[patch] Fix internal error on canonicalization of clang types [Re: why in cplus_demangle_operators operation sizeof is expected to be followed with space]

Jan Kratochvil
2012-09-17T06:27:14Z

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On Mon, 17 Sep 2012 07:49:16 +0200, Vasyl Vavrychuk wrote:
> This looks to be not a symbol but type name.

OK, reproduced [attached], patched DWARF of "int" in C++: void f(int i) {}

> But I have found it directly in the binary. Line containing this text looks like

readelf -wi
<1><59>: Abbrev Number: 4 (DW_TAG_base_type)
<5c> DW_AT_name : exact_unsigned_base_helper<sizeof(unsigned int) * 8>

> Do you think the problem is in clang? Could you point out some
> specification, so I can reference it while contacting clang people.

Itanium C++ ABI does not say anything about spacing:
http://www.swag.uwaterloo.ca/acd/docs/ItaniumC++ABI.htm
(the original URL is 404 now)

I guess so far it is only agreed upon between GCC and GDB, it is true GDB
should accept any valid spacing of the language, this is also what
cp_canonicalize_string is there for.

Your patch would belons to the GCC mailing lists where libiberty/ is
maintained.

But I find more correct patch the one below.

For a testcase could you provide a minimal C++ code to produce such type?

No regressions on {x86_64,x86_64-m32,i686}-fedora18-linux-gnu.

Thanks,
Jan

gdb/
2012-09-17 Jan Kratochvil <jan.kratochvil@redhat.com>

Fix internal error on canonicalization of clang types.
* cp-name-parser.y (exp): Use "sizeof ".

diff --git a/gdb/cp-name-parser.y b/gdb/cp-name-parser.y
index 6767fa5..c57ce64 100644
--- a/gdb/cp-name-parser.y
+++ b/gdb/cp-name-parser.y
@@ -1183,7 +1183,7 @@ exp : FLOAT
;

exp : SIZEOF '(' type ')' %prec UNARY
- { $$ = d_unary ("sizeof", $3); }
+ { $$ = d_unary ("sizeof ", $3); }
;

