.TH urweb 1 "August 5, 2016" .\" urweb.1 -- man page for urweb \" Copyright (C) 2013, 2015, 2016 Benjamin Barenblat \" \" Licensed under the Apache License, Version 2.0 (the "License"); you may not \" use this file except in compliance with the License. You may obtain a copy \" of the License at \" \" http://www.apache.org/licenses/LICENSE-2.0 \" \" Unless required by applicable law or agreed to in writing, software \" distributed under the License is distributed on an "AS IS" BASIS, WITHOUT \" WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the \" License for the specific language governing permissions and limitations \" under the License. .SH NAME \fBurweb\fP \- compiler for the Ur/Web programming language .SH SYNOPSIS \fBurweb\fP [\fIoption\fP|\fIproject-name\fP]... .br \fBurweb daemon\fP [\fBstart\fP|\fBstop\fP] .SH DESCRIPTION .PP This manual page briefly documents the \fBurweb\fP compiler. Extensive documentation is available in the Ur/Web reference manual. \fBurweb\fP is an optimizing compiler for Ur/Web, a functional, pure, statically typed, strictly evaluated programming language designed for constructing dynamic Web applications backed by SQL databases. \fBurweb\fP produces very efficient object code that does not use garbage collection; compiled programs will often be even more efficient than what most programmers would bother to write in C. The first invocation described compiles an Ur/Web project (see \fBCOMPILATION\fP), while the second invocation controls the type inference daemon (see \fBTYPE INFERENCE DAEMON\fP). For simple projects, only familiarity with the first invocation is required. .SH COMPILATION \fBurweb\fP is a whole-program compiler (i.e., incremental compilation is not supported). Thus, it operates at project granularity, and it is run from the command line with a collection of options and a project name. The simplest case is to run \fBurweb foo\fP, where the file \fBfoo.ur\fP contains a valid Ur/Web program, in which case \fBurweb\fP will compile the program to the file \fBfoo.exe\fP. (Despite the extension of the generated files, \fBurweb\fP does not necessarily produce COFF executables; rather, it produces the default object format of the default C compiler.) Larger programs, spanning many files, may be compiled by specifying an \fB.urp\fP (i.e., an Ur/Web project) file. The syntax of an \fB.urp\fP file is relatively simple; see section 3.1 of the Ur/Web reference manual for details. With no arguments, \fBurweb\fP prints the version number and exits. .SH "Compiler options" .TP \fB\-ccompiler\fP \fIprogram\fP Sets the executable name corresponding to the C compiler. \fBurweb\fP uses \fBgcc\fP by default, but \fBclang\fP should also work. .TP \fB\-db\fP \fIname\fP=\fIvalue\fP,... Sets database information using the format expected by Postgres's \fIPQconnectdb\fP. If the database backend is MySQL or SQLite, \fBurweb\fP will parse the information string to set connection parameters appropriately. For MySQL, the only relevant parameters are \fIhost\fP, \fIhostaddr\fP, \fIport\fP, \fIdbname\fP, \fIuser\fP, and \fIpassword\fP; for SQLite, the only relevant parameter is \fIdbname\fP, which is interpreted as the file system path to the database file. All unrecognized parameters are silently ignored. .TP \fB\-dbms\fP (\fBpostgres\fP|\fBmysql\fP|\fBsqlite\fP) Sets the database backend. If requested, \fBurweb\fP will also emit initialization code for the selected backend; see the \fB\-sql\fP option. .TP \fB\-debug\fP Instructs \fBurweb\fP to emit the generated C code as \fI/tmp/webapp.c\fP. Additionally, \fBurweb\fP will print the command-line options it passes to the C compiler and linker as it executes. .TP \fB\-dumpSource\fP Instructs \fBurweb\fP to print a text-based form of the current intermediate representation (IR) when compilation fails. Output will likely be extremely long and not very human-readable. .TP \fB\-dumpVerboseSource\fP Instructs \fBurweb\fP to print a text-based form of every intermediate representation it generates during compilation. Output will likely be extremely long and not very human-readable. .TP \fB\-dumpTypes\fP If specified, \fBurweb\fP will print the types of all named values it finds during compilation. .TP \fB\-dumpTypesOnError\fP Identical to \fB\-dumpTypes\fP, but only prints the types if compilation fails. .TP \fB\-explainEmbed\fP Enables verbose error messages when \fBurweb\fP is unable to embed server-side values in client-side code. .TP \fB\-limit \fIclass\fP \fInum\fP Sets a resource usage limit for generated applications. The limit \fIclass\fP will be set to the non-negative integer \fInum\fP. The classes are: .RS .IP \fBcleanup\fP maximum number of cleanup operations (e.g., entries recording the need to deallocate certain temporary objects) that may be active at once per request .IP \fBclients\fP maximum number of clients that can be simultaneously blocked waiting for new messages (sent by \fIBasis.send\fP) .IP \fBdatabase\fP maximum size of database file (currently only used by SQLite), in