id	summary	reporter	owner	description	type	status	priority	component	version	resolution	keywords	cc
220	Reference to Array of Generics does not work	mlbrooks		"The declaration `float (&a)[7]`, which is pronounced, ""a is a reference to a length-7 array of floats,"" is well-defined, useful, and works.

Its generic version, where the element type T replaces float, ought to be equivalently usable, but it is broken.

{{{
#ifndef __cforall
#include <stdio.h>
#endif

void doPrint(float v) {
    printf(""%f\n"", v);
}

void try1( float (&a)[7] ) {
    printf(""%ld %p %p\n"", sizeof(a), &a, &a[0]);
    doPrint(a[0]);
}

#ifdef __cforall
forall( otype T | {void doPrint(T);} )
void try2( T (&a)[7] ) {
    printf(""%ld %p %p\n"", sizeof(a), &a, &a[0]); // prints
    doPrint(a[0]);  // crashes
}
#endif

int main() {
    float items[7];
    items[0] = 3.14;
    printf(""%f is 0x%x\n"", items[0], *(unsigned int *)&items[0]);
    try1(items);
  #ifdef __cforall
    try2(items);
  #endif
}

}}}

CFA Actual: compiles with output
{{{
3.140000 is 0x4048f5c3
try1: 28 0x7fffffffe2b0 0x7fffffffe2b0
doPrint: 3.140000
try2: 8 0x7fffffffe2b0 0x4048f5c3
Cforall Runtime error (UNIX pid:920) Segment fault at memory location 0x4048f5c3.
}}}

CFA Expected: compiles with output
{{{
3.140000 is 0x4048f5c3
try1: 28 0x7fffffffe2b0 0x7fffffffe2b0
doPrint: 3.140000
try2: 28 0x7fffffffe2b0 0x7fffffffe2b0
doPrint: 3.140000
}}}

g++ Actual and Expected: compiles with output
{{{
3.140000 is 0x4048f5c3
try1: 28 0x7fffffffe370 0x7fffffffe370
doPrint: 3.140000
}}}

The CFA try2 output suggests that `typeof(a)` is `float*` instead of `float[7]`.

The fact that g++ treats try1 consistently with CFA-actual supports CFA-try1 behaviour being a model for the expected behaviour, with the inconsistency of CFA-try2 being a bug.

For the printed in-stack address (0x7ff...), it is not relevant what the absolute value is.  The same value occurs throughout one program run.  It is relevant when the program prints that value, vs 0x4048f5c3.
"	defect	new	major	cfa-cc	1.0