/* This testcase is part of GDB, the GNU debugger. Copyright 2012-2023 Free Software Foundation, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program 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 a copy of the GNU General Public License along with this program. If not, see . */ /* Test the behaviour of gdb in the following situation, the dwarf debug information describes a parameter as being in a register but a more recent (inner) frame marks the register as being undefined. This can arrise if the dwarf producer has the location of a parameter in a callee clobbered register at the time of a call. Older versions of gcc used to do this, newer versions seem to avoid this issue. Though it could be argued that such dwarf is incorrect, we would still like gdb to behave in a user friendly, and helpful way when presented with such dwarf. */ /* There are 4 test cases in this assembler file. In each case function main calls each test function in turn, each test case then calls the breakpt function. We don't actually pass any parameters around, we don't need to, instead the dwarf for each test function declares that the function has some parameters, and tells us which registers these parameters are in. The breakpt function marks some of these registers as undefined. The main function helpfully places some marker values into all the registers that are used as parameters so we can see if they ever get printed. We use gdb to break in the breakpt function for each of the 4 test cases, and then backtrace through the test function back to main. In each case some or all of the parameters to the test function should be marked as optimized out, due to the breakpt function effectively clobbering them. The dwarf register numbering is different to the gdb register number. In some of the tests we rely on gdb behaviour of being able to specify a struct using a single register location, the structure will then "flow" into the next gdb register. The initial register is specified using a dwarf register number, but the "next" register will depend on gdb register ordering. Exposing this internal gdb register numbering is really a gdb bug, the functionality for selecting the "next" register should be moved into target dependent code (such as AVR). Right now we work around this bug in this test; if the bug is ever fixed this test is going to need some tweaking. The breakpt function always marks rcx, rsi, and rdi as undefined. register | dwarf | gdb | | name | reg # | reg # | breakpt | ----------|-------|-------|---------| rdx | 1 | 3 | | rcx | 2 | 2 | undef | rbx | 3 | 1 | | rsi | 4 | 4 | undef | rdi | 5 | 5 | undef | We declare the test parameters to be in the register rdx, rcx, rbx, rsi, and rdi. Of these, rdx and rbx are not traditionally used for parameter passing, but that really doesn't matter for this test. int_param_single_reg_loc: Passes 8-byte