Improve diagnostic for the case when a non-defined function-like macro is used

in a preprocessor constant expression.

llvm-svn: 266495

1 files changed, 26 insertions, 4 deletions

diff --git a/clang/lib/Lex/PPExpressions.cpp b/clang/lib/Lex/PPExpressions.cpp
index 058e2741d7a..94075ece35c 100644
--- a/clang/lib/Lex/PPExpressions.cpp
+++ b/clang/lib/Lex/PPExpressions.cpp
@@ -33,12 +33,18 @@ namespace {
 /// conditional and the source range covered by it.
 class PPValue {
   SourceRange Range;
+  IdentifierInfo *II;
 public:
   llvm::APSInt Val;
 
   // Default ctor - Construct an 'invalid' PPValue.
   PPValue(unsigned BitWidth) : Val(BitWidth) {}
 
+  // If this value was produced by directly evaluating an identifier, produce
+  // that identifier.
+  IdentifierInfo *getIdentifier() const { return II; }
+  void setIdentifier(IdentifierInfo *II) { this->II = II; }
+
   unsigned getBitWidth() const { return Val.getBitWidth(); }
   bool isUnsigned() const { return Val.isUnsigned(); }
 
@@ -209,6 +215,8 @@ static bool EvaluateValue(PPValue &Result, Token &PeekTok, DefinedTracker &DT,
                           bool ValueLive, Preprocessor &PP) {
   DT.State = DefinedTracker::Unknown;
 
+  Result.setIdentifier(nullptr);
+
   if (PeekTok.is(tok::code_completion)) {
     if (PP.getCodeCompletionHandler())
       PP.getCodeCompletionHandler()->CodeCompletePreprocessorExpression();
@@ -234,6 +242,7 @@ static bool EvaluateValue(PPValue &Result, Token &PeekTok, DefinedTracker &DT,
       PP.Diag(PeekTok, diag::warn_pp_undef_identifier) << II;
     Result.Val = II->getTokenID() == tok::kw_true;
     Result.Val.setIsUnsigned(false);  // "0" is signed intmax_t 0.
+    Result.setIdentifier(II);
     Result.setRange(PeekTok.getLocation());
     PP.LexNonComment(PeekTok);
     return false;
@@ -392,6 +401,7 @@ static bool EvaluateValue(PPValue &Result, Token &PeekTok, DefinedTracker &DT,
       DT.State = DefinedTracker::Unknown;
     }
     Result.setRange(Start, PeekTok.getLocation());
+    Result.setIdentifier(nullptr);
     PP.LexNonComment(PeekTok);  // Eat the ).
     return false;
   }
@@ -401,6 +411,7 @@ static bool EvaluateValue(PPValue &Result, Token &PeekTok, DefinedTracker &DT,
     PP.LexNonComment(PeekTok);
     if (EvaluateValue(Result, PeekTok, DT, ValueLive, PP)) return true;
     Result.setBegin(Start);
+    Result.setIdentifier(nullptr);
     return false;
   }
   case tok::minus: {
@@ -408,6 +419,7 @@ static bool EvaluateValue(PPValue &Result, Token &PeekTok, DefinedTracker &DT,
     PP.LexNonComment(PeekTok);
     if (EvaluateValue(Result, PeekTok, DT, ValueLive, PP)) return true;
     Result.setBegin(Loc);
+    Result.setIdentifier(nullptr);
 
     // C99 6.5.3.3p3: The sign of the result matches the sign of the operand.
     Result.Val = -Result.Val;
@@ -428,6 +440,7 @@ static bool EvaluateValue(PPValue &Result, Token &PeekTok, DefinedTracker &DT,
     PP.LexNonComment(PeekTok);
     if (EvaluateValue(Result, PeekTok, DT, ValueLive, PP)) return true;
     Result.setBegin(Start);
+    Result.setIdentifier(nullptr);
 
     // C99 6.5.3.3p4: The sign of the result matches the sign of the operand.
     Result.Val = ~Result.Val;
@@ -443,6 +456,7 @@ static bool EvaluateValue(PPValue &Result, Token &PeekTok, DefinedTracker &DT,
     Result.Val = !Result.Val;
     // C99 6.5.3.3p5: The sign of the result is 'int', aka it is signed.
     Result.Val.setIsUnsigned(false);
+    Result.setIdentifier(nullptr);
 
     if (DT.State == DefinedTracker::DefinedMacro)
       DT.State = DefinedTracker::NotDefinedMacro;
@@ -491,6 +505,15 @@ static unsigned getPrecedence(tok::TokenKind Kind) {
   }
 }
 
+static void diagnoseUnexpectedOperator(Preprocessor &PP, PPValue &LHS,
+                                       Token &Tok) {
+  if (Tok.is(tok::l_paren) && LHS.getIdentifier())
+    PP.Diag(LHS.getRange().getBegin(), diag::err_pp_expr_bad_token_lparen)
+        << LHS.getIdentifier();
+  else
+    PP.Diag(Tok.getLocation(), diag::err_pp_expr_bad_token_binop)
+        << LHS.getRange();
+}
 
 /// EvaluateDirectiveSubExpr - Evaluate the subexpression whose first token is
 /// PeekTok, and whose precedence is PeekPrec.  This returns the result in LHS.
@@ -504,8 +527,7 @@ static bool EvaluateDirectiveSubExpr(PPValue &LHS, unsigned MinPrec,
   unsigned PeekPrec = getPrecedence(PeekTok.getKind());
   // If this token isn't valid, report the error.
   if (PeekPrec == ~0U) {
-    PP.Diag(PeekTok.getLocation(), diag::err_pp_expr_bad_token_binop)
-      << LHS.getRange();
+    diagnoseUnexpectedOperator(PP, LHS, PeekTok);
     return true;
   }
 
@@ -548,8 +570,7 @@ static bool EvaluateDirectiveSubExpr(PPValue &LHS, unsigned MinPrec,
 
     // If this token isn't valid, report the error.
     if (PeekPrec == ~0U) {
-      PP.Diag(PeekTok.getLocation(), diag::err_pp_expr_bad_token_binop)
-        << RHS.getRange();
+      diagnoseUnexpectedOperator(PP, RHS, PeekTok);
       return true;
     }
 
@@ -769,6 +790,7 @@ static bool EvaluateDirectiveSubExpr(PPValue &LHS, unsigned MinPrec,
     // Put the result back into 'LHS' for our next iteration.
     LHS.Val = Res;
     LHS.setEnd(RHS.getRange().getEnd());
+    RHS.setIdentifier(nullptr);
   }
 }