libxl: IDL: autogenerate functions to produce JSON from libxl data structures.

Two functions are provided. TYPE_gen_json exposes an interface which is
compatible with the YAGL generator infrastructure. TYPE_to_string uses this to
produce a pretty printed string.

The TYPE_gen_json functions are defined in a new header libxl_json.h which is
not exposed via libxl.h due to the use of YAGL datatypes to avoid poluting the
namespace us libxl users which don't use the library themselves.  If a libxl
user is interested in integrating at the YAGL level then it should #include
this file itself.

Also update testidl to generate a random version of each IDL datastructure and
convert it to JSON. Unfortunately this requires a libxl_ctx and therefore the
test must be run on a Xen system now.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <ian.jackson.citrix.com>
Committed-by: Ian Jackson <ian.jackson.citrix.com>

1 files changed, 245 insertions, 8 deletions

diff --git a/tools/libxl/gentest.py b/tools/libxl/gentest.py
index 47c7f0b4ae..6697ac5a56 100644
--- a/tools/libxl/gentest.py
+++ b/tools/libxl/gentest.py
@@ -5,6 +5,7 @@ import re
 import random
 
 import libxltypes
+
 def randomize_char(c):
     if random.random() < 0.5:
         return str.lower(c)
@@ -15,6 +16,55 @@ def randomize_case(s):
     r = [randomize_char(c) for c in s]
     return "".join(r)
 
+def randomize_enum(e):
+    return random.choice([v.name for v in e.values])
+
+handcoded = ["libxl_cpumap", "libxl_key_value_list",
+             "libxl_cpuid_policy_list", "libxl_file_reference",
+             "libxl_string_list", "libxl_cpuarray"]
+
+def gen_rand_init(ty, v, indent = "    ", parent = None):
+    s = ""
+    if isinstance(ty, libxltypes.Enumeration):
+        s += "%s = %s;\n" % (ty.pass_arg(v, parent is None), randomize_enum(ty))
+    elif isinstance(ty, libxltypes.KeyedUnion):
+        if parent is None:
+            raise Exception("KeyedUnion type must have a parent")
+        s += "switch (%s) {\n" % (parent + ty.keyvar_name)
+        for f in ty.fields:
+            (nparent,fexpr) = ty.member(v, f, parent is None)
+            s += "case %s:\n" % f.enumname
+            s += gen_rand_init(f.type, fexpr, indent + "    ", nparent)
+            s += "    break;\n"
+        s += "}\n"
+    elif isinstance(ty, libxltypes.Struct) \
+     and (parent is None or ty.json_fn is None):
+        for f in [f for f in ty.fields if not f.const]:
+            (nparent,fexpr) = ty.member(v, f, parent is None)
+            s += gen_rand_init(f.type, fexpr, "", nparent)
+    elif hasattr(ty, "rand_init") and ty.rand_init is not None:
+        s += "%s(%s);\n" % (ty.rand_init,
+                            ty.pass_arg(v, isref=parent is None,
+                                        passby=libxltypes.PASS_BY_REFERENCE))
+    elif ty.typename in ["libxl_uuid", "libxl_mac", "libxl_hwcap"]:
+        s += "rand_bytes((uint8_t *)%s, sizeof(*%s));\n" % (v,v)
+    elif ty.typename in ["libxl_domid"] or isinstance(ty, libxltypes.Number):
+        s += "%s = rand() %% (sizeof(%s)*8);\n" % \
+             (ty.pass_arg(v, parent is None),
+              ty.pass_arg(v, parent is None))
+    elif ty.typename in ["bool"]:
+        s += "%s = rand() %% 2;\n" % v
+    elif ty.typename in ["char *"]:
+        s += "%s = rand_str();\n" % v
+    elif ty.typename in handcoded:
+        raise Exception("Gen for handcoded %s" % ty.typename)
+    else:
+        raise Exception("Cannot randomly init %s" % ty.typename)
+
+    if s != "":
+        s = indent + s
+    return s.replace("\n", "\n%s" % indent).rstrip(indent)
+
 if __name__ == '__main__':
     if len(sys.argv) < 3:
         print >>sys.stderr, "Usage: gentest.py <idl> <implementation>"
@@ -23,27 +73,208 @@ if __name__ == '__main__':
     random.seed()
 
     idl = sys.argv[1]
-    (_,types) = libxltypes.parse(idl)
+    (builtins,types) = libxltypes.parse(idl)
 
