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[binutils.git] / gdb / testsuite / gdb.base / structs.exp

# This testcase is part of GDB, the GNU debugger.

# Copyright 1996-2022 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 <http://www.gnu.org/licenses/>.


# Some targets can't call functions, so don't even bother with this
# test.

if [target_info exists gdb,cannot_call_functions] {
    unsupported "this target can not call functions"
    return
}

standard_testfile .c

# Regex matching any value of `char' type like: a = 65 'A'
set anychar_re {-?[0-9]{1,3} '(.|\\([0-7]{3}|[a-z]|\\|'))'}

set skip_float_test [gdb_skip_float_test]

# Compile a variant of structs.c using TYPES to specify the type of
# the first N struct elements (the remaining elements take the type of
# the last TYPES field).  Run the compmiled program up to "main".
# Also updates the global "testfile" to reflect the most recent build.

set first 1
proc start_structs_test { types } {
    global testfile
    global srcfile
    global binfile
    global subdir
    global srcdir
    global gdb_prompt
    global anychar_re
    global first

    # Create the additional flags
    set flags "debug"
    set testfile "structs"
    set n 0
    for {set n 0} {$n<[llength ${types}]} {incr n} {
	set m [I2A ${n}]
	set t [lindex ${types} $n]
	lappend flags "additional_flags=-Dt${m}=${t}"
	append testfile "-" "$t"
    }

    set binfile [standard_output_file ${testfile}]
    if { [prepare_for_testing "failed to prepare" $binfile $srcfile $flags] } {
	return -1
    }

    # Make certain that the output is consistent
    gdb_test_no_output "set print sevenbit-strings"
    gdb_test_no_output "set print address off"
    gdb_test_no_output "set width 0"
    gdb_test_no_output "set print elements 300"

    # Advance to main
    if {![runto_main]} {
	return
    }

    # Get the debug format
    get_debug_format

    # Limit the slow $anychar_re{256} matching for better performance.
    if $first {
	set first 0

	# Verify $anychar_re can match all the values of `char' type.
	gdb_breakpoint [gdb_get_line_number "chartest-done"]
	gdb_continue_to_breakpoint "chartest-done" ".*chartest-done.*"
	gdb_test_sequence "p chartest" "" \
	    [concat \
		 [list "= \{"] \
		 [lrepeat 255 "^\{c = ${anychar_re}\}, "] \
		 [list "^\{c = ${anychar_re}\}\}"]]
    }

    # check that at the struct containing all the relevant types is correct
    set foo_t "type = struct struct[llength ${types}] \{"
    for {set n 0} {$n<[llength ${types}]} {incr n} {
	append foo_t "\[\r\n \]+[lindex ${types} $n] [i2a $n];"
    }
    append foo_t "\[\r\n \]+\}"
    gdb_test "ptype foo[llength ${types}]" "${foo_t}" \
	    "ptype foo[llength ${types}]; ${testfile}"
}

# The expected value for fun${n}, L${n} and foo${n}.  First element is
# empty to make indexing easier.  "foo" returns the modified value,
# "zed" returns the invalid value.

