Fix a couple of bugs, add some new cool stuff.

1. Fix a todo in Parser::ParseTag, to recover better.  On code like
   that in test/Sema/decl-invalid.c it causes us to return a single
   error instead of multiple.
2. Fix an error in Sema::ParseDeclarator, where it would crash if the
   declarator didn't have an identifier.  Instead, diagnose the problem.
3. Start adding infrastructure to track the range of locations covered
   by a declspec or declarator.  This is mostly implemented for declspec,
   but could be improved, it is missing for declarator.

Thanks to Neil for pointing out this crash.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@40482 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Basic/TargetInfo.cpp b/Basic/TargetInfo.cpp
new file mode 100644
index 0000000..1b78010
--- /dev/null
+++ b/Basic/TargetInfo.cpp
@@ -0,0 +1,248 @@
+//===--- TargetInfo.cpp - Information about Target machine ----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Chris Lattner and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file implements the TargetInfo and TargetInfoImpl interfaces.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Basic/TargetInfo.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/AST/Builtins.h"
+#include "llvm/ADT/StringMap.h"
+#include <set>
+using namespace clang;
+
+void TargetInfoImpl::ANCHOR() {} // out-of-line virtual method for class.
+
+
+/// DiagnoseNonPortability - When a use of a non-portable target feature is
+/// used, this method emits the diagnostic and marks the translation unit as
+/// non-portable.
+void TargetInfo::DiagnoseNonPortability(SourceLocation Loc, unsigned DiagKind) {
+  NonPortable = true;
+  if (Diag && Loc.isValid()) Diag->Report(Loc, DiagKind);
+}
+
+/// GetTargetDefineMap - Get the set of target #defines in an associative
+/// collection for easy lookup.
+static void GetTargetDefineMap(const TargetInfoImpl *Target,
+                               llvm::StringMap<std::string> &Map) {
+  std::vector<std::string> PrimaryDefines;
+  Target->getTargetDefines(PrimaryDefines);
+
+  while (!PrimaryDefines.empty()) {
+    std::string &PrimDefineStr = PrimaryDefines.back();
+    const char *Str    = PrimDefineStr.c_str();
+    const char *StrEnd = Str+PrimDefineStr.size();
+    
+    if (const char *Equal = strchr(Str, '=')) {
+      // Split at the '='.
+      
+      std::string &Entry = Map.GetOrCreateValue(Str, Equal).getValue();
+      Entry = std::string(Equal+1, StrEnd);
+    } else {
+      // Remember "macroname=1".
+      std::string &Entry = Map.GetOrCreateValue(Str, StrEnd).getValue();
+      Entry = "1";
+    }
+    PrimaryDefines.pop_back();
+  }
+}
+
+/// getTargetDefines - Appends the target-specific #define values for this
+/// target set to the specified buffer.
+void TargetInfo::getTargetDefines(std::vector<char> &Buffer) {
+  // This is tricky in the face of secondary targets.  Specifically, 
+  // target-specific #defines that are present and identical across all
+  // secondary targets are turned into #defines, #defines that are present in
+  // the primary target but are missing or different in the secondary targets
+  // are turned into #define_target, and #defines that are not defined in the
+  // primary, but are defined in a secondary are turned into
+  // #define_other_target.  This allows the preprocessor to correctly track uses
+  // of target-specific macros.
+  
+  // Get the set of primary #defines.
+  llvm::StringMap<std::string> PrimaryDefines;
+  GetTargetDefineMap(PrimaryTarget, PrimaryDefines);
+  
+  // If we have no secondary targets, be a bit more efficient.
+  if (SecondaryTargets.empty()) {
+    for (llvm::StringMap<std::string>::iterator I = 
+           PrimaryDefines.begin(), E = PrimaryDefines.end(); I != E; ++I) {
+      // If this define is non-portable, turn it into #define_target, otherwise
+      // just use #define.
+      const char *Command = "#define ";
+      Buffer.insert(Buffer.end(), Command, Command+strlen(Command));
+      
+      // Insert "defname defvalue\n".
+      const char *KeyStart = I->getKeyData();
+      const char *KeyEnd = KeyStart + I->getKeyLength();
+      
+      Buffer.insert(Buffer.end(), KeyStart, KeyEnd);
+      Buffer.push_back(' ');
+      Buffer.insert(Buffer.end(), I->getValue().begin(), I->getValue().end());
+      Buffer.push_back('\n');
+    }
+    return;
+  }
+  
+  // Get the sets of secondary #defines.
+  llvm::StringMap<std::string> *SecondaryDefines
+    = new llvm::StringMap<std::string>[SecondaryTargets.size()];
+  for (unsigned i = 0, e = SecondaryTargets.size(); i != e; ++i)
+    GetTargetDefineMap(SecondaryTargets[i], SecondaryDefines[i]);
+
+  // Loop over all defines in the primary target, processing them until we run
+  // out.
+  for (llvm::StringMap<std::string>::iterator PDI = 
+         PrimaryDefines.begin(), E = PrimaryDefines.end(); PDI != E; ++PDI) {
+    std::string DefineName(PDI->getKeyData(),
+                           PDI->getKeyData() + PDI->getKeyLength());
+    std::string DefineValue = PDI->getValue();
+    
+    // Check to see whether all secondary targets have this #define and whether
+    // it is to the same value.  Remember if not, but remove the #define from
+    // their collection in any case if they have it.
+    bool isPortable = true;
+    
+    for (unsigned i = 0, e = SecondaryTargets.size(); i != e; ++i) {
+      llvm::StringMap<std::string>::iterator I = 
+        SecondaryDefines[i].find(&DefineName[0],
+                                 &DefineName[0]+DefineName.size());
+      if (I == SecondaryDefines[i].end()) {
+        // Secondary target doesn't have this #define.
