-
Notifications
You must be signed in to change notification settings - Fork 2
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
Showing
13 changed files
with
980 additions
and
372 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -1,75 +1,89 @@ | ||
| /* | ||
| * controlflow.c - 用来进行流程控制 | ||
| */ | ||
| #include<stdio.h> | ||
| #include<string.h> | ||
| #include "winshell.h" | ||
|
|
||
| enum states {NEUTRAL, WANT_THEN, THEN_BLOCK}; // 将流程控制分为三个分区 | ||
| enum results {SUCCESS, FAIL}; | ||
|
|
||
| static int if_state = NEUTRAL; | ||
| static int if_result = SUCCESS; | ||
| static int processed_stat = 0; // 流程控制语句中进程执行的状态 | ||
|
|
||
| // 通过当前的if_state判断是否可以进行语句的执行任务 | ||
| int execute_check() { | ||
| int rv = 0; // 检查结果 | ||
|
|
||
| if (if_state == WANT_THEN) // if后面本应紧跟then却未出现 | ||
| rv = syn_err((char*)"then expected"); // rv == -1 | ||
| else if (if_state == THEN_BLOCK && if_result == FAIL) // 未成功执行条件语句 | ||
| rv = -1; | ||
| // 其余情况或中立区，直接执行命令即可，无需判断 | ||
| return rv; | ||
| } | ||
|
|
||
| // 判断是否为流程控制语句 | ||
| int is_control_command(char* s) { | ||
| return (strcmp(s, "if") == 0 | ||
| || strcmp(s, "then") == 0 | ||
| || strcmp(s, "fi") == 0 | ||
| ); | ||
| } | ||
|
|
||
| // 根据当前if_state的状态进行条件语句的执行 | ||
| int do_control_command(char** args) { | ||
| char* ctrlflag = args[0]; | ||
| int rv = -1; // 条件语句执行成功标志，默认为不成功 | ||
|
|
||
| if (strcmp(ctrlflag, "if") == 0) { | ||
| if (if_state != NEUTRAL) // 当前不在中立区当中 | ||
| rv = syn_err((char*)"if unexpected"); | ||
| else { | ||
| processed_stat = process(args + 1); // 指向流程控制语句后的第一部分 | ||
| if_result = (processed_stat == 0 ? SUCCESS : FAIL); | ||
| if_state = WANT_THEN; // 期望then语句，shell中IF后面必须跟then语句 | ||
| rv = 0; // 返回成功执行标志 | ||
| } | ||
| } | ||
| else if (strcmp(ctrlflag, "then") == 0) { | ||
| if (if_state != WANT_THEN) // 当前不在WANT_THEN区域中却出现了then | ||
| rv = syn_err((char*)"then unexpected"); | ||
| else { | ||
| if_state = THEN_BLOCK; | ||
| rv = 0; | ||
| } | ||
| } | ||
| else if (strcmp(ctrlflag, "fi") == 0) { | ||
| if (if_state != THEN_BLOCK) | ||
| rv = syn_err((char*)"fi unexpected"); | ||
| else { | ||
| if_state = NEUTRAL; | ||
| rv = 0; | ||
| } | ||
| } | ||
| else | ||
| fatal((char*)"internal error processing: ", ctrlflag, 2); | ||
| return rv; | ||
| } | ||
|
|
||
| int syn_err(char* msg) { | ||
| if_state = NEUTRAL; | ||
| fprintf_s(stderr, "syntax error: %s\n", msg); | ||
| return -1; | ||
| } | ||
| ///* | ||
| //* controlflow.c - 用来进行流程控制 | ||
| //*/ | ||
| //#include<stdio.h> | ||
| //#include<string.h> | ||
| //#include "winshell.h" | ||
| // | ||
| //enum states {NEUTRAL, WANT_THEN, THEN_BLOCK}; // 将流程控制分为三个分区 | ||
| //enum results {SUCCESS, FAIL}; | ||
| // | ||
| //static int if_state = NEUTRAL; | ||
| //static int if_result = SUCCESS; | ||
| //static int processed_stat = 0; // 流程控制语句中进程执行的状态 | ||
| // | ||
| //// 通过当前的if_state判断是否可以进行语句的执行任务 | ||
| //int execute_check() { | ||
| // int rv = 0; // 检查结果 | ||
