https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92362
Bug ID: 92362
Summary: Compiler generates 2 function calls in a 'with
Address' aspect specification that uses a function
Product: gcc
Version: 9.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: ada
Assignee: unassigned at gcc dot gnu.org
Reporter: cthowie at netzero dot net
Target Milestone: ---
PLATFORM USED: GCC 9.2 toolchain on Windows 10 Intel x64 using MSYS2 (mingw64).
Note the GNAT FSF 8.2 compiler does NOT have the bug.
ISSUE: Multiple calls to a function that returns an address for use "with
Address".
Note that if you use the alternative (non-aspect) attribute definition clause,
the bug doesn't appear in 9.2, so a statement like:
bar : Integer;
for bar'Address use Get_Address;
is handled properly but:
bar : Integer with Address => Get_Address;
is compiled defectively.
EXAMPLE PROGRAM DEMONSTRATING THE BUG:
with Ada.Text_IO; use Ada.Text_IO;
with System;
procedure Main
is
foo : Integer := 0;
function Get_Address return System.Address
is
begin
Put_Line ("Get_Address called");
return foo'Address;
end Get_Address;
bar : Integer with Address => Get_Address; -- Get_Address called
TWICE = BUG!
begin
bar := 100;
Put_Line ("foo = " & foo'Img);
end Main;
BUILD INSTRUCTIONS:
Save the above example program to e.g., "main.adb" then run: gnatmake main.adb
then run the program "main.exe" and you'll see GCC GNAT FSF 9.2 output is
incorrect:
Get_Address called
Get_Address called
foo = 100
whereas earlier version GNAT FSF 8.2 produces correct output:
Get_Address called
foo = 100
and so does current GNAT FSF 9.2 but only if you use the more verbose attribute
definition clause shown above.
