From: Tracey Emery Subject: Re: [RFC] template system for gotwebd To: Omar Polo Cc: gameoftrees@openbsd.org Date: Thu, 22 Sep 2022 07:43:02 -0600 On Thu, Sep 22, 2022 at 11:44:13AM +0200, Omar Polo wrote: > For some personal project(s) I ended up writing a small template > """engine""" to generate HTML (but not only.) I did this because I > found a bit of a pain to (safely) generate HTML by means of printf or > the like. Since this has been working fine for me, I thought gotwebd > could benefit from it too. > > Diff below is not intended to be committed as-is, neither to be > reviewed or even tested, it's just for demonstration purpose: the > added code is not used at runtime! If y'all like the direction, I can > work on a better diff that moves the HTML generation to this template > system. I'll be afk a lot and gone all next week, so I wanted to throw my two cents in really quickly. I don't hate this idea at all and it's totally worth further discussion. I'll need to re-read this a few times to fully grasp it, but I think templating is fine! > > > How it works? > ============= > > At a higher level the templates are file written in a custom syntax > which is mostly HTML except for some special constructs embedded > within {{ ... }} or {! ... !}. Producing HTML (or anything else > really) is achieved by defining "blocks". These blocks are turned at > *compile time* into plain C functions that output the text via some > provided functions. > > I'd like to stress the point that the templates are *compiled* into C > and not executed at runtime, as happens with many other template > systems. > > here's an example of how to define a block: > > {{ define gw_base(struct template *tp, const char *title) }} > > > > {{ title }} > > > {{ render tp->tp_body }} > > > {{ end }} > > that gets turned into something like the following pseudo code: > > int > gw_base(struct template *tp, const char *title) > { > /* print from to */ > /* ... */ > > print(htmlescape(title)); > > /* print until <body> */ > /* ... */ > > if (tp->tp_body(tp) == -1) > return (-1); > > /* print </body></html> */ > > return (0); > } > > In short, it just turn some HTML fragments into glorified printfs, but > providing an easy way to safely interpolate variables. > > It implicitly HTML-escape the variables and provides a mean to choose > a different escape strategy case-by-case (e.g. to urlencode something > or to *not* escape something else.) Everything is implicitly escaped, > you have to be verbose to change/disable it. > > Different escaping "strategies" can be choosen as follows: > > {{ foo | unsafe }} aka don't escape > {{ foo | urlescape }} > > There's also some small syntax for conditionals: > > {{ if something }} > ... > {{ else if x && !y }} > ... > {{ else }} > ... > {{ end }} > > and loops: > > {{ tailq-foreach rc &t->repo_commits entry }} > ... > {{ end }} > > Since these templates are turned into C code, there's a mean to inline > some code that will be left as-is in the generated file using the > > {! /* code ... */ !} > > construct. > > Finally, there's a small syntax sugar for calling another block using > the `render' keyword: > > {{ render another_block }} > > > Pros and cons > ============= > > The main advantage is that it avoids very ugly sections of > > if (fcgi_printf(c, "...") == -1) > goto err; > > Writing HTML in a separate file allows to use a proper indentation and > makes leaving dangling tags open harder. The template system also > implicitly discards blanks at the start of the lines, so it also > avoids sending blanks to the browser. > > I'd argue that it's easier/fun to hack on these templates files rather > than writing HTML as bits of C strings. > > Turning this templates into C code that gets then compiled and linked > as part of gotwebd also avoids interpreting stuff at runtime and > allows for the compiler to do some optimizations here and there (not > that I think it can optimize much tho.) > > It's possibly more efficient than what we currently have. The > generated code uses a sequence of puts-like and putc-like functions to > both output the HTML and do the escaping, so it avoids the overhead of > the implicit vasprintf in fcgi_printf and all the alloc/free we're > currently doing to escape the strings. > > The interpolated strings are automatically escaped by default, instead > of requiring to manually escaping them (and free the allocated escaped > string.) > > The "compiler" uses the #line directive, just like yacc does, so > eventual C error or warnings are reported relatively to the template > file and not the generated code. Even the debugger shows the template > being processed. > > We can probably leverage the template system to write some regress > tests for gotwebd. The template system is "output agnostic", it just > uses the given functions to do the output. In gotwebd the output will > be through fastcgi, but in a hypothetical regress suite we could > override the templates and just print plain text to standard