[clang-tidy] bugprone-assert-side-effect can detect side effect from non-const reference parameters (#84095)

Fixes: #84092

3 files changed, 43 insertions, 5 deletions

diff --git a/clang-tools-extra/clang-tidy/bugprone/AssertSideEffectCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/AssertSideEffectCheck.cpp
index 43bedd4..c650aae 100644
--- a/clang-tools-extra/clang-tidy/bugprone/AssertSideEffectCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/AssertSideEffectCheck.cpp
@@ -60,16 +60,26 @@ AST_MATCHER_P2(Expr, hasSideEffect, bool, CheckFunctionCalls,
   }
 
   if (const auto *CExpr = dyn_cast<CallExpr>(E)) {
-    bool Result = CheckFunctionCalls;
+    if (!CheckFunctionCalls)
+      return false;
     if (const auto *FuncDecl = CExpr->getDirectCallee()) {
       if (FuncDecl->getDeclName().isIdentifier() &&
           IgnoredFunctionsMatcher.matches(*FuncDecl, Finder,
                                           Builder)) // exceptions come here
-        Result = false;
-      else if (const auto *MethodDecl = dyn_cast<CXXMethodDecl>(FuncDecl))
-        Result &= !MethodDecl->isConst();
+        return false;
+      for (size_t I = 0; I < FuncDecl->getNumParams(); I++) {
+        const ParmVarDecl *P = FuncDecl->getParamDecl(I);
+        const Expr *ArgExpr =
+            I < CExpr->getNumArgs() ? CExpr->getArg(I) : nullptr;
+        const QualType PT = P->getType().getCanonicalType();
+        if (ArgExpr && !ArgExpr->isXValue() && PT->isReferenceType() &&
+            !PT.getNonReferenceType().isConstQualified())
+          return true;
+      }
+      if (const auto *MethodDecl = dyn_cast<CXXMethodDecl>(FuncDecl))
+        return !MethodDecl->isConst();
     }
-    return Result;
+    return true;
   }
 
   return isa<CXXNewExpr>(E) || isa<CXXDeleteExpr>(E) || isa<CXXThrowExpr>(E);
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 1b839a3..d98c4ff 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -128,6 +128,10 @@ New check aliases
 Changes in existing checks
 ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
+- Improved :doc:`bugprone-assert-side-effect
+  <clang-tidy/checks/bugprone/assert-side-effect>` check by detecting side
+  effect from calling a method with non-const reference parameters.
+
 - Improved :doc:`bugprone-non-zero-enum-to-bool-conversion
   <clang-tidy/checks/bugprone/non-zero-enum-to-bool-conversion>` check by
   eliminating false positives resulting from direct usage of bitwise operators
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/assert-side-effect.cpp b/clang-tools-extra/test/clang-tidy/checkers/bugprone/assert-side-effect.cpp
index c11638a..5cdc1af 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/bugprone/assert-side-effect.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/bugprone/assert-side-effect.cpp
@@ -108,3 +108,27 @@ int main() {
 
   return 0;
 }
+
+namespace parameter_anaylysis {
+
+struct S {
+  bool value(int) const;
+  bool leftValueRef(int &) const;
+  bool constRef(int const &) const;
+  bool rightValueRef(int &&) const;
+};
+
+void foo() {
+  S s{};
+  int i = 0;
+  assert(s.value(0));
+  assert(s.value(i));
+  assert(s.leftValueRef(i));
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: side effect in assert() condition discarded in release builds
+  assert(s.constRef(0));
+  assert(s.constRef(i));
+  assert(s.rightValueRef(0));
+  assert(s.rightValueRef(static_cast<int &&>(i)));
+}
+
+} // namespace parameter_anaylysis