Fix internal error on DW_OP_bregx(-1)
https://bugzilla.redhat.com/show_bug.cgi?id=1270564#c15
https://bugzilla.redhat.com/attachment.cgi?id=1081772
clang-3.5.0-9.fc22.x86_64
<3><22b2>: Abbrev Number: 69 (DW_TAG_variable)
<22b3> DW_AT_location : 7 byte block: 92 ff ff ff ff f 0 (DW_OP_bregx:
4294967295 (r-1) 0)
<22bb> DW_AT_name : (indirect string, offset: 0x2a36): texture_data
<22c1> DW_AT_type : <0x1d3>
(gdb) p variable
warning: Unmapped DWARF Register #-1 encountered.
regcache.c:177: internal-error: register_size: Assertion `regnum >= 0 && regnum < (gdbarch_num_regs (gdbarch) + gdbarch_num_pseudo_regs
(gdbarch))' failed.
[...]
Quit this debugging session? (y or n) FAIL: gdb.dwarf2/dw2-regno-invalid.exp: p variable (GDB internal error)
-> (x86_64)
(gdb) p variable
warning: Unmapped DWARF Register #-1 encountered.
Invalid register #-1, expecting 0 <= # < 220
(gdb) PASS: gdb.dwarf2/dw2-regno-invalid.exp: p variable
-> (i386)
(gdb) p variable
Invalid register #104, expecting 0 <= # < 104
(gdb) PASS: gdb.dwarf2/dw2-regno-invalid.exp: p variable
GDB calls gdbarch_dwarf2_reg_to_regnum() first which returns -1 in the x86_64
case
if (regnum == -1)
warning (_("Unmapped DWARF Register #%d encountered."), reg);
but in i386 case it does:
/* This will hopefully provoke a warning. */
return gdbarch_num_regs (gdbarch) + gdbarch_num_pseudo_regs (gdbarch);
and the default implementation is a nop, leaving whatever register number
the DWARF specified.
gdb/ChangeLog
2015-10-20 Jan Kratochvil <jan.kratochvil@redhat.com>
* findvar.c (address_from_register): Check REGNUM validity.
gdb/testsuite/ChangeLog
2015-10-20 Jan Kratochvil <jan.kratochvil@redhat.com>
Pedro Alves <palves@redhat.com>
* gdb.dwarf2/dw2-regno-invalid.exp: New file.
* lib/dwarf.exp (Dwarf): Add DW_OP_bregx.