integer parameters in 8-byte registers using DW_OP_regn style location information. The parameters are placed as follows, operand0 (rcx), operand1 (rbx), operand2 (rsi). We expect operand0 and operand2 to be marked as optimised out, but operand1 to be valid. struct_param_single_reg_loc: Passes 16-byte structures in two 8-byte registers using dwarf DW_OP_regn location information to describe a single register, gdb will assume that the structure flows into the next sequential register. The parameters are placed as follows, operand0 (rbx/rcx), operand1 (rcx/rdx), and operand2 (rsi/rdi). The reuse of rcx between operand0 and operand1 is intentional. struct_param_two_reg_pieces: Passes 16-byte structure in two 8-byte registers using dwarf DW_OP_piece based location information to describe both registers. The parameters are placed as follows, operand0 (rdx/rcx), operand1 (rcx/rbx), and operand2 (rsi/rdi). The reuse of rcx between operand0 and operand1 is intentional. int_param_two_reg_pieces: Passes 8-byte integer values in two 8-byte registers with 4-bytes being placed in each register, using dwarf DW_OP_piece based location information to describe how the parameters are split up.The parameters are placed as follows, operand0 (rdx/rcx), operand1 (rcx/rbx), and operand2 (rsi/rdi). The reuse of rcx between operand0 and operand1 is intentional. */ .text .Ltext0: /* main */ .globl main .type main, @function main: .Ltext1: sub $0x8,%rsp .Ltext2: movq $0xdeadbe00deadbe01, %rbx movq $0xdeadbe02deadbe03, %rcx movq $0xdeadbe04deadbe05, %rdx movq $0xdeadbe06deadbe07, %rsi movq $0xdeadbe08deadbe09, %rdi callq int_param_single_reg_loc nop callq struct_param_single_reg_loc nop callq struct_param_two_reg_pieces nop callq int_param_two_reg_pieces nop add $0x8,%rsp retq .Ltext3: .size main, .-main /* breakpt */ .globl breakpt .type breakpt, @function breakpt: .Ltext4: sub $0x8,%rsp add $0x8, %rsp retq .Ltext5a: .size breakpt, .-breakpt /* int_param_single_reg_loc */ .globl int_param_single_reg_loc .type int_param_single_reg_loc, @function int_param_single_reg_loc: .Ltext5b: sub $0x8,%rsp .Ltext6: nop callq breakpt nop add $0x8,%rsp retq .Ltext7: .size int_param_single_reg_loc, .-int_param_single_reg_loc /* struct_param_single_reg_loc */ .globl struct_param_single_reg_loc .type struct_param_single_reg_loc, @function struct_param_single_reg_loc: .Ltext8: sub $0x8,%rsp .Ltext9: nop callq breakpt nop add $0x8,%rsp retq .Ltext10: .size struct_param_single_reg_loc, .-struct_param_single_reg_loc /* struct_param_two_reg_pieces */ .globl struct_param_two_reg_pieces .type struct_param_two_reg_pieces, @function struct_param_two_reg_pieces: .Ltext11: sub $0x8,%rsp .Ltext12: nop callq breakpt nop add $0x8,%rsp retq .Ltext13: .size struct_param_two_reg_pieces, .