bpo-23699: Use a macro to reduce boilerplate code in rich comparison functions (GH-793)

diff --git a/Objects/bytearrayobject.c b/Objects/bytearrayobject.c
index c92cfc0..83c3549 100644
--- a/Objects/bytearrayobject.c
+++ b/Objects/bytearrayobject.c
@@ -1012,8 +1012,6 @@
 {
     Py_ssize_t self_size, other_size;
     Py_buffer self_bytes, other_bytes;
-    PyObject *res;
-    Py_ssize_t minsize;
     int cmp, rc;
 
     /* Bytes can be compared to anything that supports the (binary)
@@ -1049,38 +1047,25 @@
 
     if (self_size != other_size && (op == Py_EQ || op == Py_NE)) {
         /* Shortcut: if the lengths differ, the objects differ */
-        cmp = (op == Py_NE);
+        PyBuffer_Release(&self_bytes);
+        PyBuffer_Release(&other_bytes);
+        return PyBool_FromLong((op == Py_NE));
     }
     else {
-        minsize = self_size;
-        if (other_size < minsize)
-            minsize = other_size;
-
-        cmp = memcmp(self_bytes.buf, other_bytes.buf, minsize);
+        cmp = memcmp(self_bytes.buf, other_bytes.buf,
+                     Py_MIN(self_size, other_size));
         /* In ISO C, memcmp() guarantees to use unsigned bytes! */
 
-        if (cmp == 0) {
-            if (self_size < other_size)
-                cmp = -1;
-            else if (self_size > other_size)
-                cmp = 1;
+        PyBuffer_Release(&self_bytes);
+        PyBuffer_Release(&other_bytes);
+
+        if (cmp != 0) {
+            Py_RETURN_RICHCOMPARE(cmp, 0, op);
         }
 
-        switch (op) {
-        case Py_LT: cmp = cmp <  0; break;
-        case Py_LE: cmp = cmp <= 0; break;
-        case Py_EQ: cmp = cmp == 0; break;
-        case Py_NE: cmp = cmp != 0; break;
-        case Py_GT: cmp = cmp >  0; break;
-        case Py_GE: cmp = cmp >= 0; break;
-        }
+        Py_RETURN_RICHCOMPARE(self_size, other_size, op);
     }
 
-    res = cmp ? Py_True : Py_False;
-    PyBuffer_Release(&self_bytes);
-    PyBuffer_Release(&other_bytes);
-    Py_INCREF(res);
-    return res;
 }
 
 static void
diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index 7ba90aa..a921d9c 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -1566,7 +1566,6 @@
     int c;
     Py_ssize_t len_a, len_b;
     Py_ssize_t min_len;
-    PyObject *result;
     int rc;
 
     /* Make sure both arguments are strings. */
@@ -1599,7 +1598,7 @@
                 }
             }
         }
-        result = Py_NotImplemented;
+        Py_RETURN_NOTIMPLEMENTED;
     }
     else if (a == b) {
         switch (op) {
@@ -1607,12 +1606,12 @@
         case Py_LE:
         case Py_GE:
             /* a string is equal to itself */
-            result = Py_True;
+            Py_RETURN_TRUE;
             break;
         case Py_NE:
         case Py_LT:
         case Py_GT:
-            result = Py_False;
+            Py_RETURN_FALSE;
             break;
         default:
             PyErr_BadArgument();
@@ -1622,7 +1621,7 @@
     else if (op == Py_EQ || op == Py_NE) {
         int eq = bytes_compare_eq(a, b);
         eq ^= (op == Py_NE);
-        result = eq ? Py_True : Py_False;
+        return PyBool_FromLong(eq);
     }
     else {
         len_a = Py_SIZE(a);
@@ -1635,22 +1634,10 @@
         }
         else
             c = 0;
-        if (c == 0)
-            c = (len_a < len_b) ? -1 : (len_a > len_b) ? 1 : 0;
-        switch (op) {
-        case Py_LT: c = c <  0; break;
-        case Py_LE: c = c <= 0; break;
-        case Py_GT: c = c >  0; break;
-        case Py_GE: c = c >= 0; break;
-        default:
-            PyErr_BadArgument();
-            return NULL;
-        }
-        result = c ? Py_True : Py_False;
+        if (c != 0)
+            Py_RETURN_RICHCOMPARE(c, 0, op);
+        Py_RETURN_RICHCOMPARE(len_a, len_b, op);
     }
-
-    Py_INCREF(result);
-    return result;
 }
 
 static Py_hash_t
diff --git a/Objects/cellobject.c b/Objects/cellobject.c
index af19229..7b05e61 100644
--- a/Objects/cellobject.c
+++ b/Objects/cellobject.c
@@ -53,22 +53,15 @@
     PyObject_GC_Del(op);
 }
 