output. > I have not yet investigated into this, it's pure speculation. > > The template 'language' is very Go html/template inspired, but is > still decently different and this can be confusing. > > The "compiler" is not even remotely smart, it just bashes strings > together, and the generated code assume there's a variable in scope > called `tp' of type `struct template', so every block needs to have an > argument with that name and of that type. > > The error reporting is not great, but as it's an internal tool I don't > think it's a big deal. > > The fact that trims out the blanks leads to some possible edge cases > where we want to include a space but the template "compiler" trims it > out. It's possible to work around it by using {{ " " }}. > > I have not found a clean way to integrate the template generation into > the bsd.prog.mk infrastructure. Diff belows assumes the template > "compiler" is in ${.CURDIR}/template/obj/template, but one can also > not `make obj'. > > -*-*- > > Diff below includes an (incomplete) example of how we could probably > rewrite gotweb_render_header/footer and the commits fragment. For a > more real-life example, you can take a look at `fragments.tmpl' in > > https://git.omarpolo.com/?action=summary&path=galileo.git > > where this template system originates from. > > > What do you think? Would something like this be a good addition to > gotwebd? > > diff /home/op/w/gwd-template > commit - 611e5fc2074d428e17f920dc595496af4dd0dc77 > path + /home/op/w/gwd-template > blob - 01296896441d21b985a59ffc870ef3d3b03f4a31 > file + gotwebd/Makefile > --- gotwebd/Makefile > +++ gotwebd/Makefile > @@ -1,13 +1,14 @@ > .PATH:${.CURDIR}/../lib > +.PATH:${.CURDIR}/template > > -SUBDIR = libexec > +SUBDIR = libexec template > > .include "../got-version.mk" > .include "Makefile.inc" > > PROG = gotwebd > SRCS = config.c sockets.c log.c gotwebd.c parse.y proc.c \ > - fcgi.c gotweb.c got_operations.c > + fcgi.c gotweb.c got_operations.c tmpl.o > SRCS += blame.c commit_graph.c delta.c diff.c \ > diffreg.c error.c fileindex.c object.c object_cache.c \ > object_idset.c object_parse.c opentemp.c path.c pack.c \ > @@ -19,9 +20,20 @@ SRCS += blame.c commit_graph.c delta.c diff.c \ > diff_output_edscript.c diff_patience.c bloom.c murmurhash2.c \ > worktree_open.c patch.c sigs.c date.c sockaddr.c > > +TEMPLATES = pages.tmpl > + > +.for t in ${TEMPLATES} > +SRCS += ${t:.tmpl=.c} > +CLEANFILES += ${t:.tmpl=.c} > + > +${t:.tmpl=.c}: ${t} > + ${.CURDIR}/template/obj/template $? > $@ > +.endfor > + > MAN = ${PROG}.conf.5 ${PROG}.8 > > CPPFLAGS += -I${.CURDIR}/../include -I${.CURDIR}/../lib -I${.CURDIR} > +CPPFLAGS += -I${.CURDIR}/template/ > LDADD += -lz -levent -lutil -lm > YFLAGS = > DPADD = ${LIBEVENT} ${LIBUTIL} > blob - /dev/null > file + gotwebd/pages.tmpl > --- /dev/null > +++ gotwebd/pages.tmpl > @@ -0,0 +1,195 @@ > +{! > + > +/* > + * Copyright (c) 2022 Omar Polo <op@omarpolo.com> > + * Copyright (c) 2016, 2019, 2020-2022 Tracey Emery <tracey@traceyemery.net> > + * > + * Permission to use, copy, modify, and distribute this software for any > + * purpose with or without fee is hereby granted, provided that the above > + * copyright notice and this permission notice appear in all copies. > + * > + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES > + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF > + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR > + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES > + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN > + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF > + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. > + */ > + > +#include <sys/types.h> > +#include <sys/queue.h> > +#include <sys/uio.h> > + > +#include <event.h> > +#include <stdint.h> > +#include <imsg.h> > + > +#include "proc.h" > +#include "tmpl.h" > + > +#include "gotwebd.h" > + > +int gw_base(struct template *, const char *); > +int gw_commits(struct template *); > +int gw_navs(struct template *); > + > +static inline const char * > +action_name(int action) > +{ > + switch (action) { > + case BLAME: > + return"blame"; > + case BRIEFS: > + return"briefs"; > + case COMMITS: > + return"commits"; > + case DIFF: > + return"diff"; > + case SUMMARY: > + return"summary"; > + case TAG: > + return"tag"; > + case TAGS: > + return"tags"; > + case TREE: > + return"tree"; > + default: > + return "unknown"; > + } > +} > + > +!} > + > +{{ define gw_base(struct template *tp, const char *title) }} > +{! > + struct request *c = tp->tp_arg; > + struct server *srv = c->srv; > + struct querystring *qs = c->t->qs; > + const char *prfx = c->script_name; > + const char *css = srv->custom_css; > + char index[32]; > + int r; > + > + r = snprintf(index, sizeof(index), "%d", qs->index_page); > + if (r < 0 || (size_t)r >= sizeof(index)) > + return -1; > +!} > +<!doctype html> > +<html> > + <head> > + <meta charset="utf-8" /> > + <title>{{ title }} > + > + > + > + > + > + > + > + > + > + > + > +