units of database pages .IP \fBdeltas\fP maximum number of messages sendable in a single request handler with \fIBasis.send\fP .IP \fBglobals\fP maximum number of global variables that FFI libraries may set in a single request context .IP \fBheaders\fP maximum size (in bytes) of per-request buffer used to hold HTTP headers for generated pages .IP \fBheap\fP maximum size (in bytes) of per-request heap for dynamically allocated data .IP \fBinputs\fP maximum number of top-level form fields per request .IP \fBmessages\fP maximum size (in bytes) of per-request buffer used to hold a single outgoing message sent with \fIBasis.send\fP .IP \fBpage\fP maximum size (in bytes) of per-request buffer used to hold HTML content of generated pages .IP \fBscript\fP maximum size (in bytes) of per-request buffer used to hold JavaScript content of generated pages .IP \fBsubinputs\fP maximum number of form fields per request, excluding top-level fields .IP \fBtime\fP maximum running time of a single page request, in units of approximately 0.1 seconds .IP \fBtransactionals\fP maximum number of custom transactional actions (e.g., sending an e-mail) that may be run in a single page generation .RE .TP \fB\-output\fP \fIfilename\fP Sets where \fBurweb\fP will store the compiled executable. .TP \fB\-path\fP \fIname\fP \fIvalue\fP Defines a new path alias for use in \fB.urp\fP files. In particular, this option specifies that all occurrences of $\fIname\fP in any \fB.urp\fP files processed will be replaced with \fIvalue\fP. You may specify this option more than once. .TP \fB\-prefix\fP \fIprefix\fP Sets the application prefix. This controls how Ur/Web functions are bound to URIs; in particular, if \fIprefix\fP is \fI/directory/myapp.exe/\fP, then URIs of the form \fI//example.com/directory/myapp.exe/Module/function\fP will resolve to the function \fIModule.function\fP in Ur/Web. .TP \fB\-protocol\fP (\fBhttp\fP|\fBcgi\fP|\fBfastcgi\fP|\fBstatic\fP) Instructs \fBurweb\fP to produce an executable which speaks the specified protocol: .RS .IP \fBhttp\fP HTTP 1.1. \fBurweb\fP will generate a standalone server executable. .IP \fBcgi\fP The Common Gateway Interface, the classic protocol that Web servers use to generate dynamic content by spawning new processes. While Ur/Web programs may in general use message-passing with the \fIsend\fP and \fIrecv\fP functions, that functionality is not yet supported in CGI, since CGI needs a fresh process for each request, and message-passing needs to use persistent sockets to deliver messages. Since Ur/Web treats paths in an unusual way, you will need to configure Ur/Web specially by setting the \fBprefix\fP directive in your \fB.urp\fP file or passing the \fB\-prefix\fP option on the command line. For example, if you deploy a Web application at \fI//example.com/directory/myapp.exe\fP, you should specify \fI/directory/myapp.exe/\fP as the application prefix. See section 3.2 of the Ur/Web reference manual for more information. .IP \fBfastcgi\fP The faster, newer protocol inspired by CGI, wherein Web servers can start and reuse persistent external processes to generate dynamic content. Ur/Web doesn't implement the whole protocol, but Ur/Web's support has been tested to work with both Apache and lighttpd. Applications which use message-passing, while supported, require special configuration. In particular, if you're using Apache, be sure to specify a large \fBidle-timout\fP; if you're using lighttpd, be sure to set \fBmax-procs\fP to 1. The rationale for these configuration changes is detailed in section 3.2 of the Ur/Web reference manual. .IP \fBstatic\fP The simplest possible protocol. \fBurweb\fP will generate an output executable which expects a single command-line argument giving the URI of a page to generate. For instance, this argument might be \fI/main\fP, in which case a static HTTP response for that page will be written to standard output. .RE .TP \fB\-root\fP \fIName\fP \fIpath\fP Triggers an alternate module convention for all source files found in directory \fIpath\fP or any of its subdirectories. In particular, any file \fIpath\fP/foo.ur will define a module called \fIName.Foo\fP instead of the usual \fIFoo\fP. Any file \fIpath\fP/subdir/foo.ur will define a module called \fIName.Subdir.Foo\fP, and so on for arbitrary nesting of subdirectories. You may specify this option more than once. .TP \fB\-sigfile\fP \fIpath\fP If specified, the compiled application will look at \fIpath\fP for a key to use in cryptographic signing. This is used to prevent cross-site request forgery attacks for any form handler that both reads a cookie and creates side effects. If the referenced file doesn't exist, the application will create it and read its saved data on future invocations. You can also initialize the file manually with any contents at least 16 bytes long; the first 16 bytes will be treated as the key. .TP \fB\-sql\fP \fIfile\fP Requests that \fBurweb\fP generate database initialization code for the selected database backend, storing it in \fIfile\fP. If \fIfile\fP already exists, \fBurweb\fP will overwrite it. Note that the generated instructions will not create the application database; you must do that yourself. .TP \fB\-static\fP Instructs \fBurweb\fP to statically link the generated executable. .TP \fB\-timing\fP If specified, \fBurweb\fP will print a timing report at the end of compilation showing the number of seconds required for each stage of the compilation process. .TP \fB\-unifyMore\fP Instructs \fBurweb\fP's type inference engine to make best-effort guesses rather than immediately failing when performing type inference. If \fB\-dumpTypes\fP shows unresolved unification variables in positions where you would like to see \fBurweb\fP make best-guesses effort instead, specify this option. Correct programs compiled with \fB\-unifyMore\fP will be identical to their counterparts compiled without it; however, \fBurweb\fP will likely generate many more (and potentially more useful) error messages at a time when asked to compile an incorrect program with this flag. .TP \fB\-verbose\fP Instructs \fBurweb\fP to announce the stages of the compilation process as it performs them. .SH "Options which inhibit compilation" When run with any of these options, \fBurweb\fP will not produce executable output. .TP \fB\-css\fP Dumps generated CSS properties and classes. The first output line is a list of categories of CSS properties that would be worth setting on the document body. The remaining lines are space-separated pairs of CSS class names and categories of properties that would be worth setting for that class. The category codes are divided into two varieties. Codes that reveal properties of a tag or its (recursive) children are .RS .IP \fBB\fP for block-level elements, .IP \fBC\fP for table captions, .IP \fBD\fP for table cells, .IP \fBL\fP for lists, and .IP \fBT\fP for tables. .RE .RS Codes that reveal properties of the precise tag that uses a class are .IP \fBb\fP for block-level elements, .IP \fBt\fP for tables, .IP \fBd\fP for table cells, .IP \fB\-\fP for table rows, .IP \fBH\fP for the possibility to set a height, .IP \fBN\fP for non-replaced inline-level elements, .IP \fBR\fP for replaced inline elements, and .IP \fBW\fP for the possibility to set a width. .RE .RE .TP \fB\-moduleOf\fP \fIfile\fP Prints the Ur module name corresponding to the source file \fIfile\fP. .TP \fB\-numeric\-version\fP Prints the version of the compiler executable without any associated English text. Suitable for use in scripts. .TP \fB\-print\-ccompiler\fP Prints the executable name of the compiler that \fBurweb\fP will use. .TP \fB\-print\-cinclude\fP Prints the file system location in which \fBurweb\fP will look for C headers. .TP \fB\-tc\fP If specified, \fBurweb\fP will stop after the typechecking phase. Liberal use of this option can substantially speed development, as \fBurweb\fP's optimization passes can take quite a while. .TP \fB\-version\fP Prints the version of the compiler executable. Output is identical to \fBurweb\fP output when run without arguments. .SH "Documentation options" These options customize Ur/Web's documentation generator. .TP \fB\-demo\fP Performs demo-style formatting. .TP \fB\-guided\-demo\fP Performs demo-style formatting, but sizes frames to allocate less space to explanatory text. Useful for generating presentations. .TP \fB\-noEmacs\fP When used with \fB\-demo\fP, causes \fBurweb\fP to \fInot\fP use Emacs to syntax-highlight code. The resulting code will not be highlighted. .TP \fB\-tutorial\fP Performs tutorial-style formatting. .SH "Internal options" These options are not meant for users; they are used to build \fBurweb\fP releases and to debug the compiler. .TP \fB\-boot\fP Places \fBurweb\fP into bootstrap mode. Used when building the standard library for the first time. \fB\-stop\fP \fIphase\fP Causes \fBurweb\fP to exit after the specified phase of compilation. .SH "TYPE INFERENCE DAEMON" Since Ur/Web type inference can take a significant amount of time, it can be helpful to cache type-inferred versions of source files. This mode can be activated by running .RS \fBurweb daemon start\fP .RE Further urweb invocations in the same working directory will send requests to a background daemon process that reuses type inference results whenever possible, tracking source file dependencies and modification times. To stop the background daemon, run .RS \fBurweb daemon stop\fP .RE Communication happens via a Unix domain socket in file .urweb_daemon in the working directory. .SH BUGS \fBurweb\fP is a product of research; while it is intended to be usable for real work, it may occasionally fail to produce optimal results. If you believe you've found a bug (e.g., the compiler throws an unhandled exception), contact the Ur/Web mailing list, \fIur@impredicative.com\fP. .SH COPYRIGHT \fBurweb\fP is copyright \(co 2008-2016 Adam Chlipala and licensed under the 3-clause BSD license . This manual page is copyright \(co 2013, 2015, 2016 Benjamin Barenblat and licensed under the Apache License, Version 2.0.