[flashrom] [PATCH] Clean up doit()

[Carl-Daniel Hailfinger]

doit() is the monster function we split off from main() when we created
cli_classic() and tried to introduce some abstraction. doit() is a
poster child of WTFs on an astronomic scale.

Make doit() marginally less bad by factoring out self-contained code.
Should have no functional changes.
The new code flow is designed to make partial writes easier to implement.

Tests appreciated.

Signed-off-by: Carl-Daniel Hailfinger

Index: flashrom-doit_refactor/flashrom.c
===================================================================
--- flashrom-doit_refactor/flashrom.c	(Revision 1211)
+++ flashrom-doit_refactor/flashrom.c	(Arbeitskopie)
@@ -1116,6 +1116,39 @@
    return ret;
 }

+int read_buf_from_file(unsigned char *buf, unsigned long size, char *filename)
+{
+	unsigned long numbytes;
+	FILE *image;
+	struct stat image_stat;
+
+	if ((image = fopen(filename, "rb")) == NULL) {
+		perror(filename);
+		return 1;
+	}
+	if (fstat(fileno(image), &image_stat) != 0) {
+		perror(filename);
+		fclose(image);
+		return 1;
+	}
+	if (image_stat.st_size != size) {
+		msg_gerr("Error: Image size doesn't match\n");
+		fclose(image);
+		return 1;
+	}
+	numbytes = fread(buf, 1, size, image);
+	if (fclose(image)) {
+		perror(filename);
+		return 1;
+	}
+	if (numbytes != size) {
+		msg_gerr("Error: Failed to read complete file. Got %ld bytes, "
+			 "wanted %ld!\n", numbytes, size);
+		return 1;
+	}
+	return 0;
+}
+
 int write_buf_to_file(unsigned char *buf, unsigned long size, char *filename)
 {
    unsigned long numbytes;
@@ -1514,8 +1547,6 @@
 int doit(struct flashchip *flash, int force, char *filename, int read_it, int write_it, int erase_it, int verify_it)
 {
    uint8_t *buf;
-	unsigned long numbytes;
-	FILE *image;
    int ret = 0;
    unsigned long size;

@@ -1537,7 +1568,19 @@
    	}
    }

-	if (erase_it) {
+	/* Given the existence of read locks, we want to unlock for read,
+	 * erase and write.
+	 */
+	if (flash->unlock)
+		flash->unlock(flash);
+
+	if (read_it) {
+		ret = read_flash_to_file(flash, filename);
+		programmer_shutdown();
+		return ret;
+	}
+	if (erase_it || write_it) {
+		/* Write needs erase. */
    	if (flash->tested & TEST_BAD_ERASE) {
    		msg_cerr("Erase is not working on this chip. ");
    		if (!force) {
@@ -1548,34 +1591,9 @@
    			msg_cerr("Continuing anyway.\n");
    		}
    	}
-		if (flash->unlock)
-			flash->unlock(flash);
-
-		if (erase_flash(flash)) {
-			emergency_help_message();
-			programmer_shutdown();
-			return 1;
-		}
-	} else if (read_it) {
-		if (flash->unlock)
-			flash->unlock(flash);
-
-		if (read_flash_to_file(flash, filename)) {
-			programmer_shutdown();
-			return 1;
-		}
-	} else if (write_it) {
-		if (flash->tested & TEST_BAD_ERASE) {
-			msg_cerr("Erase is not working on this chip "
-				"and erase is needed for write. ");
-			if (!force) {
-				msg_cerr("Aborting.\n");
-				programmer_shutdown();
-				return 1;
-			} else {
-				msg_cerr("Continuing anyway.\n");
-			}
-		}
+		/* FIXME: Check if at least one erase function exists. */
+	}
+	if (write_it) {
    	if (flash->tested & TEST_BAD_WRITE) {
    		msg_cerr("Write is not working on this chip. ");
    		if (!force) {
@@ -1591,39 +1609,25 @@
    		programmer_shutdown();
    		return 1;
    	}
-		if (flash->unlock)
-			flash->unlock(flash);
-
    }
-	if (write_it || verify_it) {
-		struct stat image_stat;

-		if ((image = fopen(filename, "rb")) == NULL) {
-			perror(filename);
+	if (erase_it) {
+		if (erase_flash(flash)) {
+			emergency_help_message();
    		programmer_shutdown();
-			exit(1);
+			return 1;
    	}
-		if (fstat(fileno(image), &image_stat) != 0) {
-			perror(filename);
+	}
+
+	if (write_it || verify_it) {
+		if (read_buf_from_file(buf, flash->total_size * 1024, filename)) {
    		programmer_shutdown();
-			exit(1);
+			return 1;
    	}
-		if (image_stat.st_size != flash->total_size * 1024) {
-			msg_gerr("Error: Image size doesn't match\n");
-			programmer_shutdown();
-			exit(1);
-		}

-		numbytes = fread(buf, 1, size, image);
 #if CONFIG_INTERNAL == 1
    	show_id(buf, size, force);
 #endif
-		fclose(image);
-		if (numbytes != size) {
-			msg_gerr("Error: Failed to read file. Got %ld bytes, wanted %ld!\n", numbytes, size);
-			programmer_shutdown();
-			return 1;
-		}
    }

// This should be moved into each flash part's code to do it