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.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@121873 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 137 insertions, 22 deletions

diff --git a/lib/Basic/Diagnostic.cpp b/lib/Basic/Diagnostic.cpp
index 5098c2e4f8..919ba8187e 100644
--- a/lib/Basic/Diagnostic.cpp
+++ b/lib/Basic/Diagnostic.cpp
@@ -49,9 +49,10 @@ Diagnostic::Diagnostic(const llvm::IntrusiveRefCntPtr<DiagnosticIDs> &diags,
   ErrorLimit = 0;
   TemplateBacktraceLimit = 0;
 
-  // Set all mappings to 'unset'.
-  DiagMappingsStack.clear();
-  DiagMappingsStack.push_back(DiagMappings());
+  // Create a DiagState and DiagStatePoint representing diagnostic changes
+  // through command-line.
+  DiagStates.push_back(DiagState());
+  PushDiagStatePoint(&DiagStates.back(), SourceLocation());
 
   Reset();
 }
@@ -62,17 +63,19 @@ Diagnostic::~Diagnostic() {
 }
 
 
-void Diagnostic::pushMappings() {
-  // Avoids undefined behavior when the stack has to resize.
-  DiagMappingsStack.reserve(DiagMappingsStack.size() + 1);
-  DiagMappingsStack.push_back(DiagMappingsStack.back());
+void Diagnostic::pushMappings(SourceLocation Loc) {
+  DiagStateOnPushStack.push_back(GetCurDiagState());
 }
 
-bool Diagnostic::popMappings() {
-  if (DiagMappingsStack.size() == 1)
+bool Diagnostic::popMappings(SourceLocation Loc) {
+  if (DiagStateOnPushStack.empty())
     return false;
 
-  DiagMappingsStack.pop_back();
+  if (DiagStateOnPushStack.back() != GetCurDiagState()) {
+    // State changed at some point between push/pop.
+    PushDiagStatePoint(DiagStateOnPushStack.back(), Loc);
+  }
+  DiagStateOnPushStack.pop_back();
   return true;
 }
 
@@ -109,6 +112,91 @@ void Diagnostic::ReportDelayed() {
   DelayedDiagArg2.clear();
 }
 
