| TOUR (245689) | TOUR (253650) |
|---|---|
| 1# @(#)TOUR 8.1 (Berkeley) 5/31/93 | 1# @(#)TOUR 8.1 (Berkeley) 5/31/93 |
| 2# $FreeBSD: head/bin/sh/TOUR 245689 2013-01-20 12:44:50Z jilles $ | 2# $FreeBSD: head/bin/sh/TOUR 253650 2013-07-25 15:08:41Z jilles $ |
| 3 4NOTE -- This is the original TOUR paper distributed with ash and 5does not represent the current state of the shell. It is provided anyway 6since it provides helpful information for how the shell is structured, 7but be warned that things have changed -- the current shell is 8still under development. 9 10================================================================ --- 9 unchanged lines hidden (view full) --- 20 21SOURCE CODE GENERATORS: Files whose names begin with "mk" are 22programs that generate source code. A complete list of these 23programs is: 24 25 program input files generates 26 ------- ----------- --------- 27 mkbuiltins builtins builtins.h builtins.c | 3 4NOTE -- This is the original TOUR paper distributed with ash and 5does not represent the current state of the shell. It is provided anyway 6since it provides helpful information for how the shell is structured, 7but be warned that things have changed -- the current shell is 8still under development. 9 10================================================================ --- 9 unchanged lines hidden (view full) --- 20 21SOURCE CODE GENERATORS: Files whose names begin with "mk" are 22programs that generate source code. A complete list of these 23programs is: 24 25 program input files generates 26 ------- ----------- --------- 27 mkbuiltins builtins builtins.h builtins.c |
| 28 mkinit *.c init.c | |
| 29 mknodes nodetypes nodes.h nodes.c 30 mksyntax - syntax.h syntax.c 31 mktokens - token.h 32 | 28 mknodes nodetypes nodes.h nodes.c 29 mksyntax - syntax.h syntax.c 30 mktokens - token.h 31 |
| 33There are undoubtedly too many of these. Mkinit searches all the 34C source files for entries looking like: | 32There are undoubtedly too many of these. |
| 35 | 33 |
| 36 RESET { 37 x = 2; /* executed when the shell does a longjmp 38 back to the main command loop */ 39 } 40 41It pulls this code out into routines which are when particular 42events occur. The intent is to improve modularity by isolating 43the information about which modules need to be explicitly 44initialized/reset within the modules themselves. 45 46Mkinit recognizes several constructs for placing declarations in 47the init.c file. 48 INCLUDE "file.h" 49includes a file. The storage class MKINIT makes a declaration 50available in the init.c file, for example: 51 MKINIT int funcnest; /* depth of function calls */ 52MKINIT alone on a line introduces a structure or union declara- 53tion: 54 MKINIT 55 struct redirtab { 56 short renamed[10]; 57 }; 58Preprocessor #define statements are copied to init.c without any 59special action to request this. 60 | |
| 61EXCEPTIONS: Code for dealing with exceptions appears in 62exceptions.c. The C language doesn't include exception handling, 63so I implement it using setjmp and longjmp. The global variable 64exception contains the type of exception. EXERROR is raised by 65calling error. EXINT is an interrupt. 66 67INTERRUPTS: In an interactive shell, an interrupt will cause an 68EXINT exception to return to the main command loop. (Exception: --- 247 unchanged lines hidden --- | 34EXCEPTIONS: Code for dealing with exceptions appears in 35exceptions.c. The C language doesn't include exception handling, 36so I implement it using setjmp and longjmp. The global variable 37exception contains the type of exception. EXERROR is raised by 38calling error. EXINT is an interrupt. 39 40INTERRUPTS: In an interactive shell, an interrupt will cause an 41EXINT exception to return to the main command loop. (Exception: --- 247 unchanged lines hidden --- |