/* C++. */

[-- Attachment #2: type.S --]
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.file "type.C"
.text
.Ltext0:
.globl _Z1fi
.type _Z1fi, @function
_Z1fi:
.LFB0:
.file 1 "type.C"
# type.C:1
.loc 1 1 0
.cfi_startproc
# BLOCK 2 seq:0
# PRED: ENTRY (fallthru)
pushq %rbp
.cfi_def_cfa_offset 16
.cfi_offset 6, -16
movq %rsp, %rbp
.cfi_def_cfa_register 6
movl %edi, -4(%rbp)
# type.C:1
.loc 1 1 0
popq %rbp
.cfi_def_cfa 7, 8
# SUCC: EXIT [100.0%]
ret
.cfi_endproc
.LFE0:
.size _Z1fi, .-_Z1fi
.Letext0:
.section .debug_info,"",@progbits
.Ldebug_info0:
.long 1f-2f # Length of Compilation Unit Info
2:
.value 0x4 # DWARF version number
.long .Ldebug_abbrev0 # Offset Into Abbrev. Section
.byte 0x8 # Pointer Size (in bytes)
.uleb128 0x1 # (DIE (0xb) DW_TAG_compile_unit)
.long .LASF0 # DW_AT_producer: "GNU C++ 4.7.1 20120720 (Red Hat 4.7.1-5) -mtune=generic -march=x86-64 -g"
.byte 0x4 # DW_AT_language
.long .LASF1 # DW_AT_name: "type.C"
.long .LASF2 # DW_AT_comp_dir: "/home/jkratoch/t"
.quad .Ltext0 # DW_AT_low_pc
.quad .Letext0 # DW_AT_high_pc
.long .Ldebug_line0 # DW_AT_stmt_list
.uleb128 0x2 # (DIE (0x2d) DW_TAG_subprogram)
# DW_AT_external
.ascii "f\0" # DW_AT_name
.byte 0x1 # DW_AT_decl_file (type.C)
.byte 0x1 # DW_AT_decl_line
.long .LASF3 # DW_AT_linkage_name: "_Z1fi"
.quad .LFB0 # DW_AT_low_pc
.quad .LFE0 # DW_AT_high_pc
.uleb128 0x1 # DW_AT_frame_base
.byte 0x9c # DW_OP_call_frame_cfa
# DW_AT_GNU_all_call_sites
.long 0x59 # DW_AT_sibling
.uleb128 0x3 # (DIE (0x4c) DW_TAG_formal_parameter)
.ascii "i\0" # DW_AT_name
.byte 0x1 # DW_AT_decl_file (type.C)
.byte 0x1 # DW_AT_decl_line
.long 0x59 # DW_AT_type
.uleb128 0x2 # DW_AT_location
.byte 0x91 # DW_OP_fbreg
.sleb128 -20
.byte 0 # end of children of DIE 0x2d
.uleb128 0x4 # (DIE (0x59) DW_TAG_base_type)
.byte 0x4 # DW_AT_byte_size
.byte 0x5 # DW_AT_encoding
#if 0
.ascii "int\0" # DW_AT_name
#else
.ascii "exact_unsigned_base_helper<sizeof(unsigned int) * 8>\0" # DW_AT_name
#endif
.byte 0 # end of children of DIE 0xb
1:
.section .debug_abbrev,"",@progbits
.Ldebug_abbrev0:
.uleb128 0x1 # (abbrev code)
.uleb128 0x11 # (TAG: DW_TAG_compile_unit)
.byte 0x1 # DW_children_yes
.uleb128 0x25 # (DW_AT_producer)
.uleb128 0xe # (DW_FORM_strp)
.uleb128 0x13 # (DW_AT_language)
.uleb128 0xb # (DW_FORM_data1)
.uleb128 0x3 # (DW_AT_name)
.uleb128 0xe # (DW_FORM_strp)
.uleb128 0x1b # (DW_AT_comp_dir)
.uleb128 0xe # (DW_FORM_strp)
.uleb128 0x11 # (DW_AT_low_pc)
.uleb128 0x1 # (DW_FORM_addr)
.uleb128 0x12 # (DW_AT_high_pc)
.uleb128 0x1 # (DW_FORM_addr)
.uleb128 0x10 # (DW_AT_stmt_list)
.uleb128 0x17 # (DW_FORM_sec_offset)
.byte 0
.byte 0
.uleb128 0x2 # (abbrev code)
.uleb128 0x2e # (TAG: DW_TAG_subprogram)
.byte 0x1 # DW_children_yes
.uleb128 0x3f # (DW_AT_external)
.uleb128 0x19 # (DW_FORM_flag_present)
.uleb128 0x3 # (DW_AT_name)
.uleb128 0x8 # (DW_FORM_string)
.uleb128 0x3a # (DW_AT_decl_file)
.uleb128 0xb # (DW_FORM_data1)
.uleb128 0x3b # (DW_AT_decl_line)
.uleb128 0xb # (DW_FORM_data1)
.uleb128 0x6e # (DW_AT_linkage_name)
.uleb128 0xe # (DW_FORM_strp)
.uleb128 0x11 # (DW_AT_low_pc)
.uleb128 0x1 # (DW_FORM_addr)
.uleb128 0x12 # (DW_AT_high_pc)
.uleb128 0x1 # (DW_FORM_addr)
.uleb128 0x40 # (DW_AT_frame_base)
.uleb128 0x18 # (DW_FORM_exprloc)
.uleb128 0x2117 # (DW_AT_GNU_all_call_sites)
.uleb128 0x19 # (DW_FORM_flag_present)
.uleb128 0x1 # (DW_AT_sibling)
.uleb128 0x13 # (DW_FORM_ref4)
.byte 0
.byte 0
.uleb128 0x3 # (abbrev code)
.uleb128 0x5 # (TAG: DW_TAG_formal_parameter)
.byte 0 # DW_children_no
.uleb128 0x3 # (DW_AT_name)
.uleb128 0x8 # (DW_FORM_string)
.uleb128 0x3a # (DW_AT_decl_file)
.uleb128 0xb # (DW_FORM_data1)
.uleb128 0x3b # (DW_AT_decl_line)
.uleb128 0xb # (DW_FORM_data1)
.uleb128 0x49 # (DW_AT_type)
.uleb128 0x13 # (DW_FORM_ref4)
.uleb128 0x2 # (DW_AT_location)
.uleb128 0x18 # (DW_FORM_exprloc)
.byte 0
.byte 0
.uleb128 0x4 # (abbrev code)
.uleb128 0x24 # (TAG: DW_TAG_base_type)
.byte 0 # DW_children_no
.uleb128 0xb # (DW_AT_byte_size)
.uleb128 0xb # (DW_FORM_data1)
.uleb128 0x3e # (DW_AT_encoding)
.uleb128 0xb # (DW_FORM_data1)
.uleb128 0x3 # (DW_AT_name)
.uleb128 0x8 # (DW_FORM_string)
.byte 0
.byte 0
.byte 0
.section .debug_aranges,"",@progbits
.long 0x2c # Length of Address Ranges Info
.value 0x2 # DWARF Version
.long .Ldebug_info0 # Offset of Compilation Unit Info
.byte 0x8 # Size of Address
.byte 0 # Size of Segment Descriptor
.value 0 # Pad to 16 byte boundary
.value 0
.quad .Ltext0 # Address
.quad .Letext0-.Ltext0 # Length
.quad 0
.quad 0
.section .debug_line,"",@progbits
.Ldebug_line0:
.section .debug_str,"MS",@progbits,1
.LASF1:
.string "type.C"
.LASF2:
.string "/home/jkratoch/t"
.LASF0:
.string "GNU C++ 4.7.1 20120720 (Red Hat 4.7.1-5) -mtune=generic -march=x86-64 -g"
.LASF3:
.string "_Z1fi"
.ident "GCC: (GNU) 4.7.1 20120720 (Red Hat 4.7.1-5)"
.section .note.GNU-stack,"",@progbits