Return strings through an output parameter

adazem009 · adazem009 · commit 6d44f64c6a56 · 2025-08-29T13:13:22.000+02:00
diff --git a/src/blocks/looksblocks.cpp b/src/blocks/looksblocks.cpp
@@ -561,25 +561,21 @@ extern "C" double looks_backdrop_number(ExecutionContext *ctx)
     return ctx->engine()->stage()->costumeIndex() + 1;
 }
 
-extern "C" StringPtr *looks_backdrop_name(ExecutionContext *ctx)
+extern "C" void looks_backdrop_name(StringPtr *ret, ExecutionContext *ctx)
 {
     const std::string &name = ctx->engine()->stage()->currentCostume()->name();
-    StringPtr *ret = string_pool_new();
     string_assign_cstring(ret, name.c_str());
-    return ret;
 }
 
 extern "C" double looks_costume_number(Target *target)
 {
     return target->costumeIndex() + 1;
 }
 
-extern "C" StringPtr *looks_costume_name(Target *target)
+extern "C" void looks_costume_name(StringPtr *ret, Target *target)
 {
     const std::string &name = target->currentCostume()->name();
-    StringPtr *ret = string_pool_new();
     string_assign_cstring(ret, name.c_str());
-    return ret;
 }
 
 extern "C" bool looks_backdrop_promise(ExecutionContext *ctx)
diff --git a/src/blocks/sensingblocks.cpp b/src/blocks/sensingblocks.cpp
@@ -522,11 +522,9 @@ extern "C" void sensing_askandwait(ExecutionContext *ctx, const StringPtr *quest
     ctx->thread()->setPromise(std::make_shared<Promise>());
 }
 
-extern "C" StringPtr *sensing_answer(ExecutionContext *ctx)
+extern "C" void sensing_answer(StringPtr *ret, ExecutionContext *ctx)
 {
-    StringPtr *ret = string_pool_new();
     string_assign(ret, ctx->engine()->answer());
-    return ret;
 }
 
 extern "C" bool sensing_keypressed(ExecutionContext *ctx, const StringPtr *key)
@@ -595,12 +593,10 @@ extern "C" double sensing_costume_number_of_target(Target *target)
     return target->costumeIndex() + 1;
 }
 
-extern "C" StringPtr *sensing_costume_name_of_target(Target *target)
+extern "C" void sensing_costume_name_of_target(StringPtr *ret, Target *target)
 {
     const std::string &name = target->currentCostume()->name();
-    StringPtr *ret = string_pool_new();
     string_assign_cstring(ret, name.c_str());
-    return ret;
 }
 
 extern "C" double sensing_size_of_sprite(Sprite *sprite)
@@ -659,17 +655,13 @@ extern "C" double sensing_costume_number_of_sprite_with_check(Target *target)
     return 0.0;
 }
 
-extern "C" StringPtr *sensing_costume_name_of_sprite_with_check(Target *target)
+extern "C" void sensing_costume_name_of_sprite_with_check(StringPtr *ret, Target *target)
 {
-    StringPtr *ret = string_pool_new();
-
     if (target && !target->isStage()) {
         const std::string &name = target->currentCostume()->name();
         string_assign_cstring(ret, name.c_str());
     } else
         string_assign_cstring(ret, "0");
-
-    return ret;
 }
 
 extern "C" double sensing_size_of_sprite_with_check(Target *target)
@@ -690,17 +682,13 @@ extern "C" double sensing_backdrop_number_of_stage_with_check(Target *target)
     return 0.0;
 }
 
-extern "C" StringPtr *sensing_backdrop_name_of_stage_with_check(Target *target)
+extern "C" void sensing_backdrop_name_of_stage_with_check(StringPtr *ret, Target *target)
 {
-    StringPtr *ret = string_pool_new();
-
     if (target && target->isStage()) {
         const std::string &name = target->currentCostume()->name();
         string_assign_cstring(ret, name.c_str());
     } else
         string_assign_cstring(ret, "");
-
-    return ret;
 }
 
 extern "C" double sensing_volume_of_target_with_check(Target *target)
diff --git a/src/engine/internal/llvm/instructions/functions.cpp b/src/engine/internal/llvm/instructions/functions.cpp
@@ -32,6 +32,15 @@ LLVMInstruction *Functions::buildFunctionCall(LLVMInstruction *ins)
     // Variables must be synchronized because the function can read them
     m_utils.syncVariables();
 