proc foo { n } {
    return [lindex {
	"{}"
	"{a = 49 '1'}"
	"{a = 97 'a', b = 50 '2'}"
	"{a = 49 '1', b = 98 'b', c = 51 '3'}"
	"{a = 97 'a', b = 50 '2', c = 99 'c', d = 52 '4'}"
	"{a = 49 '1', b = 98 'b', c = 51 '3', d = 100 'd', e = 53 '5'}"
	"{a = 97 'a', b = 50 '2', c = 99 'c', d = 52 '4', e = 101 'e', f = 54 '6'}"
	"{a = 49 '1', b = 98 'b', c = 51 '3', d = 100 'd', e = 53 '5', f = 102 'f', g = 55 '7'}"
	"{a = 97 'a', b = 50 '2', c = 99 'c', d = 52 '4', e = 101 'e', f = 54 '6', g = 103 'g', h = 56 '8'}"
	"{a = 49 '1', b = 98 'b', c = 51 '3', d = 100 'd', e = 53 '5', f = 102 'f', g = 55 '7', h = 104 'h', i = 57 '9'}"
	"{a = 97 'a', b = 50 '2', c = 99 'c', d = 52 '4', e = 101 'e', f = 54 '6', g = 103 'g', h = 56 '8', i = 105 'i', j = 65 'A'}"
	"{a = 49 '1', b = 98 'b', c = 51 '3', d = 100 'd', e = 53 '5', f = 102 'f', g = 55 '7', h = 104 'h', i = 57 '9', j = 106 'j', k = 66 'B'}"
	"{a = 97 'a', b = 50 '2', c = 99 'c', d = 52 '4', e = 101 'e', f = 54 '6', g = 103 'g', h = 56 '8', i = 105 'i', j = 65 'A', k = 107 'k', l = 67 'C'}"
	"{a = 49 '1', b = 98 'b', c = 51 '3', d = 100 'd', e = 53 '5', f = 102 'f', g = 55 '7', h = 104 'h', i = 57 '9', j = 106 'j', k = 66 'B', l = 108 'l', m = 68 'D'}"
	"{a = 97 'a', b = 50 '2', c = 99 'c', d = 52 '4', e = 101 'e', f = 54 '6', g = 103 'g', h = 56 '8', i = 105 'i', j = 65 'A', k = 107 'k', l = 67 'C', m = 109 'm', n = 69 'E'}"
	"{a = 49 '1', b = 98 'b', c = 51 '3', d = 100 'd', e = 53 '5', f = 102 'f', g = 55 '7', h = 104 'h', i = 57 '9', j = 106 'j', k = 66 'B', l = 108 'l', m = 68 'D', n = 110 'n', o = 70 'F'}"
	"{a = 97 'a', b = 50 '2', c = 99 'c', d = 52 '4', e = 101 'e', f = 54 '6', g = 103 'g', h = 56 '8', i = 105 'i', j = 65 'A', k = 107 'k', l = 67 'C', m = 109 'm', n = 69 'E', o = 111 'o', p = 71 'G'}"
	"{a = 49 '1', b = 98 'b', c = 51 '3', d = 100 'd', e = 53 '5', f = 102 'f', g = 55 '7', h = 104 'h', i = 57 '9', j = 106 'j', k = 66 'B', l = 108 'l', m = 68 'D', n = 110 'n', o = 70 'F', p = 112 'p', q = 72 'H'}"
    } $n]
}

