[Qemu-devel] [PATCH 1/2] qemu-opts: introduce a function to compare option names

[Anthony Liguori <aliguori@us.ibm.com>]

We don't use the standard C functions for conversion because we don't want to
depend on the user's locale.  All option names in QEMU are en_US in plain ASCII.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
---
 qemu-option.c |   53 +++++++++++++++++++++++++++++++++++++++++++++--------
 qemu-option.h |    2 ++
 2 files changed, 47 insertions(+), 8 deletions(-)

diff --git a/qemu-option.c b/qemu-option.c
index 8334190..6494c99 100644
--- a/qemu-option.c
+++ b/qemu-option.c
@@ -89,6 +89,43 @@ const char *get_opt_value(char *buf, int buf_size, const char *p)
     return p;
 }
 
+static int opt_tolower(int ch)
+{
+    if (ch >= 'A' && ch <= 'Z') {
+        return 'a' + (ch - 'A');
+    } else if (ch == '_') {
+        return '-';
+    }
+
+    return ch;
+}
+
+int qemu_opt_name_cmp(const char *lhs, const char *rhs)
+{
+    int i;
+    
+    g_assert(lhs && rhs);
+
+    for (i = 0; lhs[i] && rhs[i]; i++) {
+        int ret;
+
+        ret = opt_tolower(lhs[i]) - opt_tolower(rhs[i]);
+        if (ret < 0) {
+            return -1;
+        } else if (ret > 0) {
+            return 1;
+        }
+    }
+
+    if (!lhs[i] && rhs[i]) {
+        return -1;
+    } else if (lhs[i] && !rhs[i]) {
+        return 1;
+    }
+    
+    return 0;
+}
+
 int get_next_param_value(char *buf, int buf_size,
                          const char *tag, const char **pstr)
 {
@@ -101,7 +138,7 @@ int get_next_param_value(char *buf, int buf_size,
         if (*p != '=')
             break;
         p++;
-        if (!strcmp(tag, option)) {
+        if (!qemu_opt_name_cmp(tag, option)) {
             *pstr = get_opt_value(buf, buf_size, p);
             if (**pstr == ',') {
                 (*pstr)++;
@@ -137,7 +174,7 @@ int check_params(char *buf, int buf_size,
         }
         p++;
         for (i = 0; params[i] != NULL; i++) {
-            if (!strcmp(params[i], buf)) {
+            if (!qemu_opt_name_cmp(params[i], buf)) {
                 break;
             }
         }
@@ -160,7 +197,7 @@ QEMUOptionParameter *get_option_parameter(QEMUOptionParameter *list,
     const char *name)
 {
     while (list && list->name) {
-        if (!strcmp(list->name, name)) {
+        if (!qemu_opt_name_cmp(list->name, name)) {
             return list;
         }
         list++;
@@ -516,7 +553,7 @@ static QemuOpt *qemu_opt_find(QemuOpts *opts, const char *name)
     QemuOpt *opt;
 
     QTAILQ_FOREACH_REVERSE(opt, &opts->head, QemuOptHead, next) {
-        if (strcmp(opt->name, name) != 0)
+        if (qemu_opt_name_cmp(opt->name, name) != 0)
             continue;
         return opt;
     }
@@ -599,7 +636,7 @@ static void opt_set(QemuOpts *opts, const char *name, const char *value,
     int i;
 
     for (i = 0; desc[i].name != NULL; i++) {
-        if (strcmp(desc[i].name, name) == 0) {
+        if (qemu_opt_name_cmp(desc[i].name, name) == 0) {
             break;
         }
     }
@@ -660,7 +697,7 @@ int qemu_opt_set_bool(QemuOpts *opts, const char *name, bool val)
     int i;
 
     for (i = 0; desc[i].name != NULL; i++) {
-        if (strcmp(desc[i].name, name) == 0) {
+        if (qemu_opt_name_cmp(desc[i].name, name) == 0) {
             break;
         }
     }
@@ -709,7 +746,7 @@ QemuOpts *qemu_opts_find(QemuOptsList *list, const char *id)
             }
             continue;
         }
-        if (strcmp(opts->id, id) != 0) {
+        if (qemu_opt_name_cmp(opts->id, id) != 0) {
             continue;
         }
         return opts;
@@ -1062,7 +1099,7 @@ void qemu_opts_validate(QemuOpts *opts, const QemuOptDesc *desc, Error **errp)
         int i;
 
         for (i = 0; desc[i].name != NULL; i++) {
-            if (strcmp(desc[i].name, opt->name) == 0) {
+            if (qemu_opt_name_cmp(desc[i].name, opt->name) == 0) {
                 break;
             }
         }
diff --git a/qemu-option.h b/qemu-option.h
index 951dec3..ee27a13 100644
--- a/qemu-option.h
+++ b/qemu-option.h
@@ -141,4 +141,6 @@ int qemu_opts_print(QemuOpts *opts, void *dummy);
 int qemu_opts_foreach(QemuOptsList *list, qemu_opts_loopfunc func, void *opaque,
                       int abort_on_failure);
 
+int qemu_opt_name_cmp(const char *lhs, const char *rhs);
+
 #endif
-- 
1.7.5.4