Revert "[-Wunsafe-buffer-usage] Initial commit - Transition away from raw buffers."

This reverts commit 200007ec85.

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

@@ -1,38 +0,0 @@
-//===- UnsafeBufferUsage.h - Replace pointers with modern C++ ---*- 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
-//
-//===----------------------------------------------------------------------===//
-//
-//  This file defines an analysis that aids replacing buffer accesses through
-//  raw pointers with safer C++ abstractions such as containers and views/spans.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_CLANG_ANALYSIS_ANALYSES_UNSAFEBUFFERUSAGE_H
-#define LLVM_CLANG_ANALYSIS_ANALYSES_UNSAFEBUFFERUSAGE_H
-
-#include "clang/ASTMatchers/ASTMatchFinder.h"
-
-namespace clang {
-
-/// The interface that lets the caller handle unsafe buffer usage analysis
-/// results by overriding this class's handle... methods.
-class UnsafeBufferUsageHandler {
-public:
-  UnsafeBufferUsageHandler() = default;
-  virtual ~UnsafeBufferUsageHandler() = default;
-
-  /// Invoked when an unsafe operation over raw pointers is found.
-  virtual void handleUnsafeOperation(const Stmt *Operation) = 0;
-};
-
-// This function invokes the analysis and allows the caller to react to it
-// through the handler class.
-void checkUnsafeBufferUsage(const Decl *D, UnsafeBufferUsageHandler &Handler);
-
-} // end namespace clang
-
-#endif /* LLVM_CLANG_ANALYSIS_ANALYSES_UNSAFEBUFFERUSAGE_H */

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -11732,9 +11732,4 @@ def err_cast_from_randomized_struct : Error<
 // LoongArch-specific Diagnostics
 def err_loongarch_builtin_requires_la64 : Error<
   "this builtin requires target: loongarch64">;
-
-// Unsafe buffer usage diagnostics.
-def warn_unsafe_buffer_usage : Warning<
-  "unchecked operation on raw buffer in expression">,
-  InGroup<DiagGroup<"unsafe-buffer-usage">>, DefaultIgnore;
 } // end of sema component.

clang/lib/Analysis/CMakeLists.txt

@@ -32,7 +32,6 @@ add_clang_library(clangAnalysis
   ThreadSafetyLogical.cpp
   ThreadSafetyTIL.cpp
   UninitializedValues.cpp
-  UnsafeBufferUsage.cpp
 
   LINK_LIBS
   clangAST

clang/lib/Analysis/UnsafeBufferUsage.cpp

@@ -1,79 +0,0 @@
-//===- UnsafeBufferUsage.cpp - Replace pointers with modern 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
-//
-//===----------------------------------------------------------------------===//
-
-#include "clang/Analysis/Analyses/UnsafeBufferUsage.h"
-#include "llvm/ADT/SmallVector.h"
-
-using namespace llvm;
-using namespace clang;
-using namespace ast_matchers;
-
-namespace {
-// TODO: Better abstractions over gadgets.
-using GadgetList = std::vector<const Stmt *>;
-}
-
-// Scan the function and return a list of gadgets found with provided kits.
-static GadgetList findGadgets(const Decl *D) {
-
-  class GadgetFinderCallback : public MatchFinder::MatchCallback {
-    GadgetList &Output;
-
-  public:
-    GadgetFinderCallback(GadgetList &Output) : Output(Output) {}
-
-    void run(const MatchFinder::MatchResult &Result) override {
-      Output.push_back(Result.Nodes.getNodeAs<Stmt>("root_node"));
-    }
-  };
-
-  GadgetList G;
-  MatchFinder M;
-
-  auto IncrementMatcher = unaryOperator(
-    hasOperatorName("++"),
-    hasUnaryOperand(hasType(pointerType()))
-  );
-  auto DecrementMatcher = unaryOperator(
-    hasOperatorName("--"),
-    hasUnaryOperand(hasType(pointerType()))
-  );
-
-  GadgetFinderCallback CB(G);
-
-  M.addMatcher(
-      stmt(forEachDescendant(
-        stmt(
-          anyOf(
-            IncrementMatcher,
-            DecrementMatcher
-            /* Fill me in! */
-          )
-          // FIXME: Idiomatically there should be a forCallable(equalsNode(D))
-          // here, to make sure that the statement actually belongs to the
-          // function and not to a nested function. However, forCallable uses
-          // ParentMap which can't be used before the AST is fully constructed.
-          // The original problem doesn't sound like it needs ParentMap though,
-          // maybe there's a more direct solution?
-        ).bind("root_node")
-      )), &CB);
-
-  M.match(*D->getBody(), D->getASTContext());
-
-  return G; // NRVO!
-}
-
-void clang::checkUnsafeBufferUsage(const Decl *D,
-                                   UnsafeBufferUsageHandler &Handler) {
-  assert(D && D->getBody());
-
-  GadgetList G = findGadgets(D);
-  for (const Stmt *S : G) {
-    Handler.handleUnsafeOperation(S);
-  }
-}

