Hi, On Tue, 2023-04-11 at 16:12 +0800, Ying Huang wrote: > From: Ying Huang <ying.hu...@oss.cipunited.com> > > add register_info, return_value_location function on mips > --- > backends/Makefile.am | 2 +- > backends/mips_init.c | 2 + > backends/mips_regs.c | 109 +++++++++++++++++ > backends/mips_retval.c | 261 +++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 373 insertions(+), 1 deletion(-) > create mode 100644 backends/mips_regs.c > create mode 100644 backends/mips_retval.c > > diff --git a/backends/Makefile.am b/backends/Makefile.am > index ddc31c9d..5453f787 100644 > --- a/backends/Makefile.am > +++ b/backends/Makefile.am > @@ -101,7 +101,7 @@ loongarch_SRCS = loongarch_init.c loongarch_symbol.c > arc_SRCS = arc_init.c arc_symbol.c > > mips_SRCS = mips_init.c mips_symbol.c mips_attrs.c mips_initreg.c \ > - mips_cfi.c mips_unwind.c > + mips_cfi.c mips_unwind.c mips_regs.c mips_retval.c
OK. > libebl_backends_a_SOURCES = $(i386_SRCS) $(sh_SRCS) $(x86_64_SRCS) \ > $(ia64_SRCS) $(alpha_SRCS) $(arm_SRCS) \ > diff --git a/backends/mips_init.c b/backends/mips_init.c > index 3caa9fee..7ca93314 100644 > --- a/backends/mips_init.c > +++ b/backends/mips_init.c > @@ -58,6 +58,8 @@ mips_init (Elf *elf __attribute__ ((unused)), > HOOK (eh, set_initial_registers_tid); > HOOK (eh, abi_cfi); > HOOK (eh, unwind); > + HOOK (eh, register_info); > + HOOK (eh, return_value_location); > eh->frame_nregs = 32; > return eh; > } OK > diff --git a/backends/mips_regs.c b/backends/mips_regs.c > new file mode 100644 > index 00000000..733caeee > --- /dev/null > +++ b/backends/mips_regs.c > @@ -0,0 +1,109 @@ > +/* Register names and numbers for mips DWARF. > + Copyright (C) 2006 Red Hat, Inc. > + Copyright (C) 2023 CIP United Inc. > + This file is part of elfutils. > + > + This file is free software; you can redistribute it and/or modify > + it under the terms of either > + > + * the GNU Lesser General Public License as published by the Free > + Software Foundation; either version 3 of the License, or (at > + your option) any later version > + > + or > + > + * the GNU General Public License as published by the Free > + Software Foundation; either version 2 of the License, or (at > + your option) any later version > + > + or both in parallel, as here. > + > + elfutils is distributed in the hope that it will be useful, but > + WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + General Public License for more details. > + > + You should have received copies of the GNU General Public License and > + the GNU Lesser General Public License along with this program. If > + not, see <http://www.gnu.org/licenses/>. */ > + > +#ifdef HAVE_CONFIG_H > +# include <config.h> > +#endif > + > +#include <assert.h> > +#include <dwarf.h> > +#include <string.h> > + > +#define BACKEND mips_ > +#include "libebl_CPU.h" > + > +ssize_t > +mips_register_info (Ebl *ebl __attribute__ ((unused)), > + int regno, char *name, size_t namelen, > + const char **prefix, const char **setname, > + int *bits, int *type) > +{ > + if (name == NULL) > + return 66; > + > + if (regno < 0 || regno > 65 || namelen < 4) > + return -1; > + > + *prefix = "$"; > + > + if (regno < 32) > + { > + *setname = "integer"; > + *type = DW_ATE_signed; > + *bits = 32; > + if (regno < 32 + 10) > + { > + name[0] = regno + '0'; > + namelen = 1; > + } > + else > + { > + name[0] = (regno / 10) + '0'; > + name[1] = (regno % 10) + '0'; > + namelen = 2; > + } > + } > + else if (regno < 64) > + { > + *setname = "FPU"; > + *type = DW_ATE_float; > + *bits = 32; > + name[0] = 'f'; > + if (regno < 32 + 10) > + { > + name[1] = (regno - 32) + '0'; > + namelen = 2; > + } > + else > + { > + name[1] = (regno - 32) / 10 + '0'; > + name[2] = (regno - 32) % 10 + '0'; > + namelen = 3; > + } > + } > + else if (regno == 64) > + { > + *type = DW_ATE_signed; > + *bits = 32; > + name[0] = 'h'; > + name[1] = 'i'; > + namelen = 2; > + } > + else > + { > + *type = DW_ATE_signed; > + *bits = 32; > + name[0] = 