proc zed { n } {
    return [lindex {
	"{}"
	"{a = 90 'Z'}"
	"{a = 90 'Z', b = 90 'Z'}"
	"{a = 90 'Z', b = 90 'Z', c = 90 'Z'}"
	"{a = 90 'Z', b = 90 'Z', c = 90 'Z', d = 90 'Z'}"
	"{a = 90 'Z', b = 90 'Z', c = 90 'Z', d = 90 'Z', e = 90 'Z'}"
	"{a = 90 'Z', b = 90 'Z', c = 90 'Z', d = 90 'Z', e = 90 'Z', f = 90 'Z'}"
	"{a = 90 'Z', b = 90 'Z', c = 90 'Z', d = 90 'Z', e = 90 'Z', f = 90 'Z', g = 90 'Z'}"
	"{a = 90 'Z', b = 90 'Z', c = 90 'Z', d = 90 'Z', e = 90 'Z', f = 90 'Z', g = 90 'Z', h = 90 'Z'}"
	"{a = 90 'Z', b = 90 'Z', c = 90 'Z', d = 90 'Z', e = 90 'Z', f = 90 'Z', g = 90 'Z', h = 90 'Z', i = 90 'Z'}"
	"{a = 90 'Z', b = 90 'Z', c = 90 'Z', d = 90 'Z', e = 90 'Z', f = 90 'Z', g = 90 'Z', h = 90 'Z', i = 90 'Z', j = 90 'Z'}"
	"{a = 90 'Z', b = 90 'Z', c = 90 'Z', d = 90 'Z', e = 90 'Z', f = 90 'Z', g = 90 'Z', h = 90 'Z', i = 90 'Z', j = 90 'Z', k = 90 'Z'}"
	"{a = 90 'Z', b = 90 'Z', c = 90 'Z', d = 90 'Z', e = 90 'Z', f = 90 'Z', g = 90 'Z', h = 90 'Z', i = 90 'Z', j = 90 'Z', k = 90 'Z', l = 90 'Z'}"
	"{a = 90 'Z', b = 90 'Z', c = 90 'Z', d = 90 'Z', e = 90 'Z', f = 90 'Z', g = 90 'Z', h = 90 'Z', i = 90 'Z', j = 90 'Z', k = 90 'Z', l = 90 'Z', m = 90 'Z'}"
	"{a = 90 'Z', b = 90 'Z', c = 90 'Z', d = 90 'Z', e = 90 'Z', f = 90 'Z', g = 90 'Z', h = 90 'Z', i = 90 'Z', j = 90 'Z', k = 90 'Z', l = 90 'Z', m = 90 'Z', n = 90 'Z'}"
	"{a = 90 'Z', b = 90 'Z', c = 90 'Z', d = 90 'Z', e = 90 'Z', f = 90 'Z', g = 90 'Z', h = 90 'Z', i = 90 'Z', j = 90 'Z', k = 90 'Z', l = 90 'Z', m = 90 'Z', n = 90 'Z', o = 90 'Z'}"
	"{a = 90 'Z', b = 90 'Z', c = 90 'Z', d = 90 'Z', e = 90 'Z', f = 90 'Z', g = 90 'Z', h = 90 'Z', i = 90 'Z', j = 90 'Z', k = 90 'Z', l = 90 'Z', m = 90 'Z', n = 90 'Z', o = 90 'Z', p = 90 'Z'}"
	"{a = 90 'Z', b = 90 'Z', c = 90 'Z', d = 90 'Z', e = 90 'Z', f = 90 'Z', g = 90 'Z', h = 90 'Z', i = 90 'Z', j = 90 'Z', k = 90 'Z', l = 90 'Z', m = 90 'Z', n = 90 'Z', o = 90 'Z', p = 90 'Z', q = 90 'Z'}"
    } $n]
}

proc any { n } {
    global anychar_re
    set ac $anychar_re
    return [lindex [list \
	"{}" \
	"{a = ${ac}}" \
	"{a = ${ac}, b = ${ac}}" \
	"{a = ${ac}, b = ${ac}, c = ${ac}}" \
	"{a = ${ac}, b = ${ac}, c = ${ac}, d = ${ac}}" \
	"{a = ${ac}, b = ${ac}, c = ${ac}, d = ${ac}, e = ${ac}}" \
	"{a = ${ac}, b = ${ac}, c = ${ac}, d = ${ac}, e = ${ac}, f = ${ac}}" \
	"{a = ${ac}, b = ${ac}, c = ${ac}, d = ${ac}, e = ${ac}, f = ${ac}, g = ${ac}}" \
	"{a = ${ac}, b = ${ac}, c = ${ac}, d = ${ac}, e = ${ac}, f = ${ac}, g = ${ac}, h = ${ac}}" \
	"{a = ${ac}, b = ${ac}, c = ${ac}, d = ${ac}, e = ${ac}, f = ${ac}, g = ${ac}, h = ${ac}, i = ${ac}}" \
	"{a = ${ac}, b = ${ac}, c = ${ac}, d = ${ac}, e = ${ac}, f = ${ac}, g = ${ac}, h = ${ac}, i = ${ac}, j = ${ac}}" \
	"{a = ${ac}, b = ${ac}, c = ${ac}, d = ${ac}, e = ${ac}, f = ${ac}, g = ${ac}, h = ${ac}, i = ${ac}, j = ${ac}, k = ${ac}}" \
	"{a = ${ac}, b = ${ac}, c = ${ac}, d = ${ac}, e = ${ac}, f = ${ac}, g = ${ac}, h = ${ac}, i = ${ac}, j = ${ac}, k = ${ac}, l = ${ac}}" \
	"{a = ${ac}, b = ${ac}, c = ${ac}, d = ${ac}, e = ${ac}, f = ${ac}, g = ${ac}, h = ${ac}, i = ${ac}, j = ${ac}, k = ${ac}, l = ${ac}, m = ${ac}}" \
	"{a = ${ac}, b = ${ac}, c = ${ac}, d = ${ac}, e = ${ac}, f = ${ac}, g = ${ac}, h = ${ac}, i = ${ac}, j = ${ac}, k = ${ac}, l = ${ac}, m = ${ac}, n = ${ac}}" \
	"{a = ${ac}, b = ${ac}, c = ${ac}, d = ${ac}, e = ${ac}, f = ${ac}, g = ${ac}, h = ${ac}, i = ${ac}, j = ${ac}, k = ${ac}, l = ${ac}, m = ${ac}, n = ${ac}, o = ${ac}}" \
	"{a = ${ac}, b = ${ac}, c = ${ac}, d = ${ac}, e = ${ac}, f = ${ac}, g = ${ac}, h = ${ac}, i = ${ac}, j = ${ac}, k = ${ac}, l = ${ac}, m = ${ac}, n = ${ac}, o = ${ac}, p = ${ac}}" \
	"{a = ${ac}, b = ${ac}, c = ${ac}, d = ${ac}, e = ${ac}, f = ${ac}, g = ${ac}, h = ${ac}, i = ${ac}, j = ${ac}, k = ${ac}, l = ${ac}, m = ${ac}, n = ${ac}, o = ${ac}, p = ${ac}, q = ${ac}}" \
    ] $n]
}