> + > +

> +

> + {{ srv->site_link }} > + {{ if qs->path }} > + {! /* ... */ !} > + {{ end }} > + {{ if qs->action != INDEX }} > + {{ " / " }} {{ action_name(qs->action) }} > + {{ end }} > +

> +

> + {{ render tp->tp_body }} > +

> +

> + > + > +{{ end }} > + > +{{ define gw_commits(struct template *tp) }} > +{! > + const struct got_error *error = NULL; > + struct repo_commit *rc; > + struct request *c = tp->tp_arg; > + struct server *srv = c->srv; > + struct transport *t = c->t; > + > + error = got_get_repo_commits(c, srv->max_commits_display); > + if (error) > + return -1; > +!} > +

Commits

> +

> + {{ tailq-foreach rc &t->repo_commits entry }} > +

> +

Commit:

> +

Author:

> +

Date:

> +

...

> +

> + {{ rc->commit_msg }} > +

> +

> + {! /* previous link */ !} > + {! /* next link */ !} > +

> +

> + {{ end }} > + {{ if t->next_id || t->prev_id }} > + {{ render gw_navs(tp) }} > + {{ end }} > +

> +{{ end }} > + > +{{ define gw_navs(struct template *tp) }} > +

> +

> + {! /* ... */ !} > +

> +

> + {! /* ... */ !} > +

> +

> +{{ end }} > + > +{! > + > +/* > + * Example usage: > + * > + * Initialize the template: > + * > + * c->tp = template(c, puts_like_fns, putc_like_fns); > + * if (c->tp == NULL) > + * return got_error_from_errno("template"); > + * > + * The call a "block" defined with ``{{ define ... }}'' as a normal C > + * function: > + * > + * if (gw_base(c->tp, "page title") == -1) > + * // error > + */ > + > +!} > blob - /dev/null > file + gotwebd/template/Makefile > --- /dev/null > +++ gotwebd/template/Makefile > @@ -0,0 +1,21 @@ > +PROG = template > +SRCS = template.c parse.y > + > +# XXX > +NOMAN = Yes > + > +CFLAGS += -I${.CURDIR} > + > +WARNINGS = yes > + > +CDIAGFLAGS = -Wall -Wextra -Wpointer-arith -Wuninitialized > +CDIAGFLAGS+= -Wstrict-prototypes -Wmissing-prototypes -Wunused > +CDIAGFLAGS+= -Wsign-compare -Wshadow -Wno-unused-parameter > +CDIAGFLAGS+= -Wno-missing-field-initializers > +CDIAGFLAGS+= -Werror > + > +.if make(regress) || make(clean) > +SUBDIR = regress > +.endif > + > +.include > blob - /dev/null > file + gotwebd/template/parse.y > --- /dev/null > +++ gotwebd/template/parse.y > @@ -0,0 +1,704 @@ > +/* > + * Copyright (c) 2022 Omar Polo > + * Copyright (c) 2007-2016 Reyk Floeter > + * Copyright (c) 2004, 2005 Esben Norby > + * Copyright (c) 2004 Ryan McBride > + * Copyright (c) 2002, 2003, 2004 Henning Brauer > + * Copyright (c) 2001 Markus Friedl. All rights reserved. > + * Copyright (c) 2001 Daniel Hartmeier. All rights reserved. > + * Copyright (c) 2001 Theo de Raadt. All rights reserved. > + * > + * Permission to use, copy, modify, and distribute this software for any > + * purpose with or without fee is hereby granted, provided that the above > + * copyright notice and this permission notice appear in all copies. > + * > + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES > + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF > + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR > + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES > + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN > + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF > + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. > + */ > + > +%{ > + > +#include > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#ifndef nitems > +#define nitems(_a) (sizeof((_a)) / sizeof((_a)[0])) > +#endif > + > +TAILQ_HEAD(files, file) files = TAILQ_HEAD_INITIALIZER(files); > +static struct file { > + TAILQ_ENTRY(file) entry; > + FILE *stream; > + char *name; > + size_t ungetpos; > + size_t ungetsize; > + u_char *ungetbuf; > + int eof_reached; > + int lineno; > + int errors; > +} *file, *topfile; > +int parse(const char *); > +struct file *pushfile(const char *, int); > +int popfile(void); > +int yyparse(void); > +int yylex(void); > +int yyerror(const char *, ...) > + __attribute__((__format__ (printf, 1, 2))) > + __attribute__((__nonnull__ (1))); > +int kw_cmp(const void *, const void *); > +int lookup(char *); > +int igetc(void); > +int lgetc(int); > +void lungetc(int); > +int findeol(void); > + > +void dbg(void); > +void printq(const char *); > + > +extern int nodebug; > + > +static int block; > +static int in_define; > +static int errors; > +static char lerr[32]; > + > +typedef struct { > + union { > + char *string; > + } v; > + int lineno; > +} YYSTYPE; > + > +%} > + > +%token DEFINE ELSE END ERROR ESCAPE FINALLY IF INCLUDE > +%token RENDER TQFOREACH UNSAFE URLESCAPE > +%token STRING > +%type string > +%type stringy > + > +%% > + > +grammar : /* empty */ > + | grammar include > + | grammar verbatim > + | grammar block > + | grammar error { file->errors++; } > + ; > + > +include : INCLUDE STRING { > + struct file *nfile; > + > + if ((nfile = pushfile($2, 0)) == NULL) { > + yyerror("failed to include file %s", $2); > + free($2); > + YYERROR; > + } > + free($2); > + > + file = nfile; > + lungetc('\n'); > + } > + ; > + > +verbatim : '!' verbatim1 '!' { > + if (in_define) { > + /* TODO: check template status and exit in case */ > + } > + } > + ; > + > +verbatim1 : /* empty */ > + | verbatim1 STRING { > + if (*$2 != '\0') { > + dbg(); > + puts($2); > + } > + free($2); > + } > + ; > + > +verbatims : /* empty */ > + | verbatims verbatim > + ; > + > +raw : STRING { > + dbg(); > + printf("if (tp->tp_puts(tp, "); > + printq($1); > + printf(") == -1) goto %s;\n", lerr); > + > + free($1); > + } > + ; > + > +block : define body end { > + printf("%s:\n", lerr); > + puts("return tp->tp_ret;"); > + puts("}"); > + in_define = 0; > + } > + | define body