Merge pull request #782 from yamt/endian

native runtime: a few endian and alignment fixes
aduros · Dec 10, 2024 · fa78acf · fa78acf
2 parents 0353c98 + 1f585d7
commit fa78acf
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Showing 3 changed files with 45 additions and 21 deletions.
diff --git a/runtimes/native/src/runtime.c b/runtimes/native/src/runtime.c
@@ -1,5 +1,6 @@
 #include "runtime.h"
 
+#include <inttypes.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -240,30 +241,30 @@ void w4_runtimeTracef (const uint8_t* str, const void* stack) {
                 break;
             case 'c':
                 bounds_check(argPtr, 4);
-                putc(*(char*)argPtr, stdout);
+                putc((char)w4_read32LE(argPtr), stdout);
                 argPtr += 4;
                 break;
             case 'd':
                 bounds_check(argPtr, 4);
-                printf("%d", *(int32_t*)argPtr);
+                printf("%" PRId32, w4_read32LE(argPtr));
                 argPtr += 4;
                 break;
             case 'x':
                 bounds_check(argPtr, 4);
-                printf("%x", *(uint32_t*)argPtr);
+                printf("%" PRIx32, w4_read32LE(argPtr));
                 argPtr += 4;
                 break;
             case 's':
                 bounds_check(argPtr, 4);
-                strPtr = *(uint32_t*)argPtr;
+                strPtr = w4_read32LE(argPtr);
                 argPtr += 4;
                 const char *strPtr_host = (const char *)memory + strPtr;
                 bounds_check_cstr(strPtr_host);
                 printf("%s", strPtr_host);
                 break;
             case 'f':
                 bounds_check(argPtr, 8);
-                printf("%lg", *(double*)argPtr);
+                printf("%lg", w4_readf64LE(argPtr));
                 argPtr += 8;
                 break;
             default:

diff --git a/runtimes/native/src/util.c b/runtimes/native/src/util.c
@@ -1,6 +1,7 @@
 #include "util.h"
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h>
 
 #if defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 #    define W4_BIG_ENDIAN
@@ -21,6 +22,7 @@ void* xrealloc(void* ptr, size_t size) {
         fputs("Allocation failed.\n", stderr);
         abort();
     }
+    return ptr;
 }
 
 uint16_t bswap16(uint16_t x) {
@@ -34,34 +36,54 @@ uint32_t bswap32(uint32_t x) {
             (( x & 0x000000ffu ) << 24 ));
 }
 
-uint16_t w4_read16LE (const uint16_t* ptr) {
+uint16_t w4_read16LE (const void* ptr) {
+    uint16_t le;
+    memcpy(&le, ptr, sizeof(le));
 #ifdef W4_BIG_ENDIAN
-    return bswap16(*ptr);
+    return bswap16(le);
 #else
-    return *ptr;
+    return le;
 #endif
 }
 
-uint32_t w4_read32LE (const uint32_t* ptr) {
+uint32_t w4_read32LE (const void* ptr) {
+    uint32_t le;
+    memcpy(&le, ptr, sizeof(le));
 #ifdef W4_BIG_ENDIAN
-    return bswap32(*ptr);
+    return bswap32(le);
 #else
-    return *ptr;
+    return le;
+#endif
+}
+
+double w4_readf64LE (const void* ptr) {
+    union {
+        uint64_t u;
+        double d;
+    } u;
+    memcpy(&u.d, ptr, sizeof(u.d));
+#ifdef W4_BIG_ENDIAN
+    u.u = bswap32(u.u);
 #endif
+    return u.d;
 }
 
-void w4_write16LE (uint16_t* ptr, uint16_t value) {
+void w4_write16LE (void* ptr, uint16_t value) {
+    uint16_t le;
 #ifdef W4_BIG_ENDIAN
-    *ptr = bswap16(value);
+    le = bswap16(value);
 #else
-    *ptr = value;
+    le = value;
 #endif
+    memcpy(ptr, &le, sizeof(le));
 }
 
-void w4_write32LE (uint32_t* ptr, uint32_t value) {
+void w4_write32LE (void* ptr, uint32_t value) {
+    uint32_t le;
 #ifdef W4_BIG_ENDIAN
-    *ptr = bswap32(value);
+    le = bswap32(value);
 #else
-    *ptr = value;
+    le = value;
 #endif
+    memcpy(ptr, &le, sizeof(le));
 }
diff --git a/runtimes/native/src/util.h b/runtimes/native/src/util.h
@@ -7,8 +7,9 @@
 void* xmalloc(size_t size);
 void* xrealloc(void* ptr, size_t size);
 
-uint16_t w4_read16LE (const uint16_t* ptr);
-uint32_t w4_read32LE (const uint32_t* ptr);
+uint16_t w4_read16LE (const void* ptr);
+uint32_t w4_read32LE (const void* ptr);
+double w4_readf64LE (const void* ptr);
 
-void w4_write16LE (uint16_t* ptr, uint16_t value);
-void w4_write32LE (uint32_t* ptr, uint32_t value);
+void w4_write16LE (void* ptr, uint16_t value);
+void w4_write32LE (void* ptr, uint32_t value);