Add -Wimplicit-fallthrough to CFLAGS and CXXFLAGS

Use it at level 4, a bit more restrictive than the default level, and
tweak our commanding comments to FALLTHROUGH.

(However, leave zic.c alone, since it's external code; to avoid the
warnings that would appear there, change CFLAGS for that file in the
Makefile.)

Author: Julien Rouhaud <[email protected]>
Author: Álvaro Herrera <[email protected]>
Reviewed-by: Tom Lane <[email protected]>
Discussion: https://postgr.es/m/20200412081825.qyo5vwwco3fv4gdo@nol
Discussion: https://postgr.es/m/flat/[email protected]

1 files changed, 72 insertions, 72 deletions

diff --git a/src/common/hashfn.c b/src/common/hashfn.c
index 990f18e610b..29c846fcc31 100644
--- a/src/common/hashfn.c
+++ b/src/common/hashfn.c
@@ -178,13 +178,13 @@ hash_bytes(const unsigned char *k, int keylen)
 		{
 			case 11:
 				c += ((uint32) k[10] << 8);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 10:
 				c += ((uint32) k[9] << 16);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 9:
 				c += ((uint32) k[8] << 24);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 8:
 				/* the lowest byte of c is reserved for the length */
 				b += ka[1];
@@ -192,22 +192,22 @@ hash_bytes(const unsigned char *k, int keylen)
 				break;
 			case 7:
 				b += ((uint32) k[6] << 8);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 6:
 				b += ((uint32) k[5] << 16);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 5:
 				b += ((uint32) k[4] << 24);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 4:
 				a += ka[0];
 				break;
 			case 3:
 				a += ((uint32) k[2] << 8);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 2:
 				a += ((uint32) k[1] << 16);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 1:
 				a += ((uint32) k[0] << 24);
 				/* case 0: nothing left to add */
@@ -217,13 +217,13 @@ hash_bytes(const unsigned char *k, int keylen)
 		{
 			case 11:
 				c += ((uint32) k[10] << 24);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 10:
 				c += ((uint32) k[9] << 16);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 9:
 				c += ((uint32) k[8] << 8);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 8:
 				/* the lowest byte of c is reserved for the length */
 				b += ka[1];
@@ -231,22 +231,22 @@ hash_bytes(const unsigned char *k, int keylen)
 				break;
 			case 7:
 				b += ((uint32) k[6] << 16);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 6:
 				b += ((uint32) k[5] << 8);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 5:
 				b += k[4];
-				/* fall through */
+				/* FALLTHROUGH */
 			case 4:
 				a += ka[0];
 				break;
 			case 3:
 				a += ((uint32) k[2] << 16);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 2:
 				a += ((uint32) k[1] << 8);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 1:
 				a += k[0];
 				/* case 0: nothing left to add */
@@ -280,35 +280,35 @@ hash_bytes(const unsigned char *k, int keylen)
 		{
 			case 11:
 				c += ((uint32) k[10] << 8);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 10:
 				c += ((uint32) k[9] << 16);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 9:
 				c += ((uint32) k[8] << 24);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 8:
 				/* the lowest byte of c is reserved for the length */
 				b += k[7];
-				/* fall through */
+				/* FALLTHROUGH */
 			case 7:
 				b += ((uint32) k[6] << 8);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 6:
 				b += ((uint32) k[5] << 16);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 5:
 				b += ((uint32) k[4] << 24);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 4:
 				a += k[3];
-				/* fall through */
+				/* FALLTHROUGH */
 			case 3:
 				a += ((uint32) k[2] << 8);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 2:
 				a += ((uint32) k[1] << 16);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 1:
 				a += ((uint32) k[0] << 24);
 				/* case 0: nothing left to add */
@@ -318,35 +318,35 @@ hash_bytes(const unsigned char *k, int keylen)
 		{
 			case 11:
 				c += ((uint32) k[10] << 24);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 10:
 				c += ((uint32) k[9] << 16);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 9:
 				c += ((uint32) k[8] << 8);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 8:
 				/* the lowest byte of c is reserved for the length */
 				b += ((uint32) k[7] << 24);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 7:
 				b += ((uint32) k[6] << 16);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 6:
 				b += ((uint32) k[5] << 8);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 5:
 				b += k[4];
-				/* fall through */
+				/* FALLTHROUGH */
 			case 4:
