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1 | %%% -*-latex-*- |
2 | %%% | |
3 | %%% Output machinery | |
4 | %%% | |
5 | %%% (c) 2015 Straylight/Edgeware | |
6 | %%% | |
7 | ||
8 | %%%----- Licensing notice --------------------------------------------------- | |
9 | %%% | |
e0808c47 | 10 | %%% This file is part of the Sensible Object Design, an object system for C. |
1f7d590d MW |
11 | %%% |
12 | %%% SOD is free software; you can redistribute it and/or modify | |
13 | %%% it under the terms of the GNU General Public License as published by | |
14 | %%% the Free Software Foundation; either version 2 of the License, or | |
15 | %%% (at your option) any later version. | |
16 | %%% | |
17 | %%% SOD is distributed in the hope that it will be useful, | |
18 | %%% but WITHOUT ANY WARRANTY; without even the implied warranty of | |
19 | %%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
20 | %%% GNU General Public License for more details. | |
21 | %%% | |
22 | %%% You should have received a copy of the GNU General Public License | |
23 | %%% along with SOD; if not, write to the Free Software Foundation, | |
24 | %%% Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
25 | ||
26 | \chapter{The output system} \label{ch:output} | |
27 | ||
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28 | This chapter deals with actually generating output files. It will be of |
29 | interest to programmers introducing new layout object classes, or new kinds | |
30 | of output files. An understanding of the material in | |
31 | \xref{sec:structures.layout} will prove valuable. | |
32 | ||
1f7d590d | 33 | %%%-------------------------------------------------------------------------- |
d3dac74a MW |
34 | \section{Output sequencing} \label{sec:output.sequencer} |
35 | ||
36 | C compilers are picky about the order in which things are presented to them | |
37 | in their input; but information about the structure of our classes is | |
38 | scattered among a variety of different layout objects. It's not the case | |
39 | that a layout object only contributes to a single localized portion of the | |
40 | output: for example, a @|vtmsgs| layout object is responsible for declaring | |
41 | both the appropriate @|struct $C$__vtmsgs_$a$| structure in the header file, | |
42 | populated with method entry pointers, but also declaring its member in the | |
43 | enclosing @|struct $C$__vt_$i$| structure. | |
44 | ||
45 | One approach would be to have the various layout objects just know how to | |
46 | call each other in the right order so as to have everything come out | |
47 | properly. That would make extending the translator, e.g., to add new kinds | |
48 | of layout objects, rather difficult. And it doesn't let users insert custom | |
49 | C fragments in flexible ways. | |
50 | ||
51 | Instead, there's a clear separation between which things need to be output, | |
52 | and the order in which they're produced. | |
53 | ||
54 | Ordering is handled by a \emph{sequencer} object. A sequencer doesn't know | |
55 | anything particular about output: its job is simply to do things in a | |
56 | particular order. It's described here because Sod only uses it for output | |
57 | scheduling. | |
58 | ||
59 | A sequencer maintains a collection of named \emph{items}, each of which has a | |
60 | name and a list of functions associated with it. A name can be any Lisp | |
61 | object. Names are compared using @|equal|, so lists can be used to construct | |
62 | a hierarchical namespace. | |
63 | ||
64 | The sequencer also maintains a collection of \emph{constraints}, which take | |
65 | the form of lists of item names. A constraint of the form @|($N_1$, $N_2$, | |
