Fix a few GCC warnings

GCC 8 now generates warnings for incompatible function pointer casts
[-Werror=cast-function-type]. Apparently there are a few of those in rts
code, which makes `./validate` unhappy (since we compile with `-Werror`)

This commit tries to fix these issues by changing the functions to have
the correct type (and, if necessary, moving the casts into those
functions).

For instance, hash/comparison function are declared (`Hash.h`) to take
`StgWord` but we want to use `StgWord64[2]` in `StaticPtrTable.c`.
Instead of casting the function pointers, we can cast the `StgWord`
parameter to `StgWord*`. I think this should be ok since `StgWord`
should be the same size as a pointer.

Signed-off-by: Michal Terepeta <michal.terepeta@gmail.com>

Test Plan: ./validate

Reviewers: bgamari, erikd, simonmar

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4673

1 files changed, 3 insertions, 3 deletions

diff --git a/rts/Hash.c b/rts/Hash.c
index b9a3cf6f33..658187b944 100644
--- a/rts/Hash.c
+++ b/rts/Hash.c
@@ -77,8 +77,9 @@ hashWord(const HashTable *table, StgWord key)
 }
 
 int
-hashStr(const HashTable *table, char *key)
+hashStr(const HashTable *table, StgWord w)
 {
+    const char *key = (char*) w;
 #ifdef x86_64_HOST_ARCH
     StgWord h = XXH64 (key, strlen(key), 1048583);
 #else
@@ -440,8 +441,7 @@ allocHashTable(void)
 HashTable *
 allocStrHashTable(void)
 {
-    return allocHashTable_((HashFunction *)hashStr,
-                           (CompareFunction *)compareStr);
+    return allocHashTable_(hashStr, compareStr);
 }
 
 void