Commit Graph

807 Commits

Author SHA1 Message Date
Ulrich Weigand fa80642205 Allow targets to define minimum alignment for global variables
This patch adds a new common code feature that allows platform code to
request minimum alignment of global symbols.  The background for this is
that on SystemZ, the most efficient way to load addresses of global symbol
is the LOAD ADDRESS RELATIVE LONG (LARL) instruction.  This instruction
provides PC-relative addressing, but only to *even* addresses.  For this
reason, existing compilers will guarantee that global symbols are always
aligned to at least 2.  [ Since symbols would otherwise already use a
default alignment based on their type, this will usually only affect global
objects of character type or character arrays. ]  GCC also allows creating
symbols without that extra alignment by using explicit "aligned" attributes
(which then need to be used on both definition and each use of the symbol).

To enable support for this with Clang, this patch adds a
TargetInfo::MinGlobalAlign variable that provides a global minimum for the
alignment of every global object (unless overridden via explicit alignment
attribute), and adds code to respect this setting.  Within this patch, no
platform actually sets the value to anything but the default 1, resulting
in no change in behaviour on any existing target.

This version of the patch incorporates feedback from reviews by
Eric Christopher and John McCall.  Thanks to all reviewers!

Patch by Richard Sandiford.

llvm-svn: 181210
2013-05-06 16:23:57 +00:00
Rafael Espindola 593537a979 Make all 'is in extern "C"' tests use the lexical context.
I was not able to find a case (other than the fix in r181163) where this
makes a difference, but it is a more obviously correct API to have.

llvm-svn: 181165
2013-05-05 20:15:21 +00:00
Enea Zaffanella acb8ecd664 In VarDecl nodes, store the thread storage class specifier as written.
llvm-svn: 181113
2013-05-04 08:27:07 +00:00
Bill Wendling 95cae88bcf Use the Itanium ABI for thread_local on Darwin.
After some discussion, it was decided to use the Itanium ABI for thread_local on
Darwin OS X platforms. This involved a couple of changes. First, we use
"_tlv_atexit" instead of "__cxa_thread_atexit". Secondly, the global variables
are marked with 'internal' linkage, because we want all access to be calls to
the Itanium-specific entry point, which has normal linkage.
<rdar://problem/13733006>

llvm-svn: 180941
2013-05-02 19:18:03 +00:00
Richard Smith e6c878c0c6 Revert r180739 and r180748: they broke C++11 thread_local on non-Darwin systems and did not do the right thing on Darwin.
Original commit message:

Emit the TLS intialization functions into a list.

Add the TLS initialization functions to a list of initialization functions. The
back-end takes this list and places the function pointers into the correct
section. This way they're called before `main().'

<rdar://problem/13733006>

llvm-svn: 180809
2013-04-30 21:34:13 +00:00
Bill Wendling 96a77693be Emit the TLS intialization functions into a list.
Add the TLS initialization functions to a list of initialization functions. The
back-end takes this list and places the function pointers into the correct
section. This way they're called before `main().'

<rdar://problem/13733006>

llvm-svn: 180739
2013-04-29 22:27:16 +00:00
David Blaikie 60a9fbf921 Support debug info for using directives at global/namespace scope.
llvm-svn: 180594
2013-04-26 05:41:06 +00:00
Richard Smith 1847baa20e Don't emit _ZTW wrappers for TLS variables which don't use the C++ thread_local keyword.
llvm-svn: 180004
2013-04-22 08:06:17 +00:00
Richard Smith 2fd1d7aee3 Implement CodeGen for C++11 thread_local, following the Itanium ABI specification as discussed on cxx-abi-dev.
llvm-svn: 179858
2013-04-19 16:42:07 +00:00
John McCall 568d4100e7 Don't propagate around TargetOptions in IR-gen; we don't use it.
Patch by Stephen Lin!

llvm-svn: 179639
2013-04-16 22:48:20 +00:00
John McCall c8e0170578 Standardize accesses to the TargetInfo in IR-gen.
Patch by Stephen Lin!

llvm-svn: 179638
2013-04-16 22:48:15 +00:00
Daniel Dunbar e246fbe40b [Modules] Convert module specific -fno-modules-autolink into -fno-autolink.
- There is no reason to have a modules specific flag for disabling
   autolinking. Instead, convert the existing flag into -fno-autolink (which
   should cover other autolinking code generation paths like #pragmas if and
   when we support them).

llvm-svn: 179612
2013-04-16 18:21:19 +00:00
Fariborz Jahanian d1b6778e69 Objective-C IRGen. Use llvm::WeakVH
for caching couple of global symbols used
for generation of CF/NS string meta-data
so they are not released prematuely in certain
corner cases. // rdar:// 13598026.
Reviewed by John M.

llvm-svn: 179599
2013-04-16 15:25:39 +00:00
Richard Smith dbf74baee5 CodeGen support for function-local static thread_local variables with
non-constant constructors or non-trivial destructors. Plus bugfixes for
thread_local references bound to temporaries (the temporaries themselves are
lifetime-extended to become thread_local), and the corresponding case for
std::initializer_list.

llvm-svn: 179496
2013-04-14 23:01:42 +00:00
Richard Smith fd3834f7a1 Annotate flavor of TLS variable (statically or dynamically initialized) onto the AST.
llvm-svn: 179447
2013-04-13 02:43:54 +00:00
Richard Smith f21c9617f8 Use MapVector rather than simulating it.
llvm-svn: 179438
2013-04-13 01:28:18 +00:00
Manman Ren e1ad74e6fd Struct-path aware TBAA: uniformize scalar tag and path tag.
For struct-path aware TBAA, we used to use scalar type node as the scalar tag,
which has an incompatible format with the struct path tag. We now use the same
format: base type, access type and offset.