-struct_param_two_reg_pieces /* int_param_two_reg_pieces */ .globl int_param_two_reg_pieces .type int_param_two_reg_pieces, @function int_param_two_reg_pieces: .Ltext14: sub $0x8,%rsp .Ltext15: nop callq breakpt nop add $0x8,%rsp retq .Ltext16: .size int_param_two_reg_pieces, .-int_param_two_reg_pieces .Letext0: /*******************************************************/ .section .debug_frame,"",@progbits /* CIE */ .Lframe0: .long .LECIE0-.LSCIE0 /* length */ .LSCIE0: .long 0xffffffff /* CIE_id */ .byte 0x1 /* version */ .string "" /* augmentation */ .uleb128 0x1 /* code alignment */ .sleb128 -8 /* data alignment */ .byte 0x10 /* R/A column */ /* Initial instructions */ .byte 0xc /* DW_CFA_def_cfa */ .uleb128 0x7 /* reg# */ .uleb128 0x8 /* offset */ .byte 0x90 /* DW_CFA_offset (r16) */ .uleb128 0x1 /* offset */ .align 8 .LECIE0: /* FDE : breakpt */ .LSFDE0: .long .LEFDE0-.LASFDE0 /* length */ .LASFDE0: .long .Lframe0 /* CIE reference */ .quad .Ltext4 /* start */ .quad .Ltext5a-.Ltext4 /* length */ /* Instructions */ .byte 0x7 /* DW_CFA_undefined */ .uleb128 0x2 /* reg# */ .byte 0x7 /* DW_CFA_undefined */ .uleb128 0x4 /* reg# */ .byte 0x7 /* DW_CFA_undefined */ .uleb128 0x5 /* reg# */ .align 8 .LEFDE0: /* FDE : int_param_single_reg_loc */ .LSFDE2: .long .LEFDE2-.LASFDE2 /* length */ .LASFDE2: .long .Lframe0 /* CIE reference */ .quad .Ltext5b /* start */ .quad .Ltext7-.Ltext5b /* length */ /* Instructions */ .byte 0x4 .long .Ltext6-.Ltext5b .byte 0xe .uleb128 0x10 .align 8 .LEFDE2: /* FDE : struct_param_single_reg_loc */ .LSFDE3: .long .LEFDE3-.LASFDE3 /* length */ .LASFDE3: .long .Lframe0 /* CIE reference */ .quad .Ltext8 /* start */ .quad .Ltext10-.Ltext8 /* length */ /* Instructions */ .byte 0x4 .long .Ltext9-.Ltext8 .byte 0xe .uleb128 0x10 .align 8 .LEFDE3: /* FDE : struct_param_two_reg_pieces */ .LSFDE4: .long .LEFDE4-.LASFDE4 /* length */ .LASFDE4: .long .Lframe0 /* CIE reference */ .quad .Ltext11 /* start */ .quad .Ltext13-.Ltext11 /* length */ /* Instructions */ .byte 0x4 .long .Ltext12-.Ltext11 .byte 0xe .uleb128 0x10 .align 8 .LEFDE4: /* FDE : int_param_two_reg_pieces */ .LSFDE5: .long .LEFDE5-.LASFDE5 /* length */ .LASFDE5: .long .Lframe0 /* CIE reference */ .quad .Ltext14 /* start */ .quad .Ltext16-.Ltext14 /* length */ /* Instructions */ .byte 0x4 .long .Ltext15-.Ltext14 .byte 0xe .uleb128 0x10 .align 8 .LEFDE5: /* FDE : main */ .LSFDE9: .long .LEFDE9-.LASFDE9 /* length */ .LASFDE9: .long .Lframe0 /* CIE reference */ .quad .Ltext1 /* start */ .quad .Ltext3-.Ltext1 /* length */ /* Instructions */ .byte 0x4 .long .Ltext2-.Ltext1 .byte 0xe .uleb128 0x10 .align 8 .LEFDE9: /*******************************************************/ .section .debug_info,"",@progbits .Ldebug_info0: .long .Ldebug_info_end - .Ldebug_info_start /* Length */ .Ldebug_info_start: .value 0x2 /* DWARF version number. */ .long .Ldebug_abbrev0 /* Offset into .debug_abbrev */ .byte 0x8 /* Pointer size */ .LDI0: .uleb128 0x1 /* DW_TAG_compile_unit */ .string "GNU C 4.2.1" /* DW_AT_producer */ .byte 0x1 /* DW_AT_language */ .quad .Ltext0 /* DW_AT_low_pc */ .quad .Letext0 /* DW_AT_high_pc */ .LDI1: .uleb128 0x2 /* DW_TAG_subprogram */ .byte 0x1 /* DW_AT_external */ .string "breakpt" /* DW_AT_name */ .byte 0x1 /* DW_AT_prototyped */ .quad .Ltext4 /* DW_AT_low_pc */ .quad .Ltext5a /* DW_AT_high_pc */ .LDI2: .uleb128 0x5 /* DW_TAG_base_type */ .byte 0x8 /* DW_AT_byte_size */ .byte 0x5 /* DW_AT_encoding (DW_ATE_signed) */ .string "long int" /* DW_AT_name */ .LDI3: .uleb128 0x7 /* DW_TAG_structure_type */ .string "big" /* DW_AT_name */ .byte 0x10 /* DW_AT_byte_size */ .long .LDI6 - .Ldebug_info0 /* DW_AT_sibling */ .LDI4: .uleb128 0x8 /* DW_TAG_member */ .string "a" /* DW_AT_name */ .long .LDI2 - .Ldebug_info0 /* DW_AT_type */ .byte 0x2 /* DW_AT_data_member_location : length */ .byte 0x23 /* DW_OP_plus_uconst */ .uleb128 0x0 /* + 0 */ .LDI5: .uleb128 0x8 /* DW_TAG_member */ .string "b" /* DW_AT_name */ .long .LDI2 - .Ldebug_info0 /* DW_AT_type */ .byte 0x2 /* DW_AT_data_member_location : length */ .byte 0x23 /* DW_OP_plus_uconst */ .uleb128 0x8 /* + 8 */ .byte 0x0 .LDI6: .uleb128 0x6 /* DW_TAG_subprogram */ .byte 0x1 /* DW_AT_external */ .string "main" /* DW_AT_name */ .long .LDI2 - .Ldebug_info0 /* DW_AT_type */ .quad .Ltext1 /* DW_AT_low_pc */ .quad .Ltext3 /* DW_AT_high_pc */ .LDI7: .uleb128 0x3 /* DW_TAG_subprogram */ .byte 0x1 /* DW_AT_external */ .string "int_param_single_reg_loc" /* DW_AT_name */ .byte 0x1 /* DW_AT_prototyped */ .quad .Ltext5b /* DW_AT_low_pc */ .quad .Ltext7 /* DW_AT_high_pc */ .long .LDI11 - .Ldebug_info0 /* DW_AT_sibling */ .LDI8: .uleb128 0x4 /* DW_TAG_formal_parameter */ .string "operand0" /* DW_AT_name */ .long .LDI2 - .Ldebug_info0 /* DW_AT_type */ .byte 1 /* DW_AT_location : length */ .byte 0x52 /* DW_OP_reg2 */ .LDI9: .uleb128 0x4 /* DW_TAG_formal_parameter */ .string "operand1" /* DW_AT_name */ .long .LDI2 - .Ldebug_info0 /* DW_AT_type */ .byte 1 /* DW_AT_location : length */ .byte 0x53 /* DW_OP_reg3 */ .LDI10: .uleb128 0x4 /* DW_TAG_formal_parameter */ .string "operand2" /* DW_AT_name */ .long .LDI2 - .Ldebug_info0 /* DW_AT_type */ .byte 1 /* DW_AT_location : length */ .byte 0x54 /* DW_OP_reg4 */ .byte 0x0 .LDI11: .uleb128 0x3 /* DW_TAG_subprogram */ .byte 0x1 /* DW_AT_external */ .string "struct_param_single_reg_loc" /* DW_AT_name */ .byte 0x1 /* DW_AT_prototyped */ .quad .Ltext8 /* DW_AT_low_pc */ .quad .Ltext10 /* DW_AT_high_pc */ .long .LDI15 - .Ldebug_info0 /* DW_AT_sibling */ .LDI12: .uleb128 0x4 /* DW_TAG_formal_parameter */ .string "operand0" /* DW_AT_name */ .long .LDI3 - .Ldebug_info0 /* DW_AT_type */ .byte 1 /* DW_AT_location : length */ .byte 0x53 /* DW_OP_reg3 */ .LDI13: .uleb128 0x4 /* DW_TAG_formal_parameter */ .string "operand1" /* DW_AT_name */ .long .LDI3 - .Ldebug_info0 /* DW_AT_type */ .byte 1 /* DW_AT_location : length */ .byte 0x52 /* DW_OP_reg2 */ .LDI14: .uleb128 0x4 /* DW_TAG_formal_parameter */ .string "operand2" /* DW_AT_name */ .long .LDI3 - .Ldebug_info0 /* DW_AT_type */ .byte 1 /* DW_AT_location : length */ .byte 0x54 /* DW_OP_reg4 */ .byte 0x0 .LDI15: .uleb128 0x3 /* DW_TAG_subprogram */ .byte 0x1 /* DW_AT_external */ .string "struct_param_two_reg_pieces" /* DW_AT_name */ .byte 0x1 /* DW_AT_prototyped */ .quad .Ltext11 /* DW_AT_low_pc */ .quad .Ltext13 /* DW_AT_high_pc */ .long .LDI19 - .Ldebug_info0 /* DW_AT_sibling */ .LDI16: .uleb128 0x4 /* DW_TAG_formal_parameter */ .string "operand0" /* DW_AT_name */ .long .LDI3 - .Ldebug_info0 /* DW_AT_type */ .byte 6 /* DW_AT_location : length */ .byte 0x51 /* DW_OP_reg1 */ .byte 0x93 /* DW_OP_piece */ .uleb128 0x8 /* 8 bytes */ .byte 0x52 /* DW_OP_reg2 */ .byte 0x93 /* DW_OP_piece */ .uleb128 0x8 /* 8 bytes */ .LDI17: .uleb128 0x4 /* DW_TAG_formal_parameter */ .string "operand1" /* DW_AT_name */ .long .LDI3 - .Ldebug_info0 /* DW_AT_type */ .byte 6 /* DW_AT_location : length */ .byte 0x52 /* DW_OP_reg2 */ .byte 0x93 /* DW_OP_piece */ .uleb128 0x8 /* 8 bytes */ .byte 0x53 /* DW_OP_reg3 */ .byte 0x93 /* DW_OP_piece */ .uleb128 0x8 /* 8 bytes */ .LDI18: .uleb128 0x4 /* DW_TAG_formal_parameter */ .string "operand2" /* DW_AT_name */ .long .LDI3 - .Ldebug_info0 /* DW_AT_type */ .byte 6 /* DW_AT_location : length */ .byte 0x54 /* DW_OP_reg4 */ .byte 0x93 /* DW_OP_piece */ .uleb128 0x8 /* 8 bytes */ .byte 0x55 /* DW_OP_reg5 */ .byte 0x93 /* DW_OP_piece */ .uleb128 0x8 /* 8 bytes */ .byte 0x0 .LDI19: .uleb128 0x3 /* DW_TAG_subprogram */ .byte 0x1 /* DW_AT_external */ .string "int_param_two_reg_pieces" /* DW_AT_name */ .byte 0x1 /* DW_AT_prototyped */ .quad .Ltext14 /* DW_AT_low_pc */ .quad .Ltext16 /* DW_AT_high_pc */ .long .LDIE0 - .Ldebug_info0 /* DW_AT_sibling */ .LDI20: .uleb128 0x4 /* DW_TAG_formal_parameter */ .string "operand0" /* DW_AT_name */ .long .LDI2 - .Ldebug_info0 /* DW_AT_type */ .byte 6 /* DW_AT_location : length */ .byte 0x51 /* DW_OP_reg1 */ .byte 0x93 /* DW_OP_piece */ .uleb128 0x4 /* 4 bytes */ .byte 0x52 /* DW_OP_reg2 */ .byte 0x93 /* DW_OP_piece */ .uleb128 0x4 /* 4 bytes */ .LDI21: .uleb128 0x4 /* DW_TAG_formal_parameter */ .string "operand1" /* DW_AT_name */ .long .LDI2 - .Ldebug_info0 /* DW_AT_type */ .byte 6 /* DW_AT_location : length */ .byte 0x52 /* DW_OP_reg2 */ .byte 0x93 /* DW_OP_piece */ .uleb128 0x4 /* 4 bytes */ .byte 0x53 /* DW_OP_reg3 */ .byte 0x93 /* DW_OP_piece */ .uleb128 0x4 /* 4 bytes */ .LDI22: .uleb128 0x4 /* DW_TAG_formal_parameter */ .string "operand2" /* DW_AT_name */ .long .LDI2 - .Ldebug_info0 /* DW_AT_type */ .byte 6 /* DW_AT_location : length */ .byte 0x54 /* DW_OP_reg4 */ .byte 0x93 /* DW_OP_piece */ .uleb128 0x4 /* 4 bytes */ .byte 0x55 /* DW_OP_reg5 */ .byte 0x93 /* DW_OP_piece */ .uleb128 0x4 /* 4 bytes */ .byte 0x0 .LDIE0: .byte 0x0 .Ldebug_info_end: /*******************************************************/ .