Mark functions with bounds attributes to process in...

importBoundsAttributes

This allows an early exit without redundant processing or extra
allocations.

Author: hnrklssn

lib/ClangImporter/ImportDecl.cpp

@@ -8439,22 +8439,26 @@ ClangImporter::Implementation::importSwiftAttrAttributes(Decl *MappedDecl) {
 }
 
 namespace {
-class PointerParamInfo {
+class PointerParamInfoPrinter {
 public:
-  virtual void print(clang::ASTContext &ctx, llvm::raw_ostream &out) const = 0;
-  virtual ~PointerParamInfo() = default;
-};
+  clang::ASTContext &ctx;
+  llvm::raw_ostream &out;
+  bool firstParam = true;
+  PointerParamInfoPrinter(clang::ASTContext &ctx, llvm::raw_ostream &out)
+      : ctx(ctx), out(out) {
+    out << "@PointerBounds(";
+  }
+  ~PointerParamInfoPrinter() { out << ")"; }
 
-class CountedByParam : public PointerParamInfo {
-public:
-  size_t pointerIndex;
-  clang::Expr *countExpr;
-  bool isSizedBy;
-  CountedByParam(size_t idx, clang::Expr *E, bool sizedBy)
-      : pointerIndex(idx), countExpr(E), isSizedBy(sizedBy) {}
-
-  virtual void print(clang::ASTContext &ctx,
-                     llvm::raw_ostream &out) const override {
+  void printCountedBy(const clang::CountAttributedType *CAT,
+                      size_t pointerIndex) {
+    if (!firstParam) {
+      out << ", ";
+    } else {
+      firstParam = false;
+    }
+    clang::Expr *countExpr = CAT->getCountExpr();
+    bool isSizedBy = CAT->isCountInBytes();
     out << ".";
     if (isSizedBy)
       out << "sizedBy";
@@ -8470,7 +8474,6 @@ class CountedByParam : public PointerParamInfo {
         out, {}, {ctx.getLangOpts()}); // TODO: map clang::Expr to Swift Expr
     out << "\")";
   }
-  virtual ~CountedByParam() {}
 };
 } // namespace
 
@@ -8480,31 +8483,21 @@ void ClangImporter::Implementation::importBoundsAttributes(
       dyn_cast_or_null<clang::FunctionDecl>(MappedDecl->getClangDecl());
   if (!ClangDecl)
     return;
-
-  SmallVector<PointerParamInfo *, 4> BoundsInfo;
-  size_t parameterIndex = 1;
-  for (auto param : ClangDecl->parameters()) {
-    if (auto CAT = param->getType()->getAs<clang::CountAttributedType>()) {
-      BoundsInfo.push_back(new CountedByParam(
-          parameterIndex, CAT->getCountExpr(), CAT->isCountInBytes()));
-    }
-    parameterIndex++;
-  }
-  if (BoundsInfo.empty())
+  if (!funcsWithPointerBounds.count(ClangDecl))
     return;
 
   llvm::SmallString<128> MacroString;
   {
     llvm::raw_svector_ostream out(MacroString);
 
-    out << "@PointerBounds(";
-    for (size_t i = 0; i < BoundsInfo.size(); i++) {
-      BoundsInfo[i]->print(getClangASTContext(), out);
-      if (i + 1 < BoundsInfo.size()) {
-        out << ", ";
+    size_t parameterIndex = 1;
+    PointerParamInfoPrinter printer(getClangASTContext(), out);
+    for (auto param : ClangDecl->parameters()) {
+      if (auto CAT = param->getType()->getAs<clang::CountAttributedType>()) {
+        printer.printCountedBy(CAT, parameterIndex);
       }
+      parameterIndex++;
     }
-    out << ")";
   }
 
   // Dig out a buffer with the attribute text.

lib/ClangImporter/ImportType.cpp

@@ -2428,6 +2428,9 @@ ClangImporter::Implementation::importParameterType(
     // Treat as a normal pointer. importBoundsAttributes() will generate a safe
     // overload later.
     paramTy = CAT->desugar();
+    if (auto FuncD =
+            dyn_cast<clang::FunctionDecl>(param->getParentFunctionOrMethod()))
+      funcsWithPointerBounds.insert(FuncD);
   } else if (isa<clang::PointerType>(paramTy) &&
              isa<clang::TemplateTypeParmType>(paramTy->getPointeeType())) {
     auto pointeeType = paramTy->getPointeeType();

lib/ClangImporter/ImporterImpl.h

@@ -545,6 +545,8 @@ class LLVM_LIBRARY_VISIBILITY ClangImporter::Implementation
   /// used when parsing the attribute text.
   llvm::SmallDenseMap<unsigned, SourceFile *> ClangSwiftAttrSourceFiles;
 
+  llvm::SmallPtrSet<const clang::FunctionDecl *, 16> funcsWithPointerBounds;
+
 public:
   /// The Swift lookup table for the bridging header.
   std::unique_ptr<SwiftLookupTable> BridgingHeaderLookupTable;