We also uniformize the scalar type node and the struct type node: name, a list
of pairs (offset + pointer to MDNode). For scalar type, we have a single pair.
These are to make implementaiton of aliasing rules easier.

llvm-svn: 179335
2013-04-11 23:02:56 +00:00
Richard Smith 85465e608d Remove nondeterminism introduced in r178950.
llvm-svn: 178952
2013-04-06 07:07:44 +00:00
Richard Smith df931ce82c When an internal-linkage function or variable is declared within an extern "C"
linkage specification, and is marked as __attribute__((used)), try to also give
it the unmangled name (by emitting an internal linkage alias) if nothing else
within the translation unit would use that name. This allows inline asm in that
translation unit to use the entity via its unmangled name, which people
apparently rely on.

llvm-svn: 178950
2013-04-06 05:00:46 +00:00
Manman Ren c451e5766e Initial support for struct-path aware TBAA.
Added TBAABaseType and TBAAOffset in LValue. These two fields are initialized to
the actual type and 0, and are updated in EmitLValueForField.
Path-aware TBAA tags are enabled for EmitLoadOfScalar and EmitStoreOfScalar.
Added command line option -struct-path-tbaa.

llvm-svn: 178797
2013-04-04 21:53:22 +00:00
Manman Ren 092d9e8f3b revert r178784 since it does not have a commit message
llvm-svn: 178796
2013-04-04 21:51:07 +00:00
Manman Ren 037d2b252d Index: include/clang/Driver/CC1Options.td
===================================================================
--- include/clang/Driver/CC1Options.td	(revision 178718)
+++ include/clang/Driver/CC1Options.td	(working copy)
@@ -161,6 +161,8 @@
   HelpText<"Use register sized accesses to bit-fields, when possible.">;
 def relaxed_aliasing : Flag<["-"], "relaxed-aliasing">,
   HelpText<"Turn off Type Based Alias Analysis">;
+def struct_path_tbaa : Flag<["-"], "struct-path-tbaa">,
+  HelpText<"Turn on struct-path aware Type Based Alias Analysis">;
 def masm_verbose : Flag<["-"], "masm-verbose">,
   HelpText<"Generate verbose assembly output">;
 def mcode_model : Separate<["-"], "mcode-model">,
Index: include/clang/Driver/Options.td
===================================================================
--- include/clang/Driver/Options.td	(revision 178718)
+++ include/clang/Driver/Options.td	(working copy)
@@ -587,6 +587,7 @@
   Flags<[CC1Option]>, HelpText<"Disable spell-checking">;
 def fno_stack_protector : Flag<["-"], "fno-stack-protector">, Group<f_Group>;
 def fno_strict_aliasing : Flag<["-"], "fno-strict-aliasing">, Group<f_Group>;
+def fstruct_path_tbaa : Flag<["-"], "fstruct-path-tbaa">, Group<f_Group>;
 def fno_strict_enums : Flag<["-"], "fno-strict-enums">, Group<f_Group>;
 def fno_strict_overflow : Flag<["-"], "fno-strict-overflow">, Group<f_Group>;
 def fno_threadsafe_statics : Flag<["-"], "fno-threadsafe-statics">, Group<f_Group>,
Index: include/clang/Frontend/CodeGenOptions.def
===================================================================
--- include/clang/Frontend/CodeGenOptions.def	(revision 178718)
+++ include/clang/Frontend/CodeGenOptions.def	(working copy)
@@ -85,6 +85,7 @@
 VALUE_CODEGENOPT(OptimizeSize, 2, 0) ///< If -Os (==1) or -Oz (==2) is specified.
 CODEGENOPT(RelaxAll          , 1, 0) ///< Relax all machine code instructions.
 CODEGENOPT(RelaxedAliasing   , 1, 0) ///< Set when -fno-strict-aliasing is enabled.
+CODEGENOPT(StructPathTBAA    , 1, 0) ///< Whether or not to use struct-path TBAA.
 CODEGENOPT(SaveTempLabels    , 1, 0) ///< Save temporary labels.
 CODEGENOPT(SanitizeAddressZeroBaseShadow , 1, 0) ///< Map shadow memory at zero
                                                  ///< offset in AddressSanitizer.
Index: lib/CodeGen/CGExpr.cpp
===================================================================
--- lib/CodeGen/CGExpr.cpp	(revision 178718)
+++ lib/CodeGen/CGExpr.cpp	(working copy)
@@ -1044,7 +1044,8 @@
 llvm::Value *CodeGenFunction::EmitLoadOfScalar(LValue lvalue) {
   return EmitLoadOfScalar(lvalue.getAddress(), lvalue.isVolatile(),
                           lvalue.getAlignment().getQuantity(),
-                          lvalue.getType(), lvalue.getTBAAInfo());
+                          lvalue.getType(), lvalue.getTBAAInfo(),
+                          lvalue.getTBAABaseType(), lvalue.getTBAAOffset());
 }
 
