All: Fix some undefined behavior warnings

CHANGES

@@ -47,6 +47,7 @@ Misc:
  - SDL: Allow GBASDLAudio to be used without a thread context
  - All: Improved PowerPC support
  - All: Add --version flag
+ - All: Fix some undefined behavior warnings
 
 0.3.0: (2015-08-16)
 Features:

src/arm/isa-thumb.c

@@ -308,7 +308,7 @@ DEFINE_LOAD_STORE_MULTIPLE_THUMB(STMIA,
 #define DEFINE_CONDITIONAL_BRANCH_THUMB(COND) \
 	DEFINE_INSTRUCTION_THUMB(B ## COND, \
 		if (ARM_COND_ ## COND) { \
-			int8_t immediate = opcode; \
+			uint8_t immediate = opcode; \
 			cpu->gprs[ARM_PC] += immediate << 1; \
 			THUMB_WRITE_PC; \
 		})

src/gba/audio.c

@@ -523,7 +523,7 @@ void GBAAudioSampleFIFO(struct GBAAudio* audio, int fifoId, int32_t cycles) {
 			channel->dmaSource = 0;
 		}
 	}
-	CircleBufferRead8(&channel->fifo, &channel->sample);
+	CircleBufferRead8(&channel->fifo, (int8_t*) &channel->sample);
 }
 
 #if RESAMPLE_LIBRARY != RESAMPLE_BLIP_BUF

src/gba/audio.h

@@ -135,7 +135,7 @@ struct GBAAudioChannel4 {
 struct GBAAudioFIFO {
 	struct CircleBuffer fifo;
 	int dmaSource;
-	int8_t sample;
+	uint8_t sample;
 };
 
 DECL_BITFIELD(GBARegisterSOUNDCNT_LO, uint16_t);

src/gba/renderers/software-mode0.c

@@ -468,7 +468,7 @@ void GBAVideoSoftwareRendererDrawBackgroundMode0(struct GBAVideoSoftwareRenderer
 
 	unsigned xBase;
 
-	int flags = (background->priority << OFFSET_PRIORITY) | (background->index << OFFSET_INDEX) | FLAG_IS_BACKGROUND;
+	uint32_t flags = (background->priority << OFFSET_PRIORITY) | (background->index << OFFSET_INDEX) | FLAG_IS_BACKGROUND;
 	flags |= FLAG_TARGET_2 * background->target2;
 	int objwinFlags = FLAG_TARGET_1 * (background->target1 && renderer->blendEffect == BLEND_ALPHA && GBAWindowControlIsBlendEnable(renderer->objwin.packed));
 	objwinFlags |= flags;

src/gba/renderers/software-obj.c

@@ -140,7 +140,7 @@ int GBAVideoSoftwareRendererPreprocessSprite(struct GBAVideoSoftwareRenderer* re
 	uint32_t flags = GBAObjAttributesCGetPriority(sprite->c) << OFFSET_PRIORITY;
 	flags |= FLAG_TARGET_1 * ((GBAWindowControlIsBlendEnable(renderer->currentWindow.packed) && renderer->target1Obj && renderer->blendEffect == BLEND_ALPHA) || GBAObjAttributesAGetMode(sprite->a) == OBJ_MODE_SEMITRANSPARENT);
 	flags |= FLAG_OBJWIN * (GBAObjAttributesAGetMode(sprite->a) == OBJ_MODE_OBJWIN);
-	int32_t x = GBAObjAttributesBGetX(sprite->b) << 23;
+	int32_t x = (uint32_t) GBAObjAttributesBGetX(sprite->b) << 23;
 	x >>= 23;
 	uint16_t* vramBase = &renderer->d.vram[BASE_TILE >> 1];
 	unsigned charBase = GBAObjAttributesCGetTile(sprite->c) * 0x20;

src/gba/renderers/software-private.h

@@ -177,7 +177,7 @@ static inline void _compositeNoBlendNoObjwin(struct GBAVideoSoftwareRenderer* re
 	int32_t localX;                                                                                                   \
 	int32_t localY;                                                                                                   \
                                                                                                                       \
-	int flags = (background->priority << OFFSET_PRIORITY) | (background->index << OFFSET_INDEX) | FLAG_IS_BACKGROUND; \
+	uint32_t flags = (background->priority << OFFSET_PRIORITY) | (background->index << OFFSET_INDEX) | FLAG_IS_BACKGROUND; \
 	flags |= FLAG_TARGET_2 * background->target2;                                                                     \
 	int objwinFlags = FLAG_TARGET_1 * (background->target1 && renderer->blendEffect == BLEND_ALPHA &&                 \
 	                                   GBAWindowControlIsBlendEnable(renderer->objwin.packed));                       \

src/gba/renderers/video-software.c

@@ -772,7 +772,7 @@ static void _drawScanline(struct GBAVideoSoftwareRenderer* renderer, int y) {
 		}
 	}
 
-	int priority;
+	unsigned priority;
 	for (priority = 0; priority < 4; ++priority) {
 		renderer->end = 0;
 		for (w = 0; w < renderer->nWindows; ++w) {

src/gba/renderers/video-software.h

@@ -23,9 +23,9 @@ struct GBAVideoSoftwareSprite {
 };
 
 struct GBAVideoSoftwareBackground {
-	int index;
+	unsigned index;
 	int enabled;
-	int priority;
+	unsigned priority;
 	uint32_t charBase;
 	int mosaic;
 	int multipalette;