/************************************************************* Copyright (c) 1993,1994 by Paul Long All rights reserved. **************************************************************/ /************************************************************* rules.c - This source file contains a typical set of rules in the rules() function that define a simple metrics tool. **************************************************************/ #include #include "metre.h" /* In addition to the parser's command-line options, e.g., -D, the rules look for a -Q option to suppress its verbose key and explanation that it otherwise generates at the beginning of the output. */ #define QUIET_OPT_CHAR 'Q' /* Defines for warnings that are generated by the rules, not the parser. */ #define W_GOTO 0, "goto statement used (%u time%s)" #define W_CONTINUE 1, "continue statement used (%u time%s)" #define W_RETURNS 2, "Multiple return statements (%u)" #define W_TAB_SPACE_INDENT 3, "Tab & space used on same line for indention" #define W_MULT_STATEMENTS 4, "Multiple statements (%u) per line" #define W_NONSTANDARD 5, "Non-standard character (0x%x) encountered" /* Nicety to evaluate as "s" if argument is greater than one; otherwise, "". */ #define NUMBER(x) ((x) > 1 ? "s" : "") /* Assign max value to integer argument regardless of type, e.g., long int. */ #define TYPE_MAX(x) ((x = ~0) < 0 ? x = ~(1 << sizeof x * CHAR_BIT - 1) : x) /* The rules maintain their function statistics in this structure. Could have also been just a bunch of separate variables, though. */ static struct { struct { unsigned min, max; } decisions; /* Min and max binary decision points in function. */ struct { unsigned min, max; /* Min and max lines in a function. */ } lines; } per_func; static BOOLEAN mixed_indent_lines; /* Whether spaces _&_ tabs in indent. */ static unsigned mod_statements; /* Total statements in module (file). */ static unsigned mod_func_lines; /* Total function lines in module. */ static unsigned fcn_gotos; /* How many gotos in a function. */ static unsigned fcn_continues; /* How many continues in a function. */ static unsigned fcn_returns; /* How many returns in a function. */ static unsigned fcn_depth_max; /* Maximum nesting level in a function.*/ void rules(void) { /* If at the beginning of a project and the quiet option has not been specified, print the key and explanation. */ if (prj.begin && !option(QUIET_OPT_CHAR)) { fprintf(out_fp, "Explanation and Guidelines:\n"); fprintf(out_fp, "< Minimum\n"); fprintf(out_fp, "> Maximum\n"); fprintf(out_fp, "~ Average\n"); fprintf(out_fp, "(nothing) Total\n"); fprintf(out_fp, "CCI McCabe's Cyclomatic Complexity Index. Number of binary\n"); fprintf(out_fp, " decision points plus one. Should be less than 10.\n"); fprintf(out_fp, "Depth Maximum control structure depth. Should be less than 6.\n\n"); fprintf(out_fp, "A goto probably indicates that there should be another function. Elses\n"); fprintf(out_fp, "are probably a better solution than multiple return statements. An else\n"); fprintf(out_fp, "is probably a better solution than a continue statement. A good size\n"); fprintf(out_fp, "for a module is 30 lines or so with an upper limit of 60 lines. One\n"); fprintf(out_fp, "statement per line. Don't mix tabs and spaces for indention.\n\n"); } /* At the beginning of the module, initialize variables. */ if (mod.begin) { per_func.decisions.max = 0; TYPE_MAX(per_func.decisions.min); per_func.lines.max = 0; TYPE_MAX(per_func.lines.min); mod_func_lines = 0; mod_statements = 0; mixed_indent_lines = FALSE; } /* At the end of the module, print a module summary. */ if (mod.end) { fprintf(out_fp, "\n\nModule Summary\n"); if (mod.functions != 0) { fprintf(out_fp, " CCI: <%u >%u ~%u\n", per_func.decisions.min + 1, per_func.decisions.max + 1, mod.decisions / mod.functions + 1); fprintf(out_fp, " Lines: <%u >%u ~%u %u\n", per_func.lines.min, per_func.lines.max, mod_func_lines / mod.functions, mod.lines.total); } fprintf(out_fp, " Exec: %u\n", mod.lines.exec); fprintf(out_fp, " Comment: %u\n", mod.lines.com); fprintf(out_fp, " White: %u\n", mod.lines.white); fprintf(out_fp, " Statements: %u\n", mod_statements); fprintf(out_fp, " Functions: %u\n", mod.functions); if (mixed_indent_lines) warn(W_TAB_SPACE_INDENT); } /* At the beginning of each function, initialize variables. */ if (fcn.begin) { fcn_gotos = 0; fcn_continues = 0; fcn_returns = 0; fcn_depth_max = 0; } /* At the end of each function, set module-wide statistics variables and print a function summary. */ if (fcn.end) { if (fcn.decisions > per_func.decisions.max) per_func.decisions.max = fcn.decisions; if (fcn.decisions < per_func.decisions.min) per_func.decisions.min = fcn.decisions; if (fcn.lines.total > per_func.lines.max) per_func.lines.max = fcn.lines.total; if (fcn.lines.total < per_func.lines.min) per_func.lines.min = fcn.lines.total; mod_func_lines += fcn.lines.total; mod_statements += fcn.low + fcn.high; fprintf(out_fp, "\n%s()\n", fcn_name()); fprintf(out_fp, " CCI: %u\n", fcn.decisions + 1); fprintf(out_fp, " Lines: %u\n", fcn.lines.total); fprintf(out_fp, " Exec: %u\n", fcn.lines.exec); fprintf(out_fp, " Comment: %u\n", fcn.lines.com); fprintf(out_fp, " White: %u\n", fcn.lines.white); fprintf(out_fp, " Statements: %u\n", fcn.low + fcn.high); fprintf(out_fp, " Depth: >%u\n", fcn_depth_max); if (fcn_gotos > 0) warn(W_GOTO, fcn_gotos, NUMBER(fcn_gotos)); if (fcn_continues > 0) warn(W_CONTINUE, fcn_continues, NUMBER(fcn_continues)); if (fcn_returns > 1) warn(W_RETURNS, fcn_returns); } /* At the end of each statement, determine if greatest depth yet reached. */ if (stm.end) if (stm.depth > fcn_depth_max) fcn_depth_max = stm.depth; /* Remember if line found with mixed indention (spaces and tabs). */ if (lin.is_mixed_indent) mixed_indent_lines = TRUE; /* Print warning if a line contains more than one statement. */ if (lin.statements > 0) warn(W_MULT_STATEMENTS, lin.statements + 1); /* Count gotos, continues, and returns. */ if (keyword("goto")) ++fcn_gotos; if (keyword("continue")) ++fcn_continues; if (keyword("return")) ++fcn_returns; /* If character encountered that is not in Standard C's source character set, print warning. */ if (lex.nonstandard) warn(W_NONSTANDARD, lex.nonstandard); }