 static bool hasBooleanRepresentation(QualType Ty) {
@@ -1106,7 +1107,9 @@
 
 llvm::Value *CodeGenFunction::EmitLoadOfScalar(llvm::Value *Addr, bool Volatile,
                                               unsigned Alignment, QualType Ty,
-                                              llvm::MDNode *TBAAInfo) {
+                                              llvm::MDNode *TBAAInfo,
+                                              QualType TBAABaseType,
+                                              uint64_t TBAAOffset) {
   // For better performance, handle vector loads differently.
   if (Ty->isVectorType()) {
     llvm::Value *V;
@@ -1158,8 +1161,11 @@
     Load->setVolatile(true);
   if (Alignment)
     Load->setAlignment(Alignment);
-  if (TBAAInfo)
-    CGM.DecorateInstruction(Load, TBAAInfo);
+  if (TBAAInfo) {
+    llvm::MDNode *TBAAPath = CGM.getTBAAStructTagInfo(TBAABaseType, TBAAInfo,
+                                                      TBAAOffset);
+    CGM.DecorateInstruction(Load, TBAAPath);
+  }
 
   if ((SanOpts->Bool && hasBooleanRepresentation(Ty)) ||
       (SanOpts->Enum && Ty->getAs<EnumType>())) {
@@ -1217,7 +1223,8 @@
                                         bool Volatile, unsigned Alignment,
                                         QualType Ty,
                                         llvm::MDNode *TBAAInfo,
-                                        bool isInit) {
+                                        bool isInit, QualType TBAABaseType,
+                                        uint64_t TBAAOffset) {
   
   // Handle vectors differently to get better performance.
   if (Ty->isVectorType()) {
@@ -1268,15 +1275,19 @@
   llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
   if (Alignment)
     Store->setAlignment(Alignment);
-  if (TBAAInfo)
-    CGM.DecorateInstruction(Store, TBAAInfo);
+  if (TBAAInfo) {
+    llvm::MDNode *TBAAPath = CGM.getTBAAStructTagInfo(TBAABaseType, TBAAInfo,
+                                                      TBAAOffset);
+    CGM.DecorateInstruction(Store, TBAAPath);
+  }
 }
 
 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *value, LValue lvalue,
                                         bool isInit) {
   EmitStoreOfScalar(value, lvalue.getAddress(), lvalue.isVolatile(),
                     lvalue.getAlignment().getQuantity(), lvalue.getType(),
-                    lvalue.getTBAAInfo(), isInit);
+                    lvalue.getTBAAInfo(), isInit, lvalue.getTBAABaseType(),
+                    lvalue.getTBAAOffset());
 }
 
 /// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
@@ -2494,9 +2505,12 @@
 
   llvm::Value *addr = base.getAddress();
   unsigned cvr = base.getVRQualifiers();
+  bool TBAAPath = CGM.getCodeGenOpts().StructPathTBAA;
   if (rec->isUnion()) {
     // For unions, there is no pointer adjustment.
     assert(!type->isReferenceType() && "union has reference member");
+    // TODO: handle path-aware TBAA for union.
+    TBAAPath = false;
   } else {
     // For structs, we GEP to the field that the record layout suggests.
     unsigned idx = CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
@@ -2508,6 +2522,8 @@
       if (cvr & Qualifiers::Volatile) load->setVolatile(true);
       load->setAlignment(alignment.getQuantity());
 
+      // Loading the reference will disable path-aware TBAA.
+      TBAAPath = false;
       if (CGM.shouldUseTBAA()) {
         llvm::MDNode *tbaa;
         if (mayAlias)
@@ -2541,6 +2557,16 @@
 
   LValue LV = MakeAddrLValue(addr, type, alignment);
   LV.getQuals().addCVRQualifiers(cvr);
+  if (TBAAPath) {
+    const ASTRecordLayout &Layout =
+        getContext().getASTRecordLayout(field->getParent());
+    // Set the base type to be the base type of the base LValue and
+    // update offset to be relative to the base type.
+    LV.setTBAABaseType(base.getTBAABaseType());
+    LV.setTBAAOffset(base.getTBAAOffset() +
+                     Layout.getFieldOffset(field->getFieldIndex()) /
+                                           getContext().getCharWidth());
+  }
 
   // __weak attribute on a field is ignored.
   if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
Index: lib/CodeGen/CGValue.h
===================================================================
--- lib/CodeGen/CGValue.h	(revision 178718)
+++ lib/CodeGen/CGValue.h	(working copy)
@@ -157,6 +157,11 @@
 
   Expr *BaseIvarExp;
 
+  /// Used by struct-path-aware TBAA.
+  QualType TBAABaseType;
+  /// Offset relative to the base type.
+  uint64_t TBAAOffset;
+
   /// TBAAInfo - TBAA information to attach to dereferences of this LValue.
   llvm::MDNode *TBAAInfo;
 
@@ -175,6 +180,10 @@
     this->ImpreciseLifetime = false;
     this->ThreadLocalRef = false;
     this->BaseIvarExp = 0;
+
+    // Initialize fields for TBAA.
+    this->TBAABaseType = Type;
+    this->TBAAOffset = 0;
     this->TBAAInfo = TBAAInfo;
   }
 
@@ -232,6 +241,12 @@
   Expr *getBaseIvarExp() const { return BaseIvarExp; }
   void setBaseIvarExp(Expr *V) { BaseIvarExp = V; }
 
