shithub: dav1d

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ref: acad1a99eaaeefacadbd1756c80365665bc7570a
parent: 69dae683fdce08dabf406787cdd8d1f76a9f0437
author: Henrik Gramner <[email protected]>
date: Wed Sep 4 21:55:23 EDT 2019 

Silence some clang-cl warnings

For some reason the MSVC CRT _wassert() function is not flagged as
 __declspec(noreturn), so when using those headers the compiler will
expect execution to continue after an assertion has been triggered
and will therefore complain about the use of uninitialized variables
when compiled in debug mode in certain code paths.

Reorder some case statements as a workaround.


--- a/src/recon_tmpl.c
+++ b/src/recon_tmpl.c
@@ -77,18 +77,23 @@
         break
 
         switch (t_dim->lw) {
+        /* For some reason the MSVC CRT _wassert() function is not flagged as
+         * __declspec(noreturn), so when using those headers the compiler will
+         * expect execution to continue after an assertion has been triggered
+         * and will therefore complain about the use of uninitialized variables
+         * when compiled in debug mode if we put the default case at the end. */
+        default: assert(0); /* fall-through */
         case TX_4X4:   MERGE_CTX(a, uint8_t,  0x3F);
         case TX_8X8:   MERGE_CTX(a, uint16_t, 0x3F3F);
         case TX_16X16: MERGE_CTX(a, uint32_t, 0x3F3F3F3FU);
         case TX_32X32: MERGE_CTX(a, uint64_t, 0x3F3F3F3F3F3F3F3FULL);
-        default: assert(0);
         }
         switch (t_dim->lh) {
+        default: assert(0); /* fall-through */
         case TX_4X4:   MERGE_CTX(l, uint8_t,  0x3F);
         case TX_8X8:   MERGE_CTX(l, uint16_t, 0x3F3F);
         case TX_16X16: MERGE_CTX(l, uint32_t, 0x3F3F3F3FU);
         case TX_32X32: MERGE_CTX(l, uint64_t, 0x3F3F3F3F3F3F3F3FULL);
-        default: assert(0);
         }
 #undef MERGE_CTX
 
@@ -111,20 +116,20 @@
         break
 
         switch (t_dim->lw) {
+        default: assert(0); /* fall-through */
         case TX_4X4:   MERGE_CTX(a, uint8_t,  TX_4X4);
         case TX_8X8:   MERGE_CTX(a, uint16_t, TX_8X8);
         case TX_16X16: MERGE_CTX(a, uint32_t, TX_16X16);
         case TX_32X32: MERGE_CTX(a, uint32_t, TX_32X32);
         case TX_64X64: MERGE_CTX(a, uint32_t, TX_64X64);
-        default: assert(0);
         }
         switch (t_dim->lh) {
+        default: assert(0); /* fall-through */
         case TX_4X4:   MERGE_CTX(l, uint8_t,  TX_4X4);
         case TX_8X8:   MERGE_CTX(l, uint16_t, TX_8X8);
         case TX_16X16: MERGE_CTX(l, uint32_t, TX_16X16);
         case TX_32X32: MERGE_CTX(l, uint32_t, TX_32X32);
         case TX_64X64: MERGE_CTX(l, uint32_t, TX_64X64);
-        default: assert(0);
         }
 #undef MERGE_CTX
 
@@ -146,6 +151,7 @@
 #endif
 
     switch(tx) {
+    default: assert(0); /* fall-through */
     case TX_4X4: {
         int t = *(const uint8_t *) a >> 6;
         t    += *(const uint8_t *) l >> 6;
@@ -284,7 +290,6 @@
         s = (int) (t >> 56) - 16 - 4;
         break;
     }
-    default: assert(0);
     }
 
     return (s != 0) + (s > 0);