# Given N (0..25), return the corresponding alphabetic letter in lower
# or upper case.  This is ment to be i18n proof.

proc i2a { n } {
    return [string range "abcdefghijklmnopqrstuvwxyz" $n $n]
}

proc I2A { n } {
    return [string toupper [i2a $n]]
}


# Use the file name, compiler and tuples to set up any needed KFAILs.

proc setup_compiler_kfails { file compiler format tuples bug } {
    global testfile
    if {[string match $file $testfile] && [test_compiler_info $compiler]  && [test_debug_format $format]} {
	foreach f $tuples { setup_kfail $bug $f }
    }
}

# Test GDB's ability to make inferior function calls to functions
# returning (or passing in a single structs.

# N identifies the number of elements in the struct that will be used
# for the test case.  FAILS is a list of target tuples that will fail
# this test.

#  start_structs_test() will have previously built a program with a
# specified combination of types for those elements.  To ensure
# robustness of the output, "p/c" is used.

# This tests the code paths "which return-value convention?" and
# "extract return-value from registers" called by "infcall.c".

proc test_struct_calls { n } {
    global testfile
    global gdb_prompt

    # Check that GDB can always extract a struct-return value from an
    # inferior function call.  Since GDB always knows the location of an
    # inferior function call's return value these should never fail
    
    # Implemented by calling the parameterless function "fun$N" and then
    # examining the return value printed by GDB.

    set tests "call $n ${testfile}"

    # Call fun${n}, checking the printed return-value.
    setup_compiler_kfails structs-tc-tll gcc-3-3-* "DWARF \[0-9\]" i*86-*-* gdb/1455
    setup_compiler_kfails structs-tc-td gcc-3-3-* "DWARF \[0-9\]" i*86-*-* gdb/1455
    gdb_test "p/c fun${n}()"  "[foo ${n}]" "p/c fun<n>(); ${tests}"

    # Check that GDB can always pass a structure to an inferior function.
    # This test can never fail.

    # Implemented by calling the one parameter function "Fun$N" which
    # stores its parameter in the global variable "L$N".  GDB then
    # examining that global to confirm that the value is as expected.

    gdb_test_no_output "call Fun${n}(foo${n})" "call Fun<n>(foo<n>); ${tests}"
    setup_compiler_kfails structs-tc-tll gcc-3-3-* "DWARF \[0-9\]" i*86-*-* gdb/1455
    setup_compiler_kfails structs-tc-td gcc-3-3-* "DWARF \[0-9\]" i*86-*-* gdb/1455
    gdb_test "p/c L${n}" [foo ${n}] "p/c L<n>; ${tests}"
}

# Test GDB's ability to both return a function (with "return" or
# "finish") and correctly extract/store any corresponding
# return-value.

