Improve compiler compatibility (#743)

* fix returns

* use standard C headers

* struct/class mismatch

* explicit this in template

* switch variable scope

* C standard compliance

* & l-value

include/JSystem/J3DGraphBase/J3DShape.h

@@ -55,7 +55,7 @@ public:
 
 class J3DMaterial;
 class J3DVertexData;
-class J3DDrawMtxData;
+struct J3DDrawMtxData;
 
 enum J3DShpFlag {
     J3DShpFlag_Hide = 0x0001,

include/JSystem/J3DGraphBase/J3DTevs.h

@@ -204,7 +204,7 @@ struct J3DNBTScale : public J3DNBTScaleInfo {
     Vec* getScale() { return &mScale; }
 };
 
-class J3DTexCoord;
+struct J3DTexCoord;
 void loadTexCoordGens(u32, J3DTexCoord*);
 void loadNBTScale(J3DNBTScale& param_0);
 

include/JSystem/J3DGraphLoader/J3DAnmLoader.h

@@ -7,29 +7,29 @@ enum J3DAnmLoaderDataBaseFlag { J3DLOADER_UNK_FLAG0 };
 
 class J3DAnmBase;
 class J3DAnmClusterFull;
-class J3DAnmClusterFullData;
+struct J3DAnmClusterFullData;
 class J3DAnmClusterKey;
-class J3DAnmClusterKeyData;
+struct J3DAnmClusterKeyData;
 class J3DAnmColorFull;
-class J3DAnmColorFullData;
+struct J3DAnmColorFullData;
 class J3DAnmColorKey;
-class J3DAnmColorKeyData;
+struct J3DAnmColorKeyData;
 class J3DAnmTevRegKey;
-class J3DAnmTevRegKeyData;
+struct J3DAnmTevRegKeyData;
 class J3DAnmTexPattern;
-class J3DAnmTexPatternFullData;
+struct J3DAnmTexPatternFullData;
 class J3DAnmTextureSRTKey;
-class J3DAnmTextureSRTKeyData;
+struct J3DAnmTextureSRTKeyData;
 class J3DAnmTransformFull;
-class J3DAnmTransformFullData;
+struct J3DAnmTransformFullData;
 class J3DAnmTransformKey;
-class J3DAnmTransformKeyData;
+struct J3DAnmTransformKeyData;
 class J3DAnmVisibilityFull;
-class J3DAnmVisibilityFullData;
+struct J3DAnmVisibilityFullData;
 class J3DAnmVtxColorFull;
-class J3DAnmVtxColorFullData;
+struct J3DAnmVtxColorFullData;
 class J3DAnmVtxColorKey;
-class J3DAnmVtxColorKeyData;
+struct J3DAnmVtxColorKeyData;
 
 struct J3DAnmLoaderDataBase {
     static J3DAnmBase* load(const void*);

include/JSystem/J3DGraphLoader/J3DMaterialFactory.h

@@ -11,7 +11,7 @@ struct J3DMaterialDLBlock;
 struct J3DMaterialInitData;
 struct J3DIndInitData;
 struct J3DColorChanInfo;
-struct J3DLightInfo;
+class J3DLightInfo;
 struct J3DTexCoordInfo;
 struct J3DTexCoord2Info;
 struct J3DTexMtxInfo;
@@ -24,13 +24,13 @@ struct J3DAlphaCompInfo;
 struct J3DBlendInfo;
 struct J3DZModeInfo;
 struct J3DNBTScaleInfo;
-struct J3DCurrentMtxInfo;
+class J3DCurrentMtxInfo;
 
 struct J3DColorChan;
 struct J3DGXColor;
 struct J3DGXColorS10;
 struct J3DTexCoord;
-struct J3DTexMtx;
+class J3DTexMtx;
 struct J3DTevOrder;
 struct J3DTevStage;
 struct J3DTevSwapMode;

