0005442: camlp4: quotation issue with strings - MantisBT

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ID

Project

Category

View Status

Date Submitted

Last Update

0005442

OCaml

Camlp4

public

2011-12-23 14:59

2012-06-19 13:08

Reporter

doligez

Assigned To

dim

Priority

normal

Severity

minor

Reproducibility

always

Status

resolved

Resolution

fixed

Platform

all

OS

OS Version

Product Version

3.12.1

Target Version

Fixed in Version

3.12.1+dev

Summary

0005442: camlp4: quotation issue with strings

Description

This was reported on 2011-07-11 by Petter Urkedal on caml-list under the subject "Quotation issue with camlp4 printer".

The attached program prints out

let x = """;;

when compiled with ocamlc and camlp4 version 3.12.0. As you can see,
the string literal lacks an escape character. I haven't tried version
3.12.1, but I didn't find anything about it in the release notes.

Steps To Reproduce

    ocamlc.opt -c -I +camlp4 -pp camlp4orf -o quotation_bug.cmo
quotation_bug.ml
    ocamlc.opt dynlink.cma -I +camlp4 camlp4lib.cma quotation_bug.cmo
-o quotation_bug.byte
    ./quotation_bug.byte

Additional Information

A tentative fix was done in commit 11119, but it breaks findlib (among others) because it double-escapes everything in string constants when preprocessing normal code with "camlp4 pa_o.cmo pr_o.cmo".

It looks like the problem is in the parsing of quotations, not in the printing code.

Tags

No tags attached.

quotation_bug.ml [^] (172 bytes) 2011-12-23 14:59

Relationships

related to	0005646	resolved	dim	Camlp4 Printer for escaped string
related to	0005633	resolved	garrigue	Camlp4Ast.ml takes very long to compile

Notes
(0006520) dim (developer) 2011-12-23 17:33	Fixed. Commits 11947 and 11948. The problem was due to the fact that strings are escaped in the camlp4 ast, so they must be escaped again when the ast is meta-expansed, but it was not done.

(0006560) doligez (manager) 2011-12-30 13:57	There is a problem with the fix: it breaks type-conv 2.3.0. To reproduce: Install type-conv version 2.3.0 (I haven't tried other version) from Jane Street web site. ---------- foo.ml module Foo = struct end;; module Bar = struct end;; ---------- camlp4o /usr/local/ocaml/3.12/lib/ocaml/site-lib/type-conv/pa_type_conv.cma foo.ml With text output, you get: Failure: "Cannot print \"\\\\$:i\" this string contains more than one token" With AST output, you get a compiler error because both identifiers Foo and Bar got replaced by \$:i I've narrowed it down to your commit. If I replace "String.escaped" with "safe_string_escaped" at line 474 of boot/Camlp4Ast.ml, it seems to fix the problem, but I'll let you decide what to do because I don't really understand camlp4.

(0006573) dim (developer) 2011-12-30 21:02	It is indeed safe_string_escaped that must be used instead of String.escaped. Fixed by commits 11983 and 11984.

Issue History
Date Modified	Username	Field	Change
2011-12-23 14:59	doligez	New Issue
2011-12-23 14:59	doligez	Status	new => assigned
2011-12-23 14:59	doligez	Assigned To	=> ertai
2011-12-23 14:59	doligez	File Added: quotation_bug.ml
2011-12-23 15:29	doligez	Assigned To	ertai =>
2011-12-23 15:30	doligez	Assigned To	=> doligez
2011-12-23 15:30	doligez	Status	assigned => acknowledged
2011-12-23 15:30	doligez	Assigned To	doligez =>
2011-12-23 17:33	dim	Note Added: 0006520
2011-12-23 17:33	dim	Assigned To	=> dim
2011-12-23 17:33	dim	Status	acknowledged => resolved
2011-12-23 17:33	dim	Resolution	open => fixed
2011-12-23 17:33	dim	Fixed in Version	=> 3.12.1+dev
2011-12-30 13:57	doligez	Note Added: 0006560
2011-12-30 13:57	doligez	Status	resolved => feedback
2011-12-30 13:57	doligez	Resolution	fixed => reopened
2011-12-30 13:58	doligez	Status	feedback => acknowledged
2011-12-30 21:02	dim	Note Added: 0006573
2011-12-30 21:02	dim	Status	acknowledged => resolved
2011-12-30 21:02	dim	Resolution	reopened => fixed
2012-06-12 17:23	dim	Relationship added	related to 0005646
2012-06-19 13:08	garrigue	Relationship added	related to 0005633

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