From: John Darrington <john@darrington.wattle.id.au>
Date: Tue, 21 May 2019 12:30:46 +0000 (+0200)
Subject: Add the WARN_UNUSED_RESULT attribute to all hash functions.
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c8765cd7639e64d5dcd8f494aee23babb3b3f179;p=pspp

Add the WARN_UNUSED_RESULT attribute to all hash functions.

A hash function has no purpose if the result is unused, and
tests will typically not pick up a mistake where the
programmer forgets to assign the result - the hash table will
merely degenerate to a linear searched array.
---

diff --git a/src/data/value-labels.h b/src/data/value-labels.h
index af98d9f9b5..61a42cff23 100644
--- a/src/data/value-labels.h
+++ b/src/data/value-labels.h
@@ -114,7 +114,7 @@ const struct val_lab *val_labs_next (const struct val_labs *,
 const struct val_lab **val_labs_sorted (const struct val_labs *);
 
 /* Properties of entire sets. */
-unsigned int val_labs_hash (const struct val_labs *, unsigned int basis);
+unsigned int val_labs_hash (const struct val_labs *, unsigned int basis) WARN_UNUSED_RESULT;
 bool val_labs_equal (const struct val_labs *, const struct val_labs *);
 
 #endif /* data/value-labels.h */
diff --git a/src/data/value.h b/src/data/value.h
index b1b27ed16e..299187285a 100644
--- a/src/data/value.h
+++ b/src/data/value.h
@@ -17,6 +17,7 @@
 #ifndef DATA_VALUE_H
 #define DATA_VALUE_H 1
 
+#include "libpspp/compiler.h"
 #include <assert.h>
 #include <stdbool.h>
 #include <stdlib.h>
@@ -71,7 +72,7 @@ void value_copy_buf_rpad (union value *dst, int dst_width,
 void value_set_missing (union value *, int width);
 int value_compare_3way (const union value *, const union value *, int width);
 bool value_equal (const union value *, const union value *, int width);
-unsigned int value_hash (const union value *, int width, unsigned int basis);
+unsigned int value_hash (const union value *, int width, unsigned int basis) WARN_UNUSED_RESULT;
 
 bool value_is_resizable (const union value *, int old_width, int new_width);
 bool value_needs_resize (int old_width, int new_width);
diff --git a/src/libpspp/hash-functions.h b/src/libpspp/hash-functions.h
index f792ba2a96..6fb339be31 100644
--- a/src/libpspp/hash-functions.h
+++ b/src/libpspp/hash-functions.h
@@ -17,12 +17,13 @@
 #ifndef LIBPSPP_HASH_FUNCTIONS_H
 #define LIBPSPP_HASH_FUNCTIONS_H 1
 
+#include "libpspp/compiler.h"
 #include <stddef.h>
 
-unsigned int hash_bytes (const void *, size_t, unsigned int basis);
-unsigned int hash_string (const char *, unsigned int basis);
-unsigned int hash_int (int, unsigned int basis);
-unsigned int hash_double (double, unsigned int basis);
-unsigned int hash_pointer (const void *, unsigned int basis);
+unsigned int hash_bytes (const void *, size_t, unsigned int basis) WARN_UNUSED_RESULT;
+unsigned int hash_string (const char *, unsigned int basis) WARN_UNUSED_RESULT;
+unsigned int hash_int (int, unsigned int basis) WARN_UNUSED_RESULT;
+unsigned int hash_double (double, unsigned int basis) WARN_UNUSED_RESULT;
+unsigned int hash_pointer (const void *, unsigned int basis) WARN_UNUSED_RESULT;
 
 #endif /* libpspp/hash-functions.h */
diff --git a/src/libpspp/i18n.h b/src/libpspp/i18n.h
index 5170c50f0d..d128fcea1a 100644
--- a/src/libpspp/i18n.h
+++ b/src/libpspp/i18n.h
@@ -17,6 +17,7 @@
 #ifndef I18N_H
 #define I18N_H
 
+#include "libpspp/compiler.h"
 #include <stdbool.h>
 #include <unistr.h>
 
@@ -71,8 +72,8 @@ bool set_encoding_from_locale (const char *loc);
 
 const char *uc_name (ucs4_t uc, char buffer[16]);
 
-unsigned int utf8_hash_case_bytes (const char *, size_t n, unsigned int basis);
-unsigned int utf8_hash_case_string (const char *, unsigned int basis);
+unsigned int utf8_hash_case_bytes (const char *, size_t n, unsigned int basis) WARN_UNUSED_RESULT;
+unsigned int utf8_hash_case_string (const char *, unsigned int basis) WARN_UNUSED_RESULT;
 int utf8_strcasecmp (const char *, const char *);
 int utf8_strncasecmp (const char *, size_t, const char *, size_t);
 int utf8_strverscasecmp (const char *, const char *);
diff --git a/src/libpspp/sparse-xarray.h b/src/libpspp/sparse-xarray.h
index 15ba49f60c..3b3de958b9 100644
--- a/src/libpspp/sparse-xarray.h
+++ b/src/libpspp/sparse-xarray.h
@@ -41,6 +41,7 @@
 #ifndef LIBPSPP_SPARSE_XARRAY_H
 #define LIBPSPP_SPARSE_XARRAY_H 1
 
+#include "libpspp/compiler.h"
 #include <stddef.h>
 #include <stdbool.h>
 
@@ -67,6 +68,6 @@ bool sparse_xarray_copy (const struct sparse_xarray *src,
 
 /* For testing purposes only. */
 unsigned int sparse_xarray_model_checker_hash (const struct sparse_xarray *,
-                                               unsigned int basis);
+                                               unsigned int basis) WARN_UNUSED_RESULT;
 
 #endif /* libpspp/sparse-libpspp.h */
diff --git a/src/math/interaction.h b/src/math/interaction.h
index ec6f88b03b..8229083f86 100644
--- a/src/math/interaction.h
+++ b/src/math/interaction.h
@@ -19,6 +19,7 @@
 #define _INTERACTION_H__ 1
 
 #include <stdbool.h>
+#include "libpspp/compiler.h"
 #include "data/missing-values.h"
 
 struct ccase;
@@ -60,7 +61,8 @@ bool interaction_is_subset (const struct interaction *,
 
 
 unsigned int interaction_case_hash (const struct interaction *,
-                                    const struct ccase *, unsigned int base);
+                                    const struct ccase *,
+				    unsigned int base) WARN_UNUSED_RESULT;
 bool interaction_case_equal (const struct interaction *, const struct ccase *,
                              const struct ccase *);
 bool interaction_case_is_missing (const struct interaction *,