[clang][ssaf] Add UnsafeBufferUsage summary extractor for functions (#182941)

The UnsafeBufferUsage summary extract reuses -Wunsafe-buffer-usage to
find all unsafe pointers in functions and translates them to
entity-based representation.

rdar://169191570

Author: ziqingluo-90

clang/include/clang/Analysis/Scalable/Analyses/UnsafeBufferUsage/UnsafeBufferUsage.h

@@ -12,7 +12,6 @@
 #include "clang/Analysis/Scalable/Model/EntityId.h"
 #include "clang/Analysis/Scalable/Model/SummaryName.h"
 #include "clang/Analysis/Scalable/TUSummary/EntitySummary.h"
-#include "llvm/ADT/iterator_range.h"
 #include <set>
 
 namespace clang::ssaf {
@@ -26,23 +25,19 @@ namespace clang::ssaf {
 /// *' of 'p'.
 ///
 /// An EntityPointerLevel can be identified by an EntityId and an unsigned
-/// integer indicating the pointer level: '(EntityId, PointerLevel)'.  An
-/// EntityPointerLevel 'P' is valid iff
-///   - 'P.EntityId' has a pointer type with at least 'P.PointerLevel' levels
-///     (This implies 'P.PointerLevel > 0');
-///   - 'P.EntityId' identifies an lvalue object and 'P.PointerLevel == 0'.
-/// The latter case represents address-of expressions.
+/// integer indicating the pointer level: '(EntityId, PointerLevel)'.
+/// An EntityPointerLevel 'P' is valid iff 'P.EntityId' has a pointer type with
+/// at least 'P.PointerLevel' levels (This implies 'P.PointerLevel > 0').
 ///
 /// For the same example 'int *p[10];', the EntityPointerLevels below are valid:
-/// '(p, 1)' is associated with 'int *[10]' of 'p';
-/// '(p, 2)' is associated with 'int *' of 'p';
-/// '(p, 0)' represents '&p'.
+/// - '(p, 2)' is associated with the 'int *' part of the declared type of 'p';
+/// - '(p, 1)' is associated with the 'int *[10]' part of the declared type of
+/// 'p'.
 class EntityPointerLevel {
   EntityId Entity;
   unsigned PointerLevel;
 
-  friend class UnsafeBufferUsageTUSummaryBuilder;
-  friend class UnsafeBufferUsageEntitySummary;
+  friend class UnsafeBufferUsageTUSummaryExtractor;
 
   EntityPointerLevel(EntityId Entity, unsigned PointerLevel)
       : Entity(Entity), PointerLevel(PointerLevel) {}
@@ -52,7 +47,8 @@ class EntityPointerLevel {
   unsigned getPointerLevel() const { return PointerLevel; }
 
   bool operator==(const EntityPointerLevel &Other) const {
-    return Entity == Other.Entity && PointerLevel == Other.PointerLevel;
+    return std::tie(Entity, PointerLevel) ==
+           std::tie(Other.Entity, Other.PointerLevel);
   }
 
   bool operator!=(const EntityPointerLevel &Other) const {
@@ -64,7 +60,8 @@ class EntityPointerLevel {
            std::tie(Other.Entity, Other.PointerLevel);
   }
 
-  // Comparator supporting partial comparison against EntityId:
+  /// Compares `EntityPointerLevel`s; additionally, partially compares
+  /// `EntityPointerLevel` with `EntityId`.
   struct Comparator {
     using is_transparent = void;
     bool operator()(const EntityPointerLevel &L,
@@ -88,32 +85,19 @@ using EntityPointerLevelSet =
 class UnsafeBufferUsageEntitySummary final : public EntitySummary {
   const EntityPointerLevelSet UnsafeBuffers;
 
-  friend class UnsafeBufferUsageTUSummaryBuilder;
+  friend class UnsafeBufferUsageTUSummaryExtractor;
 
-  UnsafeBufferUsageEntitySummary(EntityPointerLevelSet &&UnsafeBuffers)
+  UnsafeBufferUsageEntitySummary(EntityPointerLevelSet UnsafeBuffers)
       : EntitySummary(), UnsafeBuffers(std::move(UnsafeBuffers)) {}
 
 public:
-  using const_iterator = EntityPointerLevelSet::const_iterator;
-
-  const_iterator begin() const { return UnsafeBuffers.begin(); }
-  const_iterator end() const { return UnsafeBuffers.end(); }
-
-  const_iterator find(const EntityPointerLevel &V) const {
-    return UnsafeBuffers.find(V);
-  }
-
-  llvm::iterator_range<const_iterator> getSubsetOf(EntityId Entity) const {
-    return llvm::make_range(UnsafeBuffers.equal_range(Entity));
-  }
-
-  /// \return the size of the set of EntityLevelPointers, which represents the
-  /// set of unsafe buffers
-  size_t getNumUnsafeBuffers() { return UnsafeBuffers.size(); }
-
   SummaryName getSummaryName() const override {
     return SummaryName{"UnsafeBufferUsage"};
   };
+
+  bool operator==(const EntityPointerLevelSet &Other) const {
+    return UnsafeBuffers == Other;
+  }
 };
 } // namespace clang::ssaf
 

