B.31 Specification for program ntree (Document ES7)

Transcription

1 ISERN B.31 Specification for program ntree (Document ES7) B.31 Specification for program ntree (Document ES7) Name ntree Functions for managing a tree Usage ntree input-file Description ntree reads commands from a file and processes them in order to test a few functions. Considered together, the functions implement a tree in which each node can have any number of child nodes. The number of children is not limited by the program. A node holds two strings (key, content). Options None. Input Data Only the following commands are allowed in the input files. Each command must start on a new line. Lower and upper case is relevant in the keys. The separator between commands and arguments is a space; this means that spaces may not appear within a string. In this implementation, command lines (command plus corresponding parameters) read from the file are limited to a maximum length of root <key> <content> Creates and initializes the root of the tree. This command must be the first command in the input file. If it does not appear as the first command, or if the command is repeated, the behavior of the program is not defined. child <father-key> <child-key> <child-content> Attaches the new child node with the given data onto the given father node. If the father node is not found in the tree, a corresponding error message is printed. If the key of the father-node appears more than once in the tree, the new child is attached to the first node found (see also search below). search <key> The tree is searched for the node with the key <key>. The tree is searched from left to right using depth-first search, in which the key of a node is checked on the first visit (preorder traversal). If the node with the given key is found, the contents are printed out; if not, a corresponding error message is printed. If multiple nodes have the same key, only the contents of the first one found are printed. sibs <key1> <key2> Tests whether the nodes with the given keys are siblings; i.e., whether they share the same father node. If one or the other key is not found in the tree, a corresponding error message is printed. Every node counts as its own sibling. See also search for a description of the search method. 108 An Empirical Evaluation of Three Defect-Detection Techniques

2 B.31 Specification for program ntree (Document ES7) ISERN print Prints out the complete contents of the tree. A new line is printed for each node with the key, content, and the depth in the tree. Each line is indented to correspond with the depth of the node (4 blanks per level). Example Because the output of the program as presented here was formatted by a typesetting program, the indentation shown here may not correspond exactly with the actual indentation. % cat eingabe root Lamb SE:_Planning_for_Change child Lamb Rombach Software_Specifications child Lamb Brackett Software_Requirements child Rombach Parnas Predicate_Logic_for_SE print % ntree eingabe Eingabedatei eingabe wird bearbeitet. Die Zeile root Lamb SE:_Planning_for_Change wird ausgewertet: Die Zeile child Lamb Rombach Software_Specifications wird ausgewertet: Die Zeile child Lamb Brackett Software_Requirements wird ausgewertet: Die Zeile child Rombach Parnas Predicate_Logic_for_SE wird ausgewertet: Die Zeile print wird ausgewertet: Knoten (Ebene 0): Schluessel Lamb, Inhalt SE:_Planning_for_Change Knoten (Ebene 1): Schluessel Rombach, Inhalt Software_Specifications Knoten (Ebene 2): Schluessel Parnas, Inhalt Predicate_Logic_for_SE Knoten (Ebene 1): Schluessel Brackett, Inhalt Software_Requirements Ende der Eingabedatei eingabe. Author Ch. Lott Bugs The functionality for reading files is only for test purposes and is therefore not especially faulttolerant. For example, one can assume that incorrectly spelled commands, commands with missing arguments, or commands with too many arguments will not be handled especially carefully. An Empirical Evaluation of Three Defect-Detection Techniques 109

3 ISERN B.32 Supplement Code reading and ntree (Document E17) B.32 Supplement Code reading and ntree (Document E17) This is the supplemental sheet for the program ntree and technique code reading. Brief description of the library functions used assert(expression) Macro that expects the expression to be true at the time the program is executed and in that case does nothing. Otherwise an error message with the expression is printed and the program is ended. char* malloc(unsigned size) Returns a pointer to a block of memory that is at least as large as size bytes. In case of failure, NULL is returned. int free(ptr) Gives a previously allocated block back to the system. ptr must have been allocated using malloc or a similar function. If successful, 1 is returned; otherwise 0 is returned. int strcmp(s1,s2) Compares two strings. Returns a value greater than, equal to, or less than 0 depending on whether st1 is lexicographically (i.e., ASCII value) greater than, equal, or less than s2. void bcopy(b1,b2,length) Copies length bytes from string b1 to stringb2. Overlapping strings are treated correctly. int sscanf(s,format,pointer) Reads characters from string s, converts them according to the specification string format, and writes the result into the variables pointed to by the pointers. This is the reverse function of printf; the format specification strings are identical. char *fgets(s,n,stream) Reads characters from the stream stream and writes them in the string s, until either n-1 characters have been read or one of NEWLINE or EOF are seen. At EOF the value NULL is returned, otherwise s. char *strdup(s1) Duplicates the string s1. Allocates memory for this purpose using malloc() and returns a pointer to the duplicate if successful, otherwise NULL. Reminder Don t produce any abstractions for the test-scaffold functions. 110 An Empirical Evaluation of Three Defect-Detection Techniques