finally end { > + puts("return tp->tp_ret;"); > + puts("}"); > + in_define = 0; > + } > + ; > + > +define : '{' DEFINE string '}' { > + in_define = 1; > + (void)snprintf(lerr, sizeof(lerr), "err%llu", > + (unsigned long long)arc4random()); > + > + dbg(); > + printf("int\n%s\n{\n", $3); > + > + free($3); > + } > + ; > + > +body : /* empty */ > + | body verbatim > + | body raw > + | body special > + ; > + > +special : '{' RENDER string '}' { > + dbg(); > + if (strrchr($3, ')') != NULL) > + printf("if (%s == -1) goto %s;\n", > + $3, lerr); > + else > + printf("if (%s != NULL && %s(tp) == -1) " > + "goto %s;\n", $3, $3, lerr); > + free($3); > + } > + | if body endif { puts("}"); } > + | loop > + | '{' string '|' ESCAPE '}' { > + dbg(); > + printf("if (tp->tp_escape(tp, %s) == -1) goto %s;\n", > + $2, lerr); > + free($2); > + } > + | '{' string '|' UNSAFE '}' { > + dbg(); > + printf("if (tp->tp_puts(tp, %s) == -1) goto %s;\n", > + $2, lerr); > + free($2); > + } > + | '{' string '|' URLESCAPE '}' { > + dbg(); > + printf("if (tp_urlescape(tp, %s) == -1) goto %s;\n", > + $2, lerr); > + free($2); > + } > + | '{' string '}' { > + dbg(); > + printf("if (tp->tp_escape(tp, %s) == -1) goto %s;\n", > + $2, lerr); > + free($2); > + } > + ; > + > +if : '{' IF stringy '}' { > + dbg(); > + printf("if (%s) {\n", $3); > + free($3); > + } > + ; > + > +endif : end > + | else body end > + | elsif body endif > + ; > + > +elsif : '{' ELSE IF string '}' { > + dbg(); > + printf("} else if (%s) {\n", $4); > + free($4); > + } > + ; > + > +else : '{' ELSE '}' { > + dbg(); > + puts("} else {"); > + } > + ; > + > +loop : '{' TQFOREACH STRING STRING STRING '}' { > + printf("TAILQ_FOREACH(%s, %s, %s) {\n", > + $3, $4, $5); > + free($3); > + free($4); > + free($5); > + } body end { > + puts("}"); > + } > + ; > + > +end : '{' END '}' > + ; > + > +finally : '{' FINALLY '}' { > + dbg(); > + printf("%s:\n", lerr); > + } verbatims > + ; > + > +string : STRING string { > + if (asprintf(&$$, "%s %s", $1, $2) == -1) > + err(1, "asprintf"); > + free($1); > + free($2); > + } > + | STRING > + ; > + > +stringy : STRING > + | STRING stringy { > + if (asprintf(&$$, "%s %s", $1, $2) == -1) > + err(1, "asprintf"); > + free($1); > + free($2); > + } > + | '|' stringy { > + if (asprintf(&$$, "|%s", $2) == -1) > + err(1, "asprintf"); > + free($2); > + } > + ; > + > +%% > + > +struct keywords { > + const char *k_name; > + int k_val; > +}; > + > +int > +yyerror(const char *fmt, ...) > +{ > + va_list ap; > + char *msg; > + > + file->errors++; > + va_start(ap, fmt); > + if (vasprintf(&msg, fmt, ap) == -1) > + err(1, "yyerror vasprintf"); > + va_end(ap); > + fprintf(stderr, "%s:%d: %s\n", file->name, yylval.lineno, msg); > + free(msg); > + return (0); > +} > + > +int > +kw_cmp(const void *k, const void *e) > +{ > + return (strcmp(k, ((const struct keywords *)e)->k_name)); > +} > + > +int > +lookup(char *s) > +{ > + /* this has to be sorted always */ > + static const struct keywords keywords[] = { > + { "define", DEFINE }, > + { "else", ELSE }, > + { "end", END }, > + { "escape", ESCAPE }, > + { "finally", FINALLY }, > + { "if", IF }, > + { "include", INCLUDE }, > + { "render", RENDER }, > + { "tailq-foreach", TQFOREACH }, > + { "unsafe", UNSAFE }, > + { "urlescape", URLESCAPE }, > + }; > + const struct keywords *p; > + > + p = bsearch(s, keywords, nitems(keywords), sizeof(keywords[0]), > + kw_cmp); > + > + if (p) > + return (p->k_val); > + else > + return (STRING); > +} > + > +#define START_EXPAND 1 > +#define DONE_EXPAND 2 > + > +static int expanding; > + > +int > +igetc(void) > +{ > + int c; > + > + while (1) { > + if (file->ungetpos > 0) > + c = file->ungetbuf[--file->ungetpos]; > + else > + c = getc(file->stream); > + > + if (c == START_EXPAND) > + expanding = 1; > + else if (c == DONE_EXPAND) > + expanding = 0; > + else > + break; > + } > + return (c); > +} > + > +int > +lgetc(int quotec) > +{ > + int c, next; > + > + if (quotec) { > + if ((c = igetc()) == EOF) { > + yyerror("reached end of filewhile parsing " > + "quoted string"); > + if (file == topfile || popfile() == EOF) > + return (EOF); > + return (quotec); > + } > + return (c); > + } > + > + while ((c = igetc()) == '\\') { > + next = igetc(); > + if (next != '\n') { > + c = next; > + break; > + } > + yylval.lineno = file->lineno; > + file->lineno++; > + } > + if (c == '\t' || c == ' ') { > + /* Compress blanks to a sigle space. */ > + do { > + c = getc(file->stream); > + } while (c == '\t' || c == ' '); > + ungetc(c, file->stream); > + c = ' '; > + } > + > + if (c == EOF) { > + /* > + * Fake EOL when hit EOF for the first time. This gets line > + * count rigchtif last line included file is syntactically > + * invalid and has no newline. > + */ > + if (file->eof_reached == 0) { > + file->eof_reached = 1; > + return ('\n'); > + } > + while (c == EOF) { > + if (file == topfile || popfile() == EOF) > + return (EOF); > + c = igetc(); > + } > + } > + return (c); > +} > + > +void > +lungetc(int c) > +{ > + if (c == EOF) > + return; > + > + if (file->ungetpos >= file->ungetsize) { > + void *p = reallocarray(file->ungetbuf, file->ungetsize, 2); > + if (p == NULL) > + err(1, "reallocarray"); > + file->ungetbuf = p; > + file->ungetsize *= 2; > + } > + file->ungetbuf[file->ungetpos++] = c; > +} > + > +int > +findeol(void) > +{ > + int c; > + > + /* skip to either EOF or the first real EOL */ > + while (1) { > + c = lgetc(0); > + if (c == '\n') { > + file->lineno++; > + break; > + } > + if (c == EOF) > + break; > + } > + return (ERROR); > +} > + > +int > +yylex(void) > +{ > + char buf[8096]; > + char *p = buf; > + int c; > + int token; > + int starting = 0; > + int ending = 0; > + > + if (!in_define && block == 0) { > + while ((c = lgetc(0)) != '{' && c != EOF) { > + if (c == '\n') > + file->lineno++; > + } > + > + if (c == EOF) > + return (0); > + > +newblock: > + c = lgetc(0); > + if (c == '{' || c == '!') { > + if (c == '{') > + block = '}'; > + else > + block = c; > + return (c); > + } > + if (c == '\n') > + file->lineno++; > + } > + > + while ((c = lgetc(0)) == ' ' || c == '\t' || c == '\n') { > + if (c == '\n') > + file->lineno++; > + } > + > + if (c == EOF) { > + yyerror("unterminated block"); > + return (0); > + } > + > + yylval.lineno = file->lineno; > + > + if (block != 0 && c == block) { > + if ((c = lgetc(0)) == '}') { > + if (block == '!') { > + block = 0; > + return ('!'); > + } > + block = 0; > + return ('}'); > + } > + lungetc(c); > + c = block; > + } > + > + if (in_define && block == 0) { > + if (c == '{') > + goto newblock; > + > + do { > + if (starting) { > + if (c == '!' || c == '{') { > + lungetc('{'); > + lungetc(c); > + break; > + } > + starting = 0; > + lungetc(c); > + c = '{'; > + } else if (c == '{') { > + starting = 1; > + continue; > + } > + > + *p++ = c; > + if ((size_t)(p - buf) >= sizeof(buf)) { > + yyerror("string too long"); > + return (findeol()); > + } > + } while ((c = lgetc(0)) != EOF && c != '\n'); > + *p = '\0'; > + if (c == EOF) { > + yyerror("unterminated block"); > + return (0); > + } > + if (c == '\n') > + file->lineno++; > + if ((yylval.v.string = strdup(buf)) == NULL) > + err(1, "strdup"); > + return (STRING); > + } > + > + if (block == '!') { > + do { > + if (ending) { > + if (c == '}') { > + lungetc(c); > + lungetc(block); > + break; > + } > + ending = 0; > + lungetc(c); > + c = block; > + } else if (c == '!') { > + ending = 1; > + continue; > + } > + > + *p++ = c; > + if ((size_t)(p - buf) >= sizeof(buf)) { > + yyerror("line too long"); > + return (findeol()); > + } > + } while ((c = lgetc(0)) != EOF && c != '\n'); > + *p = '\0'; > + > + if (c == EOF) { > + yyerror("unterminated block"); > + return (0); > + } > + if (c == '\n') > + file->lineno++; > + > + if ((yylval.v.string = strdup(buf)) == NULL) > + err(1, "strdup"); > + return (STRING); > + } > + > + if (c == '|') > + return (c); > + > + do { > + if (c == '|') { > + lungetc(c); > + break; > + } > + > + if (ending) { > + if (c == '}') { > + lungetc(c); > + lungetc('}'); > + break; > + } > + ending = 0; > + lungetc(c); > + c = block; > + } else if (c == '}') { > + ending = 1; > + continue; > + } > + > + *p++ = c; > + if ((size_t)(p - buf) >= sizeof(buf)) { > + yyerror("string too long"); > + return (findeol()); > + } > + } while ((c = lgetc(0)) != EOF && !isspace((unsigned char)c)); > + *p = '\0'; > + > + if (c == EOF) { > + yyerror("unterminated block"); > + return (0); > + } > + if (c == '\n') > + file->lineno++; > + if ((token = lookup(buf)) == STRING) > + if ((yylval.v.string = strdup(buf)) == NULL) > + err(1, "strdup"); > + return (token); > +} > + > +struct file * > +pushfile(const char *name, int secret) > +{ > + struct file *nfile; > + > + if ((nfile = calloc(1, sizeof(*nfile))) == NULL) > + err(1, "calloc"); > + if ((nfile->name = strdup(name)) == NULL) > + err(1, "strdup"); > + if ((nfile->stream = fopen(nfile->name, "r")) == NULL) { > + warn("can't open %s", nfile->name); > + free(nfile->name); > + free(nfile); > + return (NULL); > + } > + nfile->lineno = TAILQ_EMPTY(&files) ? 1 : 0; > + nfile->ungetsize = 16; > + nfile->ungetbuf = malloc(nfile->ungetsize); > + if (nfile->ungetbuf == NULL) > + err(1, "malloc"); > + TAILQ_INSERT_TAIL(&files, nfile, entry); > + return (nfile); > +} > + > +int > +popfile(void) > +{ > + struct file *prev; > + > + if ((prev = TAILQ_PREV(file, files, entry)) != NULL) > + prev->errors += file->errors; > + > + TAILQ_REMOVE(&files, file, entry); > + fclose(file->stream); > + free(file->name); > + free(file->ungetbuf); > + free(file); > + file = prev; > + return (file ? 0 : EOF); > +} > + > +int > +parse(const char *filename) > +{ > + if ((file = pushfile(filename, 0)) == 0) > + return (-1); > + topfile = file; > + > + yyparse(); > + errors = file->errors; > + popfile(); > + > + return (errors ? -1 : 0); > +} > + > +void > +dbg(void) > +{ > + if (nodebug) > + return; > + > + printf("#line %d ", yylval.lineno); > + printq(file->name); > + putchar('\n'); > +} > + > +void > +printq(const char *str) > +{ > + putchar('"'); > + for (; *str; ++str) { > + if (*str == '"') > + putchar('\\'); > + putchar(*str); > + } > + putchar('"'); > +} > blob - /dev/null > file + gotwebd/template/regress/00-empty.tmpl > blob - /dev/null > file + gotwebd/template/regress/01-noise-only.tmpl > --- /dev/null > +++ gotwebd/template/regress/01-noise-only.tmpl > @@ -0,0 +1,2 @@ > +only > +noise > blob - /dev/null > file + gotwebd/template/regress/02-only-verbatim.tmpl > --- /dev/null > +++ gotwebd/template/regress/02-only-verbatim.tmpl > @@ -0,0 +1,13 @@ > +{! #include !} > + > +noise > +here > + > +{! > +int > +main(void) > +{ > + puts("hello, world!"); > + return 0; > +} > +!} > blob - /dev/null > file + gotwebd/template/regress/02.expected > --- /dev/null > +++ gotwebd/template/regress/02.expected > @@ -0,0 +1 @@ > +hello, world! > blob - /dev/null > file + gotwebd/template/regress/03-block.tmpl > --- /dev/null > +++ gotwebd/template/regress/03-block.tmpl > @@ -0,0 +1,17 @@ > +{! #include !} > + > +{{ define base(struct template *tp, const char *title) }} > +{! char *foo = NULL; !} > + > + > + > + {{ title }} > + > + > +

