1# This testcase is part of GDB, the GNU debugger. 2 3# Copyright 2004-2020 Free Software Foundation, Inc. 4 5# This program is free software; you can redistribute it and/or modify 6# it under the terms of the GNU General Public License as published by 7# the Free Software Foundation; either version 3 of the License, or 8# (at your option) any later version. 9# 10# This program is distributed in the hope that it will be useful, 11# but WITHOUT ANY WARRANTY; without even the implied warranty of 12# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13# GNU General Public License for more details. 14# 15# You should have received a copy of the GNU General Public License 16# along with this program. If not, see <http://www.gnu.org/licenses/>. 17 18# Test "return", "finish", and "call" of functions that a scalar (int, 19# float, enum) and/or take a single scalar parameter. 20 21 22# Some targets can't call functions, so don't even bother with this 23# test. 24 25if [target_info exists gdb,cannot_call_functions] { 26 unsupported "this target can not call functions" 27 continue 28} 29 30standard_testfile .c 31 32# Create and source the file that provides information about the 33# compiler used to compile the test case. 34 35if [get_compiler_info] { 36 return -1 37} 38set skip_float_test [gdb_skip_float_test] 39 40# Compile a variant of scalars.c using TYPE to specify the type of the 41# parameter and return-type. Run the compiled program up to "main". 42# Also updates the global "testfile" to reflect the most recent build. 43 44proc start_scalars_test { type } { 45 global testfile 46 global srcfile 47 global binfile 48 global subdir 49 global srcdir 50 global gdb_prompt 51 global expect_out 52 53 # Create the additional flags 54 set flags "debug additional_flags=-DT=${type}" 55 set testfile "call-sc-${type}" 56 57 set binfile [standard_output_file ${testfile}] 58 if { [prepare_for_testing "failed to prepare" $binfile $srcfile $flags] } { 59 return -1 60 } 61 62 # Make certain that the output is consistent 63 with_test_prefix "testfile=$testfile" { 64 gdb_test_no_output "set print sevenbit-strings" 65 gdb_test_no_output "set print address off" 66 gdb_test_no_output "set width 0" 67 } 68 69 # Advance to main 70 if { ![runto_main] } then { 71 gdb_suppress_tests 72 } 73 74 # Get the debug format 75 get_debug_format 76 77 # check that type matches what was passed in 78 set test "ptype; ${testfile}" 79 set foo_t "xxx" 80 gdb_test_multiple "ptype/r ${type}" "${test}" { 81 -re "type = (\[^\r\n\]*)\r\n$gdb_prompt $" { 82 set foo_t "$expect_out(1,string)" 83 pass "$test (${foo_t})" 84 } 85 } 86 gdb_test "ptype/r foo" "type = ${foo_t}" "ptype foo; ${testfile} $expect_out(1,string)" 87} 88 89 90# Given N (0..25), return the corresponding alphabetic letter in lower 91# or upper case. This is ment to be i18n proof. 92 93proc i2a { n } { 94 return [string range "abcdefghijklmnopqrstuvwxyz" $n $n] 95} 96 97proc I2A { n } { 98 return [string toupper [i2a $n]] 99} 100 101 102# Test GDB's ability to make inferior function calls to functions 103# returning (or passing) in a single scalar. 104 105# start_scalars_test() will have previously built a program with a 106# specified scalar type. To ensure robustness of the output, "p/c" is 107# used. 108 109# This tests the code paths "which return-value convention?" and 110# "extract return-value from registers" called by "infcall.c". 111 112proc test_scalar_calls { } { 113 global testfile 114 global gdb_prompt 115 116 # Check that GDB can always extract a scalar-return value from an 117 # inferior function call. Since GDB always knows the location of 118 # an inferior function call's return value these should never fail 119 120 # Implemented by calling the parameterless function "fun" and then 121 # examining the return value printed by GDB. 122 123 set tests "call ${testfile}" 124 125 # Call fun, checking the printed return-value. 126 gdb_test "p/c fun()" "= 49 '1'" "p/c fun(); ${tests}" 127 128 # Check that GDB can always pass a structure to an inferior function. 129 # This test can never fail. 130 131 # Implemented by calling the one parameter function "Fun" which 132 # stores its parameter in the global variable "L". GDB then 133 # examining that global to confirm that the value is as expected. 134 135 gdb_test_no_output "call Fun(foo)" "call Fun(foo); ${tests}" 136 gdb_test "p/c L" " = 49 '1'" "p/c L; ${tests}" 137} 138 139# Test GDB's ability to both return a function (with "return" or 140# "finish") and correctly extract/store any corresponding 141# return-value. 142 143# Check that GDB can consistently extract/store structure return 144# values. There are two cases - returned in registers and returned in 145# memory. For the latter case, the return value can't be found and a 146# failure is "expected". However GDB must still both return the 147# function and display the final source and line information. 