+  QualType getTBAABaseType() const { return TBAABaseType; }
+  void setTBAABaseType(QualType T) { TBAABaseType = T; }
+
+  uint64_t getTBAAOffset() const { return TBAAOffset; }
+  void setTBAAOffset(uint64_t O) { TBAAOffset = O; }
+
   llvm::MDNode *getTBAAInfo() const { return TBAAInfo; }
   void setTBAAInfo(llvm::MDNode *N) { TBAAInfo = N; }
 
Index: lib/CodeGen/CodeGenFunction.h
===================================================================
--- lib/CodeGen/CodeGenFunction.h	(revision 178718)
+++ lib/CodeGen/CodeGenFunction.h	(working copy)
@@ -2211,7 +2211,9 @@
   /// the LLVM value representation.
   llvm::Value *EmitLoadOfScalar(llvm::Value *Addr, bool Volatile,
                                 unsigned Alignment, QualType Ty,
-                                llvm::MDNode *TBAAInfo = 0);
+                                llvm::MDNode *TBAAInfo = 0,
+                                QualType TBAABaseTy = QualType(),
+                                uint64_t TBAAOffset = 0);
 
   /// EmitLoadOfScalar - Load a scalar value from an address, taking
   /// care to appropriately convert from the memory representation to
@@ -2224,7 +2226,9 @@
   /// the LLVM value representation.
   void EmitStoreOfScalar(llvm::Value *Value, llvm::Value *Addr,
                          bool Volatile, unsigned Alignment, QualType Ty,
-                         llvm::MDNode *TBAAInfo = 0, bool isInit=false);
+                         llvm::MDNode *TBAAInfo = 0, bool isInit = false,
+                         QualType TBAABaseTy = QualType(),
+                         uint64_t TBAAOffset = 0);
 
   /// EmitStoreOfScalar - Store a scalar value to an address, taking
   /// care to appropriately convert from the memory representation to
Index: lib/CodeGen/CodeGenModule.cpp
===================================================================
--- lib/CodeGen/CodeGenModule.cpp	(revision 178718)
+++ lib/CodeGen/CodeGenModule.cpp	(working copy)
@@ -227,6 +227,20 @@
   return TBAA->getTBAAStructInfo(QTy);
 }
 
+llvm::MDNode *CodeGenModule::getTBAAStructTypeInfo(QualType QTy) {
+  if (!TBAA)
+    return 0;
+  return TBAA->getTBAAStructTypeInfo(QTy);
+}
+
+llvm::MDNode *CodeGenModule::getTBAAStructTagInfo(QualType BaseTy,
+                                                  llvm::MDNode *AccessN,
+                                                  uint64_t O) {
+  if (!TBAA)
+    return 0;
+  return TBAA->getTBAAStructTagInfo(BaseTy, AccessN, O);
+}
+
 void CodeGenModule::DecorateInstruction(llvm::Instruction *Inst,
                                         llvm::MDNode *TBAAInfo) {
   Inst->setMetadata(llvm::LLVMContext::MD_tbaa, TBAAInfo);
Index: lib/CodeGen/CodeGenModule.h
===================================================================
--- lib/CodeGen/CodeGenModule.h	(revision 178718)
+++ lib/CodeGen/CodeGenModule.h	(working copy)
@@ -501,6 +501,11 @@
   llvm::MDNode *getTBAAInfo(QualType QTy);
   llvm::MDNode *getTBAAInfoForVTablePtr();
   llvm::MDNode *getTBAAStructInfo(QualType QTy);
+  /// Return the MDNode in the type DAG for the given struct type.
+  llvm::MDNode *getTBAAStructTypeInfo(QualType QTy);
+  /// Return the path-aware tag for given base type, access node and offset.
+  llvm::MDNode *getTBAAStructTagInfo(QualType BaseTy, llvm::MDNode *AccessN,
+                                     uint64_t O);
 
   bool isTypeConstant(QualType QTy, bool ExcludeCtorDtor);
 
