[Tinycc-devel] Fix indirections with function pointers (***fn)() (grischka-2005-09-29 case_9)

[David A. Wheeler]

Another patch, case_9. This one is:
Fix indirections with function pointers (***fn)() (grischka-2005-09-29 case_9)

==============================================
Fix indirections with function pointers (***fn)() (grischka-2005-09-29 case_9)
This fixes handling of indirections with function pointers.
This patch was originally posted in grischka's 2005-09-25 email as
required fix case_9 to compile gcc 2.95.  David A. Wheeler modified the
test case to fit into tcc's test framework.  Wheeler removed printing the
specific addresses of the functions, whch was in the original test case,
because that breaks the test harness.  After all, addresses assigned to
functions will vary between compilers, versions of compilers,
and in some configurations each run. Instead, the test case
simply shows if the function pointer has the same address as the address of
the function it's supposed to be pointing to, which is all that is required.


diff -ur tinycc-rl-1.0.0-orig/tcc.c tinycc-rl-1.0.0-grischka9/tcc.c
--- tinycc-rl-1.0.0-orig/tcc.c  2007-04-18 14:52:22.000000000 -0400
+++ tinycc-rl-1.0.0-grischka9/tcc.c     2007-05-03 17:13:17.000000000 -0400
@@ -6267,13 +6267,17 @@
 /* indirection with full error checking and bound check */
 static void indir(void)
 {
-    if ((vtop->type.t & VT_BTYPE) != VT_PTR)
+    if ((vtop->type.t & VT_BTYPE) != VT_PTR) {
+        if ((vtop->type.t & VT_BTYPE) == VT_FUNC)
+            return;
         expect("pointer");
+    }
     if ((vtop->r & VT_LVAL) && !nocode_wanted)
         gv(RC_INT);
     vtop->type = *pointed_type(&vtop->type);
-    /* an array is never an lvalue */
-    if (!(vtop->type.t & VT_ARRAY)) {
+    /* Arrays and functions are never lvalues */
+    if (!(vtop->type.t & VT_ARRAY)
+        && (vtop->type.t & VT_BTYPE) != VT_FUNC) {
         vtop->r |= lvalue_type(vtop->type.t);
         /* if bound checking, the referenced pointer must be checked */
         if (do_bounds_check) 
diff -ur tinycc-rl-1.0.0-orig/tests/tcctest.c 
tinycc-rl-1.0.0-grischka9/tests/tcctest.c
--- tinycc-rl-1.0.0-orig/tests/tcctest.c        2007-04-18 14:52:22.000000000 
-0400
+++ tinycc-rl-1.0.0-grischka9/tests/tcctest.c   2007-05-03 17:14:18.000000000 
-0400
@@ -1450,6 +1450,11 @@
         return fib(n-1) + fib(n-2);
 }
 
+int reply_self(int x)
+{
+    return x;
+}
+
 void funcptr_test()
 {
     void (*func)(int);
@@ -1473,6 +1478,14 @@
     printf("sizeof2 = %d\n", sizeof funcptr_test);
     printf("sizeof3 = %d\n", sizeof(&funcptr_test));
     printf("sizeof4 = %d\n", sizeof &funcptr_test);
+
+    /* Test function pointer indirection */
+    {
+        int (*pfn)(int) = reply_self;
+        printf("case_9: 1 (7,8) -> %d (%d,%d)\n",
+            (int) (reply_self == *pfn), pfn(7), (******pfn)(8));
+    }
+
 }
 
 void lloptest(long long a, long long b)

--- David A. Wheeler

grischka9.patch
Description: Text Data