https://gcc.gnu.org/bugzilla/show_bug.cgi?id=128485
Bug ID: 128485
Summary: [RX] Incorrect DWARF variable location offset (4
bytes) due to CFA calculation mismatch in prologue
Product: gcc
Version: 17.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: yoshinori.sato at nifty dot com
Target Milestone: ---
When compiling for the RX target under specific conditions (e.g., using
-fomit-frame-pointer with a mix of register-passed and stack-passed arguments),
the generated DWARF debugging information for variable locations is offset by 4
bytes relative to their actual memory layout.
Consequently, when debugging with GDB, the values of local variables and
arguments are displayed incorrectly, often showing the value of an adjacent
variable or uninitialized memory.
It can be reproduced using the following method.
code.
int foo(int a, int b, int c, int d)
{
return a + b + c - d;
}
int main(int argc, char *argv[])
{
return foo(1, 2, 3, 4);
}
build on "rx-elf-gcc -g -fomit-frame-pointer test.c"
run as "rx-elf-gdb" and show arguments.
Breakpoint 1, main (argc=0, argv=0x0 <_preinit_array_start>) at argtest.c:8
8 return foo(1, 2, 3, 4);
(gdb) s
foo (a=0, b=1, c=2, d=3) at argtest.c:3
3 return a + b + c - d;
The arguments for `foo` are shifted by one.