# Check that GDB can consistently extract/store structure return
# values.  There are two cases - returned in registers and returned in
# memory.  For the latter case, the return value can't be found and a
# failure is "expected".  However GDB must still both return the
# function and display the final source and line information.

# N identifies the number of elements in the struct that will be used
# for the test case.  FAILS is a list of target tuples that will fail
# this test.

# This tests the code paths "which return-value convention?", "extract
# return-value from registers", and "store return-value in registers".
# Unlike "test struct calls", this test is expected to "fail" when the
# return-value is in memory (GDB can't find the location).  The test
# is in three parts: test "return"; test "finish"; check that the two
# are consistent.  GDB can sometimes work for one command and not the
# other.

proc test_struct_returns { n } {
    global gdb_prompt
    global testfile

    set tests "return $n ${testfile}"


    # Check that "return" works.

    # GDB must always force the return of a function that has
    # a struct result.  Dependant on the ABI, it may, or may not be
    # possible to store the return value in a register.

    # The relevant code looks like "L{n} = fun{n}()".  The test forces
    # "fun{n}" to "return" with an explicit value.  Since that code
    # snippet will store the returned value in "L{n}" the return
    # is tested by examining "L{n}".  This assumes that the
    # compiler implemented this as fun{n}(&L{n}) and hence that when
    # the value isn't stored "L{n}" remains unchanged.  Also check for
    # consistency between this and the "finish" case.

    # Get into a call of fun${n}
    gdb_test "advance fun${n}" \
	    "fun${n} .*\[\r\n\]+\[0-9\].*return foo${n}.*" \
	    "advance to fun<n> for return; ${tests}"

    # Check that the program invalidated the relevant global.
    gdb_test "p/c L${n}" " = [zed $n]" "zed L<n> for return; ${tests}"

    # Force the "return".  This checks that the return is always
    # performed, and that GDB correctly reported this to the user.
    # GDB 6.0 and earlier, when the return-value's location wasn't
    # known, both failed to print a final "source and line" and misplaced
    # the frame ("No frame").

    # The test is writen so that it only reports one FAIL/PASS for the
    # entire operation.  The value returned is checked further down.
    # "return_value_known", if non-zero, indicates that GDB knew where
    # the return value was located.

    set test "return foo<n>; ${tests}"
    set return_value_known 1
    set return_value_unimplemented 0
    gdb_test_multiple "return foo${n}" "${test}" {
	-re "The location" {
	    # Ulgh, a struct return, remember this (still need prompt).
	    set return_value_known 0
	    exp_continue
	}
	-re "A structure or union" {
	    # Ulgh, a struct return, remember this (still need prompt).
	    set return_value_known 0
	    # Double ulgh.  Architecture doesn't use return_value and
	    # hence hasn't implemented small structure return.
	    set return_value_unimplemented 1
	    exp_continue
	}
	-re "Make fun${n} return now.*y or n. $" {
	    gdb_test_multiple "y" "${test}" {
		-re "L${n} *= fun${n}.*${gdb_prompt} $" {
		    # Need to step off the function call
		    gdb_test "next" "L.* *= fun.*" "${test}"
		}
		-re "L[expr ${n} + 1] *= fun[expr ${n} + 1].*${gdb_prompt} $" {
		    pass "${test}"
		}
	    }
	}
    }

    # Check that the return-value is as expected.  At this stage we're
    # just checking that GDB has returned a value consistent with
    # "return_value_known" set above.
    #
    # Note that, when return_value_known is false, we can't make any
    # assumptions at all about the value L<n>:
    #
    # - If the caller passed the address of L<n> directly as fun<n>'s
    #   return value buffer, then L<n> will be unchanged, because we
    #   forced fun<n> to return before it could store anything in it.
    #
    # - If the caller passed the address of some temporary buffer to
    #   fun<n>, and then copied the buffer into L<n>, then L<n> will
    #   have been overwritten with whatever garbage was in the
    #   uninitialized buffer.
    #
    # - However, if the temporary buffer just happened to have the
    #   "right" value of foo<n> in it, then L<n> will, in fact, have
    #   the value you'd expect to see if the 'return' had worked!
    #   This has actually been observed to happen on the Renesas M32C.
    #
    # So, really, anything is acceptable unless return_value_known is
    # true.

