How to indent relative to start of the previous line rather than relative to the beginning of the expression?

In php-mode – and in many others I believe – indentation of an expression spreading over several lines is computed relative to the starting column of the expression rather than the column of the first non-blank character of the line where the expression starts.

This is displayed by the following snippet, where the return keyword is indented four columns counting from the a starting the array_map(…) expression:

<?php function weights($volumes, $density) { $weights = array_map(function ($volume) { return $volume * $density; }, $volumes); return $weights; } 

I must follow another indentation style, where the return keyword is indented four columns counting from the $ of $weights which is the first non-blank character of the line where the array_map expression starts.

<?php function weights($volumes, $density) { $weights = array_map(function ($volume) { return $volume * $density; }, $volumes); return $weights; } 

How can I configure Emacs and the c-mode to use this second style? I could not find any reference to this behaviour on the emacs-wiki.

The indentation settings in use are the following:

(c-add-style "my-php-style" '("gnu" (c-basic-offset . 4) (c-offsets-alist (arglist-cont . 0) (arglist-intro . +) (block-close . 0) (defun-block-intro . +) (defun-close . 0) (defun-open . 0) (statement . 0) (statement-block-intro . +) (topmost-intro . 0) (access-label . -) (annotation-top-cont . 0) (annotation-var-cont . +) (arglist-close . c-lineup-arglist-operators) (arglist-cont-nonempty . c-lineup-math) (block-open . 0) (brace-entry-open . 0) (brace-list-close . 0) (brace-list-entry . 0) (brace-list-intro . +) (brace-list-open . +) (c . c-lineup-C-comments) (case-label . +) (catch-clause . 0) (class-close . 0) (class-open . 0) (comment-intro . c-lineup-comment) (composition-close . 0) (composition-open . 0) (cpp-define-intro c-lineup-cpp-define +) (cpp-macro . -1000) (cpp-macro-cont . +) (do-while-closure . 0) (else-clause . 0) (extern-lang-close . 0) (extern-lang-open . 0) (friend . 0) (func-decl-cont . +) (inclass . +) (incomposition . +) (inexpr-class . +) (inexpr-statement . +) (inextern-lang . +) (inher-cont . c-lineup-multi-inher) (inher-intro . +) (inlambda . c-lineup-inexpr-block) (inline-close . 0) (inline-open . 0) (inmodule . +) (innamespace . +) (knr-argdecl . 0) (knr-argdecl-intro . 5) (label . 0) (lambda-intro-cont . +) (member-init-cont . c-lineup-multi-inher) (member-init-intro . +) (module-close . 0) (module-open . 0) (namespace-close . 0) (namespace-open . 0) (objc-method-args-cont . c-lineup-ObjC-method-args) (objc-method-call-cont c-lineup-ObjC-method-call-colons c-lineup-ObjC-method-call +) (objc-method-intro . [0]) (statement-case-intro . +) (statement-case-open . +) (statement-cont . +) (stream-op . c-lineup-streamop) (string . -1000) (substatement . +) (substatement-label . 0) (substatement-open . +) (template-args-cont c-lineup-template-args +) (topmost-intro-cont first c-lineup-topmost-intro-cont c-lineup-gnu-DEFUN-intro-cont))))