[waffle] [PATCH v2 8/8] nacl: add implementation for waffle_dl_sym

[Tapani Pälli]

v2: use wcore_calloc, code cleanup (Emil Velikov)
    open dll only once in can_open (Chad Versace)

Signed-off-by: Tapani Pälli <tapani.palli at intel.com>
---
 src/waffle/nacl/nacl_platform.c | 69 +++++++++++++++++++++++++++++++++++++++--
 src/waffle/nacl/nacl_platform.h |  1 +
 2 files changed, 68 insertions(+), 2 deletions(-)

diff --git a/src/waffle/nacl/nacl_platform.c b/src/waffle/nacl/nacl_platform.c
index c4fefe5..22169da 100644
--- a/src/waffle/nacl/nacl_platform.c
+++ b/src/waffle/nacl/nacl_platform.c
@@ -43,6 +43,11 @@ nacl_platform_destroy(struct wcore_platform *wc_self)
 
     nacl_teardown(self->nacl);
 
+    if (self->gl_dl)
+        if (dlclose(self->gl_dl) != 0)
+            wcore_errorf(WAFFLE_ERROR_UNKNOWN, "dlclose failed: %s",
+                         dlerror());
+
     free(self);
     return ok;
 }
@@ -51,7 +56,41 @@ static bool
 nacl_platform_dl_can_open(struct wcore_platform *wc_self,
                           int32_t waffle_dl)
 {
-    return false;
+    struct nacl_platform *self = nacl_platform(wc_self);
+
+    switch (waffle_dl) {
+        case WAFFLE_DL_OPENGL_ES2:
+            if (!self->gl_dl)
+                self->gl_dl = dlopen(NACL_GLES2_LIBRARY, RTLD_LAZY);
+            break;
+        // API not supported
+        default:
+            return false;
+    }
+
+    if (!self->gl_dl)
+        wcore_errorf(WAFFLE_ERROR_UNKNOWN, "dlopen failed: %s", dlerror());
+
+    return self->gl_dl ? true : false;
+}
+
+// Construct a string that maps GL function to NaCl function
+// by concating given prefix and function name tail from 'src'.
+static char *
+nacl_prefix(const char *src, const char *prefix)
+{
+    if (strncmp(src, "gl", 2) != 0)
+        return NULL;
+
+    uint32_t len = strlen(src) + strlen(prefix);
+
+    char *dst = wcore_calloc(len);
+    if (!dst)
+        return NULL;
+
+    snprintf(dst, len, "%s%s", prefix, src + 2);
+
+    return dst;
 }
 
 static void*
@@ -59,7 +98,33 @@ nacl_platform_dl_sym(struct wcore_platform *wc_self,
                      int32_t waffle_dl,
                      const char *name)
 {
-    return NULL;
+    struct nacl_platform *self = nacl_platform(wc_self);
+    char *nacl_name = NULL;
+    void *func = NULL;
+
+    if (!self->gl_dl)
+        if (!nacl_platform_dl_can_open(wc_self, waffle_dl))
+            return false;
+
+    nacl_name = nacl_prefix(name, "GLES2");
+
+    if (!nacl_name)
+        return NULL;
+
+    func = dlsym(self->gl_dl, nacl_name);
+
+    if (!func) {
+        const char *error = dlerror();
+        if (error) {
+            wcore_errorf(WAFFLE_ERROR_UNKNOWN,
+                         "dlsym(libname=\"%s\", symbol=\"%s\") failed: %s",
+                         NACL_GLES2_LIBRARY, nacl_name, error);
+        }
+    }
+
+    free(nacl_name);
+
+    return func;
 }
 
 static bool
diff --git a/src/waffle/nacl/nacl_platform.h b/src/waffle/nacl/nacl_platform.h
index ba58de5..fa2d364 100644
--- a/src/waffle/nacl/nacl_platform.h
+++ b/src/waffle/nacl/nacl_platform.h
@@ -38,6 +38,7 @@
 struct nacl_platform {
     struct wcore_platform wcore;
     struct nacl_container *nacl;
+    void *gl_dl;
 };
 
 DEFINE_CONTAINER_CAST_FUNC(nacl_platform,
-- 
2.1.0