Index: lib/CodeGen/CodeGenTBAA.cpp
===================================================================
--- lib/CodeGen/CodeGenTBAA.cpp	(revision 178718)
+++ lib/CodeGen/CodeGenTBAA.cpp	(working copy)
@@ -21,6 +21,7 @@
 #include "clang/AST/Mangle.h"
 #include "clang/AST/RecordLayout.h"
 #include "clang/Frontend/CodeGenOptions.h"
+#include "llvm/ADT/SmallSet.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Metadata.h"
@@ -225,3 +226,87 @@
   // For now, handle any other kind of type conservatively.
   return StructMetadataCache[Ty] = NULL;
 }
+
+/// Check if the given type can be handled by path-aware TBAA.
+static bool isTBAAPathStruct(QualType QTy) {
+  if (const RecordType *TTy = QTy->getAs<RecordType>()) {
+    const RecordDecl *RD = TTy->getDecl()->getDefinition();
+    // RD can be struct, union, class, interface or enum.
+    // For now, we only handle struct.
+    if (RD->isStruct() && !RD->hasFlexibleArrayMember())
+      return true;
+  }
+  return false;
+}
+
+llvm::MDNode *
+CodeGenTBAA::getTBAAStructTypeInfo(QualType QTy) {
+  const Type *Ty = Context.getCanonicalType(QTy).getTypePtr();
+  assert(isTBAAPathStruct(QTy));
+
+  if (llvm::MDNode *N = StructTypeMetadataCache[Ty])
+    return N;
+
+  if (const RecordType *TTy = QTy->getAs<RecordType>()) {
+    const RecordDecl *RD = TTy->getDecl()->getDefinition();
+
+    const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
+    SmallVector <std::pair<uint64_t, llvm::MDNode*>, 4> Fields;
+    // To reduce the size of MDNode for a given struct type, we only output
+    // once for all the fields with the same scalar types.
+    // Offsets for scalar fields in the type DAG are not used.
+    llvm::SmallSet <llvm::MDNode*, 4> ScalarFieldTypes;
+    unsigned idx = 0;
+    for (RecordDecl::field_iterator i = RD->field_begin(),
+         e = RD->field_end(); i != e; ++i, ++idx) {
+      QualType FieldQTy = i->getType();
+      llvm::MDNode *FieldNode;
+      if (isTBAAPathStruct(FieldQTy))
+        FieldNode = getTBAAStructTypeInfo(FieldQTy);
+      else {
+        FieldNode = getTBAAInfo(FieldQTy);
+        // Ignore this field if the type already exists.
+        if (ScalarFieldTypes.count(FieldNode))
+          continue;
+        ScalarFieldTypes.insert(FieldNode);
+       }
+      if (!FieldNode)
+        return StructTypeMetadataCache[Ty] = NULL;
+      Fields.push_back(std::make_pair(
+          Layout.getFieldOffset(idx) / Context.getCharWidth(), FieldNode));
+    }
+
+    // TODO: This is using the RTTI name. Is there a better way to get
+    // a unique string for a type?
+    SmallString<256> OutName;
+    llvm::raw_svector_ostream Out(OutName);
+    MContext.mangleCXXRTTIName(QualType(Ty, 0), Out);
+    Out.flush();
+    // Create the struct type node with a vector of pairs (offset, type).
+    return StructTypeMetadataCache[Ty] =
+      MDHelper.createTBAAStructTypeNode(OutName, Fields);
+  }
+
+  return StructMetadataCache[Ty] = NULL;
+}
+
+llvm::MDNode *
+CodeGenTBAA::getTBAAStructTagInfo(QualType BaseQTy, llvm::MDNode *AccessNode,
+                                  uint64_t Offset) {
+  if (!CodeGenOpts.StructPathTBAA)
+    return AccessNode;
+
+  const Type *BTy = Context.getCanonicalType(BaseQTy).getTypePtr();
+  TBAAPathTag PathTag = TBAAPathTag(BTy, AccessNode, Offset);
+  if (llvm::MDNode *N = StructTagMetadataCache[PathTag])
+    return N;
+
+  llvm::MDNode *BNode = 0;
+  if (isTBAAPathStruct(BaseQTy))
+    BNode  = getTBAAStructTypeInfo(BaseQTy);
+  if (!BNode)
+    return StructTagMetadataCache[PathTag] = AccessNode;
+
+  return StructTagMetadataCache[PathTag] =
+    MDHelper.createTBAAStructTagNode(BNode, AccessNode, Offset);
+}
Index: lib/CodeGen/CodeGenTBAA.h
===================================================================
--- lib/CodeGen/CodeGenTBAA.h	(revision 178718)
+++ lib/CodeGen/CodeGenTBAA.h	(working copy)
@@ -35,6 +35,14 @@
 namespace CodeGen {
   class CGRecordLayout;
 
+  struct TBAAPathTag {
+    TBAAPathTag(const Type *B, const llvm::MDNode *A, uint64_t O)
+      : BaseT(B), AccessN(A), Offset(O) {}
+    const Type *BaseT;
+    const llvm::MDNode *AccessN;
+    uint64_t Offset;
+  };
+
 /// CodeGenTBAA - This class organizes the cross-module state that is used
 /// while lowering AST types to LLVM types.
 class CodeGenTBAA {
@@ -46,8 +54,13 @@
   // MDHelper - Helper for creating metadata.
   llvm::MDBuilder MDHelper;
 
-  /// MetadataCache - This maps clang::Types to llvm::MDNodes describing them.
+  /// MetadataCache - This maps clang::Types to scalar llvm::MDNodes describing
+  /// them.
   llvm::DenseMap<const Type *, llvm::MDNode *> MetadataCache;
+  /// This maps clang::Types to a struct node in the type DAG.
+  llvm::DenseMap<const Type *, llvm::MDNode *> StructTypeMetadataCache;
+  /// This maps TBAAPathTags to a tag node.
+  llvm::DenseMap<TBAAPathTag, llvm::MDNode *> StructTagMetadataCache;
 
   /// StructMetadataCache - This maps clang::Types to llvm::MDNodes describing
   /// them for struct assignments.
@@ -89,9 +102,49 @@
   /// getTBAAStructInfo - Get the TBAAStruct MDNode to be used for a memcpy of
   /// the given type.
   llvm::MDNode *getTBAAStructInfo(QualType QTy);
+
+  /// Get the MDNode in the type DAG for given struct type QType.
+  llvm::MDNode *getTBAAStructTypeInfo(QualType QType);
+  /// Get the tag MDNode for a given base type, the actual sclar access MDNode
+  /// and offset into the base type.
+  llvm::MDNode *getTBAAStructTagInfo(QualType BaseQType,
+                                     llvm::MDNode *AccessNode, uint64_t Offset);
 };
 