+    // Strings are returned through an output parameter
+    llvm::Value *stringRet = nullptr;
+
+    if (ins->functionReturnReg && ins->functionReturnReg->type() == Compiler::StaticType::String) {
+        stringRet = m_builder.CreateCall(m_utils.functions().resolve_string_pool_new(), { m_builder.getInt1(true) });
+        types.push_back(m_utils.getType(Compiler::StaticType::String, false));
+        args.push_back(stringRet);
+    }
+
     // Add execution context arg
     if (ins->functionCtxArg) {
         types.push_back(llvm::PointerType::get(llvm::Type::getInt8Ty(m_utils.llvmCtx()), 0));
@@ -54,15 +63,15 @@ LLVMInstruction *Functions::buildFunctionCall(LLVMInstruction *ins)
     llvm::Value *ret = m_builder.CreateCall(m_utils.functions().resolveFunction(ins->functionName, llvm::FunctionType::get(retType, types, false)), args);
 
     if (ins->functionReturnReg) {
-        if (m_utils.isSingleType(ins->functionReturnReg->type()))
+        if (ins->functionReturnReg->type() == Compiler::StaticType::String) {
+            ins->functionReturnReg->value = stringRet;
+            m_utils.freeStringLater(stringRet);
+        } else if (m_utils.isSingleType(ins->functionReturnReg->type()))
             ins->functionReturnReg->value = ret;
         else {
             ins->functionReturnReg->value = m_utils.addAlloca(retType);
             m_builder.CreateStore(ret, ins->functionReturnReg->value);
         }
-
-        if (ins->functionReturnReg->type() == Compiler::StaticType::String)
-            m_utils.freeStringLater(ins->functionReturnReg->value);
     }
 
     return ins->next;
diff --git a/src/engine/internal/llvm/llvmbuildutils.cpp b/src/engine/internal/llvm/llvmbuildutils.cpp
@@ -707,7 +707,11 @@ llvm::Type *LLVMBuildUtils::getType(Compiler::StaticType type, bool isReturnType
             return m_builder.getInt1Ty();
 
         case Compiler::StaticType::String:
-            return m_stringPtrType->getPointerTo();
+            // Strings are returned through an output parameter
+            if (isReturnType)
+                return m_builder.getVoidTy();
+            else
+                return m_stringPtrType->getPointerTo();
 
         case Compiler::StaticType::Pointer:
             return m_builder.getVoidTy()->getPointerTo();
diff --git a/test/blocks/util.cpp b/test/blocks/util.cpp
@@ -68,11 +68,9 @@ extern "C" bool test_condition()
     return conditionReturnValue;
 }
 
-extern "C" StringPtr *test_const_string(const StringPtr *str)
+extern "C" void test_const_string(StringPtr *ret, const StringPtr *str)
 {
-    StringPtr *ret = string_pool_new();
     string_assign(ret, str);
-    return ret;
 }
 
 } // namespace libscratchcpp
diff --git a/test/llvm/testfunctions.cpp b/test/llvm/testfunctions.cpp
@@ -63,14 +63,12 @@ extern "C"
         std::cout << "no_args" << std::endl;
     }
 
-    StringPtr *test_function_no_args_ret(Target *target)
+    void test_function_no_args_ret(StringPtr *ret, Target *target)
     {
         target->isStage();
         std::cout << "no_args_ret" << std::endl;
         Value v("no_args_output");
-        StringPtr *ret = string_pool_new();
         value_toStringPtr(&v.data(), ret);
-        return ret;
     }
 
     void test_function_1_arg(Target *target, const StringPtr *arg1)
@@ -79,14 +77,12 @@ extern "C"
         std::cout << "1_arg " << utf8::utf16to8(std::u16string(arg1->data)) << std::endl;
     }
 
-    StringPtr *test_function_1_arg_ret(Target *target, const StringPtr *arg1)
+    void test_function_1_arg_ret(StringPtr *ret, Target *target, const StringPtr *arg1)
     {
         target->isStage();
         std::cout << "1_arg_ret " << utf8::utf16to8(std::u16string(arg1->data)) << std::endl;
         Value v("1_arg_output");
-        StringPtr *ret = string_pool_new();
         value_toStringPtr(&v.data(), ret);
-        return ret;
     }
 
     void test_function_3_args(Target *target, const StringPtr *arg1, const StringPtr *arg2, const StringPtr *arg3)
@@ -95,14 +91,12 @@ extern "C"
         std::cout << "3_args " << utf8::utf16to8(std::u16string(arg1->data)) << " " << utf8::utf16to8(std::u16string(arg2->data)) << " " << utf8::utf16to8(std::u16string(arg3->data)) << std::endl;
     }
 
