1 files changed, 114 insertions, 0 deletions
diff --git a/clang-tools-extra/clang-tidy/misc/AssertSideEffectCheck.cpp b/clang-tools-extra/clang-tidy/misc/AssertSideEffectCheck.cpp
new file mode 100644
index 00000000000..9d21b499ee9
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/misc/AssertSideEffectCheck.cpp
@@ -0,0 +1,114 @@
+//===--- AssertSideEffectCheck.cpp - clang-tidy ---------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "AssertSideEffectCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Lex/Lexer.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/Casting.h"
+#include <algorithm>
+#include <string>
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace ast_matchers {
+
+AST_MATCHER_P(Expr, hasSideEffect, bool, CheckFunctionCalls) {
+  const Expr *E = &Node;
+
+  if (const auto *Op = dyn_cast<UnaryOperator>(E)) {
+    UnaryOperator::Opcode OC = Op->getOpcode();
+    return OC == UO_PostInc || OC == UO_PostDec || OC == UO_PreInc ||
+           OC == UO_PreDec;
+  }
+
+  if (const auto *Op = dyn_cast<BinaryOperator>(E)) {
+    BinaryOperator::Opcode OC = Op->getOpcode();
+    return OC == BO_Assign || OC == BO_MulAssign || OC == BO_DivAssign ||
+           OC == BO_RemAssign || OC == BO_AddAssign || OC == BO_SubAssign ||
+           OC == BO_ShlAssign || OC == BO_ShrAssign || OC == BO_AndAssign ||
+           OC == BO_XorAssign || OC == BO_OrAssign;
+  }
+
+  if (const auto *OpCallExpr = dyn_cast<CXXOperatorCallExpr>(E)) {
+    OverloadedOperatorKind OpKind = OpCallExpr->getOperator();
+    return OpKind == OO_Equal || OpKind == OO_PlusEqual ||
+           OpKind == OO_MinusEqual || OpKind == OO_StarEqual ||
+           OpKind == OO_SlashEqual || OpKind == OO_AmpEqual ||
+           OpKind == OO_PipeEqual || OpKind == OO_CaretEqual ||
+           OpKind == OO_LessLessEqual || OpKind == OO_GreaterGreaterEqual ||
+           OpKind == OO_PlusPlus || OpKind == OO_MinusMinus ||
+           OpKind == OO_PercentEqual || OpKind == OO_New ||
+           OpKind == OO_Delete || OpKind == OO_Array_New ||
+           OpKind == OO_Array_Delete;
+  }
+
+  if (const auto *CExpr = dyn_cast<CallExpr>(E)) {
+    bool Result = CheckFunctionCalls;
+    if (const auto *FuncDecl = CExpr->getDirectCallee())
+      if (const auto *MethodDecl = dyn_cast<CXXMethodDecl>(FuncDecl))
+        Result &= !MethodDecl->isConst();
+    return Result;
+  }
+
+  return isa<CXXNewExpr>(E) || isa<CXXDeleteExpr>(E) || isa<CXXThrowExpr>(E);
+}
+
+} // namespace ast_matchers
+
+namespace tidy {
+
+AssertSideEffectCheck::AssertSideEffectCheck(StringRef Name,
+                                             ClangTidyContext *Context)
+    : ClangTidyCheck(Name, Context),
+      CheckFunctionCalls(Options.get("CheckFunctionCalls", false)),
+      RawAssertList(Options.get("AssertMacros", "assert")) {
+  StringRef(RawAssertList).split(AssertMacros, ",", -1, false);
+}
+
+// The options are explained in AssertSideEffectCheck.h.
+void AssertSideEffectCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
+  Options.store(Opts, "CheckFunctionCalls", CheckFunctionCalls);
+  Options.store(Opts, "AssertMacros", RawAssertList);
+}
+
+void AssertSideEffectCheck::registerMatchers(MatchFinder *Finder) {
+  auto ConditionWithSideEffect =
+      hasCondition(hasDescendant(expr(hasSideEffect(CheckFunctionCalls))));
+  Finder->addMatcher(
+      stmt(anyOf(conditionalOperator(ConditionWithSideEffect),
+                 ifStmt(ConditionWithSideEffect))).bind("condStmt"),
+      this);
+}
+
+void AssertSideEffectCheck::check(const MatchFinder::MatchResult &Result) {
+  const ASTContext *ASTCtx = Result.Context;
+  const auto *CondStmt = Result.Nodes.getNodeAs<Stmt>("condStmt");
+  SourceLocation Loc = CondStmt->getLocStart();
+
+  if (!Loc.isValid() || !Loc.isMacroID())
+    return;
+
+  StringRef MacroName = Lexer::getImmediateMacroName(
+      Loc, ASTCtx->getSourceManager(), ASTCtx->getLangOpts());
+
+  // Check if this macro is an assert.
+  if (std::find(AssertMacros.begin(), AssertMacros.end(), MacroName) ==
+      AssertMacros.end())
+    return;
+
+  diag(Loc, "found " + MacroName.str() + "() with side effect");
+}
+
+} // namespace tidy
+} // namespace clang