RAA: add functions for storing pointers in RAA's

RAAs can, and should be, usable for storing pointers as well as
integers. In reality it is exactly the same code, but make it explicit
by having different entry points.  In the actual RAA the data is
stored as a union, which in practice will not occupy any more space
than the existing code.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

include/raa.h

@@ -41,6 +41,8 @@ struct RAA;
 struct RAA * never_null raa_init(void);
 void raa_free(struct RAA *);
 int64_t raa_read(struct RAA *, int32_t);
-struct RAA *raa_write(struct RAA *r, int32_t posn, int64_t value);
+void *raa_read_ptr(struct RAA *, int32_t);
+struct RAA * never_null raa_write(struct RAA *r, int32_t posn, int64_t value);
+struct RAA * never_null raa_write_ptr(struct RAA *r, int32_t posn, void *value);
 
 #endif                          /* NASM_RAA_H */

nasmlib/raa.c

@@ -1,6 +1,6 @@
 /* ----------------------------------------------------------------------- *
- *   
- *   Copyright 1996-2009 The NASM Authors - All Rights Reserved
+ *
+ *   Copyright 1996-2018 The NASM Authors - All Rights Reserved
  *   See the file AUTHORS included with the NASM distribution for
  *   the specific copyright holders.
  *
@@ -14,7 +14,7 @@
  *     copyright notice, this list of conditions and the following
  *     disclaimer in the documentation and/or other materials provided
  *     with the distribution.
- *     
+ *
  *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
  *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
  *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
@@ -50,6 +50,11 @@ typedef union RAA_UNION RAA_UNION;
 typedef struct RAA_LEAF RAA_LEAF;
 typedef struct RAA_BRANCH RAA_BRANCH;
 
+union intorptr {
+    int64_t i;
+    void *p;
+};
+
 struct RAA {
     /*
      * Number of layers below this one to get to the real data. 0
@@ -71,7 +76,7 @@ struct RAA {
 
     union RAA_UNION {
         struct RAA_LEAF {
-            int64_t data[RAA_BLKSIZE];
+            union intorptr data[RAA_BLKSIZE];
         } l;
         struct RAA_BRANCH {
             struct RAA *data[RAA_LAYERSIZE];
@@ -87,18 +92,14 @@ struct RAA {
 static struct RAA *real_raa_init(int layers)
 {
     struct RAA *r;
-    int i;
 
     if (layers == 0) {
         r = nasm_zalloc(LEAFSIZ);
         r->shift = 0;
     } else {
-        r = nasm_malloc(BRANCHSIZ);
+        r = nasm_zalloc(BRANCHSIZ);
         r->layers = layers;
-        for (i = 0; i < RAA_LAYERSIZE; i++)
-            r->u.b.data[i] = NULL;
-        r->shift =
-            (RAA_BLKSHIFT - RAA_LAYERSHIFT) + layers * RAA_LAYERSHIFT;
+        r->shift = (RAA_BLKSHIFT - RAA_LAYERSHIFT) + layers * RAA_LAYERSHIFT;
     }
     return r;
 }
@@ -119,21 +120,39 @@ void raa_free(struct RAA *r)
     nasm_free(r);
 }
 
-int64_t raa_read(struct RAA *r, int32_t posn)
+static const union intorptr *real_raa_read(struct RAA *r, int32_t posn)
 {
     if ((uint32_t) posn >= (UINT32_C(1) << (r->shift + LAYERSHIFT(r))))
-        return 0;               /* Return 0 for undefined entries */
+        return NULL;            /* Beyond the end */
     while (r->layers > 0) {
         int32_t l = posn >> r->shift;
         posn &= (UINT32_C(1) << r->shift) - 1;
         r = r->u.b.data[l];
         if (!r)
-            return 0;           /* Return 0 for undefined entries */
+            return NULL;        /* Not present */
     }
-    return r->u.l.data[posn];
+    return &r->u.l.data[posn];
 }
 
-struct RAA *raa_write(struct RAA *r, int32_t posn, int64_t value)
+int64_t raa_read(struct RAA *r, int32_t pos)
+{
+    const union intorptr *ip;
+
+    ip = real_raa_read(r, pos);
+    return ip ? ip->i : 0;
+}
+
+void *raa_read_ptr(struct RAA *r, int32_t pos)
+{
+    const union intorptr *ip;
+
+    ip = real_raa_read(r, pos);
+    return ip ? ip->p : NULL;
+}
+
+
+static struct RAA *
+real_raa_write(struct RAA *r, int32_t posn, union intorptr value)
 {
     struct RAA *result;
 
@@ -144,11 +163,8 @@ struct RAA *raa_write(struct RAA *r, int32_t posn, int64_t value)
          * Must add a layer.
          */
         struct RAA *s;
-        int i;
 
-        s = nasm_malloc(BRANCHSIZ);
-        for (i = 0; i < RAA_LAYERSIZE; i++)
-            s->u.b.data[i] = NULL;
+        s = nasm_zalloc(BRANCHSIZ);
         s->layers = r->layers + 1;
         s->shift = LAYERSHIFT(r) + r->shift;
         s->u.b.data[0] = r;
@@ -171,3 +187,19 @@ struct RAA *raa_write(struct RAA *r, int32_t posn, int64_t value)
 
     return result;
 }
+
+struct RAA *raa_write(struct RAA *r, int32_t posn, int64_t value)
+{
+    union intorptr ip;
+
+    ip.i = value;
+    return real_raa_write(r, posn, ip);
+}
+
+struct RAA *raa_write_ptr(struct RAA *r, int32_t posn, void *value)
+{
+    union intorptr ip;
+
+    ip.p = value;
+    return real_raa_write(r, posn, ip);
+}