Fix #15126 FP syntaxError (function try block with override in struct) - #8955

AI review

The fix works for the common forms, void f() [const|noexcept|noexcept(true)] override|final try {...} catch(...) {...}, and I found no regressions. It only handles a single override or final directly after ) or after a keyword, though. Two forms with override still give the same syntaxError:

• a ref-qualifier: void i() & override try, void i() && override try, void i() const & override try
• a trailing return type: auto k() -> void override try

The base version fails on these forms without override as well (void i() & try, auto k() -> void try), so they are a gap that already existed rather than a regression. It is still a gap in the same ticket area. When final or override is used as a variable name before a try inside a function body, the PR gives no new false positive.

Testing

I built cppcheck and testrunner in pr/. ./testrunner TestTokenizer TestGarbage TestSymbolDatabase TestSimplifyTokens TestClass passed with 0 failures.

Handled correctly, no errors:

• const override
• noexcept override
• noexcept(true) override
• override final
• int final = 0; try {...} inside a function body
• int override[2]; ... try {...} inside a function body

Still syntaxError, ./cppcheck -q x.cpp in each case:

struct E : B {
    void i() & override try {} catch (...) {}
};

error: syntax error: keyword 'try' is not allowed in class/struct/union/enum scope [syntaxError]

These forms give the same error:

• void i() && override try {} catch (...) {}
• void i() const & override try {} catch (...) {}
• auto k() -> void override try {} catch (...) {}

Without override, the base version also rejects void i() & try {} catch (...) {} and auto k() -> void try {} catch (...) {}, so this limitation existed before the PR.

Automated review of aa91b3a by Claude. The pull request was built and tested locally.

AI review

The fix now covers ref-qualifiers and trailing return types, but the trailing return type part only works when the return type is made of plain names and ::. The backward walk in simplifyFunctionTryCatch stops at any other token, so these still give syntaxError:

• a pointer return type: auto k() -> int* override try {} catch (...) {}
• a template return type: auto k() -> std::vector<int> override try {} catch (...) {}

Forms that do work now include -> std::size_t final, -> const int& override, -> decltype(1) override and -> int (*)() override, so whether this case works depends on the spelling of the return type. Apart from this, I found no new problems: I saw no regressions in function bodies or in constructor try blocks. The earlier review already covered -> T try without override, which still fails in both base and the PR.

Testing

I built cppcheck and testrunner in pr/, and cppcheck in base/. ./testrunner TestTokenizer TestGarbage TestSymbolDatabase TestSimplifyTokens TestClass TestFunctions TestVarID passed: 1627 tests, 0 failures.

Still syntaxError. I put each member below in struct B{virtual ~B();}; struct D : B { <member> }; and ran ./cppcheck -q t.cpp:

auto k() -> int* override try {} catch (...) {}
auto k() -> std::vector<int> override try {} catch (...) {}

Output:

t1.cpp:3:28: error: syntax error: keyword 'try' is not allowed in class/struct/union/enum scope [syntaxError]
t2.cpp:3:40: error: syntax error: keyword 'try' is not allowed in class/struct/union/enum scope [syntaxError]

Fixed by the PR (base gives syntaxError, the PR gives none):

• -> const int& override
• -> decltype(1) override
• -> int (*)() override
• -> std::size_t final
• const & noexcept override
• noexcept(false) override
• throw() override
• void f() &
• override final

Some of these give missingReturn, which is correct for those bodies.

Function bodies. I compared the --debug-normal output of base and the PR on try blocks after if (x) MACRO, while (x), x = x && p; and for (;;), and on a constructor try block with an initializer list. The output is identical.

Automated review of bb851af by Claude. The pull request was built and tested locally.