[joostwaaijer]

Note

This pull request description was prepared with assistance from OpenAI Codex and reviewed by the contributor.

zend_compile_return() currently leaves CG(zend_lineno) at the last line compiled inside a multiline return expression. As a result, VERIFY_RETURN_TYPE and RETURN are attributed to a match arm or ternary branch instead of the return statement. Coverage drivers then omit the actual return line and may report a different branch line as executed. This is the specific return-expression case described in GH-22727 and is part of the broader GH-18985 issue.

This patch captures the statement line before compiling the expression and restores it before emitting return-related opcodes. It deliberately avoids the broader expression compiler changes from GH-22833 that were reverted.

A PHPT regression test verifies the user-visible TypeError line. The test fails on PHP 8.4.24 with line 6 instead of line 5, and passes on the patched PHP 8.4.26-dev build.

Validation: debug NTS build with all Zend/tests (4,837 passed, 134 skipped, 1 expected failure, 0 failures); debug ZTS build with the focused regression test; and PCOV 1.0.12 verification showing the direct return match line changes from absent to hit count 1.

[ndossche]

So the original fix was rejected by @derickr because it influenced too many things in xdebug. I assume he meant tests.
So I guess this depends on @derickr and @iluuu1994

[anun333]

Quoted below: written with Claude, an LLM, as CONTRIBUTING.md asks us to mark. The builds and test runs behind it are on my machine; the commands to repeat them are under the fold.

Tested on today's PHP-8.4 (8d63e87a496) with this PR cherry-picked, debug builds. The line PHP reports for something that happens at a multi-line return, in one test file:

Return on line	What is reported	PHP-8.4	this PR
12: return match (true) {, the arm on 13 returns a string from an int function	TypeError	13	12
17: return $b, the : 'no' branch on 19	TypeError	19	17
28: return implode(, an argument on 30	TypeError	30	28
34: return 1 / + 2; in function &f()	"Only variable references should be returned by reference"	35	34
22: return [, the first element on 23	TypeError	23	23
37: fn(): int =>, the body 'x' on 38	TypeError	38	38
46: return intdiv(, the 0 on 48 (control: thrown inside the call)	DivisionByZeroError	46	46

So the errors raised by the return itself now point at the statement. Two shapes keep the later line: a multi-line array literal, because the return statement's line comes from the array node, whose line is its first element's (23 rather than the [ on 22); and an arrow function whose body starts on the next line, where there is no return to point at. Zend/tests passes on both (5,023; 5,024 with the new test), so no existing expectation moves, and the new test fails without the fix.

For the merge-up: on today's master Zend/zend_compile.c conflicts, right next to the "Returning a value from a constructor is deprecated" block in zend_compile_return(), so it needs a small hand merge. #23305 also changes zend_compile_return() on master.

How this was tested

Linux x86_64, gcc 13.3, debug builds of origin/PHP-8.4 and of it with this PR's commits cherry-picked:

./buildconf --force
./configure --enable-debug --disable-cgi --disable-phpdbg --disable-fileinfo --enable-pcntl --enable-zend-test --enable-fpm --with-curl --enable-mbstring --disable-mbregex --with-mysqli --with-pdo-mysql --with-openssl --with-bz2
make -j4

One PHP file holds the seven functions; each is called inside try/catch with an error handler, and the getLine() of the throwable (or the handler's line) is printed. Suites: TEST_PHP_EXECUTABLE=$PWD/sapi/cli/php sapi/cli/php run-tests.php -n -q -j4 Zend/tests.