    set test "value foo<n> returned; ${tests}"
    gdb_test_multiple "p/c L${n}" "${test}" {
	-re " = [foo ${n}].*${gdb_prompt} $" {
            # This answer is okay regardless of whether GDB claims to
            # have set the return value: if it did, then this is what
            # we expected; and if it didn't, then any answer is okay.
            pass "${test}"
	}
	-re " = [any $n].*${gdb_prompt} $" {
	    if $return_value_known {
		# This contradicts the above claim that GDB knew
		# the location of the return value.
		fail "${test}"
	    } else {
                # We expected L${n} to be set to garbage, so any
                # answer is acceptable.
		pass "${test}"
	    }
	}
	-re ".*${gdb_prompt} $" {
	    if $return_value_unimplemented {
		# What a suprize.  The architecture hasn't implemented
		# return_value, and hence has to fail.
		kfail "$test" gdb/1444
	    } else {
		fail "$test"
	    }
	}
    }	
    
    # Check that a "finish" works.

    # This is almost but not quite the same as "call struct funcs".
    # Architectures can have subtle differences in the two code paths.

    # The relevant code snippet is "L{n} = fun{n}()".  The program is
    # advanced into a call to  "fun{n}" and then that function is
    # finished.  The returned value that GDB prints, reformatted using
    # "p/c", is checked.

    # Get into "fun${n}()".
    gdb_test "advance fun${n}" \
	    "fun${n} .*\[\r\n\]+\[0-9\].*return foo${n}.*" \
	    "advance to fun<n> for finish; ${tests}"

    # Check that the program invalidated the relevant global.
    gdb_test "p/c L${n}" " = [zed $n]" "zed L<n> for finish; ${tests}"

    # Finish the function, set 'finish_value_known" to non-empty if
    # the return-value was found.

    set test "finish foo<n>; ${tests}"
    set finish_value_known 1
    gdb_test_multiple "finish" "${test}" {
	-re "Value returned is .*${gdb_prompt} $" {
	    pass "${test}"
	}
	-re "Value returned has type: struct struct$n. Cannot determine contents.*${gdb_prompt} $" {
	    # Expected bad value.  For the moment this is ok.
	    set finish_value_known 0
	    pass "${test}"
	}
    }

    # Re-print the last (return-value) using the more robust
    # "p/c".  If no return value was found, the 'Z' from the previous
    # check that the variable was cleared, is printed.
    set test "value foo<n> finished; ${tests}"
    gdb_test_multiple "p/c" "${test}" {
	-re "[foo ${n}]\[\r\n\]+${gdb_prompt} $" {
	    if $finish_value_known {
		pass "${test}"
	    } else {
		# This contradicts the above claim that GDB didn't
		# know the location of the return-value.
		fail "${test}"
	    }
	}
	-re "[zed ${n}]\[\r\n\]+${gdb_prompt} $" {
	    # The value didn't get found.  This is "expected".
	    if $finish_value_known {
		# This contradicts the above claim that GDB did
		# know the location of the return-value.
		fail "${test}"
	    } else {
		pass "${test}"
	    }
	}
    }

    # Finally, check that "return" and finish" have consistent
    # behavior.

    # Since "finish" works in more cases than "return" (see
    # RETURN_VALUE_ABI_RETURNS_ADDRESS and
    # RETURN_VALUE_ABI_PRESERVES_ADDRESS), the "return" value being
    # known implies that the "finish" value is known (but not the
    # reverse).

    set test "return value known implies finish value known; ${tests}"
    if {$return_value_known && ! $finish_value_known} {
	kfail gdb/1444 "${test}"
    } else {
	pass "${test}"
    }
}

# ABIs pass anything >8 or >16 bytes in memory but below that things
# randomly use register and/and structure conventions.  Check all
# possible sized char structs in that range.  But only a restricted
# range of the other types.