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 0x8 /* DW_FORM_string */ .uleb128 0x13 /* DW_AT_language */ .uleb128 0xb /* DW_FORM_data1 */ .uleb128 0x11 /* DW_AT_low_pc */ .uleb128 0x1 /* DW_FORM_addr */ .uleb128 0x12 /* DW_AT_high_pc */ .uleb128 0x1 /* DW_FORM_addr */ .byte 0x0 .byte 0x0 .uleb128 0x2 /* abbrev code */ .uleb128 0x2e /* TAG: DW_TAG_subprogram */ .byte 0x0 /* DW_CHILDREN_no */ .uleb128 0x3f /* DW_AT_external */ .uleb128 0xc /* DW_FORM_flag */ .uleb128 0x3 /* DW_AT_name */ .uleb128 0x8 /* DW_FORM_string */ .uleb128 0x27 /* DW_AT_prototyped */ .uleb128 0xc /* DW_FORM_flag*/ .uleb128 0x11 /* DW_AT_low_pc */ .uleb128 0x1 /* DW_FORM_addr */ .uleb128 0x12 /* DW_AT_high_pc */ .uleb128 0x1 /* DW_FORM_addr */ .byte 0x0 .byte 0x0 .uleb128 0x3 /* abbrev code */ .uleb128 0x2e /* TAG: DW_TAG_subprogram */ .byte 0x1 /* DW_CHILDREN_yes */ .uleb128 0x3f /* DW_AT_external */ .uleb128 0xc /* DW_FORM_flag */ .uleb128 0x3 /* DW_AT_name */ .uleb128 0x8 /* DW_FORM_string */ .uleb128 0x27 /* DW_AT_prototyped */ .uleb128 0xc /* DW_FORM_flag*/ .uleb128 0x11 /* DW_AT_low_pc */ .uleb128 0x1 /* DW_FORM_addr */ .uleb128 0x12 /* DW_AT_high_pc */ .uleb128 0x1 /* DW_FORM_addr */ .uleb128 0x1 /* DW_AT_sibling */ .uleb128 0x13 /* DW_FORM_ref4 */ .byte 0x0 .byte 0x0 .uleb128 0x4 /* abbrev code */ .uleb128 0x5 /* TAG: DW_TAG_formal_parameter */ .byte 0x0 /* DW_CHILDREN_no */ .uleb128 0x3 /* DW_AT_name */ .uleb128 0x8 /* DW_FORM_string */ .uleb128 0x49 /* DW_AT_type */ .uleb128 0x13 /* DW_FORM_ref4 */ .uleb128 0x2 /* DW_AT_location */ .uleb128 0xa /* DW_FORM_block1 */ .byte 0x0 .byte 0x0 .uleb128 0x5 /* abbrev code */ .uleb128 0x24 /* TAG: DW_TAG_base_type */ .byte 0x0 /* 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 0x0 .byte 0x0 .uleb128 0x6 /* abbrev code */ .uleb128 0x2e /* TAG: DW_TAG_subprogram */ .byte 0x0 /* DW_CHILDREN_no */ .uleb128 0x3f /* DW_AT_external */ .uleb128 0xc /* DW_FORM_flag */ .uleb128 0x3 /* DW_AT_name */ .uleb128 0x8 /* DW_FORM_string */ .uleb128 0x49 /* DW_AT_type */ .uleb128 0x13 /* DW_FORM_ref4 */ .uleb128 0x11 /* DW_AT_low_pc */ .uleb128 0x1 /* DW_FORM_addr */ .uleb128 0x12 /* DW_AT_high_pc */ .uleb128 0x1 /* DW_FORM_addr */ .byte 0x0 .byte 0x0 .uleb128 0x7 /* abbrev code */ .uleb128 0x13 /* DW_TAG_structure_type */ .byte 0x1 /* DW_CHILDREN_yes */ .uleb128 0x3 /* DW_AT_name */ .uleb128 0x8 /* DW_FORM_string */ .uleb128 0xb /* DW_AT_byte_size */ .uleb128 0xb /* DW_FORM_data1 */ .uleb128 0x1 /* DW_AT_sibling */ .uleb128 0x13 /* DW_FORM_ref4 */ .byte 0x0 .byte 0x0 .uleb128 0x8 /* abbrev code */ .uleb128 0xd /* DW_TAG_member */ .byte 0x0 /* DW_children_no */ .uleb128 0x3 /* DW_AT_name */ .uleb128 0x8 /* DW_FORM_string */ .uleb128 0x49 /* DW_AT_type */ .uleb128 0x13 /* DW_FORM_ref4 */ .uleb128 0x38 /* DW_AT_data_member_location */ .uleb128 0xa /* DW_FORM_block1 */ .byte 0x0 .byte 0x0 .byte 0x0 .section .note.GNU-stack,"",@progbits