 }  // end namespace CodeGen
 }  // end namespace clang
 
+namespace llvm {
+
+template<> struct DenseMapInfo<clang::CodeGen::TBAAPathTag> {
+  static clang::CodeGen::TBAAPathTag getEmptyKey() {
+    return clang::CodeGen::TBAAPathTag(
+      DenseMapInfo<const clang::Type *>::getEmptyKey(),
+      DenseMapInfo<const MDNode *>::getEmptyKey(),
+      DenseMapInfo<uint64_t>::getEmptyKey());
+  }
+
+  static clang::CodeGen::TBAAPathTag getTombstoneKey() {
+    return clang::CodeGen::TBAAPathTag(
+      DenseMapInfo<const clang::Type *>::getTombstoneKey(),
+      DenseMapInfo<const MDNode *>::getTombstoneKey(),
+      DenseMapInfo<uint64_t>::getTombstoneKey());
+  }
+
+  static unsigned getHashValue(const clang::CodeGen::TBAAPathTag &Val) {
+    return DenseMapInfo<const clang::Type *>::getHashValue(Val.BaseT) ^
+           DenseMapInfo<const MDNode *>::getHashValue(Val.AccessN) ^
+           DenseMapInfo<uint64_t>::getHashValue(Val.Offset);
+  }
+
+  static bool isEqual(const clang::CodeGen::TBAAPathTag &LHS,
+                      const clang::CodeGen::TBAAPathTag &RHS) {
+    return LHS.BaseT == RHS.BaseT &&
+           LHS.AccessN == RHS.AccessN &&
+           LHS.Offset == RHS.Offset;
+  }
+};
+
+}  // end namespace llvm
+
 #endif
Index: lib/Driver/Tools.cpp
===================================================================
--- lib/Driver/Tools.cpp	(revision 178718)
+++ lib/Driver/Tools.cpp	(working copy)
@@ -2105,6 +2105,8 @@
                     options::OPT_fno_strict_aliasing,
                     getToolChain().IsStrictAliasingDefault()))
     CmdArgs.push_back("-relaxed-aliasing");
+  if (Args.hasArg(options::OPT_fstruct_path_tbaa))
+    CmdArgs.push_back("-struct-path-tbaa");
   if (Args.hasFlag(options::OPT_fstrict_enums, options::OPT_fno_strict_enums,
                    false))
     CmdArgs.push_back("-fstrict-enums");
Index: lib/Frontend/CompilerInvocation.cpp
===================================================================
--- lib/Frontend/CompilerInvocation.cpp	(revision 178718)
+++ lib/Frontend/CompilerInvocation.cpp	(working copy)
@@ -324,6 +324,7 @@
   Opts.UseRegisterSizedBitfieldAccess = Args.hasArg(
     OPT_fuse_register_sized_bitfield_access);
   Opts.RelaxedAliasing = Args.hasArg(OPT_relaxed_aliasing);
+  Opts.StructPathTBAA = Args.hasArg(OPT_struct_path_tbaa);
   Opts.DwarfDebugFlags = Args.getLastArgValue(OPT_dwarf_debug_flags);
   Opts.MergeAllConstants = !Args.hasArg(OPT_fno_merge_all_constants);
   Opts.NoCommon = Args.hasArg(OPT_fno_common);
Index: test/CodeGen/tbaa.cpp
===================================================================
--- test/CodeGen/tbaa.cpp	(revision 0)
+++ test/CodeGen/tbaa.cpp	(working copy)
@@ -0,0 +1,217 @@
+// RUN: %clang_cc1 -O1 -disable-llvm-optzns %s -emit-llvm -o - | FileCheck %s
+// RUN: %clang_cc1 -O1 -struct-path-tbaa -disable-llvm-optzns %s -emit-llvm -o - | FileCheck %s -check-prefix=PATH
+// Test TBAA metadata generated by front-end.
+
+#include <stdint.h>
+typedef struct
+{
+   uint16_t f16;
+   uint32_t f32;
+   uint16_t f16_2;
+   uint32_t f32_2;
+} StructA;
+typedef struct
+{
+   uint16_t f16;
+   StructA a;
+   uint32_t f32;
+} StructB;
+typedef struct
+{
+   uint16_t f16;
+   StructB b;
+   uint32_t f32;
+} StructC;
+typedef struct
+{
+   uint16_t f16;
+   StructB b;
+   uint32_t f32;
+   uint8_t f8;
+} StructD;
+
+typedef struct
+{
+   uint16_t f16;
+   uint32_t f32;
+} StructS;
+typedef struct
+{
+   uint16_t f16;
+   uint32_t f32;
+} StructS2;
+
+uint32_t g(uint32_t *s, StructA *A, uint64_t count) {
+// CHECK: define i32 @{{.*}}(
+// CHECK: store i32 1, i32* %{{.*}}, align 4, !tbaa !4
+// CHECK: store i32 4, i32* %{{.*}}, align 4, !tbaa !4
+// PATH: define i32 @{{.*}}(
+// PATH: store i32 1, i32* %{{.*}}, align 4, !tbaa !4
