Misc warnings and cross-compile improvements (#3281)

5 files changed, 48 insertions, 27 deletions

diff --git a/src/H5Iint.c b/src/H5Iint.c
index 5ffac4d..8a6b7ae 100644
--- a/src/H5Iint.c
+++ b/src/H5Iint.c
@@ -389,9 +389,9 @@ H5I__mark_node(void *_info, void H5_ATTR_UNUSED *key, void *_udata)
 #ifdef H5I_DEBUG
                     if (H5DEBUG(I)) {
                         HDfprintf(H5DEBUG(I),
-                                  "H5I: discard type=%d obj=0x%08lx "
+                                  "H5I: discard type=%d obj=%p "
                                   "failure ignored\n",
-                                  (int)udata->type_info->cls->type, (unsigned long)(info->object));
+                                  (int)udata->type_info->cls->type, info->object);
                     }
 #endif /* H5I_DEBUG */
 
@@ -412,9 +412,9 @@ H5I__mark_node(void *_info, void H5_ATTR_UNUSED *key, void *_udata)
 #ifdef H5I_DEBUG
                     if (H5DEBUG(I)) {
                         HDfprintf(H5DEBUG(I),
-                                  "H5I: free type=%d obj=0x%08lx "
+                                  "H5I: free type=%d obj=%p "
                                   "failure ignored\n",
-                                  (int)udata->type_info->cls->type, (unsigned long)(info->object));
+                                  (int)udata->type_info->cls->type, info->object);
                     }
 #endif /* H5I_DEBUG */
 
