M projects/08/src/codewriter.h → projects/08/src/codewriter.h

@@ -362,18 +362,45 @@ }
 
 static bool write_function(struct vm_instruction_t *vm_instr, FILE *fp)
 {
+	/*
+	 * (functionName)       // injects function entry label into the code
+	 * repeat nVars times:  // nVars = number of local variables
+	 *     push 0           // initializes local variable to 0
+	 */
 	print_vm_instruction(vm_instr, fp);
 	return true;  // STUB TODO implement
 }
 
 static bool write_return(struct vm_instruction_t *vm_instr, FILE *fp)
 {
+	/*
+	 * frame = LCL             // frame is a temporary variable
+	 * retAddr = *(frame - 5)  // put return address in a temporary variable
+	 * *ARG = pop()            // repositions the return value for the caller
+	 * SP = ARG+1              // repositions SP for the caller
+	 * THAT = *(frame - 1)     // restores THAT for the caller
+	 * THIS = *(frame - 2)     // restores THIS for the caller
+	 * ARG = *(frame - 3)      // restores ARG for the caller
+	 * LCL = *(frame - 4)      // restores LCL for the caller
+	 * goto retAddr            // jump to where return address points
+	 */
 	print_vm_instruction(vm_instr, fp);
 	return true;  // STUB TODO implement
 }
 
 static bool write_call(struct vm_instruction_t *vm_instr, FILE *fp)
 {
+	/*
+	 * push retAddr          // generates a label and pushes it to the stack
+	 * push LCL              // saves LCL of caller
+	 * push ARG              // saves ARG of caller
+	 * push THIS             // saves THIS of caller
+	 * push THAT             // saves THAT of caller
+	 * ARG = SP - 5 - nArgs  // repositions ARG
+	 * LCL = SP              // repositions LCL
+	 * goto functionName     // transfers control to the callee
+	 * (retAddr)             // injects the return address label into the code
+	 */
 	print_vm_instruction(vm_instr, fp);
 	return true;  // STUB TODO implement
 }

M projects/08/src/vmtranslator.c → projects/08/src/vmtranslator.c

@@ -1,9 +1,13 @@ 
+#include <dirent.h>
 #include <libgen.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
 
 #include "codewriter.h"
 #include "parser.h"
@@ -11,11 +15,55 @@ #include "util.h"
 
 #define _DEBUG
 
+#define MAX_FILE_PATH_LEN (4096)
+
 char  *file_line;
 size_t file_line_no;
 
 
-bool set_static_symbol_name(char *filename) {
+static int is_directory(const char *path)
+{
+	struct stat statbuf;
+	if (stat(path, &statbuf) != 0) return 0;
+	return S_ISDIR(statbuf.st_mode);
+}
+
+static int is_regular_file(const char *path)
+{
+	struct stat statbuf;
+	if (stat(path, &statbuf) != 0) return 0;
+	return S_ISREG(statbuf.st_mode);
+}
+
+static const char *filename_ext(const char *filepath)
+{
+	const char *pos = strrchr(filepath, '.');
+	if (!pos || pos == filepath) return NULL;
+	return pos + 1;
+}
+
+static char *concat_filepath(const char *filename, const char *dirname)
+{
+	char *filepath;
+	size_t filename_len = strlen(filename);
+	size_t dirname_len = strlen(dirname);
+
+	if ((size_t)(dirname_len + filename_len)
+	     > (size_t) MAX_FILE_PATH_LEN) {
+		printf("resulting file path name too long\n");
+		return NULL;
+	}
+
+	filepath = malloc(MAX_FILE_PATH_LEN);
+	filepath[0] = '\0';
+	strncat(filepath, dirname, dirname_len);
+	strncat(filepath, filename, filename_len);
+
+	return filepath;
+}
+
+// sets symbol name (used for statc vars) to base name of file before extension
+static bool set_static_symbol_name(char *filename) {
 	size_t i, filename_len, base_name_len;
 	char *tmp, *base_name;
 
@@ -44,13 +92,14 @@ }
 
 // translate: iterate over lines in in_file, translate VM instructions to
 // assembly, write to out_file
-bool translate(FILE *in_file, FILE *out_file)
+bool translate(FILE *in_file, FILE *out_file, bool add_init)
 {
 	char *line, in_line[MAX_LINE_LEN];
 	struct vm_instruction_t vm_instr;
 	size_t i, line_len;
 
-	write_vm_init(out_file);
+	if (add_init)
+		write_vm_init(out_file);
 	for (i = 0; i < MAX_STATIC_SYMBOLS; ++i)
 		static_symbol_map[i] = -1;  // initialize symbol map table
 
@@ -91,13 +140,37 @@ write_vm_stop(out_file);
 	return true;
 }
 
+bool translate_vm_file(char *vm_file_path, FILE *out_file, bool add_init)
+{
+	FILE *in_file = fopen(vm_file_path, "r"); // read input file
+	if (in_file == NULL)
+		die("failed to open %s for reading\n", vm_file_path);
+
+	if (!set_static_symbol_name(vm_file_path))
+		die("error reading file name %s\n", vm_file_path);
+	fprintf(out_file, "// path: %s\n", vm_file_path);  // for debugging
+	if (!translate(in_file, out_file, add_init)) // first pass
+		die("failed to translate VM code in file\n");
+
+	if (fclose(in_file))
+		die("failed to close VM file\n");
+	free(static_sym_name);
+	return true;
+}
+
 
 char *usage_msg = "Usage: vmtranslator [input/file.vm] [translated/output]\n"
                   "       vmtranslator [input/file.vm]  # output to STDOUT\n";
 
 int main(int argc, char *argv[])
 {
-	FILE *in_file, *out_file;
+	bool init;
+	char *fpath;
+	const char *fname, *ext;
+	struct dirent *de;
+	DIR *dr;
+	FILE *out_file;
+
 	if (argc == 2) {
 		out_file = stdout;
 	} else if (argc == 3) {
@@ -105,23 +178,35 @@ out_file = fopen(argv[2], "wb");
 		if (out_file == NULL)
 			die("failed to open %s for writing\n", argv[2]);
 	} else {
-		die(usage_msg);
+		die("%s", usage_msg);
 	}
 
-	in_file = fopen(argv[1], "r"); // read input file
-	if (in_file == NULL)
-		die("failed to open %s for reading\n", argv[1]);
+	if (is_directory(argv[1])) {
+		init = true;
+		dr = opendir(argv[1]);
+		if (dr == NULL)
+			die("failed to open directory '%s'\n", argv[1]);
 
-	if (!set_static_symbol_name(argv[1]))
-		die("error reading file name %s\n", argv[1]);
-	if (!translate(in_file, out_file)) // first pass
-		die("failed to translate VM code in file\n");
+		while ((de = readdir(dr)) != NULL) {
+			fname = de->d_name;
+			ext = filename_ext(fname);
+			if (ext != NULL) {
+				if (!strcmp("vm", ext)) {
+					fpath = concat_filepath(fname, argv[1]);
+					translate_vm_file(fpath, out_file, init);
+					init = false;
+					free(fpath);
+				}
+			} // else skip file...
+		}
+	} else if (is_regular_file(argv[1])) {
+		translate_vm_file(argv[1], out_file, true);
+	} else {
+		die("error: '%s' isn't a directory or regular file\n", argv[1]);
+	}
 
-	if (fclose(in_file))
-		die("failed to close VM file\n");
 	if (fclose(out_file)) // TODO check if stdout
 		die("failed to close assembly output file\n");
-	free(static_sym_name);
 
 	return 0;
 }