 				a += ((uint32) k[3] << 24);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 3:
 				a += ((uint32) k[2] << 16);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 2:
 				a += ((uint32) k[1] << 8);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 1:
 				a += k[0];
 				/* case 0: nothing left to add */
@@ -417,13 +417,13 @@ hash_bytes_extended(const unsigned char *k, int keylen, uint64 seed)
 		{
 			case 11:
 				c += ((uint32) k[10] << 8);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 10:
 				c += ((uint32) k[9] << 16);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 9:
 				c += ((uint32) k[8] << 24);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 8:
 				/* the lowest byte of c is reserved for the length */
 				b += ka[1];
@@ -431,22 +431,22 @@ hash_bytes_extended(const unsigned char *k, int keylen, uint64 seed)
 				break;
 			case 7:
 				b += ((uint32) k[6] << 8);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 6:
 				b += ((uint32) k[5] << 16);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 5:
 				b += ((uint32) k[4] << 24);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 4:
 				a += ka[0];
 				break;
 			case 3:
 				a += ((uint32) k[2] << 8);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 2:
 				a += ((uint32) k[1] << 16);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 1:
 				a += ((uint32) k[0] << 24);
 				/* case 0: nothing left to add */
@@ -456,13 +456,13 @@ hash_bytes_extended(const unsigned char *k, int keylen, uint64 seed)
 		{
 			case 11:
 				c += ((uint32) k[10] << 24);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 10:
 				c += ((uint32) k[9] << 16);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 9:
 				c += ((uint32) k[8] << 8);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 8:
 				/* the lowest byte of c is reserved for the length */
 				b += ka[1];
@@ -470,22 +470,22 @@ hash_bytes_extended(const unsigned char *k, int keylen, uint64 seed)
 				break;
 			case 7:
 				b += ((uint32) k[6] << 16);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 6:
 				b += ((uint32) k[5] << 8);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 5:
 				b += k[4];
-				/* fall through */
+				/* FALLTHROUGH */
 			case 4:
 				a += ka[0];
 				break;
 			case 3:
 				a += ((uint32) k[2] << 16);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 2:
 				a += ((uint32) k[1] << 8);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 1:
 				a += k[0];
 				/* case 0: nothing left to add */
@@ -519,35 +519,35 @@ hash_bytes_extended(const unsigned char *k, int keylen, uint64 seed)
 		{
 			case 11:
 				c += ((uint32) k[10] << 8);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 10:
 				c += ((uint32) k[9] << 16);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 9:
 				c += ((uint32) k[8] << 24);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 8:
 				/* the lowest byte of c is reserved for the length */
 				b += k[7];
-				/* fall through */
+				/* FALLTHROUGH */
 			case 7:
 				b += ((uint32) k[6] << 8);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 6:
 				b += ((uint32) k[5] << 16);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 5:
 				b += ((uint32) k[4] << 24);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 4:
 				a += k[3];
-				/* fall through */
+				/* FALLTHROUGH */
 			case 3:
 				a += ((uint32) k[2] << 8);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 2:
 				a += ((uint32) k[1] << 16);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 1:
 				a += ((uint32) k[0] << 24);
 				/* case 0: nothing left to add */
@@ -557,35 +557,35 @@ hash_bytes_extended(const unsigned char *k, int keylen, uint64 seed)
 		{
 			case 11:
 				c += ((uint32) k[10] << 24);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 10:
 				c += ((uint32) k[9] << 16);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 9:
 				c += ((uint32) k[8] << 8);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 8:
 				/* the lowest byte of c is reserved for the length */
 				b += ((uint32) k[7] << 24);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 7:
 				b += ((uint32) k[6] << 16);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 6:
 				b += ((uint32) k[5] << 8);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 5:
 				b += k[4];
-				/* fall through */
+				/* FALLTHROUGH */
 			case 4:
 				a += ((uint32) k[3] << 24);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 3:
 				a += ((uint32) k[2] << 16);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 2:
 				a += ((uint32) k[1] << 8);
-				/* fall through */
+				/* FALLTHROUGH */
 			case 1:
 				a += k[0];
 				/* case 0: nothing left to add */