| // | ||
| // if (if_state == WANT_THEN) // if后面本应紧跟then却未出现 | ||
| // rv = syn_err((char*)"then expected"); // rv == -1 | ||
| // else if (if_state == THEN_BLOCK && if_result == FAIL) // 未成功执行条件语句 | ||
| // rv = -1; | ||
| // // 其余情况或中立区，直接执行命令即可，无需判断 | ||
| // return rv; | ||
| //} | ||
| // | ||
| //// 判断是否为流程控制语句 | ||
| //int is_control_command(char* s) { | ||
| // return (strcmp(s, "if") == 0 | ||
| // || strcmp(s, "then") == 0 | ||
| // || strcmp(s, "fi") == 0 | ||
| // ); | ||
| //} | ||
| // | ||
| //// 根据当前if_state的状态进行条件语句的执行 | ||
| //int do_control_command(char** args) { | ||
| // char* ctrlflag = args[0]; | ||
| // int rv = -1; // 条件语句执行成功标志，默认为不成功 | ||
| // | ||
| // if (strcmp(ctrlflag, "if") == 0) { | ||
| // if (if_state != NEUTRAL) // 当前不在中立区当中 | ||
| // rv = syn_err((char*)"if unexpected"); | ||
| // else { | ||
| // processed_stat = process(args + 1); // 指向流程控制语句后的第一部分 | ||
| // if_result = (processed_stat == 0 ? SUCCESS : FAIL); | ||
| // if_state = WANT_THEN; // 期望then语句，shell中IF后面必须跟then语句 | ||
| // rv = 0; // 返回成功执行标志 | ||
| // } | ||
| // } | ||
| // else if (strcmp(ctrlflag, "then") == 0) { | ||
| // if (if_state != WANT_THEN) // 当前不在WANT_THEN区域中却出现了then | ||
| // rv = syn_err((char*)"then unexpected"); | ||
| // else { | ||
| // if_state = THEN_BLOCK; | ||
| // rv = 0; | ||
| // } | ||
| // } | ||
| // else if (strcmp(ctrlflag, "fi") == 0) { | ||
| // if (if_state != THEN_BLOCK) | ||
| // rv = syn_err((char*)"fi unexpected"); | ||
| // else { | ||
| // if_state = NEUTRAL; | ||
| // rv = 0; | ||
| // } | ||
| // } | ||
| // else | ||
| // fatal((char*)"internal error processing: ", ctrlflag, 2); | ||
| // return rv; | ||
| //} | ||
| // | ||
| //int syn_err(char* msg) { | ||
| // if_state = NEUTRAL; | ||
| // fprintf_s(stderr, "syntax error: %s\n", msg); | ||
| // return -1; | ||
| //} | ||
| // | ||
| //int read_if_block(FILE* fp) | ||
| //{ | ||
| // int ch; | ||
| // while ((ch = getc(fp)) != EOF) { | ||
| // | ||
| // } | ||
| // return 0; | ||
| //} | ||
| // | ||
| //int read_loop_block(FILE* fp) | ||
| //{ | ||
| // return 0; | ||
| //} |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,136 @@ | ||
| #include <stdio.h> | ||
| #include "winshell2.h" | ||
|
|
||
| /* | ||
| * if_mode - 用来进行语法上的if、else、then的控制 | ||
| * laststat - 用来进行逻辑上的判定，通过语法检查+条件的判定，返回是否执行的标志给主程序 | ||
| */ | ||
| static int if_mode = NO_IF; // 初始的if状态 | ||
| static int laststat; // 用来存储上个命令的执行状态 | ||
|
|
||
| /* 接下来是维护的if状态栈的定义 */ | ||
| #define maxn 10 // 支持的嵌套最大值 | ||
| typedef struct { | ||
| int if_mode_store; | ||
| int laststat_store; | ||
| }env; // 环境变量 | ||
|
|
||
| typedef struct { | ||
| int top; // 栈顶的索引 | ||
| int fi_empty; // 用来判断当前栈是否还有未弹出的fi | ||
| env elements[maxn]; | ||
| }Stack; | ||
|
|
||
| Stack stack = { 0, 0 ,NULL }; // 声明栈 | ||
|
|
||
| int if_check(char *cmd) { | ||
| char* cp; | ||
|
|
||
| // 当前读取进来的命令为空，抛出文件尾异常 | ||
| if (cmd == NULL) { | ||
