[PATCH v8 19/21] libxlu: introduce new APIs

[Wei Liu <wei.liu2@citrix.com>]

These APIs can be used to manipulate XLU_ConfigValue and XLU_ConfigList.

APIs introduced:
1. xlu_cfg_value_type
2. xlu_cfg_value_get_string
3. xlu_cfg_value_get_list
4. xlu_cfg_get_listitem2

Move some definitions from private header to public header as needed.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
---
Changes in v6:
1. Report value's line and column number on error.

Changes in v5:
1. Use calling convention like old APIs.
---
 tools/libxl/libxlu_cfg.c      | 47 +++++++++++++++++++++++++++++++++++++++++++
 tools/libxl/libxlu_internal.h |  7 -------
 tools/libxl/libxlutil.h       | 13 ++++++++++++
 3 files changed, 60 insertions(+), 7 deletions(-)

diff --git a/tools/libxl/libxlu_cfg.c b/tools/libxl/libxlu_cfg.c
index 938ea96..abf6b06 100644
--- a/tools/libxl/libxlu_cfg.c
+++ b/tools/libxl/libxlu_cfg.c
@@ -199,6 +199,53 @@ static int find_atom(const XLU_Config *cfg, const char *n,
     return 0;
 }
 
+
+enum XLU_ConfigValueType xlu_cfg_value_type(const XLU_ConfigValue *value)
+{
+    return value->type;
+}
+
+int xlu_cfg_value_get_string(const XLU_Config *cfg, XLU_ConfigValue *value,
+                             char **value_r, int dont_warn)
+{
+    if (value->type != XLU_STRING) {
+        if (!dont_warn)
+            fprintf(cfg->report,
+                    "%s:%d:%d: warning: value is not a string\n",
+                    cfg->config_source, value->loc.first_line,
+                    value->loc.first_column);
+        *value_r = NULL;
+        return EINVAL;
+    }
+
+    *value_r = value->u.string;
+    return 0;
+}
+
+int xlu_cfg_value_get_list(const XLU_Config *cfg, XLU_ConfigValue *value,
+                           XLU_ConfigList **value_r, int dont_warn)
+{
+    if (value->type != XLU_LIST) {
+        if (!dont_warn)
+            fprintf(cfg->report,
+                    "%s:%d:%d: warning: value is not a list\n",
+                    cfg->config_source, value->loc.first_line,
+                    value->loc.first_column);
+        *value_r = NULL;
+        return EINVAL;
+    }
+
+    *value_r = &value->u.list;
+    return 0;
+}
+
+XLU_ConfigValue *xlu_cfg_get_listitem2(const XLU_ConfigList *list,
+                                       int entry)
+{
+    if (entry < 0 || entry >= list->nvalues) return NULL;
+    return list->values[entry];
+}
+
 int xlu_cfg_get_string(const XLU_Config *cfg, const char *n,
                        const char **value_r, int dont_warn) {
     XLU_ConfigSetting *set;
diff --git a/tools/libxl/libxlu_internal.h b/tools/libxl/libxlu_internal.h
index 600ff68..3451cfe 100644
--- a/tools/libxl/libxlu_internal.h
+++ b/tools/libxl/libxlu_internal.h
@@ -25,13 +25,6 @@
 
 #include "libxlutil.h"
 
-enum XLU_ConfigValueType {
-    XLU_STRING,
-    XLU_LIST,
-};
-
-typedef struct XLU_ConfigValue XLU_ConfigValue;
-
 typedef struct XLU_ConfigList {
     int avalues; /* available slots */
     int nvalues; /* actual occupied slots */
diff --git a/tools/libxl/libxlutil.h b/tools/libxl/libxlutil.h
index 0333e55..989605a 100644
--- a/tools/libxl/libxlutil.h
+++ b/tools/libxl/libxlutil.h
@@ -20,9 +20,15 @@
 
 #include "libxl.h"
 
+enum XLU_ConfigValueType {
+    XLU_STRING,
+    XLU_LIST,
+};
+
 /* Unless otherwise stated, all functions return an errno value. */
 typedef struct XLU_Config XLU_Config;
 typedef struct XLU_ConfigList XLU_ConfigList;
+typedef struct XLU_ConfigValue XLU_ConfigValue;
 
 XLU_Config *xlu_cfg_init(FILE *report, const char *report_filename);
   /* 0 means we got ENOMEM. */
@@ -66,6 +72,13 @@ const char *xlu_cfg_get_listitem(const XLU_ConfigList*, int entry);
   /* xlu_cfg_get_listitem cannot fail, except that if entry is
    * out of range it returns 0 (not setting errno) */
 
+enum XLU_ConfigValueType xlu_cfg_value_type(const XLU_ConfigValue *value);
+int xlu_cfg_value_get_string(const XLU_Config *cfg,  XLU_ConfigValue *value,
+                             char **value_r, int dont_warn);
+int xlu_cfg_value_get_list(const XLU_Config *cfg, XLU_ConfigValue *value,
+                           XLU_ConfigList **value_r, int dont_warn);
+XLU_ConfigValue *xlu_cfg_get_listitem2(const XLU_ConfigList *list,
+                                       int entry);
 
 /*
  * Disk specification parsing.
-- 
1.9.1