[PATCH 1/2] msrtool: Add endptr to str2msr() showing how many characters were parsed

[Peter Stuge]

This also introduces a small change in the user interface for immediate
mode (-i). Previously, whitespace could separate high and low words in
an MSR as such:

msrtool -i 4c00000f='f2f100ff 56960004'

That is no longer allowed, a space character now ends the MSR value. Any
other character can still be used as separator however, so the following
syntax still works as expected:

msrtool -i 4c00000f=f2f100ff:56960004

Signed-off-by: Peter Stuge 
---
 msrtool.c  |    4 ++--
 msrtool.h  |    2 +-
 msrutils.c |    9 +++++----
 3 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/msrtool.c b/msrtool.c
index 570f1fb..41e7e2c 100644
--- a/msrtool.c
+++ b/msrtool.c
@@ -208,7 +208,7 @@ int do_diff(const char *difffn) {
    	m1start = line + tmp + m1pos;
    	for (len = strlen(m1start) - 1; NULL != strchr("\r\n", m1start[len]); --len)
    		m1start[len] = 0;
-		if (!str2msr(m1start, &m1)) {
+		if (!str2msr(m1start, &m1, NULL)) {
    		fprintf(stderr, "%s:%d: invalid MSR value '%s'\n", difffn, linenum, m1start);
    		continue;
    	}
@@ -288,7 +288,7 @@ int main(int argc, char *argv[]) {
    			fprintf(stderr, "missing value in -i argument!\n");
    			break;
    		}
-			if (!str2msr(++optarg, &msrval))
+			if (!str2msr(++optarg, &msrval, NULL))
    			fprintf(stderr, "invalid value in -i argument!\n");
    		break;
    	case 's':
diff --git a/msrtool.h b/msrtool.h
index d8fc00f..cf77b49 100644
--- a/msrtool.h
+++ b/msrtool.h
@@ -170,7 +170,7 @@ const struct msrdef *findmsrdef(const uint32_t addr);
 uint32_t msraddrbyname(const char *name);
 void dumpmsrdefs(const struct targetdef *t);
 int dumpmsrdefsvals(FILE *f, const struct targetdef *t, const uint8_t cpu);
-uint8_t str2msr(char *str, struct msr *msr);
+uint8_t str2msr(char *str, struct msr *msr, char **endptr);
 void decodemsr(const uint8_t cpu, const uint32_t addr, const struct msr val);
 uint8_t diff_msr(FILE *fout, const uint32_t addr, const struct msr a, const struct msr b);

diff --git a/msrutils.c b/msrutils.c
index dfb6617..5a5fbd8 100644
--- a/msrutils.c
+++ b/msrutils.c
@@ -193,7 +193,7 @@ int dumpmsrdefsvals(FILE *f, const struct targetdef *t, const uint8_t cpu) {
  * Parse a hexadecimal string into an MSR value.
  *
  * Leading 0x or 0X is optional, the string is always parsed as hexadecimal.
- * Any non-hexadecimal character can be used to separate the high 32 bits and
+ * Any non-hexadecimal character except ' ' can separate the high 32 bits and
  * the low 32 bits. If there is such a separator, high and low values do not
  * need to be zero padded. If there is no separator, the last <=8 digits are
  * the low 32 bits and any characters before them are the high 32 bits.
@@ -205,15 +205,16 @@ int dumpmsrdefsvals(FILE *f, const struct targetdef *t, const uint8_t cpu) {
  * @param str The string to parse. The string must be writable but will be
  * restored before return.
  * @param msr Pointer to the struct msr where the value will be stored.
+ * @param endptr If endpotr is not NULL, *endptr will point to after the MSR.
  * @return 1 on success, 0 on parse failure. msr is unchanged on failure.
  */
-uint8_t str2msr(char *str, struct msr *msr) {
+uint8_t str2msr(char *str, struct msr *msr, char **endptr) {
    char c;
    size_t len, lo;
    if (0 == strncmp(str, "0x", 2) || 0 == strncmp(str, "0X", 2))
    	str += 2;
    len = strspn(str, HEXCHARS);
-	if (len <= 8 && 0 == str[len]) {
+	if (len <= 8 && (0 == str[len] || ' ' == str[len])) {
    	msr->hi = 0;
    	lo = 0;
    } else if (len <= 8) {
@@ -231,7 +232,7 @@ uint8_t str2msr(char *str, struct msr *msr) {
    	msr->hi = strtoul(str, NULL, 16);
    	str[lo] = c;
    }
-	msr->lo = strtoul(str + lo, NULL, 16);
+	msr->lo = strtoul(str + lo, endptr, 16);
    return 1;
 }