'l'; > + name[1] = 'o'; > + namelen = 2; > + } > + > + name[namelen++] = '\0'; > + return namelen; > +} OK, but indentation seems slightly off. space vs tabs? > diff --git a/backends/mips_retval.c b/backends/mips_retval.c > new file mode 100644 > index 00000000..fd9aaefa > --- /dev/null > +++ b/backends/mips_retval.c > @@ -0,0 +1,261 @@ > +/* Function return value location for Linux/mips ABI. > + Copyright (C) 2005 Red Hat, Inc. > + Copyright (C) 2023 CIP United Inc. > + This file is part of elfutils. > + > + This file is free software; you can redistribute it and/or modify > + it under the terms of either > + > + * the GNU Lesser General Public License as published by the Free > + Software Foundation; either version 3 of the License, or (at > + your option) any later version > + > + or > + > + * the GNU General Public License as published by the Free > + Software Foundation; either version 2 of the License, or (at > + your option) any later version > + > + or both in parallel, as here. > + > + elfutils is distributed in the hope that it will be useful, but > + WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + General Public License for more details. > + > + You should have received copies of the GNU General Public License and > + the GNU Lesser General Public License along with this program. If > + not, see <http://www.gnu.org/licenses/>. */ > + > +#ifdef HAVE_CONFIG_H > +# include <config.h> > +#endif > + > +#include <assert.h> > +#include <dwarf.h> > +#include <string.h> > +#include <elf.h> > +#include <stdio.h> > + > +#define BACKEND mips_ > +#include "libebl_CPU.h" > +#include "libdwP.h" > + > +/* All the possible MIPS ARCHs. */ > +enum mips_arch > + { > + MIPS_ARCH_UNKNOWN = 0, > + MIPS_ARCH_32, > + MIPS_ARCH_64, > + MIPS_ARCH_LAST > + }; > + > +/* Find the mips ARCH of the current file */ > +enum mips_arch find_mips_arch(Elf *elf) > +{ > + GElf_Ehdr ehdr_mem; > + GElf_Ehdr *ehdr = gelf_getehdr (elf, &ehdr_mem); > + > + if (ehdr == NULL) > + return MIPS_ARCH_LAST; > + > + GElf_Word elf_flags = ehdr->e_flags; > + > + /* Check elf_flags to see if it specifies the ARCH being used. */ > + switch ((elf_flags & EF_MIPS_ARCH)) > + { > + case E_MIPS_ARCH_32: > + case EF_MIPS_ARCH_32R2: > + case E_MIPS_ARCH_32R6: > + return MIPS_ARCH_32; > + case E_MIPS_ARCH_64: > + case EF_MIPS_ARCH_64R2: > + case E_MIPS_ARCH_64R6: > + return MIPS_ARCH_64; > + default: > + return MIPS_ARCH_32; > + } > + > + return MIPS_ARCH_UNKNOWN; > +} > > +unsigned int > +mips_arch_regsize (enum mips_arch arch) > +{ > + switch (arch) > + { > + case MIPS_ARCH_32: > + return 4; > + case MIPS_ARCH_64: > + return 8; > + case MIPS_ARCH_UNKNOWN: > + case MIPS_ARCH_LAST: > + default: > + return 0; > + } > +} So this is different from checking ELFCLASS32/64? > +/* $v0 or pair $v0, $v1 */ > +static const Dwarf_Op loc_intreg_o32[] = > + { > + { .atom = DW_OP_reg2 }, { .atom = DW_OP_piece, .number = 4 }, > + { .atom = DW_OP_reg3 }, { .atom = DW_OP_piece, .number = 4 }, > + }; > + > +static const Dwarf_Op loc_intreg[] = > + { > + { .atom = DW_OP_reg2 }, { .atom = DW_OP_piece, .number = 8 }, > + { .atom = DW_OP_reg3 }, { .atom = DW_OP_piece, .number = 8 }, > + }; > +#define nloc_intreg 1 > +#define nloc_intregpair 4 > + > +/* $f0 (float), or pair $f0, $f1 (double). > + * f2/f3 are used for COMPLEX (= 2 doubles) returns in Fortran */ > +static const Dwarf_Op loc_fpreg_o32[] = > + { > + { .atom = DW_OP_regx, .number = 32 }, { .atom = DW_OP_piece, .number = 4 > }, > + { .atom = DW_OP_regx, .number = 33 }, { .atom = DW_OP_piece, .number = 4 > }, > + { .atom = DW_OP_regx, .number = 34 }, { .atom = DW_OP_piece, .number = 4 > }, > + { .atom = DW_OP_regx, .number = 35 }, { .atom = DW_OP_piece, .number = 4 > }, > + }; > + > +/* $f0, or pair $f0, $f2. */ > +static const Dwarf_Op loc_fpreg[] = > + { > + { .atom = DW_OP_regx, .number = 32 }, { .atom = DW_OP_piece, .number = 8 > }, > + { .atom = DW_OP_regx, .number = 34 }, { .atom = DW_OP_piece, .number = 8 > }, > + }; > +#define nloc_fpreg 1 > +#define nloc_fpregpair 4 > +#define nloc_fpregquad 8 > + > +/* The return value is a structure and is actually stored in stack space > + passed in a hidden argument by the caller. But, the compiler > + helpfully returns the address of that space in $v0. */ > +static const Dwarf_Op loc_aggregate[] = > + { > + { .atom = DW_OP_breg2, .number = 0 } > + }; > +#define nloc_aggregate 1 > + > +int > +mips_return_value_location (Dwarf_Die *functypedie, const Dwarf_Op **locp) > +{ > + /* First find the ARCH used by the elf object */ > + enum mips_arch arch = find_mips_arch(functypedie->cu->dbg->elf); > + /* Something went seriously wrong while trying to figure out the ARCH */ > + if (arch == MIPS_ARCH_LAST) > + return -1; > + > + /* We couldn't identify the ARCH, but the file seems valid */ > + if (arch == MIPS_ARCH_UNKNOWN) > + return -3; > + > + unsigned int regsize = mips_arch_regsize (arch); > + if (!regsize) > + return -2; > + > + /* Start with the function's type, and get the DW_AT_type attribute, > + which is the type of the return value. */ > + > + Dwarf_Attribute attr_mem; > + Dwarf_Attribute *attr = dwarf_attr_integrate (functypedie, DW_AT_type, > &attr_mem); > + if (attr == NULL) > + /* The function has no return value, like a `void' function in C. */ > + return 0; > + > + Dwarf_Die die_mem; > + Dwarf_Die *typedie = dwarf_formref_die (attr, &die_mem); > + int tag = dwarf_tag (typedie); > + > + /* Follow typedefs and qualifiers to get to the actual type. */ > + while (tag == DW_TAG_typedef > + || tag == DW_TAG_const_type || tag == DW_TAG_volatile_type > + || tag == DW_TAG_restrict_type) > + { > + attr = dwarf_attr_integrate (typedie, DW_AT_type, &attr_mem); > + typedie = dwarf_formref_die (attr, &die_mem); > + tag = dwarf_tag (typedie); > + } > + > + switch (tag) > + { > + case -1: > + return -1; > + > + case DW_TAG_subrange_type: > + if (! dwarf_hasattr_integrate (typedie, DW_AT_byte_size)) > + { > + attr = dwarf_attr_integrate (typedie, DW_AT_type, &attr_mem); > + typedie = dwarf_formref_die (attr, &die_mem); > + tag = dwarf_tag (typedie); > + } > + /* Fall through. */ > + FALLTHROUGH; > + > + case DW_TAG_base_type: > + case DW_TAG_enumeration_type: > + CASE_POINTER: > + { > + Dwarf_Word size; > + if (dwarf_formudata (dwarf_attr_integrate (typedie, DW_AT_byte_size, > + &attr_mem), &size) != 0) > + { > + if (dwarf_is_pointer (tag)) > + size = regsize; > + else > + return -1; > + } > + if (tag == DW_TAG_base_type) > + { > + Dwarf_Word encoding; > + if (dwarf_formudata (dwarf_attr_integrate (typedie, DW_AT_encoding, > + &attr_mem), &encoding) != 0) > + return -1; > + > +#define ARCH_LOC(loc, regsize) ((regsize) == 4 ? (loc ## _o32) : (loc)) > + > + if (encoding == DW_ATE_float) > + { > + *locp = ARCH_LOC(loc_fpreg, regsize); > + if (size <= regsize) > + return nloc_fpreg; > + > + if (size <= 2*regsize) > + return nloc_fpregpair; > + > + if (size <= 4*regsize && arch == MIPS_ARCH_32) > + return nloc_fpregquad; > + > + goto aggregate; > + } > + } > + *locp = ARCH_LOC(loc_intreg, regsize); > + if (size <= regsize) > + return nloc_intreg; > + if (size <= 2*regsize) > + return nloc_intregpair; > + > + /* Else fall through. Shouldn't happen though (at least with gcc) */ > + } > + FALLTHROUGH; > + > + case DW_TAG_structure_type: > + case DW_TAG_class_type: > + case DW_TAG_union_type: > + case DW_TAG_array_type: > + aggregate: > + /* XXX TODO: Can't handle structure return with other ABI's yet :-/ */ > + if ((arch != MIPS_ARCH_32) && (arch != MIPS_ARCH_64)) > + return -2; > + > + *locp = loc_aggregate; > + return nloc_aggregate; > + } > + > + /* XXX We don't have a good way to return specific errors from ebl calls. > + This value means we do not understand the type, but it is well-formed > + DWARF and might be valid. */ > + return -2; > +} OK. This looks plausible. Would be good to have a reference to the actual calling convention. Thanks, Mark