66 | $\ldots$, $N_k$)| requires that the item named $N_1$ must be scheduled before | |
67 | the item named $N_2$, and so on, all of which must be scheduled before the | |
68 | item named $N_k$. Items with these names do not need to exist or be known to | |
69 | the sequencer. An item name may appear in any number of constraints, all of | |
70 | which apply. | |
71 | ||
72 | It might be that a collection of constraints is impossible to satisfy: for | |
73 | example, the set | |
74 | \begin{center} \codeface | |
75 | (alice bob) \qquad (bob carol) \qquad (carol alice) | |
76 | \end{center} | |
77 | can't be satisfied, since the first constraint requires that @|alice| | |
78 | precedes @|bob|, but the third says that @|alice| must come after @|carol|, | |
79 | and the second that @|carol| comes after @|bob|: it's not possible that | |
80 | @|alice| comes before @|bob| and after @|bob|. In this case, the sequencer | |
81 | fails and signals an error of type @|inconsistent-merge-error|. | |
82 | ||
83 | It is possible, but tedious, to explicitly order an entire collection of | |
84 | items by adding constraints. In the absence of explicit constraints to order | |
85 | them, items are ordered according to the order in which constraints naming | |
86 | them were first added to the sequencer. Items not named in any constraint | |
87 | are not processed at all. | |
88 | ||
89 | For example, suppose we have the following constraints. | |
90 | \begin{center} \codeface | |
91 | (perl java) \qquad | |
92 | (lisp java) \qquad | |
93 | (python icon) \qquad | |
94 | (icon perl) | |
95 | \end{center} | |
96 | The constraints give us that $@|python| < @|icon| < @|perl| < @|java|$, and | |
97 | also $@|lisp| < @|java|$. In this case, @|lisp| precedes @|python| because | |
98 | @|lisp| is mentioned in the second constraint while @|python| isn't mentioned | |
99 | until the third. So the final processing order is | |
100 | \begin{center} | |
101 | @|lisp|, \quad | |
102 | @|python|, \quad | |
103 | @|icon|, \quad | |
104 | @|perl|, \quad | |
105 | @|java| | |
106 | \end{center} | |
107 | ||
1f7d590d | 108 | |
bca101d9 | 109 | \begin{describe}{cls}{sequencer-item} |
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110 | An object of class @|sequencer-item| represents a sequencer item. |
111 | Sequencer items maintain a \emph{name} and a list of \emph{functions}. | |
112 | Names are compared using @|equal|. | |
113 | ||
114 | The functions are maintained in \emph{reverse order}, because it's | |
115 | convenient to be able to add new functions using @|push|. | |
bca101d9 MW |
116 | \end{describe} |
117 | ||
118 | \begin{describe}{fun}{sequencer-item-p @<object> @> @<generalized-boolean>} | |
d3dac74a | 119 | Return non-nil if and only if @<object> is a @|sequencer-item|. |
bca101d9 MW |
120 | \end{describe} |
121 | ||
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122 | \begin{describe}{fun} |
123 | {make-sequencer-item @<name> \&optional @<functions> @> @<item>} | |
124 | Create and return a new sequencer item with the given @<name> and list of | |
125 | @<functions>; the list of functions defaults to nil if omitted. | |
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126 | \end{describe} |
127 | ||
128 | \begin{describe*} | |
129 | {\dhead{fun}{sequencer-item-name @<item> @> @<name>} | |
130 | \dhead{fun}{sequencer-item-functions @<item> @> @<list>} | |
131 | \dhead{fun}{setf (sequencer-item-functions @<item>) @<list>}} | |
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132 | These functions read or modify the state of a sequencer @<item>, as |
133 | originally established by @|make-sequencer-item|. | |
134 | ||
135 | It is an error to modify an item's list of functions during a call to | |