148 149# N identifies the number of elements in the struct that will be used 150# for the test case. FAILS is a list of target tuples that will fail 151# this test. 152 153# This tests the code paths "which return-value convention?", "extract 154# return-value from registers", and "store return-value in registers". 155# Unlike "test struct calls", this test is expected to "fail" when the 156# return-value is in memory (GDB can't find the location). The test 157# is in three parts: test "return"; test "finish"; check that the two 158# are consistent. GDB can sometimes work for one command and not the 159# other. 160 161proc test_scalar_returns { } { 162 global gdb_prompt 163 global testfile 164 165 set tests "return ${testfile}" 166 167 168 # Check that "return" works. 169 170 # GDB must always force the return of a function that has 171 # a struct result. Dependant on the ABI, it may, or may not be 172 # possible to store the return value in a register. 173 174 # The relevant code looks like "L{n} = fun{n}()". The test forces 175 # "fun{n}" to "return" with an explicit value. Since that code 176 # snippet will store the returned value in "L{n}" the return 177 # is tested by examining "L{n}". This assumes that the 178 # compiler implemented this as fun{n}(&L{n}) and hence that when 179 # the value isn't stored "L{n}" remains unchanged. Also check for 180 # consistency between this and the "finish" case. 181 182 # Get into a call of fun 183 gdb_test "advance fun" \ 184 "fun .*\[\r\n\]+\[0-9\].*return foo.*" \ 185 "advance to fun for return; ${tests}" 186 187 # Check that the program invalidated the relevant global. 188 gdb_test "p/c L" " = 90 'Z'" "zed L for return; ${tests}" 189 190 # Force the "return". This checks that the return is always 191 # performed, and that GDB correctly reported this to the user. 192 # GDB 6.0 and earlier, when the return-value's location wasn't 193 # known, both failed to print a final "source and line" and misplaced 194 # the frame ("No frame"). 195 196 # The test is writen so that it only reports one FAIL/PASS for the 197 # entire operation. The value returned is checked further down. 198 # "return_value_unknown", if non-empty, records why GDB realised 199 # that it didn't know where the return value was. 200 201 set test "return foo; ${tests}" 202 set return_value_unknown 0 203 set return_value_unimplemented 0 204 gdb_test_multiple "return foo" "${test}" { 205 -re "The location" { 206 # Ulgh, a struct return, remember this (still need prompt). 207 set return_value_unknown 1 208 exp_continue 209 } 210 -re "A structure or union" { 211 # Ulgh, a struct return, remember this (still need prompt). 212 set return_value_unknown 1 213 # Double ulgh. Architecture doesn't use return_value and 214 # hence hasn't implemented small structure return. 215 set return_value_unimplemented 1 216 exp_continue 217 } 218 -re "Make fun return now.*y or n. $" { 219 gdb_test_multiple "y" "${test}" { 220 -re "L *= fun.*${gdb_prompt} $" { 221 # Need to step off the function call 222 gdb_test "next" "zed.*" "${test}" 223 } 224 -re "zed \\(\\);.*$gdb_prompt $" { 225 pass "${test}" 226 } 227 } 228 } 229 } 230 231 # If the previous test did not work, the program counter might 232 # still be inside foo() rather than main(). Make sure the program 233 # counter is is main(). 234 # 235 # This happens on ppc64 GNU/Linux with gcc 3.4.1 and a buggy GDB 236 237 set test "return foo; synchronize pc to main() for '${testfile}'" 238 for {set loop_count 0} {$loop_count < 2} {incr loop_count} { 239 gdb_test_multiple "backtrace 1" $test { 240 -re "#0.*main \\(\\).*${gdb_prompt} $" { 241 pass $test 242 set loop_count 2 243 } 244 -re "#0.*fun \\(\\).*${gdb_prompt} $" { 245 if {$loop_count < 1} { 246 gdb_test "finish" ".*" "" 247 } else { 248 fail $test 249 set loop_count 2 250 } 251 } 252 } 253 } 254 255 # Check that the return-value is as expected. At this stage we're 256 # just checking that GDB has returned a value consistent with 257 # "return_value_unknown" set above. 258 259 set test "value foo returned; ${tests}" 260 gdb_test_multiple "p/c L" "${test}" { 261 -re " = 49 '1'.*${gdb_prompt} $" { 262 if $return_value_unknown { 263 # This contradicts the above claim that GDB didn't 264 # know the location of the return-value. 265 fail "${test}" 266 } else { 267 pass "${test}" 268 } 269 } 270 -re " = 90 .*${gdb_prompt} $" { 271 if $return_value_unknown { 272 # The struct return case. Since any modification 273 # would be by reference, and that can't happen, the 274 # value should be unmodified and hence Z is expected. 275 # Is this a reasonable assumption? 276 pass "${test}" 277 } else { 278 # This contradicts the above claim that GDB knew 279 # the location of the return-value. 280 fail "${test}" 281 } 282 } 283 -re ".