include/JSystem/J3DGraphLoader/J3DMaterialFactory_v21.h

@@ -7,24 +7,24 @@
 
 class J3DMaterial;
 struct J3DMaterialBlock_v21;
-class J3DMaterialInitData_v21;
-class J3DIndInitData;
-class J3DColorChanInfo;
+struct J3DMaterialInitData_v21;
+struct J3DIndInitData;
+struct J3DColorChanInfo;
 class J3DLightInfo;
-class J3DTexCoordInfo;
-class J3DTexCoord2Info;
-class J3DTexMtxInfo;
-class J3DTevOrderInfo;
-class J3DTevStageInfo;
-class J3DTevSwapModeInfo;
-class J3DTevSwapModeTableInfo;
-class J3DFogInfo;
-class J3DAlphaCompInfo;
-class J3DBlendInfo;
-class J3DZModeInfo;
-class J3DNBTScaleInfo;
-class J3DDisplayListInit;
-class J3DPatchingInfo;
+struct J3DTexCoordInfo;
+struct J3DTexCoord2Info;
+struct J3DTexMtxInfo;
+struct J3DTevOrderInfo;
+struct J3DTevStageInfo;
+struct J3DTevSwapModeInfo;
+struct J3DTevSwapModeTableInfo;
+struct J3DFogInfo;
+struct J3DAlphaCompInfo;
+struct J3DBlendInfo;
+struct J3DZModeInfo;
+struct J3DNBTScaleInfo;
+struct J3DDisplayListInit;
+struct J3DPatchingInfo;
 class J3DCurrentMtxInfo;
 
 struct J3DMaterialInitData_v21 {

include/JSystem/JAudio/JAIAnimation.h

@@ -3,7 +3,7 @@
 
 #include "dolphin/types.h"
 
-class Vec;
+struct Vec;
 class JAISound;
 class JAIBasic;
 namespace JAInter {

include/JSystem/JAudio/JASDrumSet.h

@@ -5,7 +5,7 @@
 
 namespace JASystem {
     class TInstEffect;
-    class TInstParam;
+    struct TInstParam;
 
     class TDrumSet : public TInst {
     public:

include/JSystem/JAudio/osdsp.h

@@ -3,6 +3,6 @@
 
 #include "dolphin/dsp.h"
 
-void DSPAddPriorTask(STRUCT_DSP_TASK*);
+void DSPAddPriorTask(DSPTaskInfo*);
 
 #endif /* OSDSP_H */

include/JSystem/JAudio/osdsp_task.h

@@ -8,7 +8,11 @@ typedef struct OSContext OSContext;
 
 extern DSPTaskInfo* DSP_prior_task;
 
+#ifdef __cplusplus
 extern "C" void __DSPHandler(int, OSContext*);
+#else
+void __DSPHandler(int, OSContext*);
+#endif
 void DsyncFrame2(u32, u32, u32);
 void Dsp_Update_Request();
 BOOL Dsp_Running_Check();

include/JSystem/JGadget/linklist.h

@@ -184,7 +184,7 @@ struct TLinkList_factory : public TLinkList<T, I> {
     virtual T* Do_create() = 0;
     virtual void Do_destroy(T*) = 0;
     void Erase_destroy(T* elem) {
-        Erase(elem);
+        this->Erase(elem);
         Do_destroy(elem);
     }
 };

include/JSystem/JMessage/processor.h

@@ -7,7 +7,7 @@ namespace JMessage {
 
 struct TReference;
 struct TControl;
-struct TResource;
+class TResource;
 
 struct TProcessor {
 public:
@@ -80,7 +80,7 @@ public:
     static const char* process_select_(TProcessor*);
 
     void pushCurrent(const char*);
-    const char* popCurrent();
+    void popCurrent();
     void on_select_begin(OnSelectBeginCallBack, const void*, const char*, u32);
     void on_select_end();
     void on_select_separate();

include/JSystem/JParticle/JPAField.h

@@ -5,7 +5,7 @@
 #include "JSystem/JGeometry.h"
 
 class JPADataBlockLinkInfo;
-class JPAEmitterInfo;
+struct JPAEmitterInfo;
 class JPAFieldData;
 class JPABaseParticle;
 class JPABaseField;

include/JSystem/JStudio/JStudio/jstudio-control.h

@@ -8,7 +8,7 @@
 #include "dolphin/mtx/mtxvec.h"
 
 namespace JStudio {
-struct TObject;
+class TObject;
 struct TCreateObject {
     TCreateObject() {}
     virtual ~TCreateObject() = 0;

include/JSystem/JStudio/JStudio/stb.h

@@ -7,7 +7,7 @@
 #include "global.h"
 
 namespace JStudio {
-struct TObject;
+class TObject;
 namespace stb {
 
 class TControl;

include/JSystem/JStudio/JStudio_JAudio/control.h

@@ -5,8 +5,8 @@
 #include "JSystem/JStudio/JStudio/jstudio-object.h"
 #include "JSystem/JStage/JSGSystem.h"
 
-struct JAIBasic;
-struct JAISound;
+class JAIBasic;
+class JAISound;
 namespace JStudio_JAudio {
 typedef JStudio::TObject* (*JStudioAudioCreateFunc)(const JStudio::stb::data::TParse_TBlock_object&, JAIBasic*);
 typedef void (JAISound::*TVVOSoundSetFunc)(f32, u32); // e.g. JAISound::setDirectVolume, JAISound::setDirectPitch