-    StringPtr *test_function_3_args_ret(Target *target, const StringPtr *arg1, const StringPtr *arg2, const StringPtr *arg3)
+    void test_function_3_args_ret(StringPtr *ret, Target *target, const StringPtr *arg1, const StringPtr *arg2, const StringPtr *arg3)
     {
         target->isStage();
         std::cout << "3_args " << utf8::utf16to8(std::u16string(arg1->data)) << " " << utf8::utf16to8(std::u16string(arg2->data)) << " " << utf8::utf16to8(std::u16string(arg3->data)) << std::endl;
         Value v("3_args_output");
-        StringPtr *ret = string_pool_new();
         value_toStringPtr(&v.data(), ret);
-        return ret;
     }
 
     const void *test_function_1_ptr_arg_ret(Target *target, const int *arg1)
@@ -138,11 +132,9 @@ extern "C"
         return v;
     }
 
-    StringPtr *test_const_string(const StringPtr *v)
+    void test_const_string(StringPtr *ret, const StringPtr *v)
     {
-        StringPtr *ret = string_pool_new();
         string_assign(ret, v);
-        return ret;
     }
 
     ValueData test_const_unknown(const ValueData *v)
diff --git a/test/llvm/testfunctions.h b/test/llvm/testfunctions.h
@@ -1,5 +1,7 @@
 #pragma once
 
+#include <scratchcpp/valuedata.h>
+
 namespace libscratchcpp
 {
 
@@ -21,11 +23,11 @@ extern "C"
     void test_ctx_function(ExecutionContext *ctx, const StringPtr *arg);
 
     void test_function_no_args(Target *target);
-    StringPtr *test_function_no_args_ret(Target *target);
+    void test_function_no_args_ret(StringPtr *ret, Target *target);
     void test_function_1_arg(Target *target, const StringPtr *arg1);
-    StringPtr *test_function_1_arg_ret(Target *target, const StringPtr *arg1);
+    void test_function_1_arg_ret(StringPtr *ret, Target *target, const StringPtr *arg1);
     void test_function_3_args(Target *target, const StringPtr *arg1, const StringPtr *arg2, const StringPtr *arg3);
-    StringPtr *test_function_3_args_ret(Target *target, const StringPtr *arg1, const StringPtr *arg2, const StringPtr *arg3);
+    void test_function_3_args_ret(StringPtr *ret, Target *target, const StringPtr *arg1, const StringPtr *arg2, const StringPtr *arg3);
 
     const void *test_function_1_ptr_arg_ret(Target *target, const int *arg1);
 
@@ -35,7 +37,7 @@ extern "C"
 
     double test_const_number(double v);
     bool test_const_bool(bool v);
-    StringPtr *test_const_string(const StringPtr *v);
+    void test_const_string(StringPtr *ret, const StringPtr *v);
     ValueData test_const_unknown(const ValueData *v);
     const void *test_const_pointer(const void *v);
 