> + {{ render tp->tp_body }} > + > + > +{{ finally }} > +{! free(foo); !} > +{{ end }} > blob - /dev/null > file + gotwebd/template/regress/03.expected > --- /dev/null > +++ gotwebd/template/regress/03.expected > @@ -0,0 +1,2 @@ > + *hello*

hello

> +<hello>

<hello>

> blob - /dev/null > file + gotwebd/template/regress/04-flow.tmpl > --- /dev/null > +++ gotwebd/template/regress/04-flow.tmpl > @@ -0,0 +1,30 @@ > +{! > +#include > +#include > +!} > + > +{{ define base(struct template *tp, const char *title) }} > +{! char *foo = NULL; !} > + > + > + > + {{ title }} > + > + > +

> + {{ if strchr(title, '*') != NULL }} > +

"{{ title }}" has a '*' in it

> + {{ if 1 }} > +

tautology!

> + {{ end }} > + {{ else if strchr(title, '=') != NULL }} > +

"{{ title }}" has a '=' in it!

> + {{ else }} > +

"{{ title }}" doesn't have a '*' in it

> + {{ end }} > + {{ render tp->tp_body }} > + > + > +{{ finally }} > +{! free(foo); !} > +{{ end }} > blob - /dev/null > file + gotwebd/template/regress/04.expected > --- /dev/null > +++ gotwebd/template/regress/04.expected > @@ -0,0 +1,2 @@ > + *hello*

hello

" *hello* " has a '*' in it

tautology!

> +<hello>

<hello>

"<hello>" doesn't have a '*' in it

> blob - /dev/null > file + gotwebd/template/regress/05-loop.tmpl > --- /dev/null > +++ gotwebd/template/regress/05-loop.tmpl > @@ -0,0 +1,31 @@ > +{! > +#include > +#include > +#include "lists.h" > + > +int list(struct template *, struct tailhead *); > + > +!} > + > +{{ define base(struct template *tp, struct tailhead *head) }} > + > + > + > + {{ render list(tp, head) }} > + > + > +{{ end }} > + > +{{ define list(struct template *tp, struct tailhead *head) }} > + {! struct entry *np; !} > + {{ if !TAILQ_EMPTY(head) }} > +

items:

> +

{{ np->text }}

> + {{ else }} > +

no items

> + {{ end }} > +{{ end }} > blob - /dev/null > file + gotwebd/template/regress/05.expected > --- /dev/null > +++ gotwebd/template/regress/05.expected > @@ -0,0 +1,2 @@ > +

items:

> +

no items

> blob - /dev/null > file + gotwebd/template/regress/06-escape.tmpl > --- /dev/null > +++ gotwebd/template/regress/06-escape.tmpl > @@ -0,0 +1,14 @@ > +{! #include !} > + > +{{ define base(struct template *tp, const char *title) }} > + > + > + > + {{ title | urlescape }} > + > + > +