diff --git a/src/H5SL.c b/src/H5SL.c
index fbd0b0d..11ccb9f 100644
--- a/src/H5SL.c
+++ b/src/H5SL.c
@@ -156,9 +156,9 @@
 #define H5SL_GROW(X, LVL, ERR)                                                                               \
     {                                                                                                        \
         /* Check if we need to increase allocation of forward pointers */                                    \
-        if (LVL + 1 >= 1u << X->log_nalloc) {                                                                \
+        if (LVL + 1 >= ((size_t)1) << X->log_nalloc) {                                                       \
             H5SL_node_t **_tmp;                                                                              \
-            HDassert(LVL + 1 == 1U << X->log_nalloc);                                                        \
+            HDassert(LVL + 1 == ((size_t)1) << X->log_nalloc);                                               \
             /* Double the amount of allocated space */                                                       \
             X->log_nalloc++;                                                                                 \
                                                                                                              \
@@ -178,7 +178,7 @@
                                                                                                              \
                 /* Create the new factory */                                                                 \
                 H5SL_fac_g[H5SL_fac_nused_g] =                                                               \
-                    H5FL_fac_init((1u << H5SL_fac_nused_g) * sizeof(H5SL_node_t *));                         \
+                    H5FL_fac_init((((size_t)1) << H5SL_fac_nused_g) * sizeof(H5SL_node_t *));                \
                 H5SL_fac_nused_g++;                                                                          \
             }                                                                                                \
                                                                                                              \
@@ -198,9 +198,9 @@
 #define H5SL_SHRINK(X, LVL)                                                                                  \
     {                                                                                                        \
         /* Check if we can reduce the allocation of forward pointers */                                      \
-        if (LVL <= 1u << (X->log_nalloc - 1)) {                                                              \
+        if (LVL <= ((size_t)1) << (X->log_nalloc - 1)) {                                                     \
             H5SL_node_t **_tmp;                                                                              \
-            HDassert(LVL == 1U << (X->log_nalloc - 1));                                                      \
+            HDassert(LVL == ((size_t)1) << (X->log_nalloc - 1));                                             \
             X->log_nalloc--;                                                                                 \
                                                                                                              \
             /* Allocate space for new forward pointers */                                                    \
diff --git a/src/H5T.c b/src/H5T.c
index 7e85227..9cbf546 100644
--- a/src/H5T.c
+++ b/src/H5T.c
@@ -1503,9 +1503,9 @@ H5T_top_term_package(void)
                         if (H5DEBUG(T)) {
                             HDfprintf(H5DEBUG(T),
                                       "H5T: conversion function "
-                                      "0x%08lx failed to free private data for "
+                                      "0x%016zx failed to free private data for "
                                       "%s (ignored)\n",
-                                      (unsigned long)(path->conv.u.app_func), path->name);
+                                      (size_t)path->conv.u.app_func, path->name);
                         } /* end if */
 #endif
                         H5E_clear_stack(NULL); /*ignore the error*/
@@ -1518,9 +1518,9 @@ H5T_top_term_package(void)
                         if (H5DEBUG(T)) {
                             HDfprintf(H5DEBUG(T),
                                       "H5T: conversion function "
-                                      "0x%08lx failed to free private data for "
+                                      "0x%016zx failed to free private data for "
                                       "%s (ignored)\n",
-                                      (unsigned long)(path->conv.u.lib_func), path->name);
+                                      (size_t)path->conv.u.lib_func, path->name);
                         } /* end if */
 #endif
                         H5E_clear_stack(NULL); /*ignore the error*/
@@ -2632,9 +2632,9 @@ H5T__register(H5T_pers_t pers, const char *name, H5T_t *src, H5T_t *dst, H5T_con
 #ifdef H5T_DEBUG
                     if (H5DEBUG(T))
                         HDfprintf(H5DEBUG(T),
-                                  "H5T: conversion function 0x%08lx "
+                                  "H5T: conversion function 0x%016zx "
                                   "failed to free private data for %s (ignored)\n",
-                                  (unsigned long)(old_path->conv.u.app_func), old_path->name);
+                                  (size_t)old_path->conv.u.app_func, old_path->name);
 #endif
                 } /* end if */
             }     /* end if */
@@ -2643,9 +2643,9 @@ H5T__register(H5T_pers_t pers, const char *name, H5T_t *src, H5T_t *dst, H5T_con
 #ifdef H5T_DEBUG
                 if (H5DEBUG(T))
                     HDfprintf(H5DEBUG(T),
-                              "H5T: conversion function 0x%08lx "
+                              "H5T: conversion function 0x%016zx "
                               "failed to free private data for %s (ignored)\n",
-                              (unsigned long)(old_path->conv.u.lib_func), old_path->name);
+                              (size_t)old_path->conv.u.lib_func, old_path->name);
 #endif
             } /* end if */
             (void)H5T_close_real(old_path->src);
@@ -2812,9 +2812,9 @@ H5T__unregister(H5T_pers_t pers, const char *name, H5T_t *src, H5T_t *dst, H5T_c
 #ifdef H5T_DEBUG
                     if (H5DEBUG(T))
                         HDfprintf(H5DEBUG(T),
-                                  "H5T: conversion function 0x%08lx failed "
+                                  "H5T: conversion function 0x%016zx failed "
                                   "to free private data for %s (ignored)\n",
-                                  (unsigned long)(path->conv.u.app_func), path->name);
+                                  (size_t)path->conv.u.app_func, path->name);
 #endif
                 } /* end if */
             }     /* end if */
@@ -2823,9 +2823,9 @@ H5T__unregister(H5T_pers_t pers, const char *name, H5T_t *src, H5T_t *dst, H5T_c
 #ifdef H5T_DEBUG
                 if (H5DEBUG(T))
                     HDfprintf(H5DEBUG(T),
-                              "H5T: conversion function 0x%08lx failed "
+                              "H5T: conversion function 0x%016zx failed "
                               "to free private data for %s (ignored)\n",
-                              (unsigned long)(path->conv.u.lib_func), path->name);
+                              (size_t)path->conv.u.lib_func, path->name);
 #endif
             } /* end if */
             (void)H5T_close_real(path->src);
@@ -5220,8 +5220,8 @@ H5T__path_find_real(const H5T_t *src, const H5T_t *dst, const char *name, H5T_co
                                          (size_t)0, NULL, NULL, H5CX_get_dxpl()) < 0) {
 #ifdef H5T_DEBUG
                 if (H5DEBUG(T))
-                    HDfprintf(H5DEBUG(T), "H5T: conversion function 0x%08lx free failed for %s (ignored)\n",
-                              (unsigned long)(path->conv.u.app_func), path->name);
+                    HDfprintf(H5DEBUG(T), "H5T: conversion function 0x%016zx free failed for %s (ignored)\n",
+                              (size_t)path->conv.u.app_func, path->name);
 #endif
                 H5E_clear_stack(NULL); /*ignore the failure*/
             }                          /* end if */
@@ -5230,8 +5230,8 @@ H5T__path_find_real(const H5T_t *src, const H5T_t *dst, const char *name, H5T_co
                                           (size_t)0, NULL, NULL) < 0) {
 #ifdef H5T_DEBUG
             if (H5DEBUG(T))
-                HDfprintf(H5DEBUG(T), "H5T: conversion function 0x%08lx free failed for %s (ignored)\n",
-                          (unsigned long)(path->conv.u.lib_func), path->name);
+                HDfprintf(H5DEBUG(T), "H5T: conversion function 0x%016zx free failed for %s (ignored)\n",
+                          (size_t)path->conv.u.lib_func, path->name);
 #endif
             H5E_clear_stack(NULL); /*ignore the failure*/
         }                          /* end if */
diff --git a/src/H5Tconv.c b/src/H5Tconv.c
index 93ca59f..8118eb0 100644
--- a/src/H5Tconv.c
+++ b/src/H5Tconv.c
@@ -887,7 +887,17 @@ done:
 /* Macro defining action on source data which needs to be aligned (before main action) */
 #define H5T_CONV_LOOP_PRE_SALIGN(ST)                                                                         \
     {                                                                                                        \
-        H5MM_memcpy(&src_aligned, src, sizeof(ST));                                                          \
+        /* The uint8_t * cast is required to avoid tripping over undefined behavior.                         \
+         *                                                                                                   \
+         * The typed pointer arrives via a void pointer, which may have any alignment.                       \
+         * We then cast it to a pointer to a type that is assumed to be aligned, which                       \
+         * is undefined behavior (section 6.3.2.3 paragraph 7 of the C99 standard).                          \
+         * In the past this hasn't caused many problems, but in some cases (e.g.                             \
+         * converting long doubles on macOS), an optimizing compiler might do the                            \
+         * wrong thing (in the macOS case, the conversion uses SSE, which has stricter                       \
+         * requirements about alignment).                                                                    \
+         */                                                                                                  \
+        H5MM_memcpy(&src_aligned, (const uint8_t *)src, sizeof(ST));                                         \
     }
 