| if (stack.fi_empty !=0) // 证明当前还有fi未弹出栈 | ||
| syn_err((char*)"lack of fi"); | ||
| if (if_mode != NO_IF) | ||
| syn_err((char*)"EOF unexpected"); | ||
| return DONT_EXEC; | ||
| } | ||
|
|
||
| // 检测if | ||
| if (strncmp(cmd, "if", 2) == 0 && is_blank(cmd[2])) { // 确保指令是'if '的格式，防止if后直接跟指令 | ||
| if (save_env() != 0) { | ||
| syn_err((char*)"to many if levels(more than 10)"); // if嵌套语法错误 | ||
| return SYN_ERR; | ||
| } | ||
| if (if_mode != NO_IF) { | ||
| set_ifenv(); // 开始进行嵌套if的执行 | ||
| // return DONT_EXEC; | ||
| } | ||
| // 开始执行if后面的语句，检查返回结果 | ||
| for (cp = cmd + 3; is_blank(*cp); cp++); // 将指针移到if后面的首个非空位置 | ||
|
|
||
| if (!*cp) { | ||
| syn_err((char*)"null command for if"); | ||
| return DONT_EXEC; | ||
| } | ||
| laststat = process(cp); | ||
| if_mode = SAW_IF; | ||
| return DONT_EXEC; | ||
| } | ||
|
|
||
| // 检测then else fi | ||
| // TODO: 检测elif | ||
| if (strcmp(cmd, "then") == 0) { // then | ||
| if (if_mode != SAW_IF) | ||
| syn_err((char*)"\'then\' unexpected"); | ||
| else | ||
| if_mode = SAW_THEN; | ||
| return DONT_EXEC; | ||
| } | ||
| if (strcmp(cmd, "else") == 0) { // else | ||
| if (if_mode != SAW_THEN) | ||
| syn_err((char*)"\'else\' unexpectd"); | ||
| else | ||
| if_mode = SAW_ELSE; | ||
| return DONT_EXEC; | ||
| } | ||
| if (strcmp(cmd, "fi") == 0) { // fi | ||
| if (if_mode != SAW_THEN && if_mode != SAW_ELSE) | ||
| syn_err((char*)"\'fi\' unexpected"); | ||
| else | ||
| restore_env(); | ||
| // 当前fi全部清除完后，无论如何都该将if_mode设为初值 | ||
| /*if (stack.fi_empty == 0) | ||
| if_mode = NO_IF;*/ | ||
| return DONT_EXEC; | ||
| } | ||
|
|
||
| // 当前在if块当中 | ||
| if (if_mode == SAW_IF) { | ||
| laststat = process(cmd); | ||
| return DONT_EXEC; | ||
| } | ||
|
|
||
| // 当前并非流程控制语句，开始根据状态执行代码 | ||
| if (if_mode == NO_IF | ||
| || if_mode == SAW_THEN && laststat == 0 | ||
| || if_mode == SAW_ELSE && laststat != 0 | ||
| ) | ||
| return OK_EXEC; | ||
|
|
||
| return DONT_EXEC; | ||
| } | ||
|
|
||
| int syn_err(char* msg) { | ||
| if_mode = NO_IF; | ||
| fprintf_s(stderr, "syntax error: %s\n", msg); | ||
| return -1; | ||
| } | ||
|
|
||
| // 保护当前的if环境，即当前的if_mode和laststat的值 | ||
| // 实质上等同于压栈操作 | ||
| int save_env() { | ||
| if (stack.top == maxn - 1) | ||
| // fatal("If syntax error:", "To many if levels(more than 10)", 2); // if嵌套层数过多 | ||
| return -1; // if嵌套层数过多 | ||
| stack.elements[stack.top].if_mode_store = if_mode; | ||
| stack.elements[stack.top].laststat_store = laststat; | ||
| stack.top++; | ||
| stack.fi_empty++; | ||
| return 0; | ||
| } | ||
|
|
||
| // 恢复原有的if环境 | ||
| // 实质上等同于出栈操作 | ||
| int restore_env() { | ||
| if (stack.top == 0) | ||
| return -1; // fi和原来的数量不匹配，比原来的要多 | ||
| if_mode = stack.elements[--stack.top].if_mode_store; | ||
| laststat = stack.elements[stack.top].laststat_store; | ||
| stack.fi_empty--; | ||
| return 0; | ||
| } | ||
|
|
||
| void set_ifenv() { | ||
| if_mode = SAW_IF; | ||
| laststat = 0; | ||
| } |
Oops, something went wrong.