136 | @|invoke-sequencer-items| on the item's owning sequencer. | |
bca101d9 MW |
137 | \end{describe*} |
138 | ||
139 | \begin{describe}{cls}{sequencer () \&key :constraints} | |
140 | \end{describe} | |
141 | ||
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142 | \begin{describe*} |
143 | {\dhead{fun}{sequencer-constraints @<sequencer> @> @<list>} | |
144 | \dhead{fun}{setf (sequencer-constraints @<sequencer>) @<list>} | |
145 | \dhead{fun}{sequencer-table @<sequencer> @> @<hash-table>}} | |
146 | \end{describe*} | |
147 | ||
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148 | \begin{describe}{fun}{ensure-sequencer-item @<sequencer> @<name> @> @<item>} |
149 | \end{describe} | |
150 | ||
151 | \begin{describe}{fun}{add-sequencer-constraint @<sequencer> @<constraint>} | |
152 | \end{describe} | |
153 | ||
a75cd932 MW |
154 | \begin{describe}{fun} |
155 | {add-sequencer-item-function @<sequencer> @<name> @<function>} | |
156 | \end{describe} | |
157 | ||
bca101d9 MW |
158 | \begin{describe}{fun} |
159 | {invoke-sequencer-items @<sequencer> \&rest @<arguments>} | |
160 | \end{describe} | |
161 | ||
d3dac74a | 162 | \begin{describe}{gf}{hook-output progn @<object> @<reason> @<sequencer>} |
87883222 | 163 | \begin{describe}{meth}{t,t} |
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164 | {hook-output progn (@<object> t) (@<reason> t) @<sequencer>} |
165 | \end{describe} | |
bca101d9 MW |
166 | \end{describe} |
167 | ||
168 | \begin{describe}{mac} | |
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169 | {sequence-output (@<stream-var> @<sequencer>) \\ \ind |
170 | @{ :constraint (@<item-name>^*) @} \\ | |
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171 | @{ (@<item-name> @<form>^*) @}^*} |
172 | \end{describe} | |
173 | ||
d3dac74a | 174 | %%%-------------------------------------------------------------------------- |
831b018f | 175 | \section{Module output} \label{output.module} |
d3dac74a | 176 | |
831b018f | 177 | \subsection{Producing output} |
d3dac74a | 178 | |
b0e21f83 MW |
179 | \begin{describe}{gf} |
180 | {module-output-file @<module> @<output-type> @<output-dir> | |
181 | @> @<pathname>} | |
182 | \begin{describe*} | |
183 | {\dhead{meth}{module,symbol} | |
184 | {module-output-file \=(@<module> module) \\ | |
185 | \>(@<output-type> symbol) \\ | |
186 | \>@<output-dir> | |
187 | \nlret @<pathname>} | |
188 | \dhead{meth}{module,pathname} | |
189 | {module-output-file \=(@<module> module) \\ | |
190 | \>(@<output-type> pathname) \\ | |
191 | \>@<output-dir> | |
192 | \nlret @<pathname>}} | |
193 | \end{describe*} | |
194 | \end{describe} | |
195 | ||
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196 | \begin{describe}{gf}{write-dependency-file @<module> @<reason> @<output-dir>} |
197 | \end{describe} | |
198 | ||
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199 | \begin{describe}{fun}{output-module @<module> @<reason> @<stream>} |
200 | \end{describe} | |
201 | ||
202 | ||
203 | \subsection{Managing output types} \label{output.module.manage} | |
204 | ||
205 | \begin{describe}{fun}{declare-output-type @<reason> @<pathname>} | |
206 | \end{describe} | |
207 | ||
208 | \begin{describe}{fun}{output-type-pathname @<reason> @> @<pathname>} | |
209 | \end{describe} | |
210 | ||
211 | ||
212 | \subsection{Utilities} \label{output.module.utilities} | |
213 | ||
214 | \begin{describe}{fun}{banner @<title> @<output> \&key :blank-line-p} | |
215 | \end{describe} | |
216 | ||
217 | \begin{describe}{fun}{guard-name @<filename> @> @<string>} | |
218 | \end{describe} | |
d3dac74a | 219 | |
e674612e MW |
220 | \begin{describe}{fun} |
221 | {one-off-output @<token> @<sequencer> @<item-name> @<function>} | |
