Implement library loader

Author: MoritzGoeckel

src/executer/ExternalFunctions.cpp

@@ -0,0 +1,93 @@
+#include "../executer/ExternalFunctions.h"
+#include <dlfcn.h>
+
+namespace ffi {
+
+#ifdef WIN // Windows
+
+ExternalFunctions::ExternalFunctions() = default;
+
+size_t ExternalFunctions::add(const std::string& library, const std::string& functionName) {
+    throwConstraintViolated("External functions are not supported on this platform");
+}
+
+qword_t ExternalFunctions::call(size_t id, const std::vector<void*>& args) {
+    throwConstraintViolated("External functions are not supported on this platform");
+    return 0;
+}
+
+ExternalFunctions::~ExternalFunctions() = default;
+
+#else // Linux
+
+ExternalFunctions::ExternalFunctions() = default;
+
+size_t ExternalFunctions::add(const std::string& library, const std::string& functionName) {
+    ExternalFunction functionInfo;
+    functionInfo.library = library;
+    functionInfo.name = functionName;
+    functionInfo.functionPtr = nullptr;
+
+    void* libraryHandle = nullptr;
+    if (auto it = libraries.find(library); it != libraries.end()) {
+        libraryHandle = it->second;
+    } else {
+        libraryHandle = dlopen(("bin/lib" + library + ".so").c_str(), RTLD_LAZY);
+        if (!libraryHandle) {
+            std::cerr << "Error: " << dlerror() << std::endl;
+            throwConstraintViolated("Failed to load library");
+        }
+        libraries[library] = libraryHandle;
+    }
+
+    ASSURE_NOT_NULL(libraryHandle);
+    dlerror(); // Clear any existing error
+
+    //void (*print)() = (void (*)())dlsym(handle, "print");
+    functionInfo.functionPtr = dlsym(libraryHandle, functionName.c_str());
+    const char* dlsym_error = dlerror();
+    if (dlsym_error) {
+        std::cerr << "Error: " << dlsym_error << std::endl;
+        throwConstraintViolated("Failed to find symbol in library");
+    }
+    ASSURE_NOT_NULL(functionInfo.functionPtr);
+
+    functions.push_back(functionInfo);
+    return functions.size() - 1;
+}
+
+qword_t ExternalFunctions::call(size_t id, const std::vector<void*>& args) {
+    ASSURE(id < functions.size(), "Function ID out of bounds");
+
+    const ExternalFunction& func = functions[id];
+
+    qword_t result;
+    void* fn = func.functionPtr;
+    __asm__ (
+        "mov $5, %%rdi\n"
+        "mov $10, %%rsi\n"
+        "call *%[fn_tag]\n"
+        "movq %%rax, %[result_tag]\n"
+        : [result_tag] "=r"(result) : [fn_tag] "r"(fn)); // Call the function using inline assembly
+
+    // https://github.com/tsoding/b/blob/main/src/codegen/fasm_x86_64.rs#L221
+    // Floating point numbers are passed in xmm0, xmm1, xmm2, xmm3, xmm4, xmm5, xmm6, xmm7
+    // Integer numbers are passed in rdi, rsi, rdx, rcx, r8, r9
+    // The result is returned in rax
+    // If we need more than 6 arguments, the rest are passed on the stack. (?)
+
+    return result;
+}
+
+ExternalFunctions::~ExternalFunctions() {
+    for (const auto& [libName, libHandle] : libraries) {
+        if (libHandle) {
+            dlclose(libHandle);
+        }
+    }
+    libraries.clear();
+}
+
+#endif
+
+} // namespace ffi

src/executer/ExternalFunctions.h

@@ -0,0 +1,50 @@
+#pragma once
+
+#include "../error/Exceptions.h"
+
+#include <string>
+#include <vector>
+#include <map>
+#include <iostream>
+
+namespace ffi {
+
+using word_t = unsigned long; // TODO?
+using dword_t = unsigned long;
+using qword_t = unsigned long long;
+
+using float_t = float;
+using double_t = double;
+
+enum class Type {
+    Word,
+    DWord,
+    QWord,
+    Float,
+    Double
+};
+
+struct ExternalFunction {
+    std::string library;
+    std::string name;
+    void* functionPtr;
+    std::vector<Type> parameters;
+    Type returnType;
+};
+
+class ExternalFunctions {
+   public:
+    ExternalFunctions();
+
+    size_t add(const std::string& library, const std::string& functionName);
+
+    qword_t call(size_t id, const std::vector<void*>& args);
+
+    ~ExternalFunctions();
+
+   private:
+    std::vector<ExternalFunction> functions;
+    std::map<std::string, void*> libraries;
+};
+
+} // namespace ffi

src/mains/Tests.cpp

@@ -1,3 +1,4 @@
+#include "../executer/ExternalFunctions.h"
 #include "../executer/ByteCode.h"
 #include <iostream>
 #include "../core/Mlang.h"
@@ -120,50 +121,12 @@ void testFile(std::string path){
     std::cout << "[ OK ] " << path << std::endl;
 }
 
-// TODO
-#include <dlfcn.h>
-
 void testLibrary(){
     std::cout << "Testing library..." << std::endl;
-
-    void* handle = dlopen("bin/libprint.so", RTLD_LAZY);
-    if (!handle) {
-        std::cerr << "Error: " << dlerror() << std::endl;
-        throwConstraintViolated("Failed to load library");
-    }
-
-    dlerror(); // Clear any existing error
-
-    //void (*print)() = (void (*)())dlsym(handle, "print");
-    void* fn = dlsym(handle, "mul");
-    const char* dlsym_error = dlerror();
-    if (dlsym_error) {
-        std::cerr << "Error: " << dlsym_error << std::endl;
-        dlclose(handle);
-        throwConstraintViolated("Failed to find symbol in library");
-    }
-
-    // print(); // Call the function from the library
-    size_t result;
-    __asm__ (
-        "mov $5, %%rdi\n"
-        "mov $10, %%rsi\n"
-        "call *%[fn_tag]\n"
-        "movq %%rax, %[result_tag]\n"
-        : [result_tag] "=r"(result) : [fn_tag] "r"(fn)); // Call the function using inline assembly
-
-    // https://github.com/tsoding/b/blob/main/src/codegen/fasm_x86_64.rs#L221
-    // Floating point numbers are passed in xmm0, xmm1, xmm2, xmm3, xmm4, xmm5, xmm6, xmm7
-    // Integer numbers are passed in rdi, rsi, rdx, rcx, r8, r9
-    // The result is returned in rax
-    // If we need more than 6 arguments, the rest are passed on the stack. (?)
-
-
-    std::cout << "Result of multiplication: " << result << std::endl;
-
-
-    dlclose(handle); // Close the library handle
-
+    ffi::ExternalFunctions externalFunctions;
+    auto id = externalFunctions.add("print", "mul");
+    auto r = externalFunctions.call(id, { }); // TODO: Args are not used yet
+    EXPECT_EQ(50, r);
     std::cout << "[ OK ] Library test passed." << std::endl;
 }