*${gdb_prompt} $" { 284 if $return_value_unimplemented { 285 # What a suprize. The architecture hasn't implemented 286 # return_value, and hence has to fail. 287 kfail "$test" gdb/1444 288 } else { 289 fail "$test" 290 } 291 } 292 } 293 294 # Check that a "finish" works. 295 296 # This is almost but not quite the same as "call struct funcs". 297 # Architectures can have subtle differences in the two code paths. 298 299 # The relevant code snippet is "L{n} = fun{n}()". The program is 300 # advanced into a call to "fun{n}" and then that function is 301 # finished. The returned value that GDB prints, reformatted using 302 # "p/c", is checked. 303 304 # Get into "fun()". 305 gdb_test "advance fun" \ 306 "fun .*\[\r\n\]+\[0-9\].*return foo.*" \ 307 "advance to fun for finish; ${tests}" 308 309 # Check that the program invalidated the relevant global. 310 gdb_test "p/c L" " = 90 'Z'" "zed L for finish; ${tests}" 311 312 # Finish the function, set 'finish_value_unknown" to non-empty if the 313 # return-value was not found. 314 set test "finish foo; ${tests}" 315 set finish_value_unknown 0 316 gdb_test_multiple "finish" "${test}" { 317 -re "Value returned is .*${gdb_prompt} $" { 318 pass "${test}" 319 } 320 -re "Cannot determine contents.*${gdb_prompt} $" { 321 # Expected bad value. For the moment this is ok. 322 set finish_value_unknown 1 323 pass "${test}" 324 } 325 } 326 327 # Re-print the last (return-value) using the more robust 328 # "p/c". If no return value was found, the 'Z' from the previous 329 # check that the variable was cleared, is printed. 330 set test "value foo finished; ${tests}" 331 gdb_test_multiple "p/c" "${test}" { 332 -re " = 49 '1'\[\r\n\]+${gdb_prompt} $" { 333 if $finish_value_unknown { 334 # This contradicts the above claim that GDB didn't 335 # know the location of the return-value. 336 fail "${test}" 337 } else { 338 pass "${test}" 339 } 340 } 341 -re " = 90 'Z'\[\r\n\]+${gdb_prompt} $" { 342 # The value didn't get found. This is "expected". 343 if $finish_value_unknown { 344 pass "${test}" 345 } else { 346 # This contradicts the above claim that GDB did 347 # know the location of the return-value. 348 fail "${test}" 349 } 350 } 351 } 352 353 # Finally, check that "return" and finish" have consistent 354 # behavior. 355 356 # Since both "return" and "finish" use equivalent "which 357 # return-value convention" logic, both commands should have 358 # identical can/can-not find return-value messages. 359 360 # Note that since "call" and "finish" use common code paths, a 361 # failure here is a strong indicator of problems with "store 362 # return-value" code paths. Suggest looking at "return_value" 363 # when investigating a fix. 364 365 set test "return and finish use same convention; ${tests}" 366 if {$finish_value_unknown == $return_value_unknown} { 367 pass "${test}" 368 } else { 369 kfail gdb/1444 "${test}" 370 } 371} 372 373# ABIs pass anything >8 or >16 bytes in memory but below that things 374# randomly use register and/and structure conventions. Check all 375# possible sized char scalars in that range. But only a restricted 376# range of the other types. 377 378# NetBSD/PPC returns "unnatural" (3, 5, 6, 7) sized scalars in memory. 379 380# Test every single char struct from 1..17 in size. This is what the 381# original "scalars" test was doing. 382 383start_scalars_test tc 384test_scalar_calls 385test_scalar_returns 386 387 388# Let the fun begin. 389 390# Assuming that any integer struct larger than 8 bytes goes in memory, 391# come up with many and varied combinations of a return struct. For 392# "struct calls" test just beyond that 8 byte boundary, for "struct 393# returns" test up to that boundary. 394 395# For floats, assumed that up to two struct elements can be stored in 396# floating point registers, regardless of their size. 397 398# The approx size of each structure it is computed assumed that tc=1, 399# ts=2, ti=4, tl=4, tll=8, tf=4, td=8, tld=16, and that all fields are 400# naturally aligned. Padding being added where needed. 401 402# Approx size: 2, 4, ... 403start_scalars_test ts 404test_scalar_calls 405test_scalar_returns 406 407# Approx size: 4, 8, ... 408start_scalars_test ti 409test_scalar_calls 410test_scalar_returns 411 412# Approx size: 4, 8, ... 413start_scalars_test tl 414test_scalar_calls 415test_scalar_returns 416 417# Approx size: 8, 16, ... 418start_scalars_test tll 419test_scalar_calls 420test_scalar_returns 421 422if {!$skip_float_test} { 423 # Approx size: 4, 8, ... 424 start_scalars_test tf 425 test_scalar_calls 426 test_scalar_returns 427 428 # Approx size: 8, 16, ... 429 start_scalars_test td 430 test_scalar_calls 431 test_scalar_returns 432 433 # Approx size: 16, 32, ... 434 start_scalars_test tld 435 test_scalar_calls 436 test_scalar_returns 437} 438 439# Approx size: 4, 8, ... 440start_scalars_test te 441test_scalar_calls 442test_scalar_returns 443 444return 0 445