     impl = sys.argv[2]
     f = open(impl, "w")
     f.write("""
 #include <stdio.h>
-#include \"libxl.h\"
+#include <stdlib.h>
+#include <string.h>
+
+#include "libxl.h"
+#include "libxl_utils.h"
+
+static char *rand_str(void)
+{
+    int i, sz = rand() % 32;
+    char *s = malloc(sz+1);
+    for (i=0; i<sz; i++)
+        s[i] = 'a' + (rand() % 26);
+    s[i] = '\\0';
+    return s;
+}
+
+static void rand_bytes(uint8_t *p, size_t sz)
+{
+    int i;
+    for (i=0; i<sz; i++)
+        p[i] = rand() % 256;
+}
 
+static void libxl_cpumap_rand_init(libxl_cpumap *cpumap)
+{
+    int i;
+    cpumap->size = rand() % 16;
+    cpumap->map = calloc(cpumap->size, sizeof(*cpumap->map));
+    libxl_for_each_cpu(i, *cpumap) {
+        if (rand() % 2)
+            libxl_cpumap_set(cpumap, i);
+        else
+            libxl_cpumap_reset(cpumap, i);
+    }
+}
+
+static void libxl_key_value_list_rand_init(libxl_key_value_list *pkvl)
+{
+    int i, nr_kvp = rand() % 16;
+    libxl_key_value_list kvl = calloc(nr_kvp+1, 2*sizeof(char *));
+
+    for (i = 0; i<2*nr_kvp; i += 2) {
+        kvl[i] = rand_str();
+        if (rand() % 8)
+            kvl[i+1] = rand_str();
+        else
+            kvl[i+1] = NULL;
+    }
+    kvl[i] = NULL;
+    kvl[i+1] = NULL;
+    *pkvl = kvl;
+}
+
+static void libxl_cpuid_policy_list_rand_init(libxl_cpuid_policy_list *pp)
+{
+    int i, nr_policies = rand() % 16;
+    struct {
+        const char *n;
+        int w;
+    } options[] = {
+      /* A random selection from libxl_cpuid_parse_config */
+        {"maxleaf",     32},
+        {"family",       8},
+        {"model",        8},
+        {"stepping",     4},
+        {"localapicid",  8},
+        {"proccount",    8},
+        {"clflush",      8},
+        {"brandid",      8},
+        {"f16c",         1},
+        {"avx",          1},
+        {"osxsave",      1},
+        {"xsave",        1},
+        {"aes",          1},
+        {"popcnt",       1},
+        {"movbe",        1},
+        {"x2apic",       1},
+        {"sse4.2",       1},
+        {"sse4.1",       1},
+        {"dca",          1},
+        {"pdcm",         1},
+        {"procpkg",      6},
+    };
+    const int nr_options = sizeof(options)/sizeof(options[0]);
+    char buf[64];
+    libxl_cpuid_policy_list p = NULL;
+
+    for (i = 0; i < nr_policies; i++) {
+        int opt = rand() % nr_options;
+        int val = rand() % (1<<options[opt].w);
+        snprintf(buf, 64, \"%s=%#x\", options[opt].n, val);
+        libxl_cpuid_parse_config(&p, buf);
+    }
+    *pp = p;
+}
+
+static void libxl_file_reference_rand_init(libxl_file_reference *p)
+{
+    memset(p, 0, sizeof(*p));
+    if (rand() % 8)
+        p->path = rand_str();
+}
+
+static void libxl_string_list_rand_init(libxl_string_list *p)
+{
+    int i, nr = rand() % 16;
+    libxl_string_list l = calloc(nr+1, sizeof(char *));
+
+    for (i = 0; i<nr; i++) {
+        l[i] = rand_str();
+    }
+    l[i] = NULL;
+    *p = l;
+}
+
+static void libxl_cpuarray_rand_init(libxl_cpuarray *p)
+{
+    int i;
+    /* Up to 16 VCPUs on 32 PCPUS */
+    p->entries = rand() % 16;
+    p->array = calloc(p->entries, sizeof(*p->array));
+    for (i = 0; i < p->entries; i++) {
+        int r = rand() % 32*1.5; /* 2:1 valid:invalid */
+        if (r >= 32)
+            p->array[i] = LIBXL_CPUARRAY_INVALID_ENTRY;
+        else
+            p->array[i] = r;
+    }
+}
+""")
+    for ty in builtins + types:
+        if ty.typename not in handcoded:
+            f.write("static void %s_rand_init(%s);\n" % \
+                    (ty.typename,
+                     ty.make_arg("p", passby=libxltypes.PASS_BY_REFERENCE)))
+            f.write("static void %s_rand_init(%s)\n" % \
+                    (ty.typename,
+                     ty.make_arg("p", passby=libxltypes.PASS_BY_REFERENCE)))
+            f.write("{\n")
+            f.write(gen_rand_init(ty, "p"))
+            f.write("}\n")
+            f.write("\n")
+        ty.rand_init = "%s_rand_init" % ty.typename
+
+    f.write("""
 int main(int argc, char **argv)
 {
 """)
 
