[Clang] fix missing source location for errors in macro-expanded (llvm#143460)

Fixes llvm#143216

--- 

This patch fixes diagnostic locations for tokens from macro expansions.

Author: a-tarasyuk

clang/docs/ReleaseNotes.rst

@@ -694,6 +694,7 @@ Bug Fixes in This Version
 - Constant evaluation now correctly runs the destructor of a variable declared in
   the second clause of a C-style ``for`` loop. (#GH139818)
 - Fixed a bug with constexpr evaluation for structs containing unions in case of C++ modules. (#GH143168)
+- Fixed incorrect token location when emitting diagnostics for tokens expanded from macros. (#GH143216)
 
 Bug Fixes to Compiler Builtins
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

clang/include/clang/Parse/Parser.h

@@ -290,9 +290,7 @@ class Parser : public CodeCompletionHandler {
     return ConsumeToken();
   }
 
-  SourceLocation getEndOfPreviousToken() {
-    return PP.getLocForEndOfToken(PrevTokLocation);
-  }
+  SourceLocation getEndOfPreviousToken() const;
 
   /// GetLookAheadToken - This peeks ahead N tokens and returns that token
   /// without consuming any tokens.  LookAhead(0) returns 'Tok', LookAhead(1)

clang/lib/Parse/ParseExprCXX.cpp

@@ -421,8 +421,8 @@ bool Parser::ParseOptionalCXXScopeSpecifier(
       // like we never saw it.
       Token Identifier = Tok; // Stash away the identifier.
       ConsumeToken();         // Eat the identifier, current token is now '::'.
-      Diag(PP.getLocForEndOfToken(ConsumeToken()), diag::err_expected)
-          << tok::identifier;
+      ConsumeToken();
+      Diag(getEndOfPreviousToken(), diag::err_expected) << tok::identifier;
       UnconsumeToken(Identifier); // Stick the identifier back.
       Next = NextToken();         // Point Next at the '{' token.
     }

clang/lib/Parse/ParseStmt.cpp

@@ -832,10 +832,13 @@ StmtResult Parser::ParseCaseStatement(ParsedStmtContext StmtCtx,
           << "'case'" << tok::colon
           << FixItHint::CreateReplacement(ColonLoc, ":");
     } else {
-      SourceLocation ExpectedLoc = PP.getLocForEndOfToken(PrevTokLocation);
+      SourceLocation ExpectedLoc = getEndOfPreviousToken();
+
       Diag(ExpectedLoc, diag::err_expected_after)
           << "'case'" << tok::colon
-          << FixItHint::CreateInsertion(ExpectedLoc, ":");
+          << FixItHint::CreateInsertion(ExpectedLoc,
+                                        tok::getTokenName(tok::colon));
+
       ColonLoc = ExpectedLoc;
     }
 

clang/lib/Parse/Parser.cpp

@@ -1873,6 +1873,11 @@ Parser::TryAnnotateName(CorrectionCandidateCallback *CCC,
   return AnnotatedNameKind::Unresolved;
 }
 
+SourceLocation Parser::getEndOfPreviousToken() const {
+  SourceLocation TokenEndLoc = PP.getLocForEndOfToken(PrevTokLocation);
+  return TokenEndLoc.isValid() ? TokenEndLoc : Tok.getLocation();
+}
+
 bool Parser::TryKeywordIdentFallback(bool DisableKeyword) {
   assert(Tok.isNot(tok::identifier));
   Diag(Tok, diag::ext_keyword_as_ident)

clang/test/Parser/macro-expansion-recovery.cpp

@@ -0,0 +1,22 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+
+namespace GH143216 {
+#define A x y
+enum { A }; // expected-error {{missing ',' between enumerators}}
+
+#define B x y
+void f() {
+    int a[2];
+    auto [B] = a; // expected-error {{expected ','}}
+}
+
+#define C <int!
+template <class T> class D;
+D C; // expected-error {{expected unqualified-id}} \
+     // expected-error {{expected '>'}} \
+     // expected-note {{to match this '<'}}
+
+#define E F::{
+class F { E }}; // expected-error {{expected identifier}} \
+                // expected-error {{expected member name or ';' after declaration specifiers}}
+}

clang/test/Parser/switch-recovery.cpp

@@ -229,3 +229,16 @@ void fn1() {
     }
 } // expected-error{{expected statement}}
 }
+
+namespace GH143216 {
+#define FOO 1 case 3:
+
+int f(int x) {
+  switch (x) {
+  case FOO // expected-error {{expected ':' after 'case'}}
+    return 0;
+  default:
+    return 1;
+  }
+}
+}