+// PATH: store i32 4, i32* %{{.*}}, align 4, !tbaa !5
+  *s = 1;
+  A->f32 = 4;
+  return *s;
+}
+
+uint32_t g2(uint32_t *s, StructA *A, uint64_t count) {
+// CHECK: define i32 @{{.*}}(
+// CHECK: store i32 1, i32* %{{.*}}, align 4, !tbaa !4
+// CHECK: store i16 4, i16* %{{.*}}, align 2, !tbaa !5
+// PATH: define i32 @{{.*}}(
+// PATH: store i32 1, i32* %{{.*}}, align 4, !tbaa !4
+// PATH: store i16 4, i16* %{{.*}}, align 2, !tbaa !8
+  *s = 1;
+  A->f16 = 4;
+  return *s;
+}
+
+uint32_t g3(StructA *A, StructB *B, uint64_t count) {
+// CHECK: define i32 @{{.*}}(
+// CHECK: store i32 1, i32* %{{.*}}, align 4, !tbaa !4
+// CHECK: store i32 4, i32* %{{.*}}, align 4, !tbaa !4
+// PATH: define i32 @{{.*}}(
+// PATH: store i32 1, i32* %{{.*}}, align 4, !tbaa !5
+// PATH: store i32 4, i32* %{{.*}}, align 4, !tbaa !9
+  A->f32 = 1;
+  B->a.f32 = 4;
+  return A->f32;
+}
+
+uint32_t g4(StructA *A, StructB *B, uint64_t count) {
+// CHECK: define i32 @{{.*}}(
+// CHECK: store i32 1, i32* %{{.*}}, align 4, !tbaa !4
+// CHECK: store i16 4, i16* %{{.*}}, align 2, !tbaa !5
+// PATH: define i32 @{{.*}}(
+// PATH: store i32 1, i32* %{{.*}}, align 4, !tbaa !5
+// PATH: store i16 4, i16* %{{.*}}, align 2, !tbaa !11
+  A->f32 = 1;
+  B->a.f16 = 4;
+  return A->f32;
+}
+
+uint32_t g5(StructA *A, StructB *B, uint64_t count) {
+// CHECK: define i32 @{{.*}}(
+// CHECK: store i32 1, i32* %{{.*}}, align 4, !tbaa !4
+// CHECK: store i32 4, i32* %{{.*}}, align 4, !tbaa !4
+// PATH: define i32 @{{.*}}(
+// PATH: store i32 1, i32* %{{.*}}, align 4, !tbaa !5
+// PATH: store i32 4, i32* %{{.*}}, align 4, !tbaa !12
+  A->f32 = 1;
+  B->f32 = 4;
+  return A->f32;
+}
+
+uint32_t g6(StructA *A, StructB *B, uint64_t count) {
+// CHECK: define i32 @{{.*}}(
+// CHECK: store i32 1, i32* %{{.*}}, align 4, !tbaa !4
+// CHECK: store i32 4, i32* %{{.*}}, align 4, !tbaa !4
+// PATH: define i32 @{{.*}}(
+// PATH: store i32 1, i32* %{{.*}}, align 4, !tbaa !5
+// PATH: store i32 4, i32* %{{.*}}, align 4, !tbaa !13
+  A->f32 = 1;
+  B->a.f32_2 = 4;
+  return A->f32;
+}
+
+uint32_t g7(StructA *A, StructS *S, uint64_t count) {
+// CHECK: define i32 @{{.*}}(
+// CHECK: store i32 1, i32* %{{.*}}, align 4, !tbaa !4
+// CHECK: store i32 4, i32* %{{.*}}, align 4, !tbaa !4
+// PATH: define i32 @{{.*}}(
+// PATH: store i32 1, i32* %{{.*}}, align 4, !tbaa !5
+// PATH: store i32 4, i32* %{{.*}}, align 4, !tbaa !14
+  A->f32 = 1;
+  S->f32 = 4;
+  return A->f32;
+}
+
+uint32_t g8(StructA *A, StructS *S, uint64_t count) {
+// CHECK: define i32 @{{.*}}(
+// CHECK: store i32 1, i32* %{{.*}}, align 4, !tbaa !4
+// CHECK: store i16 4, i16* %{{.*}}, align 2, !tbaa !5
+// PATH: define i32 @{{.*}}(
+// PATH: store i32 1, i32* %{{.*}}, align 4, !tbaa !5
+// PATH: store i16 4, i16* %{{.*}}, align 2, !tbaa !16
+  A->f32 = 1;
+  S->f16 = 4;
+  return A->f32;
+}
+
+uint32_t g9(StructS *S, StructS2 *S2, uint64_t count) {
+// CHECK: define i32 @{{.*}}(
+// CHECK: store i32 1, i32* %{{.*}}, align 4, !tbaa !4
+// CHECK: store i32 4, i32* %{{.*}}, align 4, !tbaa !4
+// PATH: define i32 @{{.*}}(
+// PATH: store i32 1, i32* %{{.*}}, align 4, !tbaa !14
+// PATH: store i32 4, i32* %{{.*}}, align 4, !tbaa !17
+  S->f32 = 1;
+  S2->f32 = 4;
+  return S->f32;
+}
+
+uint32_t g10(StructS *S, StructS2 *S2, uint64_t count) {
+// CHECK: define i32 @{{.*}}(
+// CHECK: store i32 1, i32* %{{.*}}, align 4, !tbaa !4
+// CHECK: store i16 4, i16* %{{.*}}, align 2, !tbaa !5
+// PATH: define i32 @{{.*}}(
+// PATH: store i32 1, i32* %{{.*}}, align 4, !tbaa !14
+// PATH: store i16 4, i16* %{{.*}}, align 2, !tbaa !19
+  S->f32 = 1;
+  S2->f16 = 4;
+  return S->f32;
+}
+
+uint32_t g11(StructC *C, StructD *D, uint64_t count) {
+// CHECK: define i32 @{{.*}}(