4 B.33 Supplement Functional testing and ntree (Document E27) ISERN B.33 Supplement Functional testing and ntree (Document E27) This is the supplemental sheet for the program ntree and technique functional testing. Necessary inputs Which documents belong to this exercise? 1. Document ES7, the specification of the component 2. Document EQ7, the source code of the component, which you will receive after you have written test cases and diagnosed failures. How do I fetch the files which I need? Do the following: 1. First create a new directory for this exercise with the mkdir command. mkdir ft-ntree 2. Then change to the new directory with the cd command. cd ft-ntree 3. Finally, enter the following command: path tar xf prakt00/exercise5/ft-ntree.tar What should I have? The following files must be available. Makefile ntree run-suite test-dir Creating equivalence classes and test cases The test scaffolding offers commands and their parameters to simplify addressing the program s functions. Do not create equivalence classes for syntactically incorrect commands! That would only test the test scaffolding. Examples of unnecessary test cases: delete all Command not defined. sibs Brackett Second parameter is missing. Reminder Make sure that your test cases generate output so that you can detect failures! An Empirical Evaluation of Three Defect-Detection Techniques 111

5 ISERN B.33 Supplement Functional testing and ntree (Document E27) Document E27, page 2: To be given out with the code! Brief description of the library functions used assert(expression) Macro that expects the expression to be true at the time the program is executed and in that case does nothing. Otherwise an error message with the expression is printed and the program is ended. char* malloc(unsigned size) Returns a pointer to a block of memory that is at least as large as size bytes. In case of failure, NULL is returned. int free(ptr) Gives a previously allocated block back to the system. ptr must have been allocated using malloc or a similar function. If successful, 1 is returned; otherwise 0 is returned. int strcmp(s1,s2) Compares two strings. Returns a value greater than, equal to, or less than 0 depending on whether st1 is lexicographically (i.e., ASCII value) greater than, equal, or less than s2. void bcopy(b1,b2,length) Copies length bytes from string b1 to stringb2. Overlapping strings are treated correctly. int sscanf(s,format,pointer) Reads characters from string s, converts them according to the specification string format, and writes the result into the variables pointed to by the pointers. This is the reverse function of printf; the format specification strings are identical. char *fgets(s,n,stream) Reads characters from the stream stream and writes them in the string s, until either n-1 characters have been read or one of NEWLINE or EOF are seen. At EOF the value NULL is returned, otherwise s. char *strdup(s1) Duplicates the string s1. Allocates memory for this purpose using malloc() and returns a pointer to the duplicate if successful, otherwise NULL. 112 An Empirical Evaluation of Three Defect-Detection Techniques

6 B.34 Supplement Structural testing and ntree (Document E37) ISERN B.34 Supplement Structural testing and ntree (Document E37) This is the supplemental sheet for the program ntree and technique structural testing. This exercise primarily tests several C functions. To save you time and effort in this exercise, a test scaffold was created. The driver functions required for this scaffold are in the precompiled file driver.o and are bound in at link time. The drivers take care of function such as testing for and opening input files, allocating necessary memory, etc. See also the notes about one visible driver function that appear below. Necessary inputs Which documents belong to this exercise? 1. Document ES7, the specification of the component, which you will receive after you have created test cases and attempted to reach 100% coverage. 2. Document EQ7, the source code of the component How do I fetch the files which I need? Do the following: 1. First create a new directory for this exercise with the mkdir command. mkdir st-ntree 2. Then change to the new directory with the cd command. cd st-ntree 3. Finally, enter the following command: path tar xf prakt00/exercise5/st-ntree.tar What should I have? The following files must be available: Makefile gct-map ntree run-suite test-dir Writing test cases All of the program s functions are fundamentally tested via the invocation ntree <input file> A parameter file holds only the name of the input file. This is somewhat awkward, but necessary to allow applying the test driver consistently. The format of the input file is as follows: command1 parameter1 paramter2 command2 paramterx... An Empirical Evaluation of Three Defect-Detection Techniques 113

7 ISERN B.34 Supplement Structural testing and ntree (Document E37) Which commands are allowed in the input and which functions are invoked by those commands can be seen in the functionfuehre kommandos aus in the file ntree.c. Because this function belongs to the test scaffold and will not be part of the eventual application, it is not especially robust. You can assume that the function, although sensitive, is free of faults. One activity of the driver from driver.o is to open the first file on the command line and to invoke the function fuehre kommandos aus with a pointer to the opened file. Don t write any test cases to cover the test scaffold! Reminder Make sure that your test cases generate output so that you can detect failures! Brief description of the library functions used assert(expression) Macro that expects the expression to be true at the time the program is executed and in that case does nothing. Otherwise an error message with the expression is printed and the program is ended. char* malloc(unsigned size) Returns a pointer to a block of memory that is at least as large as size bytes. In case of failure, NULL is returned. int free(ptr) Gives a previously allocated block back to the system. ptr must have been allocated using malloc or a similar function. If successful, 1 is returned; otherwise 0 is returned. int strcmp(s1,s2) Compares two strings. Returns a value greater than, equal to, or less than 0 depending on whether st1 is lexicographically (i.e., ASCII value) greater than, equal, or less than s2. void bcopy(b1,b2,length) Copies length bytes from string b1 to stringb2. Overlapping strings are treated correctly. int sscanf(s,format,pointer) Reads characters from string s, converts them according to the specification string format, and writes the result into the variables pointed to by the pointers. This is the reverse function of printf; the format specification strings are identical. char *fgets(s,n,stream) Reads characters from the stream stream and writes them in the string s, until either n-1 characters have been read or one of NEWLINE or EOF are seen. At EOF the value NULL is returned, otherwise s. char *strdup(s1) Duplicates the string s1. Allocates memory for this purpose using malloc() and returns a pointer to the duplicate if successful, otherwise NULL. 114 An Empirical Evaluation of Three Defect-Detection Techniques