11#include " CIRGenTBAA.h"
2- #include " CIRGenCXXABI.h"
32#include " CIRGenTypes.h"
43#include " mlir/IR/BuiltinAttributes.h"
54#include " mlir/IR/MLIRContext.h"
65#include " mlir/Interfaces/DataLayoutInterfaces.h"
76#include " clang/AST/ASTContext.h"
87#include " clang/AST/RecordLayout.h"
8+ #include " clang/CIR/Dialect/IR/CIRTypes.h"
9+ #include " clang/CIR/MissingFeatures.h"
910#include " llvm/Support/ErrorHandling.h"
1011namespace clang ::CIRGen {
1112
@@ -21,44 +22,159 @@ CIRGenTBAA::CIRGenTBAA(mlir::MLIRContext *mlirContext,
2122 : mlirContext(mlirContext), astContext(astContext), types(types),
2223 moduleOp (moduleOp), codeGenOpts(codeGenOpts), features(features) {}
2324
25+ cir::TBAAAttr CIRGenTBAA::getChar () {
26+ return cir::TBAAScalarAttr::get (mlirContext,
27+ cir::IntType::get (mlirContext, 1 , true ));
28+ }
29+
30+ static bool typeHasMayAlias (clang::QualType qty) {
31+ // Tagged types have declarations, and therefore may have attributes.
32+ if (auto *td = qty->getAsTagDecl ())
33+ if (td->hasAttr <MayAliasAttr>())
34+ return true ;
35+
36+ // Also look for may_alias as a declaration attribute on a typedef.
37+ // FIXME: We should follow GCC and model may_alias as a type attribute
38+ // rather than as a declaration attribute.
39+ while (auto *tt = qty->getAs <TypedefType>()) {
40+ if (tt->getDecl ()->hasAttr <MayAliasAttr>())
41+ return true ;
42+ qty = tt->desugar ();
43+ }
44+ return false ;
45+ }
46+
47+ // / Check if the given type is a valid base type to be used in access tags.
48+ static bool isValidBaseType (clang::QualType qty) {
49+ if (const clang::RecordType *tty = qty->getAs <clang::RecordType>()) {
50+ const clang::RecordDecl *rd = tty->getDecl ()->getDefinition ();
51+ // Incomplete types are not valid base access types.
52+ if (!rd)
53+ return false ;
54+ if (rd->hasFlexibleArrayMember ())
55+ return false ;
56+ // rd can be struct, union, class, interface or enum.
57+ // For now, we only handle struct and class.
58+ if (rd->isStruct () || rd->isClass ())
59+ return true ;
60+ }
61+ return false ;
62+ }
63+
2464cir::TBAAAttr CIRGenTBAA::getTypeInfo (clang::QualType qty) {
25- return tbaa_NYI (mlirContext);
65+ // At -O0 or relaxed aliasing, TBAA is not emitted for regular types.
66+ if (codeGenOpts.OptimizationLevel == 0 || codeGenOpts.RelaxedAliasing ) {
67+ return nullptr ;
68+ }
69+
70+ // If the type has the may_alias attribute (even on a typedef), it is
71+ // effectively in the general char alias class.
72+ if (typeHasMayAlias (qty)) {
73+ assert (!cir::MissingFeatures::tbaaMayAlias ());
74+ return getChar ();
75+ }
76+ // We need this function to not fall back to returning the "omnipotent char"
77+ // type node for aggregate and union types. Otherwise, any dereference of an
78+ // aggregate will result into the may-alias access descriptor, meaning all
79+ // subsequent accesses to direct and indirect members of that aggregate will
80+ // be considered may-alias too.
81+ // function.
82+ if (isValidBaseType (qty)) {
83+ // TODO(cir): support TBAA with struct
84+ return tbaa_NYI (mlirContext);
85+ }
86+
87+ const clang::Type *ty = astContext.getCanonicalType (qty).getTypePtr ();
88+ if (metadataCache.contains (ty)) {
89+ return metadataCache[ty];
90+ }
91+
92+ // Note that the following helper call is allowed to add new nodes to the
93+ // cache, which invalidates all its previously obtained iterators. So we
94+ // first generate the node for the type and then add that node to the
95+ // cache.
