Currently, unexpected tokens in the parser are shown as the text
found, plus the internal token name, including the notorious
"unexpected '::' (T_PAAMAYIM_NEKUDOTAYIM)".
This commit replaces that with a more user-friendly format, with
two main types of token:
* Tokens which always represent the same text are shown like
'unexpected token "::"' and 'expected "::"'
* Tokens which have variable text are given a user-friendly
name, and show like 'unexpected identifier "foo"', and
'expected identifer'.
A few tokens have special cases:
* unexpected token """ -> unexpected double-quote mark
* unexpected quoted string "'foo'" -> unexpected single-quoted
string "foo"
* unexpected quoted string ""foo"" -> unexpected double-quoted
string "foo"
* unexpected illegal character "_" -> unexpected character 0xNN
(where _ is almost certainly a control character, and NN is the
hexadecimal value of the byte)
The \ token has a special case in the implementation just to stop
bison making a mess of escaping it and it coming out as \\
When performing an RW modification of an array offset, the undefined
offset warning may call an error handler / OB callback, which may
destroy the array we're supposed to change. Detect this by temporarily
incrementing the reference count. If we find that the array has been
modified/destroyed in the meantime, we do nothing -- the execution
model here would be that the modification has happened on the destroyed
version of the array.
Some code paths were checking this manually, but we can turn this
into a general assertion to avoid surprises (functions returning
failure without throwing).
I haven't tracked down in detail where the interaction with
increment_function comes from, but the root problem here is failure
to handle the illegal offset type exception.
In the interest of avoiding side-effects during dumping, I'm
replacing the value with a <constant ast> string instead of
performing an update constant operation.
As part of my work on typed class constants, I wanted to make a
separate pull request for unrelated changes.
These include:
* Moving from ast->child[0]->attr to ast->attr
* Making zend_ast_export_ex() export class constants' visibility
* Extracting an additional zend_compile_class_const_group() function
Closes GH-5812.
