Lab 3

.gitlab-ci.yml

@@ -1 +1,14 @@
----
+lab_3_tests:
+  stage: test
+  image: gitlab.cs.wallawalla.edu:5050/cs_department/docker-images/cpp
+  script:
+    - apt update
+    - apt install -y flex bison
+    - bison --version
+    - cd lab-3
+    - echo "Lab 3 - Flex"
+    - flex -o scanner.c scanner.flex
+    - echo "Lab 3 - Compile Tests"
+    - gcc main_test.c scanner.c -o scanner_test.out
+    - echo "Lab 3 - Run Tests"
+    - ./scanner_test.out

lab-3/README.md

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+# Flex Scanner
+
+Create a scanner for your sample programs.
+See the [example lab for Python](https://gitlab.cs.wallawalla.edu/cptr354/language-interpreter-lab-python).
+
+## Language Scanner
+
+Add the tokens needed to scan your sample code files.
+
+In addition include the following:
+
+* All the math operations (+,-,/,* etc.)
+* All boolean expression (==,>,< etc.)
+* All relational operators (not,and,or)
+* ...
+
+## Testing the Language Scanner
+
+Write unit test for your sample code.
+The sample program uses `utest.h` which is a simple c unit test framework.
+The documentation can be found at <https://github.com/sheredom/utest.h>.
+
+The `main.c` has been replaced with unit test code.
+Your task is to create one unit test for each sample file.
+
+When you submit the code to GitLab, the CI should automatically compile and run your test code.
+To recieve full credit, the tests must pass when run through GitLab CI.
+
+## Build Process
+
+To build the `scanner.c` run the following **flex** command.
+
+```sh
+flex -o scanner.c scanner.flex
+```
+
+Then build the `main.c` and `scanner.c` using **gcc**.
+
+```sh
+gcc main_test.c scanner.c -o scanner_test.out
+```
+
+Then execute the test suite using `./scanner_test.out`.
+
+```sh
+./scanner_test.out
+```
+
+## Scanner Only
+
+```sh
+flex -o scanner.c scanner.flex
+gcc main.c scanner.c -o scanner.out
+./scanner.out
+```
+
+
+## Grading Rubric
+
+The grading will be over the following categories.
+
+Points      Description
+----------- ------------------------------------
+30 points   Tests for individual language tokens
+10 points   Ability to scan — Hello world
+20 points   Ability to scan — Quadratic equation
+20 points   Ability to scan — Integer sorting
+20 points   Passes continuous integration
+
+## Turn In
+
+Please submit the URL of your gitlab project to D2L's Brightspace with your report.
+On gitlab update the `lab-3` folder to have your report and code snippets before the due date.

lab-3/main.c

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+#include "token.h"
+#include <stdio.h>
+#include <stdlib.h>
+
+extern FILE *yyin;
+extern int yylex();
+extern char *yytext;
+
+int main(int argc, char *argv[]) {
+  FILE *file;
+  const char *filename = "samples/hello.py"; // Default filename
+
+  // Check if a filename is provided as a command-line argument
+  if (argc > 1) {
+    filename = argv[1];
+  }
+
+  // Open the file
+  yyin = fopen(filename, "r");
+  if (!yyin) {
+    printf("could not open file!\n");
+    return 1;
+  }
+  while (1) {
+    token_t t = yylex();
+    if (t == TOKEN_EOF)
+      break;
+    printf("token: %d text: %s\n", t, yytext);
+  }
+}

lab-3/main_test.c

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+#include "token.h"
+// https://github.com/sheredom/utest.h/blob/master/utest.h
+#include "utest.h"
+#include <stdio.h>
+
+typedef struct yy_buffer_state *YY_BUFFER_STATE;
+extern void yyrestart(FILE * input_file);
+extern YY_BUFFER_STATE yy_scan_buffer(char *str, int i);
+extern void yy_delete_buffer(YY_BUFFER_STATE buffer);
+extern FILE *yyin;
+extern int yylex();
+extern char *yytext;
+
+UTEST_MAIN();
+
+struct token_st {
+  token_t t;
+  char *p;
+};
+
+UTEST(scanner, identifier) {
+  token_t t;
+  // Must include the null character to terminate input
+  char string[] = "test\0"; 
+  YY_BUFFER_STATE buffer = yy_scan_buffer(string, sizeof(string));
+
+  ASSERT_EQ(TOKEN_IDENT, (t = yylex()));
+  ASSERT_STREQ("test", yytext);
+
+  ASSERT_EQ(TOKEN_EOF, (t = yylex()));
+  ASSERT_STREQ("", yytext);
+
+  yy_delete_buffer(buffer);
+}
+
+UTEST(scanner, assignment) {
+  token_t t;
+  // Must include the null character to terminate input
+  char string[] = "=\0"; 
+  YY_BUFFER_STATE buffer = yy_scan_buffer(string, sizeof(string));
+
+  ASSERT_EQ(TOKEN_ASSIGNMENT, (t = yylex()));
+  ASSERT_STREQ("=", yytext);
+
+  ASSERT_EQ(TOKEN_EOF, (t = yylex()));
+  ASSERT_STREQ("", yytext);
+
+  yy_delete_buffer(buffer);
+}
+
+UTEST(scanner, sample) {
+  struct token_st tokens[] = {
+    {TOKEN_IDENT, "answer"},
+    {TOKEN_ASSIGNMENT, "="},
+    {TOKEN_NUMBER, "2020"},
+    {TOKEN_ADD, "+"},
+    {TOKEN_NUMBER, "4"},
+    {TOKEN_EOF, ""}
+  };
+
+  yyin = fopen("samples/program.c", "r");
+  yyrestart(yyin);
+  ASSERT_TRUE(yyin);
+
+  int index = 0;
+  token_t t;
+  do {
+    ASSERT_EQ(tokens[index].t, (t = yylex()));
+    ASSERT_STREQ(tokens[index].p, yytext);
+    ++index;
+  } while (t != TOKEN_EOF);
+}

lab-3/samples/program.c

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+answer = 2020+4

lab-3/scanner.flex

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+%{
+#include "token.h"
+%}
+DIGIT [0-9]
+LETTER [a-zA-Z]
+%%
+(" "|\t|\n) /* skip whitespace */
+\+ { return TOKEN_ADD; }
+"=" { return TOKEN_ASSIGNMENT; }
+while { return TOKEN_WHILE; }
+{LETTER}+ { return TOKEN_IDENT; }
+{DIGIT}+ { return TOKEN_NUMBER; }
+. { return TOKEN_ERROR; }
+%%
+int yywrap() { return 1; }

lab-3/token.h

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+typedef enum {
+  TOKEN_EOF = 0,
+  TOKEN_WHILE,
+  TOKEN_ADD,
+  TOKEN_ASSIGNMENT,
+  TOKEN_IDENT,
+  TOKEN_NUMBER,
+  TOKEN_ERROR
+} token_t;