96+ auto typeNode = cir::TBAAScalarAttr::get (mlirContext, types.ConvertType (qty));
97+ return metadataCache[ty] = typeNode;
2698}
2799
28100TBAAAccessInfo CIRGenTBAA::getAccessInfo (clang::QualType accessType) {
29- return TBAAAccessInfo ();
101+ // Pointee values may have incomplete types, but they shall never be
102+ // dereferenced.
103+ if (accessType->isIncompleteType ()) {
104+ assert (!cir::MissingFeatures::tbaaIncompleteType ());
105+ return TBAAAccessInfo::getIncompleteInfo ();
106+ }
107+
108+ if (typeHasMayAlias (accessType)) {
109+ assert (!cir::MissingFeatures::tbaaMayAlias ());
110+ return TBAAAccessInfo::getMayAliasInfo ();
111+ }
112+
113+ uint64_t size = astContext.getTypeSizeInChars (accessType).getQuantity ();
114+ return TBAAAccessInfo (getTypeInfo (accessType), size);
30115}
31116
32117TBAAAccessInfo CIRGenTBAA::getVTablePtrAccessInfo (mlir::Type vtablePtrType) {
118+ // TODO(cir): support vtable ptr
119+ assert (!cir::MissingFeatures::tbaaVTablePtr ());
33120 return TBAAAccessInfo ();
34121}
35122
36123mlir::ArrayAttr CIRGenTBAA::getTBAAStructInfo (clang::QualType qty) {
37- return mlir::ArrayAttr::get (mlirContext, {});
124+ assert (!cir::MissingFeatures::tbaaStruct () && " tbaa.struct NYI"
125+ return mlir::ArrayAttr ();
38126}
39127
40128cir::TBAAAttr CIRGenTBAA::getBaseTypeInfo (clang::QualType qty) {
41129 return tbaa_NYI (mlirContext);
42130}
43131
44- mlir::ArrayAttr CIRGenTBAA::getAccessTagInfo (TBAAAccessInfo tbaaInfo) {
45- return mlir::ArrayAttr::get (mlirContext, {tbaa_NYI (mlirContext)});
132+ cir::TBAAAttr CIRGenTBAA::getAccessTagInfo (TBAAAccessInfo tbaaInfo) {
133+ assert (!tbaaInfo.isIncomplete () &&
134+ " Access to an object of an incomplete type!"
135+
136+ if (tbaaInfo.isMayAlias ()) {
137+ assert (!cir::MissingFeatures::tbaaMayAlias ());
138+ tbaaInfo = TBAAAccessInfo (getChar (), tbaaInfo.size );
139+ }
140+ if (!tbaaInfo.accessType ) {
141+ return nullptr ;
142+ }
143+
144+ if (!codeGenOpts.StructPathTBAA )
145+ tbaaInfo = TBAAAccessInfo (tbaaInfo.accessType , tbaaInfo.size );
146+
147+ if (!tbaaInfo.baseType ) {
148+ tbaaInfo.baseType = tbaaInfo.accessType ;
149+ assert (!tbaaInfo.offset &&
150+ " Nonzero offset for an access with no base type!"
151+ }
152+ if (codeGenOpts.NewStructPathTBAA ) {
153+ llvm_unreachable (" NYI"
154+ }
155+ if (tbaaInfo.baseType == tbaaInfo.accessType ) {
156+ return tbaaInfo.accessType ;
157+ }
158+ return tbaa_NYI (mlirContext);
46159}
47160
48161TBAAAccessInfo CIRGenTBAA::mergeTBAAInfoForCast (TBAAAccessInfo sourceInfo,
49162 TBAAAccessInfo targetInfo) {
163+ assert (!cir::MissingFeatures::tbaaMergeTBAAInfo ());
50164 return TBAAAccessInfo ();
51165}
52166
53167TBAAAccessInfo
54168CIRGenTBAA::mergeTBAAInfoForConditionalOperator (TBAAAccessInfo infoA,
55169 TBAAAccessInfo infoB) {
170+ assert (!cir::MissingFeatures::tbaaMergeTBAAInfo ());
56171 return TBAAAccessInfo ();
57172}
58173
59174TBAAAccessInfo
60175CIRGenTBAA::mergeTBAAInfoForMemoryTransfer (TBAAAccessInfo destInfo,
61176 TBAAAccessInfo srcInfo) {
177+ assert (!cir::MissingFeatures::tbaaMergeTBAAInfo ());
62178 return TBAAAccessInfo ();
63179}
64180
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