+Diagnostic::DiagStatePointsTy::iterator
+Diagnostic::GetDiagStatePointForLoc(SourceLocation L) const {
+  assert(!DiagStatePoints.empty());
+  assert(DiagStatePoints.front().Loc.isInvalid() &&
+         "Should have created a DiagStatePoint for command-line");
+
+  FullSourceLoc Loc(L, *SourceMgr);
+  if (Loc.isInvalid())
+    return DiagStatePoints.end() - 1;
+
+  DiagStatePointsTy::iterator Pos = DiagStatePoints.end();
+  FullSourceLoc LastStateChangePos = DiagStatePoints.back().Loc;
+  if (LastStateChangePos.isValid() &&
+      Loc.isBeforeInTranslationUnitThan(LastStateChangePos))
+    Pos = std::upper_bound(DiagStatePoints.begin(), DiagStatePoints.end(),
+                           DiagStatePoint(0, Loc));
+  --Pos;
+  return Pos;
+}
+
+/// \brief This allows the client to specify that certain
+/// warnings are ignored.  Notes can never be mapped, errors can only be
+/// mapped to fatal, and WARNINGs and EXTENSIONs can be mapped arbitrarily.
+///
+/// \param The source location that this change of diagnostic state should
+/// take affect. It can be null if we are setting the latest state.
+void Diagnostic::setDiagnosticMapping(diag::kind Diag, diag::Mapping Map,
+                                      SourceLocation L) {
+  assert(Diag < diag::DIAG_UPPER_LIMIT &&
+         "Can only map builtin diagnostics");
+  assert((Diags->isBuiltinWarningOrExtension(Diag) ||
+          (Map == diag::MAP_FATAL || Map == diag::MAP_ERROR)) &&
+         "Cannot map errors into warnings!");
+  assert(!DiagStatePoints.empty());
+
+  FullSourceLoc Loc(L, *SourceMgr);
+  FullSourceLoc LastStateChangePos = DiagStatePoints.back().Loc;
+
+  // Common case; setting all the diagnostics of a group in one place.
+  if (Loc.isInvalid() || Loc == LastStateChangePos) {
+    setDiagnosticMappingInternal(Diag, Map, GetCurDiagState(), true);
+    return;
+  }
+
+  // Another common case; modifying diagnostic state in a source location
+  // after the previous one.
+  if ((Loc.isValid() && LastStateChangePos.isInvalid()) ||
+      LastStateChangePos.isBeforeInTranslationUnitThan(Loc)) {
+    // A diagnostic pragma occured, create a new DiagState initialized with
+    // the current one and a new DiagStatePoint to record at which location
+    // the new state became active.
+    DiagStates.push_back(*GetCurDiagState());
+    PushDiagStatePoint(&DiagStates.back(), Loc);
+    setDiagnosticMappingInternal(Diag, Map, GetCurDiagState(), true);
+    return;
+  }
+
+  // We allow setting the diagnostic state in random source order for
+  // completeness but it should not be actually happening in normal practice.
+
+  DiagStatePointsTy::iterator Pos = GetDiagStatePointForLoc(Loc);
+  assert(Pos != DiagStatePoints.end());
+
+  // Update all diagnostic states that are active after the given location.
+  for (DiagStatePointsTy::iterator
+         I = Pos+1, E = DiagStatePoints.end(); I != E; ++I) {
+    setDiagnosticMappingInternal(Diag, Map, I->State, true);
+  }
+
+  // If the location corresponds to an existing point, just update its state.
+  if (Pos->Loc == Loc) {
+    setDiagnosticMappingInternal(Diag, Map, Pos->State, true);
+    return;
+  }
+
+  // Create a new state/point and fit it into the vector of DiagStatePoints
+  // so that the vector is always ordered according to location.
+  Pos->Loc.isBeforeInTranslationUnitThan(Loc);
+  DiagStates.push_back(*Pos->State);
+  DiagState *NewState = &DiagStates.back();
+  setDiagnosticMappingInternal(Diag, Map, NewState, true);
+  DiagStatePoints.insert(Pos+1, DiagStatePoint(NewState,
+                                               FullSourceLoc(Loc, *SourceMgr)));
+}
+
 void DiagnosticBuilder::FlushCounts() {
   DiagObj->NumDiagArgs = NumArgs;
   DiagObj->NumDiagRanges = NumRanges;
diff --git a/lib/Basic/DiagnosticIDs.cpp b/lib/Basic/DiagnosticIDs.cpp
index 5d5bf7b72a..29a8d9270a 100644
--- a/lib/Basic/DiagnosticIDs.cpp
+++ b/lib/Basic/DiagnosticIDs.cpp
@@ -282,32 +282,42 @@ const char *DiagnosticIDs::getDescription(unsigned DiagID) const {
 /// getDiagnosticLevel - Based on the way the client configured the Diagnostic
 /// object, classify the specified diagnostic ID into a Level, consumable by
 /// the DiagnosticClient.
-DiagnosticIDs::Level DiagnosticIDs::getDiagnosticLevel(unsigned DiagID,
-                                        const Diagnostic &Diag) const {
+DiagnosticIDs::Level
+DiagnosticIDs::getDiagnosticLevel(unsigned DiagID, SourceLocation Loc,
+                                  const Diagnostic &Diag) const {
   // Handle custom diagnostics, which cannot be mapped.
   if (DiagID >= diag::DIAG_UPPER_LIMIT)
     return CustomDiagInfo->getLevel(DiagID);
 
   unsigned DiagClass = getBuiltinDiagClass(DiagID);
   assert(DiagClass != CLASS_NOTE && "Cannot get diagnostic level of a note!");
-  return getDiagnosticLevel(DiagID, DiagClass, Diag);
+  return getDiagnosticLevel(DiagID, DiagClass, Loc, Diag);
 }
 
-/// getDiagnosticLevel - Based on the way the client configured the Diagnostic
+/// \brief Based on the way the client configured the Diagnostic
 /// object, classify the specified diagnostic ID into a Level, consumable by
 /// the DiagnosticClient.
+///
+/// \param Loc The source location we are interested in finding out the
+/// diagnostic state. Can be null in order to query the latest state.
 DiagnosticIDs::Level
 DiagnosticIDs::getDiagnosticLevel(unsigned DiagID, unsigned DiagClass,
-                               const Diagnostic &Diag) const {
+                                  SourceLocation Loc,
+                                  const Diagnostic &Diag) const {
   // Specific non-error diagnostics may be mapped to various levels from ignored
   // to error.  Errors can only be mapped to fatal.
   DiagnosticIDs::Level Result = DiagnosticIDs::Fatal;
 
