readSourceLocation());
   E->SourceTy = Record.readType();
 }
 
 void ASTStmtReader::VisitSYCLBuiltinBaseTypeExpr(SYCLBuiltinBaseTypeExpr *E) {
+  VisitExpr(E);
   E->setLocation(readSourceLocation());
   E->SourceTy = Record.readType();
   E->Index = Record.readExpr();

clang/lib/Serialization/ASTWriterStmt.cpp

@@ -1869,25 +1869,29 @@ void ASTStmtWriter::VisitBuiltinBitCastExpr(BuiltinBitCastExpr *E) {
 }
 
 void ASTStmtWriter::VisitSYCLBuiltinNumFieldsExpr(SYCLBuiltinNumFieldsExpr *E) {
+  VisitExpr(E);
   Record.AddSourceLocation(E->getLocation());
   Record.AddTypeRef(E->getSourceType());
   Code = serialization::EXPR_SYCL_BUILTIN_NUM_FIELDS;
 }
 
 void ASTStmtWriter::VisitSYCLBuiltinFieldTypeExpr(SYCLBuiltinFieldTypeExpr *E) {
+  VisitExpr(E);
   Record.AddSourceLocation(E->getLocation());
   Record.AddTypeRef(E->getSourceType());
   Record.AddStmt(E->getIndex());
   Code = serialization::EXPR_SYCL_BUILTIN_FIELD_TYPE;
 }
 
 void ASTStmtWriter::VisitSYCLBuiltinNumBasesExpr(SYCLBuiltinNumBasesExpr *E) {
+  VisitExpr(E);
   Record.AddSourceLocation(E->getLocation());
   Record.AddTypeRef(E->getSourceType());
   Code = serialization::EXPR_SYCL_BUILTIN_NUM_BASES;
 }
 
 void ASTStmtWriter::VisitSYCLBuiltinBaseTypeExpr(SYCLBuiltinBaseTypeExpr *E) {
+  VisitExpr(E);
   Record.AddSourceLocation(E->getLocation());
   Record.AddTypeRef(E->getSourceType());
   Record.AddStmt(E->getIndex());

clang/test/SemaSYCL/builtin-fields-pch.cpp

@@ -0,0 +1,26 @@
+// Test that __builtin_num_fields, __builtin_num_bases, __builtin_field_type,
+// and __builtin_base_type work correctly with PCH.
+
+// RUN: rm -rf %t
+// RUN: split-file %s %t
+// RUN: %clang_cc1 -std=c++17 -triple spir64-unknown-unknown -fsycl-is-device -emit-pch -x c++-header \
+// RUN:   %t/pch.h -o %t/pch.h.device.pch
+// RUN: %clang_cc1 -std=c++17 -triple spir64-unknown-unknown -fsycl-is-device -verify \
+// RUN:   -include-pch %t/pch.h.device.pch %t/test.cpp
+
+#--- pch.h
+struct Base {};
+template <typename T> struct X {
+  static_assert(__is_same(Base, decltype(__builtin_base_type(T, 0))));
+  static_assert(__is_same(int, decltype(__builtin_field_type(T, 0))));
+  static_assert(__builtin_num_fields(T) == 1);
+  static_assert(__builtin_num_bases(T) == 1);
+};
+
+#--- test.cpp
+// expected-no-diagnostics
+struct A : public Base { int i; };
+void foo() {
+  X<A> x;
+}
+

sycl/test-e2e/PerformanceTests/KernelCompiler/auto-pch.cpp

@@ -102,4 +102,5 @@ int main(int argc, char **argv) {
   run({"sycl/multi_ptr.hpp"});
   run({"sycl/builtins.hpp"});
   run({"sycl/ext/oneapi/matrix/matrix.hpp"});
+  run({"sycl/sycl.hpp"});
 }