-    for ty in [t for t in types if isinstance(t,libxltypes.Enumeration)]:
+    for ty in types:
         f.write("    %s %s_val;\n" % (ty.typename, ty.typename))
-    f.write("    int rc;\n")
-    f.write("\n")
+    f.write("""
+    int rc;
+    char *s;
+    xentoollog_logger_stdiostream *logger;
+    libxl_ctx *ctx;
+
+    logger = xtl_createlogger_stdiostream(stderr, XTL_DETAIL, 0);
+    if (!logger) exit(1);
+
+    if (libxl_ctx_alloc(&ctx, LIBXL_VERSION, (xentoollog_logger*)logger)) {
+        fprintf(stderr, "cannot init xl context\\n");
+        exit(1);
+    }
+""")
+    f.write("    printf(\"Testing TYPE_to_json()\\n\");\n")
+    f.write("    printf(\"----------------------\\n\");\n")
+    f.write("    printf(\"\\n\");\n")
+    for ty in [t for t in types if t.json_fn is not None]:
+        arg = ty.typename + "_val"
+        f.write("    %s_rand_init(%s);\n" % (ty.typename, \
+            ty.pass_arg(arg, isref=False, passby=libxltypes.PASS_BY_REFERENCE)))
+        f.write("    s = %s_to_json(ctx, %s);\n" % \
+                (ty.typename, ty.pass_arg(arg, isref=False)))
+        f.write("    printf(\"%%s: %%s\\n\", \"%s\", s);\n" % ty.typename)
+        f.write("    if (s == NULL) abort();\n")
+        f.write("    free(s);\n")
+        if ty.destructor_fn is not None:
+            f.write("    %s(&%s_val);\n" % (ty.destructor_fn, ty.typename))
+        f.write("\n")
 
+    f.write("    printf(\"Testing Enumerations\\n\");\n")
+    f.write("    printf(\"--------------------\\n\");\n")
+    f.write("    printf(\"\\n\");\n")
     for ty in [t for t in types if isinstance(t,libxltypes.Enumeration)]:
         f.write("    printf(\"%s -- to string:\\n\");\n" % (ty.typename))
         for v in ty.values:
-            f.write("    printf(\"\\t%s = %%d = \\\"%%s\\\"\\n\", %s, %s_to_string(%s));\n" %\
+            f.write("    printf(\"\\t%s = %%d = \\\"%%s\\\"\\n\", " \
+                    "%s, %s_to_string(%s));\n" % \
+                    (v.valuename, v.name, ty.typename, v.name))
+        f.write("\n")
+
+        f.write("    printf(\"%s -- to JSON:\\n\");\n" % (ty.typename))
+        for v in ty.values:
+            f.write("    printf(\"\\t%s = %%d = %%s\", " \
+                    "%s, %s_to_json(ctx, %s));\n" %\
                     (v.valuename, v.name, ty.typename, v.name))
         f.write("\n")
 
@@ -54,10 +285,16 @@ int main(int argc, char **argv)
             f.write("    rc = %s_from_string(\"%s\", &%s_val);\n" %\
                     (ty.typename, n, ty.typename))
 
-            f.write("    printf(\"\\t%s = \\\"%%s\\\" = %%d (rc %%d)\\n\", \"%s\", %s_val, rc);\n" %\
+            f.write("    printf(\"\\t%s = \\\"%%s\\\" = %%d (rc %%d)\\n\", " \
+                    "\"%s\", %s_val, rc);\n" %\
                     (v, n, ty.typename))
         f.write("\n")
 
-    f.write("""return 0;
+    f.write("""
+
+    libxl_ctx_free(ctx);
+    xtl_logger_destroy((xentoollog_logger*)logger);
+
+    return 0;
 }
 """)