Merge pull request #2404 from herwinw/ffi_load_array

Support array argument in ffi_lib
natalie-lang · Dec 19, 2024 · dbd9658 · dbd9658
2 parents dfcad8c + 33c2705
commit dbd9658
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Showing 2 changed files with 57 additions and 5 deletions.
diff --git a/lib/ffi.cpp b/lib/ffi.cpp
@@ -13,10 +13,29 @@ Value init_ffi(Env *env, Value self) {
 Value FFI_Library_ffi_lib(Env *env, Value self, Args &&args, Block *) {
     args.ensure_argc_is(env, 1);
     auto name = args.at(0);
-    name->assert_type(env, Object::Type::String, "String");
-    auto handle = dlopen(name->as_string()->c_str(), RTLD_LAZY);
-    if (!handle)
-        env->raise("LoadError", "Could not open library '{}': {}.", name->as_string()->c_str(), dlerror());
+    void *handle = nullptr;
+    if (name->is_array()) {
+        for (auto name2 : *name->as_array()) {
+            name2->assert_type(env, Object::Type::String, "String");
+            handle = dlopen(name2->as_string()->c_str(), RTLD_LAZY);
+            if (handle) {
+                name = name2;
+                break;
+            }
+        }
+        if (!handle) {
+            auto error = new StringObject;
+            for (auto name2 : *name->as_array())
+                error->append_sprintf("Could not open library '%s': %s.\n", name2->as_string()->string().c_str(), dlerror());
+            error->chomp_in_place(env, nullptr);
+            env->raise("LoadError", error->string());
+        }
+    } else {
+        name->assert_type(env, Object::Type::String, "String");
+        handle = dlopen(name->as_string()->c_str(), RTLD_LAZY);
+        if (!handle)
+            env->raise("LoadError", "Could not open library '{}': {}.", name->as_string()->c_str(), dlerror());
+    }
     auto handle_ptr = new VoidPObject { handle, [](auto p) { dlclose(p->void_ptr()); } };
     auto libs = self->ivar_get(env, "@ffi_libs"_s);
     if (libs->is_nil())

diff --git a/test/natalie/ffi_test.rb b/test/natalie/ffi_test.rb
@@ -34,7 +34,7 @@ module LibRubyParser
 describe 'FFI' do
   it 'raises an error if the library cannot be found' do
     lambda do
-      module Foo
+      Module.new do
         extend FFI::Library
         ffi_lib "non_existent.so"
       end
@@ -44,6 +44,39 @@ module Foo
     )
   end
 
+  it 'supports an array of strings as library and uses the first one available' do
+    foo = Module.new do
+      extend FFI::Library
+      ffi_lib ['non_existent.so', STUB_LIBRARY_PATH, PRISM_LIBRARY_PATH]
+    end
+    libs = foo.instance_variable_get(:@ffi_libs)
+    libs.size.should == 1
+    lib = libs.first
+    lib.should be_an_instance_of FFI::DynamicLibrary
+    lib.name.should == STUB_LIBRARY_PATH
+  end
+
+  it 'raises an error if no library can be found' do
+    lambda do
+      Module.new do
+        extend FFI::Library
+        ffi_lib ["non_existent.so", "neither_existent.so"]
+      end
+    end.should raise_error(
+      LoadError,
+      /Could not open library.*non_existent\.so.*Could not open library.*neither_existent\.so/m
+    )
+  end
+
+  it 'raises an error if an empty list is provided' do
+    lambda do
+      Module.new do
+        extend FFI::Library
+        ffi_lib []
+      end
+    end.should raise_error(LoadError)
+  end
+
   it 'links to a shared object' do
     libs = LibRubyParser.instance_variable_get(:@ffi_libs)
     libs.size.should == 1