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Fix #14530 FP redundantCopyLocalConst with dissimilar types #8259

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Merged
chrchr-github merged 1 commit into from
Feb 26, 2026
Merged

Fix #14530 FP redundantCopyLocalConst with dissimilar types #8259

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14 changes: 9 additions & 5 deletions lib/checkother.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -3294,9 +3294,11 @@ static bool constructorTakesReference(const Scope * const classScope)

static bool isLargeObject(const Variable* var, const Settings& settings)
{
return var && !var->isGlobal() &&
(!var->type() || !var->type()->classScope ||
(var->valueType() && var->valueType()->getSizeOf(settings, ValueType::Accuracy::LowerBound, ValueType::SizeOf::Pointer) > 2 * settings.platform.sizeof_pointer));
if (!var || var->isGlobal() || !var->valueType())
return false;
ValueType vt = *var->valueType();
vt.reference = Reference::None;
return vt.getSizeOf(settings, ValueType::Accuracy::LowerBound, ValueType::SizeOf::Pointer) > 2 * settings.platform.sizeof_pointer;
}

//---------------------------------------------------------------------------
Expand Down Expand Up @@ -3332,13 +3334,15 @@ static bool checkFunctionReturnsRef(const Token* tok, const Settings& settings)
return false;
}

static bool checkVariableAssignment(const Token* tok, const Settings& settings)
static bool checkVariableAssignment(const Token* tok, const ValueType* vtLhs, const Settings& settings)
{
if (!Token::Match(tok, "%var% ;"))
return false;
const Variable* var = tok->variable();
if (!var || !isLargeObject(var, settings))
return false;
if (!vtLhs || !vtLhs->isTypeEqual(var->valueType()))
return false;
if (findVariableChanged(tok->tokAt(2), tok->scope()->bodyEnd, /*indirect*/ 0, var->declarationId(), /*globalvar*/ false, settings))
return false;
if (var->isLocal() || (var->isArgument() && !var->isReference()))
Expand Down Expand Up @@ -3381,7 +3385,7 @@ void CheckOther::checkRedundantCopy()
const Token* tok = startTok->next()->astOperand2();
if (!tok)
continue;
if (!checkFunctionReturnsRef(tok, *mSettings) && !checkVariableAssignment(tok, *mSettings))
if (!checkFunctionReturnsRef(tok, *mSettings) && !checkVariableAssignment(tok, var->valueType(), *mSettings))
continue;
redundantCopyError(startTok, startTok->str());
}
Expand Down
15 changes: 15 additions & 0 deletions test/testother.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -9944,6 +9944,21 @@ class TestOther : public TestFixture {
"}\n");
ASSERT_EQUALS("[test.cpp:7:17]: (performance, inconclusive) Use const reference for 'c' to avoid unnecessary data copying. [redundantCopyLocalConst]\n",
errout_str());

check("int f(const char* c) {\n" // #14530
" std::string s = c;\n"
" return s.rfind('.');\n"
"}\n"
"struct M {\n"
" M(const std::array<double, 9>& a);\n"
" double m[3][3];\n"
" double trace() const;\n"
"};\n"
"double g(const std::array<double, 9>& a) {\n"
" M m = a;\n"
" return m.trace();\n"
"}\n");
ASSERT_EQUALS("", errout_str());
}

void checkNegativeShift() {
Expand Down
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