[Bug modula2/110174] New: Using illegal constraints for builtin return_address gives ICE

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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110174

            Bug ID: 110174
           Summary: Using illegal constraints for builtin return_address
                    gives ICE
           Product: gcc
           Version: 13.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: modula2
          Assignee: gaius at gcc dot gnu.org
          Reporter: ad...@tho-otto.de
  Target Milestone: ---

When compiling the the following module with -O2

MODULE foo;
FROM Builtins IMPORT return_address;
FROM SYSTEM IMPORT ADDRESS;

VAR x: ADDRESS;

PROCEDURE test();
BEGIN
  ASM VOLATILE("" : "=m"(x) : "m"(return_address(0)) : );
END test;

BEGIN
  test();
END foo.


I get an ICE:

during RTL pass: expand
In function ‘test’,
    inlined from ‘_M2_foo_init’ at foo.mod:13:3:
foo.mod:9:56: internal compiler error: in expand_asm_stmt, at cfgexpand.cc:3419
    9 |   ASM VOLATILE("" : "=m"(x) : "m"(return_address(0)) : );
      |                                                        ^

The ICE is triggered at
https://github.com/gcc-mirror/gcc/blob/9589a46ddadc8b93c224c3f84fa94746c04596bf/gcc/cfgexpand.cc#L3419

Using "m" as constraint is actually wrong, however the C backend handles that
correctly:

foo.c:5:39: error: memory input 1 is not directly addressable
    5 |   __asm__ volatile("" : "=m"(x) : "m"(__builtin_return_address(0)) : );