Warn on duplicate function specifier

This patch fixes PR8264. Duplicate qualifiers already are diagnozed,
now the same diagnostics is issued for duplicate function specifiers.

Differential Revision: http://llvm-reviews.chandlerc.com/D2025

llvm-svn: 194559

2 files changed, 61 insertions, 17 deletions

diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp
index c5904933133..36d704d31a9 100644
--- a/clang/lib/Parse/ParseDecl.cpp
+++ b/clang/lib/Parse/ParseDecl.cpp
@@ -2730,7 +2730,7 @@ void Parser::ParseDeclarationSpecifiers(DeclSpec &DS,
 
     // Microsoft single token adornments.
     case tok::kw___forceinline: {
-      isInvalid = DS.setFunctionSpecInline(Loc);
+      isInvalid = DS.setFunctionSpecForceInline(Loc, PrevSpec, DiagID);
       IdentifierInfo *AttrName = Tok.getIdentifierInfo();
       SourceLocation AttrNameLoc = Tok.getLocation();
       // FIXME: This does not work correctly if it is set to be a declspec
@@ -2822,18 +2822,18 @@ void Parser::ParseDeclarationSpecifiers(DeclSpec &DS,
 
     // function-specifier
     case tok::kw_inline:
-      isInvalid = DS.setFunctionSpecInline(Loc);
+      isInvalid = DS.setFunctionSpecInline(Loc, PrevSpec, DiagID);
       break;
     case tok::kw_virtual:
-      isInvalid = DS.setFunctionSpecVirtual(Loc);
+      isInvalid = DS.setFunctionSpecVirtual(Loc, PrevSpec, DiagID);
       break;
     case tok::kw_explicit:
-      isInvalid = DS.setFunctionSpecExplicit(Loc);
+      isInvalid = DS.setFunctionSpecExplicit(Loc, PrevSpec, DiagID);
       break;
     case tok::kw__Noreturn:
       if (!getLangOpts().C11)
         Diag(Loc, diag::ext_c11_noreturn);
-      isInvalid = DS.setFunctionSpecNoreturn(Loc);
+      isInvalid = DS.setFunctionSpecNoreturn(Loc, PrevSpec, DiagID);
       break;
 
     // alignment-specifier
diff --git a/clang/lib/Sema/DeclSpec.cpp b/clang/lib/Sema/DeclSpec.cpp
index 46914f68040..538c16eeb25 100644
--- a/clang/lib/Sema/DeclSpec.cpp
+++ b/clang/lib/Sema/DeclSpec.cpp
@@ -349,7 +349,7 @@ unsigned DeclSpec::getParsedSpecifiers() const {
     Res |= PQ_TypeSpecifier;
 
   if (FS_inline_specified || FS_virtual_specified || FS_explicit_specified ||
-      FS_noreturn_specified)
+      FS_noreturn_specified || FS_forceinline_specified)
     Res |= PQ_FunctionSpecifier;
   return Res;
 }
@@ -739,9 +739,10 @@ bool DeclSpec::SetTypeSpecError() {
 
 bool DeclSpec::SetTypeQual(TQ T, SourceLocation Loc, const char *&PrevSpec,
                            unsigned &DiagID, const LangOptions &Lang) {
-  // Duplicates are permitted in C99, but are not permitted in C++. However,
-  // since this is likely not what the user intended, we will always warn.  We
-  // do not need to set the qualifier's location since we already have it.
+  // Duplicates are permitted in C99 onwards, but are not permitted in C89 or
+  // C++.  However, since this is likely not what the user intended, we will
+  // always warn.  We do not need to set the qualifier's location since we
+  // already have it.
   if (TypeQualifiers & T) {
     bool IsExtension = true;
     if (Lang.C99)
@@ -761,29 +762,72 @@ bool DeclSpec::SetTypeQual(TQ T, SourceLocation Loc, const char *&PrevSpec,
   llvm_unreachable("Unknown type qualifier!");
 }
 
-bool DeclSpec::setFunctionSpecInline(SourceLocation Loc) {
-  // 'inline inline' is ok.
+bool DeclSpec::setFunctionSpecInline(SourceLocation Loc, const char *&PrevSpec,
+                                     unsigned &DiagID) {
+  // 'inline inline' is ok.  However, since this is likely not what the user
+  // intended, we will always warn, similar to duplicates of type qualifiers.
+  if (FS_inline_specified) {
+    DiagID = diag::warn_duplicate_declspec;
+    PrevSpec = "inline";
+    return true;
+  }
   FS_inline_specified = true;
   FS_inlineLoc = Loc;
   return false;
 }
 
-bool DeclSpec::setFunctionSpecVirtual(SourceLocation Loc) {
-  // 'virtual virtual' is ok.
+bool DeclSpec::setFunctionSpecForceInline(SourceLocation Loc, const char *&PrevSpec,
+                                          unsigned &DiagID) {
+  if (FS_forceinline_specified) {
+    DiagID = diag::warn_duplicate_declspec;
+    PrevSpec = "__forceinline";
+    return true;
+  }
+  FS_forceinline_specified = true;
+  FS_forceinlineLoc = Loc;
+  return false;
+}
+
+bool DeclSpec::setFunctionSpecVirtual(SourceLocation Loc,
+                                      const char *&PrevSpec,
+                                      unsigned &DiagID) {
+  // 'virtual virtual' is ok, but warn as this is likely not what the user
+  // intended.
+  if (FS_virtual_specified) {
+    DiagID = diag::warn_duplicate_declspec;
+    PrevSpec = "virtual";
+    return true;
+  }
   FS_virtual_specified = true;
   FS_virtualLoc = Loc;
   return false;
 }
 
-bool DeclSpec::setFunctionSpecExplicit(SourceLocation Loc) {
-  // 'explicit explicit' is ok.
+bool DeclSpec::setFunctionSpecExplicit(SourceLocation Loc,
+                                       const char *&PrevSpec,
+                                       unsigned &DiagID) {
+  // 'explicit explicit' is ok, but warn as this is likely not what the user
+  // intended.
+  if (FS_explicit_specified) {
+    DiagID = diag::warn_duplicate_declspec;
+    PrevSpec = "explicit";
+    return true;
+  }
   FS_explicit_specified = true;
   FS_explicitLoc = Loc;
   return false;
 }
 
-bool DeclSpec::setFunctionSpecNoreturn(SourceLocation Loc) {
-  // '_Noreturn _Noreturn' is ok.
+bool DeclSpec::setFunctionSpecNoreturn(SourceLocation Loc,
+                                       const char *&PrevSpec,
+                                       unsigned &DiagID) {
+  // '_Noreturn _Noreturn' is ok, but warn as this is likely not what the user
+  // intended.
+  if (FS_noreturn_specified) {
+    DiagID = diag::warn_duplicate_declspec;
+    PrevSpec = "_Noreturn";
+    return true;
+  }
   FS_noreturn_specified = true;
   FS_noreturnLoc = Loc;
   return false;