gdb/testsuite/gdb.dwarf2/variant.exp

# Copyright 2018-2026 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.
#
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# along with this program.  If not, see <http://www.gnu.org/licenses/>.

# Test DW_TAG_variant_part and DW_TAG_variant.

load_lib dwarf.exp

# This test can only be run on targets which support DWARF-2 and use
# gas.
require dwarf2_support

standard_testfile .c .S

# Make some DWARF for the test.
set asm_file [standard_output_file $srcfile2]
Dwarf::assemble $asm_file {
    upvar cu_lang cu_lang

    declare_labels uinteger_label float_label int8_label
    declare_labels discr_1_label discr_2_label discr_3_label
    declare_labels one_label two_label

    # Creating a CU with 4-byte addresses lets this test link on
    # both 32- and 64-bit machines.
    cu { addr_size 4 } {
	compile_unit {
	    DW_AT_name file1.txt
	    DW_AT_language @DW_LANG_Rust
	} {
	    uinteger_label: DW_TAG_base_type {
		DW_AT_byte_size 4 DW_FORM_sdata
		DW_AT_encoding	@DW_ATE_unsigned
		DW_AT_name	{unsigned integer}
	    }

	    int8_label: DW_TAG_base_type {
		DW_AT_byte_size 1 DW_FORM_sdata
		DW_AT_encoding	@DW_ATE_signed
		DW_AT_name	i8
	    }

	    float_label: base_type {
		DW_AT_name float
		DW_AT_encoding @DW_ATE_float
		DW_AT_byte_size 4 DW_FORM_sdata
	    }

	    one_label: structure_type {
		DW_AT_name One
		DW_AT_byte_size 4 DW_FORM_sdata
	    } {
		member {
		    DW_AT_name __0
		    DW_AT_type :$uinteger_label
		    DW_AT_data_member_location 0 data1
		}
	    }

	    two_label: structure_type {
		DW_AT_name Two
		DW_AT_byte_size 4 DW_FORM_sdata
	    } {
		member {
		    DW_AT_name __0
		    DW_AT_type :$float_label
		    DW_AT_data_member_location 0 data1
		}
	    }

	    structure_type {
		DW_AT_name Simple
		DW_AT_byte_size 8 DW_FORM_sdata
	    } {
		variant_part {
		    DW_AT_discr :$discr_1_label DW_FORM_ref4
		} {
		    discr_1_label: member {
			DW_AT_type :$uinteger_label
			DW_AT_data_member_location 0 data1
			DW_AT_artificial 1 DW_FORM_flag_present
		    }

		    variant {
			DW_AT_discr_value 23 udata
		    } {
			member {
			    DW_AT_type :$one_label
			    DW_AT_data_member_location 4 data1
			}
		    }

		    variant {
			DW_AT_discr_value 1 udata
		    } {
			member {
			    DW_AT_type :$two_label
			    DW_AT_data_member_location 4 data1
			}
		    }
		}
	    }

	    structure_type {
		DW_AT_name Defaulted
		DW_AT_byte_size 8 DW_FORM_sdata
	    } {
		variant_part {
		    DW_AT_discr :$discr_2_label DW_FORM_ref4
		} {
		    discr_2_label: member {
			DW_AT_type :$uinteger_label
			DW_AT_data_member_location 0 data1
			DW_AT_artificial 1 DW_FORM_flag_present
		    }

		    variant {
		    } {
			member {
			    DW_AT_type :$one_label
			    DW_AT_data_member_location 4 data1
			}
		    }

		    variant {
			DW_AT_discr_value 1 udata
		    } {
			member {
			    DW_AT_type :$two_label
			    DW_AT_data_member_location 4 data1
			}
		    }
		}
	    }

	    structure_type {
		DW_AT_name Univariant
		DW_AT_byte_size 8 DW_FORM_sdata
	    } {
		variant_part {
		} {
		    variant {
		    } {
			member {
			    DW_AT_type :$one_label
			    DW_AT_data_member_location 4 data1
			}
		    }
		}
	    }

	    # Rust won't emit a negative discriminant like this, but
	    # we want to test the code path anyway.
	    structure_type {
		DW_AT_name Negative
		DW_AT_byte_size 8 DW_FORM_sdata
	    } {
		variant_part {
		    DW_AT_discr :$discr_3_label DW_FORM_ref4
		} {
		    discr_3_label: member {
			DW_AT_type :$int8_label
			DW_AT_data_member_location 0 data1
			DW_AT_artificial 1 DW_FORM_flag_present
		    }

		    variant {
			DW_AT_discr_value -1 sdata
		    } {
			member {
			    DW_AT_type :$one_label
			    DW_AT_data_member_location 4 data1
			}
		    }

		    # Make this the default value so we'll see an
		    # incorrect result if we mishandle signed
		    # discriminants.
		    variant {
		    } {
			member {
			    DW_AT_type :$two_label
			    DW_AT_data_member_location 4 data1
			}
		    }
		}
	    }
	}
    }
}

if { [prepare_for_testing "failed to prepare" ${testfile} \
	  [list $srcfile $asm_file] debug] } {
    return
}

if {![runto func]} {
    return
}

# Get the values into history so we can use it from Rust.
gdb_test "print (void *) buffer" "\\\$1 = .void .. $hex .buffer."
gdb_test "print (void *) buffer2" "\\\$2 = .void .. $hex .buffer2."

gdb_test "set language rust"
gdb_test "print *(\$1 as *mut Simple)" " = One\\(23\\)" \
    "print as Simple"
gdb_test "print *(\$1 as *mut Defaulted)" " = One\\(23\\)" \
    "print as Defaulted"
gdb_test "print *(\$1 as *mut Univariant)" " = One\\(23\\)" \
    "print as Univariant"

gdb_test "print *(\$2 as *mut Negative)" " = One\\(23\\)" \
    "print as Negative"