# NetBSD/PPC returns "unnatural" (3, 5, 6, 7) sized structs in memory.

# Test every single char struct from 1..17 in size.  This is what the
# original "structs" test was doing.

proc test { types c r } {
    with_test_prefix types=[join $types "-"] {
	if { [start_structs_test $types] } {
	    return
	}

	if { [llength $c] == 0 } {
	    # Done.
	} elseif { [llength $c] == 1 } {
	    test_struct_calls [lindex $c 0]
	} elseif { [llength $c] == 2 } {
	    set low_c [lindex $c 0]
	    set high_c [lindex $c 1]
	    for {set i $low_c} {$i <= $high_c} {incr i} {
		test_struct_calls $i
	    }
	} else {
	    error "invalid list length"
	}

	if { [llength $r] == 0 } {
	    # Done.
	} elseif { [llength $r] == 1 } {
	    test_struct_returns [lindex $r 0]
	} elseif { [llength $r] == 2 } {
	    set low_r [lindex $r 0]
	    set high_r [lindex $r 1]
	    for {set i $low_r} {$i <= $high_r} {incr i} {
		test_struct_returns $i
	    }
	} else {
	    error "invalid list length"
	}
    }
}

test { tc } {1 17} {1 8}

# Let the fun begin.

# Assuming that any integer struct larger than 8 bytes goes in memory,
# come up with many and varied combinations of a return struct.  For
# "struct calls" test just beyond that 8 byte boundary, for "struct
# returns" test up to that boundary.

# For floats, assumed that up to two struct elements can be stored in
# floating point registers, regardless of their size.

# The approx size of each structure it is computed assumed that tc=1,
# ts=2, ti=4, tl=4, tll=8, tf=4, td=8, tld=16, and that all fields are
# naturally aligned.  Padding being added where needed.

# Approx size: 2, 4, ...
test { ts } {1 5} {1 4}

# Approx size: 4, 8, ...
test { ti } {1 3} {1 2}

# Approx size: 4, 8, ...
test { tl } {1 3} {1 2}

# Approx size: 8, 16, ...
test { tll } {1 2} {1}

if { !$skip_float_test } {
    # Approx size: 4, 8, ...
    test { tf } {1 3} {1 2}

    # Approx size: 8, 16, ...
    test { td } {1 2} {1}

    # Approx size: 16, 32, ...
    test { tld } {1 2} {1}
}

# Approx size: 2+1=3, 4, ...
test { ts tc } {2 8} {2}

# Approx size: 4+1=5, 6, ...
test { ti tc } {2 6} {2}

# Approx size: 4+1=5, 6, ...
test { tl tc } {2 6} {2}

# Approx size: 8+1=9, 10, ...
test { tll tc } {2} {}

if { !$skip_float_test } {
    # Approx size: 4+1=5, 6, ...
    test { tf tc } {2 6} {2}

    # Approx size: 8+1=9, 10, ...
    test { td tc } {2} {}

    # Approx size: 16+1=17, 18, ...
    test { tld tc } {2} {}
}

# Approx size: (1+1)+2=4, 6, ...
test { tc ts } {2 6} {2}

# Approx size: (1+3)+4=8, 12, ...
test { tc ti } {2 4} {2}

# Approx size: (1+3)+4=8, 12, ...
test { tc tl } {2 4} {2}

# Approx size: (1+7)+8=16, 24, ...
test { tc tll } {2} {}

if { !$skip_float_test } {
    # Approx size: (1+3)+4=8, 12, ...
    test { tc tf } {2 4} {}

    # Approx size: (1+7)+8=16, 24, ...
    test { tc td } {2} {}

    # Approx size: (1+15)+16=32, 48, ...
    test { tc tld } {2} {}

    # Some float combinations

    # Approx size: 8+4=12, 16, ...
    test { td tf } {2} {2}

    # Approx size: (4+4)+8=16, 32, ...
    test { tf td } {2} {2}
}
return 0