Fix diagnostic pragmas.

Diagnostic pragmas are broken because we don't keep track of the diagnostic state changes and we only check the current/latest state.
Problems manifest if a diagnostic is emitted for a source line that has different diagnostic state than the current state; this can affect
a lot of places, like C++ inline methods, template instantiations, the lexer, etc.

Fix the issue by having the Diagnostic object keep track of the source location of the pragmas so that it is able to know what is the diagnostic state at any given source location.

Fixes rdar://8365684.

llvm-svn: 121873

1 files changed, 8 insertions, 14 deletions

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 17a1a1badb5..6182e8663b4 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -809,7 +809,7 @@ NamedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid,
       << Context.BuiltinInfo.GetName(BID)
       << R;
     if (Context.BuiltinInfo.getHeaderName(BID) &&
-        Diags.getDiagnosticLevel(diag::ext_implicit_lib_function_decl)
+        Diags.getDiagnosticLevel(diag::ext_implicit_lib_function_decl, Loc)
           != Diagnostic::Ignored)
       Diag(Loc, diag::note_please_include_header)
         << Context.BuiltinInfo.getHeaderName(BID)
@@ -3081,7 +3081,8 @@ Sema::ActOnVariableDeclarator(Scope *S, Declarator &D, DeclContext *DC,
 ///
 void Sema::CheckShadow(Scope *S, VarDecl *D, const LookupResult& R) {
   // Return if warning is ignored.
-  if (Diags.getDiagnosticLevel(diag::warn_decl_shadow) == Diagnostic::Ignored)
+  if (Diags.getDiagnosticLevel(diag::warn_decl_shadow, R.getNameLoc()) ==
+        Diagnostic::Ignored)
     return;
 
   // Don't diagnose declarations at file scope.  The scope might not
@@ -3135,6 +3136,10 @@ void Sema::CheckShadow(Scope *S, VarDecl *D, const LookupResult& R) {
 
 /// \brief Check -Wshadow without the advantage of a previous lookup.
 void Sema::CheckShadow(Scope *S, VarDecl *D) {
+  if (Diags.getDiagnosticLevel(diag::warn_decl_shadow, D->getLocation()) ==
+        Diagnostic::Ignored)
+    return;
+
   LookupResult R(*this, D->getDeclName(), D->getLocation(),
                  Sema::LookupOrdinaryName, Sema::ForRedeclaration);
   LookupName(R, S);
@@ -5014,10 +5019,6 @@ ParmVarDecl *Sema::BuildParmVarDeclForTypedef(DeclContext *DC,
 
 void Sema::DiagnoseUnusedParameters(ParmVarDecl * const *Param,
                                     ParmVarDecl * const *ParamEnd) {
-  if (Diags.getDiagnosticLevel(diag::warn_unused_parameter) ==
-        Diagnostic::Ignored)
-    return;
-
   // Don't diagnose unused-parameter errors in template instantiations; we
   // will already have done so in the template itself.
   if (!ActiveTemplateInstantiations.empty())
@@ -5048,9 +5049,6 @@ void Sema::DiagnoseSizeOfParametersAndReturnValue(ParmVarDecl * const *Param,
           << D->getDeclName() << Size;
   }
 
-  if (Diags.getDiagnosticLevel(diag::warn_parameter_size)==Diagnostic::Ignored)
-    return;
-
   // Warn if any parameter is pass-by-value and larger than the specified
   // threshold.
   for (; Param != ParamEnd; ++Param) {
@@ -5255,9 +5253,6 @@ Decl *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Decl *D) {
   CheckParmsForFunctionDef(FD->param_begin(), FD->param_end(),
                            /*CheckParameterNames=*/true);
 
-  bool ShouldCheckShadow =
-    Diags.getDiagnosticLevel(diag::warn_decl_shadow) != Diagnostic::Ignored;
-
   // Introduce our parameters into the function scope
   for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) {
     ParmVarDecl *Param = FD->getParamDecl(p);
@@ -5265,8 +5260,7 @@ Decl *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Decl *D) {
 
     // If this has an identifier, add it to the scope stack.
     if (Param->getIdentifier() && FnBodyScope) {
-      if (ShouldCheckShadow)
-        CheckShadow(FnBodyScope, Param);
+      CheckShadow(FnBodyScope, Param);
 
       PushOnScopeChains(Param, FnBodyScope);
     }