Original file line number	Diff line number	Diff line change
`@@ -561,25 +561,21 @@ extern "C" double looks_backdrop_number(ExecutionContext *ctx)`
`561`	`561`	`return ctx->engine()->stage()->costumeIndex() + 1;`
`562`	`562`	`}`
`563`	`563`
`564`		`-extern "C" StringPtr looks_backdrop_name(ExecutionContext ctx)`
	`564`	`+extern "C" void looks_backdrop_name(StringPtr ret, ExecutionContext ctx)`
`565`	`565`	`{`
`566`	`566`	`const std::string &name = ctx->engine()->stage()->currentCostume()->name();`
`567`		`- StringPtr *ret = string_pool_new();`
`568`	`567`	`string_assign_cstring(ret, name.c_str());`
`569`		`- return ret;`
`570`	`568`	`}`
`571`	`569`
`572`	`570`	`extern "C" double looks_costume_number(Target *target)`
`573`	`571`	`{`
`574`	`572`	`return target->costumeIndex() + 1;`
`575`	`573`	`}`
`576`	`574`
`577`		`-extern "C" StringPtr looks_costume_name(Target target)`
	`575`	`+extern "C" void looks_costume_name(StringPtr ret, Target target)`
`578`	`576`	`{`
`579`	`577`	`const std::string &name = target->currentCostume()->name();`
`580`		`- StringPtr *ret = string_pool_new();`
`581`	`578`	`string_assign_cstring(ret, name.c_str());`
`582`		`- return ret;`
`583`	`579`	`}`
`584`	`580`
`585`	`581`	`extern "C" bool looks_backdrop_promise(ExecutionContext *ctx)`
Original file line number	Diff line number	Diff line change
`@@ -522,11 +522,9 @@ extern "C" void sensing_askandwait(ExecutionContext ctx, const StringPtr quest`
`522`	`522`	`ctx->thread()->setPromise(std::make_shared<Promise>());`
`523`	`523`	`}`
`524`	`524`
`525`		`-extern "C" StringPtr sensing_answer(ExecutionContext ctx)`
	`525`	`+extern "C" void sensing_answer(StringPtr ret, ExecutionContext ctx)`
`526`	`526`	`{`
`527`		`- StringPtr *ret = string_pool_new();`
`528`	`527`	`string_assign(ret, ctx->engine()->answer());`
`529`		`- return ret;`
`530`	`528`	`}`
`531`	`529`
`532`	`530`	`extern "C" bool sensing_keypressed(ExecutionContext ctx, const StringPtr key)`
`@@ -595,12 +593,10 @@ extern "C" double sensing_costume_number_of_target(Target *target)`
`595`	`593`	`return target->costumeIndex() + 1;`
`596`	`594`	`}`
`597`	`595`
`598`		`-extern "C" StringPtr sensing_costume_name_of_target(Target target)`
	`596`	`+extern "C" void sensing_costume_name_of_target(StringPtr ret, Target target)`
`599`	`597`	`{`
`600`	`598`	`const std::string &name = target->currentCostume()->name();`
`601`		`- StringPtr *ret = string_pool_new();`
`602`	`599`	`string_assign_cstring(ret, name.c_str());`
`603`		`- return ret;`
`604`	`600`	`}`
`605`	`601`
`606`	`602`	`extern "C" double sensing_size_of_sprite(Sprite *sprite)`
`@@ -659,17 +655,13 @@ extern "C" double sensing_costume_number_of_sprite_with_check(Target *target)`
`659`	`655`	`return 0.0;`
`660`	`656`	`}`
`661`	`657`
`662`		`-extern "C" StringPtr sensing_costume_name_of_sprite_with_check(Target target)`
	`658`	`+extern "C" void sensing_costume_name_of_sprite_with_check(StringPtr ret, Target target)`
`663`	`659`	`{`
`664`		`- StringPtr *ret = string_pool_new();`
`665`		`-`
`666`	`660`	`if (target && !target->isStage()) {`
`667`	`661`	`const std::string &name = target->currentCostume()->name();`
`668`	`662`	`string_assign_cstring(ret, name.c_str());`
`669`	`663`	`} else`
`670`	`664`	`string_assign_cstring(ret, "0");`
`671`		`-`
`672`		`- return ret;`
`673`	`665`	`}`
`674`	`666`
`675`	`667`	`extern "C" double sensing_size_of_sprite_with_check(Target *target)`
`@@ -690,17 +682,13 @@ extern "C" double sensing_backdrop_number_of_stage_with_check(Target *target)`
`690`	`682`	`return 0.0;`
`691`	`683`	`}`
`692`	`684`
`693`		`-extern "C" StringPtr sensing_backdrop_name_of_stage_with_check(Target target)`
	`685`	`+extern "C" void sensing_backdrop_name_of_stage_with_check(StringPtr ret, Target target)`
`694`	`686`	`{`
`695`		`- StringPtr *ret = string_pool_new();`
