From dc42e902cc54af2b7e7b54a1171d562f867342d5 Mon Sep 17 00:00:00 2001 From: Andrew Burgess Date: Tue, 21 May 2019 22:14:05 +0100 Subject: [PATCH 1/1] gdb/fortran: Handle gdbarch_floatformat_for_type returning nullptr In this commit: commit 34d11c682fd96c7dbe3ebd6cd9033e65d51ec7a3 Date: Fri May 3 15:23:55 2019 +0100 gdb/fortran: Use floatformats_ia64_quad for fortran 16-byte floats GDB was changed such that the Fortran's 16-byte float format was obtained by calling gdbarch_floatformat_for_type instead of just using gdbarch_long_double_format as it was before. The problem with this default_floatformat_for_type can return NULL in some cases, and the code introduced in 34d11c682f didn't consider this. This commit introduces several alternative strategies for finding a suitable 16-byte floating point type. First GDB calls gdbarch_floatformat_for_type (this was what 34d11c682f added), if this returns null GDB will use gdbarch_long_double_format if it is the correct size (this was the format used before 34d11c682f). Finally, if neither of the above provides a suitable type then GDB will create a new dummy type. This final dummy type is unlikely to provide an correct debug experience as far as examining the 16-byte floats, but it should prevent GDB crashing. gdb/ChangeLog: PR gdb/18644: * f-lang.c (build_fortran_types): Handle the case where gdbarch_floatformat_for_type returns a nullptr. --- gdb/ChangeLog | 6 ++++++ gdb/f-lang.c | 12 ++++++++++-- 2 files changed, 16 insertions(+), 2 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 86f522d..b0b7503 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,9 @@ +2019-05-21 Andrew Burgess + + PR gdb/18644: + * f-lang.c (build_fortran_types): Handle the case where + gdbarch_floatformat_for_type returns a nullptr. + 2019-05-21 Tom de Vries PR cli/24587 diff --git a/gdb/f-lang.c b/gdb/f-lang.c index 5855c68..e612eed 100644 --- a/gdb/f-lang.c +++ b/gdb/f-lang.c @@ -728,8 +728,16 @@ build_fortran_types (struct gdbarch *gdbarch) = arch_float_type (gdbarch, gdbarch_double_bit (gdbarch), "real*8", gdbarch_double_format (gdbarch)); auto fmt = gdbarch_floatformat_for_type (gdbarch, "real(kind=16)", 128); - builtin_f_type->builtin_real_s16 - = arch_float_type (gdbarch, 128, "real*16", fmt); + if (fmt != nullptr) + builtin_f_type->builtin_real_s16 + = arch_float_type (gdbarch, 128, "real*16", fmt); + else if (gdbarch_long_double_bit (gdbarch) == 128) + builtin_f_type->builtin_real_s16 + = arch_float_type (gdbarch, gdbarch_long_double_bit (gdbarch), + "real*16", gdbarch_long_double_format (gdbarch)); + else + builtin_f_type->builtin_real_s16 + = arch_type (gdbarch, TYPE_CODE_ERROR, 128, "real*16"); builtin_f_type->builtin_complex_s8 = arch_complex_type (gdbarch, "complex*8", -- 2.7.4