222 | \end{describe} | |
223 | ||
d3dac74a | 224 | %%%-------------------------------------------------------------------------- |
831b018f | 225 | \section{Class output} \label{output.class} |
d3dac74a MW |
226 | |
227 | \begin{describe}{var}{*instance-class*} | |
228 | \end{describe} | |
bca101d9 | 229 | |
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230 | %% output for `h' files |
231 | %% | |
232 | %% prologue | |
233 | %% guard start | |
234 | %% typedefs start | |
235 | %% typedefs | |
236 | %% typedefs end | |
237 | %% includes start | |
238 | %% includes | |
239 | %% includes end | |
240 | %% classes start | |
a3e1423b MW |
241 | %% early-user start |
242 | %% early-user | |
243 | %% early-user end | |
1f7d590d MW |
244 | %% CLASS banner |
245 | %% CLASS islots start | |
246 | %% CLASS islots slots | |
247 | %% CLASS islots end | |
248 | %% CLASS vtmsgs start | |
249 | %% CLASS vtmsgs CLASS start | |
250 | %% CLASS vtmsgs CLASS slots | |
251 | %% CLASS vtmsgs CLASS end | |
252 | %% CLASS vtmsgs end | |
253 | %% CLASS vtables start | |
254 | %% CLASS vtables CHAIN-HEAD start | |
255 | %% CLASS vtables CHAIN-HEAD slots | |
256 | %% CLASS vtables CHAIN-HEAD end | |
257 | %% CLASS vtables end | |
258 | %% CLASS vtable-externs | |
259 | %% CLASS vtable-externs-after | |
260 | %% CLASS methods start | |
261 | %% CLASS methods | |
262 | %% CLASS methods end | |
263 | %% CLASS ichains start | |
264 | %% CLASS ichains CHAIN-HEAD start | |
265 | %% CLASS ichains CHAIN-HEAD slots | |
266 | %% CLASS ichains CHAIN-HEAD end | |
267 | %% CLASS ichains end | |
268 | %% CLASS ilayout start | |
269 | %% CLASS ilayout slots | |
270 | %% CLASS ilayout end | |
271 | %% CLASS conversions | |
272 | %% CLASS object | |
273 | %% classes end | |
a3e1423b MW |
274 | %% user start |
275 | %% user | |
276 | %% user end | |
1f7d590d MW |
277 | %% guard end |
278 | %% epilogue | |
279 | ||
280 | %% output for `c' files | |
281 | %% | |
282 | %% prologue | |
283 | %% includes start | |
284 | %% includes | |
285 | %% includes end | |
a3e1423b MW |
286 | %% early-user start |
287 | %% early-user | |
288 | %% early-user end | |
1f7d590d MW |
289 | %% classes start |
290 | %% CLASS banner | |
291 | %% CLASS direct-methods start | |
292 | %% CLASS direct-methods METHOD start | |
293 | %% CLASS direct-methods METHOD body | |
294 | %% CLASS direct-methods METHOD end | |
295 | %% CLASS direct-methods end | |
296 | %% CLASS effective-methods | |
297 | %% CLASS vtables start | |
298 | %% CLASS vtables CHAIN-HEAD start | |
299 | %% CLASS vtables CHAIN-HEAD class-pointer METACLASS | |
300 | %% CLASS vtables CHAIN-HEAD base-offset | |
301 | %% CLASS vtables CHAIN-HEAD chain-offset TARGET-HEAD | |
302 | %% CLASS vtables CHAIN-HEAD vtmsgs CLASS start | |
303 | %% CLASS vtables CHAIN-HEAD vtmsgs CLASS slots | |
304 | %% CLASS vtables CHAIN-HEAD vtmsgs CLASS end | |
305 | %% CLASS vtables CHAIN-HEAD end | |
306 | %% CLASS vtables end | |
307 | %% CLASS object prepare | |
308 | %% CLASS object start | |
309 | %% CLASS object CHAIN-HEAD ichain start | |
310 | %% CLASS object SUPER slots start | |
311 | %% CLASS object SUPER slots | |
312 | %% CLASS object SUPER vtable | |
313 | %% CLASS object SUPER slots end | |
314 | %% CLASS object CHAIN-HEAD ichain end | |
315 | %% CLASS object end | |
316 | %% classes end | |
a3e1423b MW |
317 | %% user start |
318 | %% user | |
319 | %% user end | |
1f7d590d MW |
320 | %% epilogue |
321 | ||
322 | %%%----- That's all, folks -------------------------------------------------- | |
323 | ||
324 | %%% Local variables: | |
325 | %%% mode: LaTeX | |
326 | %%% TeX-master: "sod.tex" | |
327 | %%% TeX-PDF-mode: t | |
328 | %%% End: |