-#define TEST_COND(cond) ((cond) ? Py_True : Py_False)
-
 static PyObject *
 cell_richcompare(PyObject *a, PyObject *b, int op)
 {
-    int result;
-    PyObject *v;
-
     /* neither argument should be NULL, unless something's gone wrong */
     assert(a != NULL && b != NULL);
 
     /* both arguments should be instances of PyCellObject */
     if (!PyCell_Check(a) || !PyCell_Check(b)) {
-        v = Py_NotImplemented;
-        Py_INCREF(v);
-        return v;
+        Py_RETURN_NOTIMPLEMENTED;
     }
 
     /* compare cells by contents; empty cells come before anything else */
@@ -77,32 +70,7 @@
     if (a != NULL && b != NULL)
         return PyObject_RichCompare(a, b, op);
 
-    result = (b == NULL) - (a == NULL);
-    switch (op) {
-    case Py_EQ:
-        v = TEST_COND(result == 0);
-        break;
-    case Py_NE:
-        v = TEST_COND(result != 0);
-        break;
-    case Py_LE:
-        v = TEST_COND(result <= 0);
-        break;
-    case Py_GE:
-        v = TEST_COND(result >= 0);
-        break;
-    case Py_LT:
-        v = TEST_COND(result < 0);
-        break;
-    case Py_GT:
-        v = TEST_COND(result > 0);
-        break;
-    default:
-        PyErr_BadArgument();
-        return NULL;
-    }
-    Py_INCREF(v);
-    return v;
+    Py_RETURN_RICHCOMPARE(b == NULL, a == NULL, op);
 }
 
 static PyObject *
diff --git a/Objects/descrobject.c b/Objects/descrobject.c
index 5dc27ef..71d5224 100644
--- a/Objects/descrobject.c
+++ b/Objects/descrobject.c
@@ -1035,22 +1035,16 @@
     Py_TRASHCAN_SAFE_END(wp)
 }
 
-#define TEST_COND(cond) ((cond) ? Py_True : Py_False)
-
 static PyObject *
 wrapper_richcompare(PyObject *a, PyObject *b, int op)
 {
-    intptr_t result;
-    PyObject *v;
     PyWrapperDescrObject *a_descr, *b_descr;
 
     assert(a != NULL && b != NULL);
 
     /* both arguments should be wrapperobjects */
     if (!Wrapper_Check(a) || !Wrapper_Check(b)) {
-        v = Py_NotImplemented;
-        Py_INCREF(v);
-        return v;
+        Py_RETURN_NOTIMPLEMENTED;
     }
 
     /* compare by descriptor address; if the descriptors are the same,
@@ -1063,32 +1057,7 @@
         return PyObject_RichCompare(a, b, op);
     }
 
-    result = a_descr - b_descr;
-    switch (op) {
-    case Py_EQ:
-        v = TEST_COND(result == 0);
-        break;
-    case Py_NE:
-        v = TEST_COND(result != 0);
-        break;
-    case Py_LE:
-        v = TEST_COND(result <= 0);
-        break;
-    case Py_GE:
-        v = TEST_COND(result >= 0);
-        break;
-    case Py_LT:
-        v = TEST_COND(result < 0);
-        break;
-    case Py_GT:
-        v = TEST_COND(result > 0);
-        break;
-    default:
-        PyErr_BadArgument();
-        return NULL;
-    }
-    Py_INCREF(v);
-    return v;
+    Py_RETURN_RICHCOMPARE(a_descr, b_descr, op);
 }
 
 static Py_hash_t
diff --git a/Objects/listobject.c b/Objects/listobject.c
index 8585322..7eba61e 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -2330,13 +2330,10 @@
 
     if (Py_SIZE(vl) != Py_SIZE(wl) && (op == Py_EQ || op == Py_NE)) {
         /* Shortcut: if the lengths differ, the lists differ */
-        PyObject *res;
         if (op == Py_EQ)
-            res = Py_False;
+            Py_RETURN_FALSE;
         else
-            res = Py_True;
-        Py_INCREF(res);
-        return res;
+            Py_RETURN_TRUE;
     }
 
     /* Search for the first index where items are different */
@@ -2351,25 +2348,7 @@
 
     if (i >= Py_SIZE(vl) || i >= Py_SIZE(wl)) {
         /* No more items to compare -- compare sizes */
-        Py_ssize_t vs = Py_SIZE(vl);
-        Py_ssize_t ws = Py_SIZE(wl);
-        int cmp;
-        PyObject *res;
-        switch (op) {
-        case Py_LT: cmp = vs <  ws; break;
-        case Py_LE: cmp = vs <= ws; break;
-        case Py_EQ: cmp = vs == ws; break;
-        case Py_NE: cmp = vs != ws; break;
-        case Py_GT: cmp = vs >  ws; break;
-        case Py_GE: cmp = vs >= ws; break;
-        default: return NULL; /* cannot happen */
-        }
-        if (cmp)
-            res = Py_True;
-        else
-            res = Py_False;
-        Py_INCREF(res);
-        return res;
+        Py_RETURN_RICHCOMPARE(Py_SIZE(vl), Py_SIZE(wl), op);
     }
 