`696`		`-`
`697`	`687`	`if (target && target->isStage()) {`
`698`	`688`	`const std::string &name = target->currentCostume()->name();`
`699`	`689`	`string_assign_cstring(ret, name.c_str());`
`700`	`690`	`} else`
`701`	`691`	`string_assign_cstring(ret, "");`
`702`		`-`
`703`		`- return ret;`
`704`	`692`	`}`
`705`	`693`
`706`	`694`	`extern "C" double sensing_volume_of_target_with_check(Target *target)`
Original file line number	Diff line number	Diff line change
`@@ -68,11 +68,9 @@ extern "C" bool test_condition()`
`68`	`68`	`return conditionReturnValue;`
`69`	`69`	`}`
`70`	`70`
`71`		`-extern "C" StringPtr test_const_string(const StringPtr str)`
	`71`	`+extern "C" void test_const_string(StringPtr ret, const StringPtr str)`
`72`	`72`	`{`
`73`		`- StringPtr *ret = string_pool_new();`
`74`	`73`	`string_assign(ret, str);`
`75`		`- return ret;`
`76`	`74`	`}`
`77`	`75`
`78`	`76`	`} // namespace libscratchcpp`
Original file line number	Diff line number	Diff line change
`@@ -63,14 +63,12 @@ extern "C"`
`63`	`63`	`std::cout << "no_args" << std::endl;`
`64`	`64`	`}`
`65`	`65`
`66`		`- StringPtr test_function_no_args_ret(Target target)`
	`66`	`+ void test_function_no_args_ret(StringPtr ret, Target target)`
`67`	`67`	`{`
`68`	`68`	`target->isStage();`
`69`	`69`	`std::cout << "no_args_ret" << std::endl;`
`70`	`70`	`Value v("no_args_output");`
`71`		`- StringPtr *ret = string_pool_new();`
`72`	`71`	`value_toStringPtr(&v.data(), ret);`
`73`		`- return ret;`
`74`	`72`	`}`
`75`	`73`
`76`	`74`	`void test_function_1_arg(Target target, const StringPtr arg1)`
`@@ -79,14 +77,12 @@ extern "C"`
`79`	`77`	`std::cout << "1_arg " << utf8::utf16to8(std::u16string(arg1->data)) << std::endl;`
`80`	`78`	`}`
`81`	`79`
`82`		`- StringPtr test_function_1_arg_ret(Target target, const StringPtr *arg1)`
	`80`	`+ void test_function_1_arg_ret(StringPtr ret, Target target, const StringPtr *arg1)`
`83`	`81`	`{`
`84`	`82`	`target->isStage();`
`85`	`83`	`std::cout << "1_arg_ret " << utf8::utf16to8(std::u16string(arg1->data)) << std::endl;`
`86`	`84`	`Value v("1_arg_output");`
`87`		`- StringPtr *ret = string_pool_new();`
`88`	`85`	`value_toStringPtr(&v.data(), ret);`
`89`		`- return ret;`
`90`	`86`	`}`
`91`	`87`
`92`	`88`	`void test_function_3_args(Target target, const StringPtr arg1, const StringPtr arg2, const StringPtr arg3)`
`@@ -95,14 +91,12 @@ extern "C"`
`95`	`91`	`std::cout << "3_args " << utf8::utf16to8(std::u16string(arg1->data)) << " " << utf8::utf16to8(std::u16string(arg2->data)) << " " << utf8::utf16to8(std::u16string(arg3->data)) << std::endl;`
`96`	`92`	`}`
`97`	`93`
`98`		`- StringPtr test_function_3_args_ret(Target target, const StringPtr arg1, const StringPtr arg2, const StringPtr *arg3)`
	`94`	`+ void test_function_3_args_ret(StringPtr ret, Target target, const StringPtr arg1, const StringPtr arg2, const StringPtr *arg3)`
`99`	`95`	`{`
`100`	`96`	`target->isStage();`
`101`	`97`	`std::cout << "3_args " << utf8::utf16to8(std::u16string(arg1->data)) << " " << utf8::utf16to8(std::u16string(arg2->data)) << " " << utf8::utf16to8(std::u16string(arg3->data)) << std::endl;`
`102`	`98`	`Value v("3_args_output");`
`103`		`- StringPtr *ret = string_pool_new();`
`104`	`99`	`value_toStringPtr(&v.data(), ret);`
`105`		`- return ret;`
`106`	`100`	`}`
`107`	`101`
`108`	`102`	`const void test_function_1_ptr_arg_ret(Target target, const int *arg1)`
`@@ -138,11 +132,9 @@ extern "C"`
`138`	`132`	`return v;`
`139`	`133`	`}`
`140`	`134`
`141`		`- StringPtr test_const_string(const StringPtr v)`
	`135`	`+ void test_const_string(StringPtr ret, const StringPtr v)`
`142`	`136`	`{`
`143`		`- StringPtr *ret = string_pool_new();`
`144`	`137`	`string_assign(ret, v);`
`145`		`- return ret;`
`146`	`138`	`}`
`147`	`139`
`148`	`140`	`ValueData test_const_unknown(const ValueData *v)`