windows: Add support for building with MSVC

decode.c

@@ -6,8 +6,13 @@
 #include <fadec.h>
 
 
+#ifdef __GNUC__
 #define LIKELY(x) __builtin_expect((x), 1)
 #define UNLIKELY(x) __builtin_expect((x), 0)
+#else
+#define LIKELY(x) (x)
+#define UNLIKELY(x) (x)
+#endif
 
 // Defines FD_TABLE_OFFSET_32 and FD_TABLE_OFFSET_64, if available
 #define FD_DECODE_TABLE_DEFINES
@@ -33,7 +38,7 @@ typedef enum DecodeMode DecodeMode;
 
 static unsigned
 table_walk(unsigned cur_idx, unsigned entry_idx, unsigned* out_kind) {
-    static __attribute__((aligned(16))) const uint16_t _decode_table[] = {
+    static _Alignas(16) const uint16_t _decode_table[] = {
 #define FD_DECODE_TABLE_DATA
 #include <fadec-decode-private.inc>
 #undef FD_DECODE_TABLE_DATA
@@ -65,7 +70,7 @@ struct InstrDesc
     uint16_t operand_indices;
     uint16_t operand_sizes;
     uint16_t reg_types;
-} __attribute__((packed));
+};
 
 #define DESC_HAS_MODRM(desc) (((desc)->operand_indices & (3 << 0)) != 0)
 #define DESC_MODRM_IDX(desc) ((((desc)->operand_indices >> 0) & 3) ^ 3)
@@ -271,7 +276,7 @@ prefix_end:
     if (UNLIKELY(kind != ENTRY_INSTR))
         return kind == 0 ? FD_ERR_UD : FD_ERR_PARTIAL;
 
-    static __attribute__((aligned(16))) const struct InstrDesc descs[] = {
+    static _Alignas(16) const struct InstrDesc descs[] = {
 #define FD_DECODE_TABLE_DESCS
 #include <fadec-decode-private.inc>
 #undef FD_DECODE_TABLE_DESCS
@@ -301,7 +306,8 @@ prefix_end:
     if (prefix_rex & PREFIX_VEXL)
         vec_size = 32;
 
-    __builtin_memset(instr->operands, 0, sizeof(instr->operands));
+    for (unsigned i = 0; i < sizeof(instr->operands) / sizeof(FdOp); i++)
+        instr->operands[i] = (FdOp) {0};
 
     if (DESC_MODRM(desc) && UNLIKELY(off++ >= len))
         return FD_ERR_PARTIAL;

encode.c

@@ -6,8 +6,13 @@
 #include <fadec-enc.h>
 
 
+#ifdef __GNUC__
 #define LIKELY(x) __builtin_expect((x), 1)
 #define UNLIKELY(x) __builtin_expect((x), 0)
+#else
+#define LIKELY(x) (x)
+#define UNLIKELY(x) (x)
+#endif
 
 enum {
     // 16:17 = escape

format.c

@@ -2,12 +2,24 @@
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
+#ifdef _MSC_VER
+#include <intrin.h>
+#endif
 
 #include <fadec.h>
 
 
+#ifdef __GNUC__
 #define LIKELY(x) __builtin_expect((x), 1)
 #define UNLIKELY(x) __builtin_expect((x), 0)
+#define DECLARE_ARRAY_SIZE(n) static n
+#define DECLARE_RESTRICTED_ARRAY_SIZE(n) restrict static n
+#else
+#define LIKELY(x) (x)
+#define UNLIKELY(x) (x)
+#define DECLARE_ARRAY_SIZE(n) n
+#define DECLARE_RESTRICTED_ARRAY_SIZE(n) n
+#endif
 
 struct FdStr {
     const char* s;
@@ -27,7 +39,11 @@ fd_strplcpy(char* restrict dst, const char* src, size_t size) {
 
 static char*
 fd_strpcat(char* restrict dst, struct FdStr src) {
+#ifdef __GNUC__
     unsigned lim = __builtin_constant_p(src.sz) && src.sz <= 8 ? 8 : 16;
+#else
+    unsigned lim = 16;
+#endif
     for (unsigned i = 0; i < lim; i++)
         dst[i] = src.s[i];
     // __builtin_memcpy(dst, src.s, 16);
@@ -36,7 +52,24 @@ fd_strpcat(char* restrict dst, struct FdStr src) {
 
 static unsigned
 fd_clz64(uint64_t v) {
+#if defined(__GNUC__)
     return __builtin_clzl(v);
+#elif defined(_MSC_VER)
+    unsigned long index;
+
+#if INTPTR_MAX == INT64_MAX
+    _BitScanReverse64(&index, v);
+#else
+    if (_BitScanReverse(&index, v >> 32))
+        return 31 - index;
+
+    _BitScanReverse(&index, v & 0xffffffff);
+#endif
+
+    return 63 - index;
+#else
+#error Unsupported compiler.
+#endif
 }
 
 #if defined(__SSE2__)
@@ -44,7 +77,7 @@ fd_clz64(uint64_t v) {
 #endif
 
 static char*
-fd_strpcatnum(char dst[static 18], uint64_t val) {
+fd_strpcatnum(char dst[DECLARE_ARRAY_SIZE(18)], uint64_t val) {
     unsigned lz = fd_clz64(val|1);
     unsigned numbytes = 16 - (lz / 4);
 #if defined(__SSE2__)
@@ -132,7 +165,7 @@ fdi_name(FdInstrType ty) {
 }
 
 static char*
-fd_mnemonic(char buf[restrict static 48], const FdInstr* instr) {
+fd_mnemonic(char buf[DECLARE_RESTRICTED_ARRAY_SIZE(48)], const FdInstr* instr) {
 #define FD_DECODE_TABLE_STRTAB1
     static const char* mnemonic_str =
 #include <fadec-decode-private.inc>
@@ -281,7 +314,7 @@ fd_mnemonic(char buf[restrict static 48], const FdInstr* instr) {
 }
 
 static char*
-fd_format_impl(char buf[restrict static 128], const FdInstr* instr, uint64_t addr) {
+fd_format_impl(char buf[DECLARE_RESTRICTED_ARRAY_SIZE(128)], const FdInstr* instr, uint64_t addr) {
     buf = fd_mnemonic(buf, instr);
 
     for (int i = 0; i < 4; i++)

meson.build

@@ -51,6 +51,22 @@ if get_option('with_encode2')
   sources += files('encode2.c')
 endif
 
+if cc.get_argument_syntax() == 'msvc'
+  # Disable some warnings to align warnings with GCC and Clang:
+  add_project_arguments('-D_CRT_SECURE_NO_WARNINGS',
+                        '/wd4018', # - Signed/unsigned comparison
+                        '/wd4146', # - Unary minus operator applied to unsigned
+                                   #   type, result still unsigned
+                        '/wd4244', # - Possible loss of data in conversion
+                                   #   from integer type to smaller integer type
+                        '/wd4245', # - Signed/unsigned assignment
+                        '/wd4267', # - Possible loss of data in conversion
+                                   #   from size_t to smaller type
+                        '/wd4310', # - Possible loss of data in conversion
+                                   #   of constant value to smaller type
+                        language: 'c')
+endif
+
 generate_args = []
 if get_option('archmode') != 'only64'
   generate_args += ['--32']