[cherry-pick][stable/20230725] [clang][CodeCompletion] Allow debuggers to code-complete reserved identifiers

clang/lib/Sema/SemaCodeComplete.cpp

@@ -700,6 +700,10 @@ ResultBuilder::ShadowMapEntry::end() const {
 // Filter out names reserved for the implementation if they come from a
 // system header.
 static bool shouldIgnoreDueToReservedName(const NamedDecl *ND, Sema &SemaRef) {
+  // Debuggers want access to all identifiers, including reserved ones.
+  if (SemaRef.getLangOpts().DebuggerSupport)
+    return false;
+
   ReservedIdentifierStatus Status = ND->isReserved(SemaRef.getLangOpts());
   // Ignore reserved names for compiler provided decls.
   if (isReservedInAllContexts(Status) && ND->getLocation().isInvalid())

clang/test/CodeCompletion/ordinary-name.c

@@ -5,6 +5,7 @@ typedef struct t _TYPEDEF;
 void foo() {
   int y;
   // RUN: %clang_cc1 -isystem %S/Inputs -fsyntax-only -code-completion-at=%s:%(line-1):9 %s -o - | FileCheck -check-prefix=CHECK-CC1 %s
+  // CHECK-CC1-NOT: __builtin_va_list
   // CHECK-CC1-NOT: __INTEGER_TYPE
   // CHECK-CC1: _Imaginary
   // CHECK-CC1: _MyPrivateType
@@ -15,4 +16,8 @@ void foo() {
   // CHECK-CC1: y
 
   // PR8744
-  // RUN: %clang_cc1 -isystem %S/Inputs -fsyntax-only -code-completion-at=%s:%(line-17):11 %s
+  // RUN: %clang_cc1 -isystem %S/Inputs -fsyntax-only -code-completion-at=%s:%(line-18):11 %s
+
+  // RUN: %clang_cc1 -isystem %S/Inputs -fsyntax-only -fdebugger-support -code-completion-at=%s:%(line-15):9 %s -o - | FileCheck -check-prefix=CHECK-DBG %s
+  // CHECK-DBG: __builtin_va_list
+  // CHECK-DBG: __INTEGER_TYPE

lldb/test/API/commands/expression/completion/Makefile

@@ -1,3 +1,4 @@
 CXX_SOURCES := main.cpp other.cpp
+CXXFLAGS += -isystem $(SRCDIR)/sys
 
 include Makefile.rules

lldb/test/API/commands/expression/completion/TestExprCompletion.py

@@ -246,6 +246,11 @@ def test_expr_completion(self):
             "expr some_expr.Self(). FooNoArgs", "expr some_expr.Self(). FooNoArgsBar()"
         )
 
+        self.complete_from_to("expr myVec.__f", "expr myVec.__func()")
+        self.complete_from_to("expr myVec._F", "expr myVec._Func()")
+        self.complete_from_to("expr myVec.__m", "expr myVec.__mem")
+        self.complete_from_to("expr myVec._M", "expr myVec._Mem")
+
     def test_expr_completion_with_descriptions(self):
         self.build()
         self.main_source = "main.cpp"

lldb/test/API/commands/expression/completion/main.cpp

@@ -1,3 +1,5 @@
+#include <reserved.h>
+
 namespace LongNamespaceName { class NestedClass { long m; }; }
 
 // Defined in other.cpp, we only have a forward declaration here.
@@ -31,5 +33,8 @@ int main()
     some_expr.FooNumbersBar1();
     Expr::StaticMemberMethodBar();
     ForwardDecl *fwd_decl_ptr = &fwd_decl;
+    MyVec myVec;
+    myVec.__func();
+    myVec._Func();
     return 0; // Break here
 }

lldb/test/API/commands/expression/completion/sys/reserved.h

@@ -0,0 +1,8 @@
+class MyVec {
+  int __mem;
+  int _Mem;
+
+public:
+  void __func() {}
+  void _Func() {}
+};