+// CHECK: store i32 1, i32* %{{.*}}, align 4, !tbaa !4
+// CHECK: store i32 4, i32* %{{.*}}, align 4, !tbaa !4
+// PATH: define i32 @{{.*}}(
+// PATH: store i32 1, i32* %{{.*}}, align 4, !tbaa !20
+// PATH: store i32 4, i32* %{{.*}}, align 4, !tbaa !22
+  C->b.a.f32 = 1;
+  D->b.a.f32 = 4;
+  return C->b.a.f32;
+}
+
+uint32_t g12(StructC *C, StructD *D, uint64_t count) {
+// CHECK: define i32 @{{.*}}(
+// CHECK: store i32 1, i32* %{{.*}}, align 4, !tbaa !4
+// CHECK: store i32 4, i32* %{{.*}}, align 4, !tbaa !4
+// TODO: differentiate the two accesses.
+// PATH: define i32 @{{.*}}(
+// PATH: store i32 1, i32* %{{.*}}, align 4, !tbaa !9
+// PATH: store i32 4, i32* %{{.*}}, align 4, !tbaa !9
+  StructB *b1 = &(C->b);
+  StructB *b2 = &(D->b);
+  // b1, b2 have different context.
+  b1->a.f32 = 1;
+  b2->a.f32 = 4;
+  return b1->a.f32;
+}
+
+// CHECK: !1 = metadata !{metadata !"omnipotent char", metadata !2}
+// CHECK: !2 = metadata !{metadata !"Simple C/C++ TBAA"}
+// CHECK: !4 = metadata !{metadata !"int", metadata !1}
+// CHECK: !5 = metadata !{metadata !"short", metadata !1}
+
+// PATH: !1 = metadata !{metadata !"omnipotent char", metadata !2}
+// PATH: !4 = metadata !{metadata !"int", metadata !1}
+// PATH: !5 = metadata !{metadata !6, metadata !4, i64 4}
+// PATH: !6 = metadata !{metadata !"_ZTS7StructA", i64 0, metadata !7, i64 4, metadata !4}
+// PATH: !7 = metadata !{metadata !"short", metadata !1}
+// PATH: !8 = metadata !{metadata !6, metadata !7, i64 0}
+// PATH: !9 = metadata !{metadata !10, metadata !4, i64 8}
+// PATH: !10 = metadata !{metadata !"_ZTS7StructB", i64 0, metadata !7, i64 4, metadata !6, i64 20, metadata !4}
+// PATH: !11 = metadata !{metadata !10, metadata !7, i64 4}
+// PATH: !12 = metadata !{metadata !10, metadata !4, i64 20}
+// PATH: !13 = metadata !{metadata !10, metadata !4, i64 16}
+// PATH: !14 = metadata !{metadata !15, metadata !4, i64 4}
+// PATH: !15 = metadata !{metadata !"_ZTS7StructS", i64 0, metadata !7, i64 4, metadata !4}
+// PATH: !16 = metadata !{metadata !15, metadata !7, i64 0}
+// PATH: !17 = metadata !{metadata !18, metadata !4, i64 4}
+// PATH: !18 = metadata !{metadata !"_ZTS8StructS2", i64 0, metadata !7, i64 4, metadata !4}
+// PATH: !19 = metadata !{metadata !18, metadata !7, i64 0}
+// PATH: !20 = metadata !{metadata !21, metadata !4, i64 12}
+// PATH: !21 = metadata !{metadata !"_ZTS7StructC", i64 0, metadata !7, i64 4, metadata !10, i64 28, metadata !4}
+// PATH: !22 = metadata !{metadata !23, metadata !4, i64 12}
+// PATH: !23 = metadata !{metadata !"_ZTS7StructD", i64 0, metadata !7, i64 4, metadata !10, i64 28, metadata !4, i64 32, metadata !1}

llvm-svn: 178784
2013-04-04 20:14:17 +00:00
Rafael Espindola 6ae7e50be4 Add 178663 back.
http://lab.llvm.org:8011/builders/clang-x86_64-darwin10-gdb went back green
before it processed the reverted 178663, so it could not have been the culprit.

Revert "Revert 178663."

This reverts commit 4f8a3eb2ce5d4ba422483439e20c8cbb4d953a41.

llvm-svn: 178682
2013-04-03 19:27:57 +00:00
Rafael Espindola 985a3abee4 Revert 178663.
Looks like it broke http://lab.llvm.org:8011/builders/clang-x86_64-darwin10-gdb

Revert "Don't compute a patched/semantic storage class."

This reverts commit 8f187f62cb0487d31bc4afdfcd47e11fe9a51d05.

llvm-svn: 178681
2013-04-03 19:22:20 +00:00
Rafael Espindola adea16bd9e Don't compute a patched/semantic storage class.
For variables and functions clang used to store two storage classes. The one
"as written" in the code and a patched one, which, for example, propagates
static to the following decls.

This apparently is from the days clang lacked linkage computation. It is now
redundant and this patch removes it.

llvm-svn: 178663
2013-04-03 15:50:00 +00:00