> + {{ render tp->tp_body }} > + > + > +{{ end }} > blob - /dev/null > file + gotwebd/template/regress/06.expected > --- /dev/null > +++ gotwebd/template/regress/06.expected > @@ -0,0 +1,2 @@ > +%20*hello*%20

hello

> +<hello>

> blob - /dev/null > file + gotwebd/template/regress/Makefile > --- /dev/null > +++ gotwebd/template/regress/Makefile > @@ -0,0 +1,55 @@ > +REGRESS_TARGETS = 00-empty \ > + 01-noise-only \ > + 02-only-verbatim \ > + 03-block \ > + 04-flow \ > + 05-loop \ > + 06-escape > + > +REGRESS_SETUP_ONCE = setup-comp > +REGRESS_CLEANUP = clean-comp > +NO_OBJ = Yes > + > +CFLAGS += -I${.CURDIR}/../ > + > +setup-comp: > + cp ${.CURDIR}/../tmpl.c . > + ln -f ${.CURDIR}/../template template || \ > + ln -f ${.CURDIR}/../obj/template template > + > +clean-comp: > + rm template > + rm -f t got 0*.[cdo] runbase.[do] runlist.[do] tmpl.* > + > +.SUFFIXES: .tmpl .c .o > + > +.tmpl.c: > + ./template $? > $@ > + > +00-empty: > + ./template 00-empty.tmpl >/dev/null > + > +01-noise-only: > + ./template 01-noise-only.tmpl >/dev/null > + > +02-only-verbatim: 02-only-verbatim.o tmpl.o > + ${CC} 02-only-verbatim.o tmpl.o -o t && ./t > got > + diff -u ${.CURDIR}/02.expected got > + > +03-block: 03-block.o runbase.o tmpl.o > + ${CC} 03-block.o runbase.o tmpl.o -o t && ./t > got > + diff -u ${.CURDIR}/03.expected got > + > +04-flow: 04-flow.o runbase.o tmpl.o > + ${CC} 04-flow.o runbase.o tmpl.o -o t && ./t > got > + diff -u ${.CURDIR}/04.expected got > + > +05-loop: 05-loop.o runlist.o tmpl.o > + ${CC} 05-loop.o runlist.o tmpl.o -o t && ./t > got > + diff -u ${.CURDIR}/05.expected got > + > +06-escape: 06-escape.o runbase.o tmpl.o > + ${CC} 06-escape.o runbase.o tmpl.o -o t && ./t > got > + diff -u ${.CURDIR}/06.expected got > + > +.include > blob - /dev/null > file + gotwebd/template/regress/lists.h > --- /dev/null > +++ gotwebd/template/regress/lists.h > @@ -0,0 +1,7 @@ > +#include > + > +TAILQ_HEAD(tailhead, entry); > +struct entry { > + char *text; > + TAILQ_ENTRY(entry) entries; > +}; > blob - /dev/null > file + gotwebd/template/regress/runbase.c > --- /dev/null > +++ gotwebd/template/regress/runbase.c > @@ -0,0 +1,69 @@ > +/* > + * Copyright (c) 2022 Omar Polo > + * > + * Permission to use, copy, modify, and distribute this software for any > + * purpose with or without fee is hereby granted, provided that the above > + * copyright notice and this permission notice appear in all copies. > + * > + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES > + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF > + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR > + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES > + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN > + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF > + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. > + */ > + > +#include > +#include > +#include > + > +#include "tmpl.h" > + > +int base(struct template *, const char *title); > + > +int > +my_putc(struct template *tp, int c) > +{ > + FILE *fp = tp->tp_arg; > + > + if (putc(c, fp) < 0) { > + tp->tp_ret = -1; > + return (-1); > + } > + > + return (0); > +} > + > +int > +my_puts(struct template *tp, const char *s) > +{ > + FILE *fp = tp->tp_arg; > + > + if (fputs(s, fp) < 0) { > + tp->tp_ret = -1; > + return (-1); > + } > + > + return (0); > +} > + > +int > +main(int argc, char **argv) > +{ > + struct template *tp; > + > + if ((tp = template(stdout, my_puts, my_putc)) == NULL) > + err(1, "template"); > + > + base(tp, " *hello* "); > + puts(""); > + > + template_reset(tp); > + > + base(tp, ""); > + puts(""); > + > + free(tp); > + return (0); > +} > blob - /dev/null > file + gotwebd/template/regress/runlist.c > --- /dev/null > +++ gotwebd/template/regress/runlist.c > @@ -0,0 +1,89 @@ > +/* > + * Copyright (c) 2022 Omar Polo > + * > + * Permission to use, copy, modify, and distribute this software for any > + * purpose with or without fee is hereby granted, provided that the above > + * copyright notice and this permission notice appear in all copies. > + * > + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES > + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF > + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR > + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES > + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN > + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF > + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. > + */ > + > +#include > +#include > +#include > + > +#include "tmpl.h" > +#include "lists.h" > + > +int base(struct template *, struct tailhead *); > + > +int > +my_putc(struct template *tp, int c) > +{ > + FILE *fp = tp->tp_arg; > + > + if (putc(c, fp) < 0) { > + tp->tp_ret = -1; > + return (-1); > + } > + > + return (0); > +} > + > +int > +my_puts(struct template *tp, const char *s) > +{ > + FILE *fp = tp->tp_arg; > + > + if (fputs(s, fp) < 0) { > + tp->tp_ret = -1; > + return (-1); > + } > + > + return (0); > +} > + > +int > +main(int argc, char **argv) > +{ > + struct template *tp; > + struct tailhead head; > + struct entry *np; > + int i; > + > + if ((tp = template(stdout, my_puts, my_putc)) == NULL) > + err(1, "template"); > + > + TAILQ_INIT(&head); > + for (i = 0; i < 2; ++i) { > + if ((np = calloc(1, sizeof(*np))) == NULL) > + err(1, "calloc"); > + if (asprintf(&np->text, "%d", i+1) == -1) > + err(1, "asprintf"); > + TAILQ_INSERT_TAIL(&head, np, entries); > + } > + > + base(tp, &head); > + puts(""); > + > + while ((np = TAILQ_FIRST(&head))) { > + TAILQ_REMOVE(&head, np, entries); > + free(np->text); > + free(np); > + } > + > + template_reset(tp); > + > + base(tp, &head); > + puts(""); > + > + free(tp); > + > + return (0); > +} > blob - /dev/null > file + gotwebd/template/template.c > --- /dev/null > +++ gotwebd/template/template.c > @@ -0,0 +1,67 @@ > +/* > + * Copyright (c) 2022 Omar Polo > + * > + * Permission to use, copy, modify, and distribute this software for any > + * purpose with or without fee is hereby granted, provided that the above > + * copyright notice and this permission notice appear in all copies. > + * > + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES > + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF > + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR > + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES > + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN > + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF > + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. > + */ > + > +#include > +#include > +#include > +#include > + > +int parse(const char *); > + > +int nodebug; > + > +static void __dead > +usage(void) > +{ > + fprintf(stderr, "usage: %s [file...]\n", > + getprogname()); > + exit(1); > +} > + > +int > +main(int argc, char **argv) > +{ > + int ch, i; > + > + if (pledge("stdio rpath", NULL) == -1) > + err(1, "pledge"); > + > + while ((ch = getopt(argc, argv, "G")) != -1) { > + switch (ch) { > + case 'G': > + nodebug = 1; > + break; > + default: > + usage(); > + } > + } > + argc -= optind; > + argv += optind; > + > + /* preamble */ > + puts("#include \"tmpl.h\""); > + > + if (argc == 0) { > + parse("/dev/stdin"); > + exit(0); > + } > + > + for (i = 0; i < argc; ++i) > + if (parse(argv[i]) == -1) > + return (1); > + > + return (0); > +} > blob - /dev/null > file + gotwebd/template/tmpl.c > --- /dev/null > +++ gotwebd/template/tmpl.c > @@ -0,0 +1,105 @@ > +/* > + * Copyright (c) 2022 Omar Polo > + * > + * Permission to use, copy, modify, and distribute this software for any > + * purpose with or without fee is hereby granted, provided that the above > + * copyright notice and this permission notice appear in all copies. > + * > + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES > + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF > + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR > + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES > + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN > + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF > + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. > + */ > + > +#include > +#include > +#include > + > +#include "tmpl.h" > + > +int > +tp_urlescape(struct template *tp, const char *str) > +{ > + int r; > + char tmp[4]; > + > + for (; *str; ++str) { > + if (iscntrl((unsigned char)*str) || > + isspace((unsigned char)*str) || > + *str == '\'' || *str == '"' || *str == '\\') { > + r = snprintf(tmp, sizeof(tmp), "%%%2X", *str); > + if (r < 0 || (size_t)r >= sizeof(tmp)) { > + tp->tp_ret = -1; > + return (-1); > + } > + if (tp->tp_puts(tp, tmp) == -1) > + return (-1); > + } else { > + if (tp->tp_putc(tp, *str) == -1) > + return (-1); > + } > + } > + > + return (0); > +} > + > +int > +tp_htmlescape(struct template *tp, const char *str) > +{ > + int r; > + > + for (; *str; ++str) { > + switch (*str) { > + case '<': > + r = tp->tp_puts(tp, "<"); > + break; > + case '>': > + r = tp->tp_puts(tp, ">"); > + break; > + case '&': > + r = tp->tp_puts(tp, "&"); > + break; > + case '"': > + r = tp->tp_puts(tp, """); > + break; > + case '\'': > + r = tp->tp_puts(tp, "'"); > + break; > + default: > + r = tp->tp_putc(tp, *str); > + break; > + } > + > + if (r == -1) { > + tp->tp_ret = -1; > + return (-1); > + } > + } > + > + return (0); > +} > + > +struct template * > +template(void *arg, tmpl_puts putsfn, tmpl_putc putcfn) > +{ > + struct template *tp; > + > + if ((tp = calloc(1, sizeof(*tp))) == NULL) > + return (NULL); > + > + tp->tp_arg = arg; > + tp->tp_escape = tp_htmlescape; > + tp->tp_puts = putsfn; > + tp->tp_putc = putcfn; > + > + return (tp); > +} > + > +void > +template_reset(struct template *tp) > +{ > + tp->tp_ret = 0; > +} > blob - /dev/null > file + gotwebd/template/tmpl.h > --- /dev/null > +++ gotwebd/template/tmpl.h > @@ -0,0 +1,42 @@ > +/* > + * Copyright (c) 2022 Omar Polo > + * > + * Permission to use, copy, modify, and distribute this software for any > + * purpose with or without fee is hereby granted, provided that the above > + * copyright notice and this permission notice appear in all copies. > + * > + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES > + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF > + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR > + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES > + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN > + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF > + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. > + */ > + > +#ifndef TMPL_H > +#define TMPL_H > + > +struct template; > + > +typedef int (*tmpl_puts)(struct template *, const char *); > +typedef int (*tmpl_putc)(struct template *, int); > + > +struct template { > + void *tp_arg; > + tmpl_puts tp_escape; > + tmpl_puts tp_puts; > + tmpl_putc tp_putc; > + > + int tp_ret; > + > + int (*tp_body)(struct template *); > +}; > + > +int tp_urlescape(struct template *, const char *); > +int tp_htmlescape(struct template *, const char *); > + > +struct template *template(void *, tmpl_puts, tmpl_putc); > +void template_reset(struct template *); > + > +#endif > -- Tracey Emery

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