Fix compile errors with no HAVE_MALLOC_SIZE. (#8533)

Also adds a new daily CI test, relying on the fact that we don't use malloc_size() on alpine libmusl.

Fixes #8531

.github/workflows/daily.yml

@@ -222,7 +222,7 @@ jobs:
           ./runtest-sentinel &&
           ./runtest-cluster
 
-  test-alpine:
+  test-alpine-jemalloc:
     runs-on: ubuntu-latest
     container: alpine:latest
     steps:
@@ -241,3 +241,23 @@ jobs:
       run: ./runtest-sentinel
     - name: cluster tests
       run: ./runtest-cluster
+
+  test-alpine-libc-malloc:
+    runs-on: ubuntu-latest
+    container: alpine:latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: make
+      run: |
+          apk add build-base
+          make REDIS_CFLAGS='-Werror' USE_JEMALLOC=no
+    - name: test
+      run: |
+        apk add tcl procps
+        ./runtest --accurate --verbose --dump-logs
+    - name: module api test
+      run: ./runtest-moduleapi --verbose
+    - name: sentinel tests
+      run: ./runtest-sentinel
+    - name: cluster tests
+      run: ./runtest-cluster

src/zmalloc.c

@@ -32,6 +32,7 @@
 #include <stdlib.h>
 #include <stdint.h>
 #include <unistd.h>
+#include <assert.h>
 
 /* This function provide us access to the original libc free(). This is useful
  * for instance to free results obtained by backtrace_symbols(). We need
@@ -49,18 +50,14 @@ void zlibc_free(void *ptr) {
 
 #ifdef HAVE_MALLOC_SIZE
 #define PREFIX_SIZE (0)
+#define ASSERT_NO_SIZE_OVERFLOW(sz)
 #else
 #if defined(__sun) || defined(__sparc) || defined(__sparc__)
 #define PREFIX_SIZE (sizeof(long long))
 #else
 #define PREFIX_SIZE (sizeof(size_t))
 #endif
-#endif
-
-#if PREFIX_SIZE > 0
 #define ASSERT_NO_SIZE_OVERFLOW(sz) assert((sz) + PREFIX_SIZE > (sz))
-#else
-#define ASSERT_NO_SIZE_OVERFLOW(sz)
 #endif
 
 /* Explicitly override malloc/free etc when using tcmalloc. */