     /* We have an item that differs -- shortcuts for EQ/NE */
diff --git a/Objects/longobject.c b/Objects/longobject.c
index c71b783..6fd4feb 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -2915,45 +2915,16 @@
     return sign < 0 ? -1 : sign > 0 ? 1 : 0;
 }
 
-#define TEST_COND(cond) \
-    ((cond) ? Py_True : Py_False)
-
 static PyObject *
 long_richcompare(PyObject *self, PyObject *other, int op)
 {
     int result;
-    PyObject *v;
     CHECK_BINOP(self, other);
     if (self == other)
         result = 0;
     else
         result = long_compare((PyLongObject*)self, (PyLongObject*)other);
-    /* Convert the return value to a Boolean */
-    switch (op) {
-    case Py_EQ:
-        v = TEST_COND(result == 0);
-        break;
-    case Py_NE:
-        v = TEST_COND(result != 0);
-        break;
-    case Py_LE:
-        v = TEST_COND(result <= 0);
-        break;
-    case Py_GE:
-        v = TEST_COND(result >= 0);
-        break;
-    case Py_LT:
-        v = TEST_COND(result == -1);
-        break;
-    case Py_GT:
-        v = TEST_COND(result == 1);
-        break;
-    default:
-        PyErr_BadArgument();
-        return NULL;
-    }
-    Py_INCREF(v);
-    return v;
+    Py_RETURN_RICHCOMPARE(result, 0, op);
 }
 
 static Py_hash_t
diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c
index c150af8..35decd8 100644
--- a/Objects/tupleobject.c
+++ b/Objects/tupleobject.c
@@ -647,23 +647,7 @@
 
     if (i >= vlen || i >= wlen) {
         /* No more items to compare -- compare sizes */
-        int cmp;
-        PyObject *res;
-        switch (op) {
-        case Py_LT: cmp = vlen <  wlen; break;
-        case Py_LE: cmp = vlen <= wlen; break;
-        case Py_EQ: cmp = vlen == wlen; break;
-        case Py_NE: cmp = vlen != wlen; break;
-        case Py_GT: cmp = vlen >  wlen; break;
-        case Py_GE: cmp = vlen >= wlen; break;
-        default: return NULL; /* cannot happen */
-        }
-        if (cmp)
-            res = Py_True;
-        else
-            res = Py_False;
-        Py_INCREF(res);
-        return res;
+        Py_RETURN_RICHCOMPARE(vlen, wlen, op);
     }
 
     /* We have an item that differs -- shortcuts for EQ/NE */
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 6533f41..194c5bc 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -11152,14 +11152,10 @@
     return unicode_compare_eq(left, right_uni);
 }
 
-#define TEST_COND(cond)                         \
-    ((cond) ? Py_True : Py_False)
-
 PyObject *
 PyUnicode_RichCompare(PyObject *left, PyObject *right, int op)
 {
     int result;
-    PyObject *v;
 
     if (!PyUnicode_Check(left) || !PyUnicode_Check(right))
         Py_RETURN_NOTIMPLEMENTED;
@@ -11174,13 +11170,11 @@
         case Py_LE:
         case Py_GE:
             /* a string is equal to itself */
-            v = Py_True;
-            break;
+            Py_RETURN_TRUE;
         case Py_NE:
         case Py_LT:
         case Py_GT:
-            v = Py_False;
-            break;
+            Py_RETURN_FALSE;
         default:
             PyErr_BadArgument();
             return NULL;
@@ -11189,32 +11183,12 @@
     else if (op == Py_EQ || op == Py_NE) {
         result = unicode_compare_eq(left, right);
         result ^= (op == Py_NE);
-        v = TEST_COND(result);
+        return PyBool_FromLong(result);
     }
     else {
         result = unicode_compare(left, right);
-
-        /* Convert the return value to a Boolean */
-        switch (op) {
-        case Py_LE:
-            v = TEST_COND(result <= 0);
-            break;
-        case Py_GE:
-            v = TEST_COND(result >= 0);
-            break;
-        case Py_LT:
-            v = TEST_COND(result == -1);
-            break;
-        case Py_GT:
-            v = TEST_COND(result == 1);
-            break;
-        default:
-            PyErr_BadArgument();
-            return NULL;
-        }
+        Py_RETURN_RICHCOMPARE(result, 0, op);
     }
-    Py_INCREF(v);
-    return v;
 }
 
 int