+  Diagnostic::DiagStatePointsTy::iterator
+    Pos = Diag.GetDiagStatePointForLoc(Loc);
+  Diagnostic::DiagState *State = Pos->State;
+
   // Get the mapping information, if unset, compute it lazily.
-  unsigned MappingInfo = Diag.getDiagnosticMappingInfo((diag::kind)DiagID);
+  unsigned MappingInfo = Diag.getDiagnosticMappingInfo((diag::kind)DiagID,
+                                                       State);
   if (MappingInfo == 0) {
     MappingInfo = GetDefaultDiagMapping(DiagID);
-    Diag.setDiagnosticMappingInternal(DiagID, MappingInfo, false);
+    Diag.setDiagnosticMappingInternal(DiagID, MappingInfo, State, false);
   }
 
   switch (MappingInfo & 7) {
@@ -404,17 +414,17 @@ static bool WarningOptionCompare(const WarningOption &LHS,
 }
 
 static void MapGroupMembers(const WarningOption *Group, diag::Mapping Mapping,
-                            Diagnostic &Diag) {
+                            SourceLocation Loc, Diagnostic &Diag) {
   // Option exists, poke all the members of its diagnostic set.
   if (const short *Member = Group->Members) {
     for (; *Member != -1; ++Member)
-      Diag.setDiagnosticMapping(*Member, Mapping);
+      Diag.setDiagnosticMapping(*Member, Mapping, Loc);
   }
 
   // Enable/disable all subgroups along with this one.
   if (const short *SubGroups = Group->SubGroups) {
     for (; *SubGroups != (short)-1; ++SubGroups)
-      MapGroupMembers(&OptionTable[(short)*SubGroups], Mapping, Diag);
+      MapGroupMembers(&OptionTable[(short)*SubGroups], Mapping, Loc, Diag);
   }
 }
 
@@ -423,7 +433,18 @@ static void MapGroupMembers(const WarningOption *Group, diag::Mapping Mapping,
 /// ignores the request if "Group" was unknown, false otherwise.
 bool DiagnosticIDs::setDiagnosticGroupMapping(const char *Group,
                                            diag::Mapping Map,
+                                           SourceLocation Loc,
                                            Diagnostic &Diag) const {
+  assert((Loc.isValid() ||
+          Diag.DiagStatePoints.empty() ||
+          Diag.DiagStatePoints.back().Loc.isInvalid()) &&
+         "Loc should be invalid only when the mapping comes from command-line");
+  assert((Loc.isInvalid() || Diag.DiagStatePoints.empty() ||
+          Diag.DiagStatePoints.back().Loc.isInvalid() ||
+          !Diag.SourceMgr->isBeforeInTranslationUnit(Loc,
+                                            Diag.DiagStatePoints.back().Loc)) &&
+         "Source location of new mapping is before the previous one!");
+
   WarningOption Key = { Group, 0, 0 };
   const WarningOption *Found =
   std::lower_bound(OptionTable, OptionTable + OptionTableSize, Key,
@@ -432,7 +453,7 @@ bool DiagnosticIDs::setDiagnosticGroupMapping(const char *Group,
       strcmp(Found->Name, Group) != 0)
     return true;  // Option not found.
 
-  MapGroupMembers(Found, Map, Diag);
+  MapGroupMembers(Found, Map, Loc, Diag);
   return false;
 }
 
@@ -475,7 +496,8 @@ bool DiagnosticIDs::ProcessDiag(Diagnostic &Diag) const {
       // *map* warnings/extensions to errors.
       ShouldEmitInSystemHeader = DiagClass == CLASS_ERROR;
 
-      DiagLevel = getDiagnosticLevel(DiagID, DiagClass, Diag);
+      DiagLevel = getDiagnosticLevel(DiagID, DiagClass, Info.getLocation(),
+                                     Diag);
     }
   }
 
diff --git a/lib/Basic/SourceLocation.cpp b/lib/Basic/SourceLocation.cpp
index 1571e2205f..5062d43f58 100644
--- a/lib/Basic/SourceLocation.cpp
+++ b/lib/Basic/SourceLocation.cpp
@@ -110,6 +110,11 @@ bool FullSourceLoc::isInSystemHeader() const {
   return SrcMgr->isInSystemHeader(*this);
 }
 
+bool FullSourceLoc::isBeforeInTranslationUnitThan(SourceLocation Loc) const {
+  assert(isValid());
+  return SrcMgr->isBeforeInTranslationUnit(*this, Loc);
+}
+
 const char *FullSourceLoc::getCharacterData(bool *Invalid) const {
   assert(isValid());
   return SrcMgr->getCharacterData(*this, Invalid);