 /* Macro defining action on source data which doesn't need to be aligned (before main action) */
@@ -919,7 +929,17 @@ done:
 /* Macro defining action on destination data which needs to be aligned (after main action) */
 #define H5T_CONV_LOOP_POST_DALIGN(DT)                                                                        \
     {                                                                                                        \
-        H5MM_memcpy(dst, &dst_aligned, sizeof(DT));                                                          \
+        /* The uint8_t * cast is required to avoid tripping over undefined behavior.                         \
+         *                                                                                                   \
+         * The typed pointer arrives via a void pointer, which may have any alignment.                       \
+         * We then cast it to a pointer to a type that is assumed to be aligned, which                       \
+         * is undefined behavior (section 6.3.2.3 paragraph 7 of the C99 standard).                          \
+         * In the past this hasn't caused many problems, but in some cases (e.g.                             \
+         * converting long doubles on macOS), an optimizing compiler might do the                            \
+         * wrong thing (in the macOS case, the conversion uses SSE, which has stricter                       \
+         * requirements about alignment).                                                                    \
+         */                                                                                                  \
+        H5MM_memcpy((uint8_t *)dst, &dst_aligned, sizeof(DT));                                               \
     }
 
 /* Macro defining action on destination data which doesn't need to be aligned (after main action) */
diff --git a/src/H5system.c b/src/H5system.c
index ecaa0f6..8991f6a 100644
--- a/src/H5system.c
+++ b/src/H5system.c
@@ -983,6 +983,7 @@ Wstrcasestr_wrap(const char *haystack, const char *needle)
     else
         return StrStrIA(haystack, needle);
 }
+
 #endif /* H5_HAVE_WIN32_API */
 
 /* dirname() and basename() are not easily ported to Windows and basename