Merge pull request #492 from a3f/raylib-master

jar_xm: Workaround for unaligned pointer accesses

CMakeLists.txt

@@ -29,6 +29,8 @@ endfunction()
 
 add_if_flag_works(-Werror=pointer-arith CMAKE_C_FLAGS)
 add_if_flag_works(-Werror=implicit-function-declaration CMAKE_C_FLAGS)
+# src/external/jar_xm.h does shady stuff
+add_if_flag_works(-fno-strict-aliasing CMAKE_C_FLAGS)
 
 if (ENABLE_ASAN)
     add_if_flag_works(-fno-omit-frame-pointer CMAKE_C_FLAGS CMAKE_LINKER_FLAGS)

src/Makefile

@@ -291,7 +291,9 @@ endif
 #  -Wno-missing-braces   ignore invalid warning (GCC bug 53119)
 #  -D_DEFAULT_SOURCE     use with -std=c99 on Linux and PLATFORM_WEB, required for timespec
 #  -Werror=pointer-arith catch unportable code that does direct arithmetic on void pointers
-CFLAGS += -O1 -Wall -std=c99 -D_DEFAULT_SOURCE -Wno-missing-braces -Werror=pointer-arith
+#  -fno-strict-aliasing  jar_xm.h does shady stuff (breaks strict aliasing)
+CFLAGS += -O1 -Wall -std=c99 -D_DEFAULT_SOURCE -Wno-missing-braces -Werror=pointer-arith 
+-fno-strict-aliasing
 
 ifeq ($(RAYLIB_BUILD_MODE), DEBUG)
     CFLAGS += -g

src/external/jar_xm.h

@@ -612,6 +612,8 @@ int jar_xm_create_context(jar_xm_context_t** ctxp, const char* moddata, uint32_t
     return jar_xm_create_context_safe(ctxp, moddata, SIZE_MAX, rate);
 }
 
+#define ALIGN(x, b) (((x) + ((b) - 1)) & ~((b) - 1))
+#define ALIGN_PTR(x, b) (void*)(((uintptr_t)(x) + ((b) - 1)) & ~((b) - 1))
 int jar_xm_create_context_safe(jar_xm_context_t** ctxp, const char* moddata, size_t moddata_length, uint32_t rate) {
 #if JAR_XM_DEFENSIVE
     int ret;
@@ -644,9 +646,11 @@ int jar_xm_create_context_safe(jar_xm_context_t** ctxp, const char* moddata, siz
 
     ctx->rate = rate;
     mempool = jar_xm_load_module(ctx, moddata, moddata_length, mempool);
+    mempool = ALIGN_PTR(mempool, 16);
 
     ctx->channels = (jar_xm_channel_context_t*)mempool;
     mempool += ctx->module.num_channels * sizeof(jar_xm_channel_context_t);
+    mempool = ALIGN_PTR(mempool, 16);
 
     ctx->global_volume = 1.f;
     ctx->amplification = .25f; /* XXX: some bad modules may still clip. Find out something better. */
@@ -671,6 +675,7 @@ int jar_xm_create_context_safe(jar_xm_context_t** ctxp, const char* moddata, siz
         ch->actual_panning = .5f;
     }
 
+    mempool = ALIGN_PTR(mempool, 16);
     ctx->row_loop_count = (uint8_t*)mempool;
     mempool += MAX_NUM_ROWS * sizeof(uint8_t);
 
@@ -856,9 +861,11 @@ size_t jar_xm_get_memory_needed_for_context(const char* moddata, size_t moddata_
 
     num_patterns = READ_U16(offset + 10);
     memory_needed += num_patterns * sizeof(jar_xm_pattern_t);
+    memory_needed  = ALIGN(memory_needed, 16);
 
     num_instruments = READ_U16(offset + 12);
     memory_needed += num_instruments * sizeof(jar_xm_instrument_t);
+    memory_needed  = ALIGN(memory_needed, 16);
 
     memory_needed += MAX_NUM_ROWS * READ_U16(offset + 4) * sizeof(uint8_t); /* Module length */
 
@@ -875,6 +882,7 @@ size_t jar_xm_get_memory_needed_for_context(const char* moddata, size_t moddata_
         /* Pattern header length + packed pattern data size */
         offset += READ_U32(offset) + READ_U16(offset + 7);
     }
+    memory_needed  = ALIGN(memory_needed, 16);
 
     /* Read instrument headers */
     for(uint16_t i = 0; i < num_instruments; ++i) {
@@ -940,9 +948,11 @@ char* jar_xm_load_module(jar_xm_context_t* ctx, const char* moddata, size_t modd
 
     mod->patterns = (jar_xm_pattern_t*)mempool;
     mempool += mod->num_patterns * sizeof(jar_xm_pattern_t);
+    mempool = ALIGN_PTR(mempool, 16);
 
     mod->instruments = (jar_xm_instrument_t*)mempool;
     mempool += mod->num_instruments * sizeof(jar_xm_instrument_t);
+    mempool = ALIGN_PTR(mempool, 16);
 
     uint16_t flags = READ_U32(offset + 14);
     mod->frequency_type = (flags & (1 << 0)) ? jar_xm_LINEAR_FREQUENCIES : jar_xm_AMIGA_FREQUENCIES;
@@ -1032,6 +1042,7 @@ char* jar_xm_load_module(jar_xm_context_t* ctx, const char* moddata, size_t modd
 
         offset += packed_patterndata_size;
     }
+    mempool = ALIGN_PTR(mempool, 16);
 
     /* Read instruments */
     for(uint16_t i = 0; i < ctx->module.num_instruments; ++i) {