…feBufferUsage/UnsafeBufferUsageBuilder.h …BufferUsage/UnsafeBufferUsageExtractor.hclang/include/clang/Analysis/Scalable/Analyses/UnsafeBufferUsage/UnsafeBufferUsageBuilder.h renamed to clang/include/clang/Analysis/Scalable/Analyses/UnsafeBufferUsage/UnsafeBufferUsageExtractor.h clang/include/clang/Analysis/Scalable/Analyses/UnsafeBufferUsage/UnsafeBufferUsageBuilder.h renamed to clang/include/clang/Analysis/Scalable/Analyses/UnsafeBufferUsage/UnsafeBufferUsageExtractor.h

@@ -1,31 +1,40 @@
-//===- UnsafeBufferUsageBuilder.h -------------------------------*- C++ -*-===//
+//===- UnsafeBufferUsageExtractor.h -----------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
-#ifndef LLVM_CLANG_ANALYSIS_SCALABLE_ANALYSES_UNSAFEBUFFERUSAGE_UNSAFEBUFFERUSAGEBUILDER_H
-#define LLVM_CLANG_ANALYSIS_SCALABLE_ANALYSES_UNSAFEBUFFERUSAGE_UNSAFEBUFFERUSAGEBUILDER_H
+#ifndef LLVM_CLANG_ANALYSIS_SCALABLE_ANALYSES_UNSAFEBUFFERUSAGE_UNSAFEBUFFERUSAGEEXTRACTOR_H
+#define LLVM_CLANG_ANALYSIS_SCALABLE_ANALYSES_UNSAFEBUFFERUSAGE_UNSAFEBUFFERUSAGEEXTRACTOR_H
 
 #include "clang/Analysis/Scalable/Analyses/UnsafeBufferUsage/UnsafeBufferUsage.h"
+#include "clang/Analysis/Scalable/Model/EntityId.h"
+#include "clang/Analysis/Scalable/Model/EntityName.h"
 #include "clang/Analysis/Scalable/TUSummary/TUSummaryBuilder.h"
+#include "clang/Analysis/Scalable/TUSummary/TUSummaryExtractor.h"
+#include "llvm/Support/Error.h"
 #include <memory>
 
 namespace clang::ssaf {
-class UnsafeBufferUsageTUSummaryBuilder : public TUSummaryBuilder {
+class UnsafeBufferUsageTUSummaryExtractor : public TUSummaryExtractor {
 public:
+  UnsafeBufferUsageTUSummaryExtractor(TUSummaryBuilder &Builder)
+      : TUSummaryExtractor(Builder) {}
+
   static EntityPointerLevel buildEntityPointerLevel(EntityId Entity,
                                                     unsigned PointerLevel) {
     return {Entity, PointerLevel};
   }
 
-  static std::unique_ptr<UnsafeBufferUsageEntitySummary>
-  buildUnsafeBufferUsageEntitySummary(EntityPointerLevelSet &&UnsafeBuffers) {
-    return std::make_unique<UnsafeBufferUsageEntitySummary>(
-        UnsafeBufferUsageEntitySummary(std::move(UnsafeBuffers)));
-  }
+  EntityId addEntity(EntityName EN) { return SummaryBuilder.addEntity(EN); }
+
+  std::unique_ptr<UnsafeBufferUsageEntitySummary>
+  extractEntitySummary(const Decl *Contributor, ASTContext &Ctx,
+                       llvm::Error &Error);
+
+  void HandleTranslationUnit(ASTContext &Ctx) override;
 };
 } // namespace clang::ssaf
 
-#endif // LLVM_CLANG_ANALYSIS_SCALABLE_ANALYSES_UNSAFEBUFFERUSAGE_UNSAFEBUFFERUSAGEBUILDER_H
+#endif // LLVM_CLANG_ANALYSIS_SCALABLE_ANALYSES_UNSAFEBUFFERUSAGE_UNSAFEBUFFERUSAGEEXTRACTOR_H