clang/lib/Sema/AnalysisBasedWarnings.cpp

@@ -29,7 +29,6 @@
 #include "clang/Analysis/Analyses/ReachableCode.h"
 #include "clang/Analysis/Analyses/ThreadSafety.h"
 #include "clang/Analysis/Analyses/UninitializedValues.h"
-#include "clang/Analysis/Analyses/UnsafeBufferUsage.h"
 #include "clang/Analysis/AnalysisDeclContext.h"
 #include "clang/Analysis/CFG.h"
 #include "clang/Analysis/CFGStmtMap.h"
@@ -2139,23 +2138,6 @@ public:
 } // namespace consumed
 } // namespace clang
 
-//===----------------------------------------------------------------------===//
-// Unsafe buffer usage analysis.
-//===----------------------------------------------------------------------===//
-
-class UnsafeBufferUsageReporter : public UnsafeBufferUsageHandler {
-  Sema &S;
-
-public:
-  UnsafeBufferUsageReporter(Sema &S) : S(S) {}
-
-  void handleUnsafeOperation(const Stmt *Operation) override {
-    S.Diag(Operation->getBeginLoc(), diag::warn_unsafe_buffer_usage)
-        << Operation->getSourceRange();
-  }
-};
-
-
 //===----------------------------------------------------------------------===//
 // AnalysisBasedWarnings - Worker object used by Sema to execute analysis-based
 //  warnings on a function, method, or block.
@@ -2448,12 +2430,6 @@ void clang::sema::AnalysisBasedWarnings::IssueWarnings(
       if (S.getLangOpts().CPlusPlus && isNoexcept(FD))
         checkThrowInNonThrowingFunc(S, FD, AC);
 
-  // Emit unsafe buffer usage warnings and fixits.
-  if (!Diags.isIgnored(diag::warn_unsafe_buffer_usage, D->getBeginLoc())) {
-    UnsafeBufferUsageReporter R(S);
-    checkUnsafeBufferUsage(D, R);
-  }
-
   // If none of the previous checks caused a CFG build, trigger one here
   // for the logical error handler.
   if (LogicalErrorHandler::hasActiveDiagnostics(Diags, D->getBeginLoc())) {

clang/test/SemaCXX/warn-unsafe-buffer-usage.cpp

@@ -1,8 +0,0 @@
-// RUN: %clang_cc1 -Wunsafe-buffer-usage -verify %s
-
-void testIncrement(char *p) {
-  ++p; // expected-warning{{unchecked operation on raw buffer in expression}}
-  p++; // expected-warning{{unchecked operation on raw buffer in expression}}
-  --p; // expected-warning{{unchecked operation on raw buffer in expression}}
-  p--; // expected-warning{{unchecked operation on raw buffer in expression}}
-}