+        isPortable = false;
+      } else {
+        // Secondary target has this define, remember if it disagrees.
+        if (isPortable)
+          isPortable = I->getValue() == DefineValue;
+        // Remove it from the secondary target unconditionally.
+        SecondaryDefines[i].erase(I);
+      }
+    }
+    
+    // If this define is non-portable, turn it into #define_target, otherwise
+    // just use #define.
+    const char *Command = isPortable ? "#define " : "#define_target ";
+    Buffer.insert(Buffer.end(), Command, Command+strlen(Command));
+
+    // Insert "defname defvalue\n".
+    Buffer.insert(Buffer.end(), DefineName.begin(), DefineName.end());
+    Buffer.push_back(' ');
+    Buffer.insert(Buffer.end(), DefineValue.begin(), DefineValue.end());
+    Buffer.push_back('\n');
+  }
+  
+  // Now that all of the primary target's defines have been handled and removed
+  // from the secondary target's define sets, go through the remaining secondary
+  // target's #defines and taint them.
+  for (unsigned i = 0, e = SecondaryTargets.size(); i != e; ++i) {
+    llvm::StringMap<std::string> &Defs = SecondaryDefines[i];
+    while (!Defs.empty()) {
+      const char *DefStart = Defs.begin()->getKeyData();
+      const char *DefEnd = DefStart + Defs.begin()->getKeyLength();
+      
+      // Insert "#define_other_target defname".
+      const char *Command = "#define_other_target ";
+      Buffer.insert(Buffer.end(), Command, Command+strlen(Command));
+      Buffer.insert(Buffer.end(), DefStart, DefEnd);
+      Buffer.push_back('\n');
+      
+      // If any other secondary targets have this same define, remove it from
+      // them to avoid duplicate #define_other_target directives.
+      for (unsigned j = i+1; j != e; ++j) {
+        llvm::StringMap<std::string>::iterator I =
+          SecondaryDefines[j].find(DefStart, DefEnd);
+        if (I != SecondaryDefines[j].end())
+          SecondaryDefines[j].erase(I);
+      }
+      Defs.erase(Defs.begin());
+    }
+  }
+  
+  delete[] SecondaryDefines;
+}
+
+/// ComputeWCharWidth - Determine the width of the wchar_t type for the primary
+/// target, diagnosing whether this is non-portable across the secondary
+/// targets.
+void TargetInfo::ComputeWCharInfo(SourceLocation Loc) {
+  PrimaryTarget->getWCharInfo(WCharWidth, WCharAlign);
+  
+  // Check whether this is portable across the secondary targets if the T-U is
+  // portable so far.
+  for (unsigned i = 0, e = SecondaryTargets.size(); i != e; ++i) {
+    unsigned Width, Align;
+    SecondaryTargets[i]->getWCharInfo(Width, Align);
+    if (Width != WCharWidth || Align != WCharAlign)
+      return DiagnoseNonPortability(Loc, diag::port_wchar_t);
+  }
+}
+
+
+/// getTargetBuiltins - Return information about target-specific builtins for
+/// the current primary target, and info about which builtins are non-portable
+/// across the current set of primary and secondary targets.
+void TargetInfo::getTargetBuiltins(const Builtin::Info *&Records,
+                                   unsigned &NumRecords,
+                                   std::vector<const char *> &NPortable) const {
+  // Get info about what actual builtins we will expose.
+  PrimaryTarget->getTargetBuiltins(Records, NumRecords);
+  if (SecondaryTargets.empty()) return;
+ 
+  // Compute the set of non-portable builtins.
+  
+  // Start by computing a mapping from the primary target's builtins to their
+  // info records for efficient lookup.
+  llvm::StringMap<const Builtin::Info*> PrimaryRecs;
+  for (unsigned i = 0, e = NumRecords; i != e; ++i) {
+    const char *BIName = Records[i].Name;
+    PrimaryRecs.GetOrCreateValue(BIName, BIName+strlen(BIName)).getValue()
+      = Records+i;
+  }
+  
+  for (unsigned i = 0, e = SecondaryTargets.size(); i != e; ++i) {
+    // Get the builtins for this secondary target.
+    const Builtin::Info *Records2nd;
+    unsigned NumRecords2nd;
+    SecondaryTargets[i]->getTargetBuiltins(Records2nd, NumRecords2nd);
+    
+    // Remember all of the secondary builtin names.
+    std::set<std::string> BuiltinNames2nd;
+
+    for (unsigned j = 0, e = NumRecords2nd; j != e; ++j) {
+      BuiltinNames2nd.insert(Records2nd[j].Name);
+      
+      // Check to see if the primary target has this builtin.
+      llvm::StringMap<const Builtin::Info*>::iterator I =
+        PrimaryRecs.find(Records2nd[j].Name,
+                         Records2nd[j].Name+strlen(Records2nd[j].Name));
+      if (I != PrimaryRecs.end()) {
+        const Builtin::Info *PrimBI = I->getValue();
+        // If does.  If they are not identical, mark the builtin as being
+        // non-portable.
+        if (Records2nd[j] != *PrimBI)
+          NPortable.push_back(PrimBI->Name);
+      } else {
+        // The primary target doesn't have this, it is non-portable.
+        NPortable.push_back(Records2nd[j].Name);
+      }
+    }
+    
+    // Now that we checked all the secondary builtins, check to see if the
+    // primary target has any builtins that the secondary one doesn't.  If so,
+    // then those are non-portable.
+    for (unsigned j = 0, e = NumRecords; j != e; ++j) {
+      if (!BuiltinNames2nd.count(Records[j].Name))
+        NPortable.push_back(Records[j].Name);
+    }
+  }
+}
+
+