configure: Put tempfiles in a subdir of the build directory

When libtool support was added to configure, the new temporary files
were left out of the list of files cleaned up on exit; this results
in a lot of stale .lo files being left around in /tmp. Worse, libtool
creates a /tmp/.libs directory which we can't easily clean up.

Put all our temporary files in a single temporary directory created
as a subdirectory of the build directory, so we can easily clean it up,
and don't need fragile or complicated code for creation to avoid it
clashing with temporary directories from other instances of QEMU
configure or being subject to attack from adversaries who can write
to /tmp.

Since the temporaries now live in the build tree, we have no
need to jump through hoops with a trap handler to try to remove
them when configure exits; this fixes some weird bugs where hitting
^C during a configure run wouldn't actually make it stop, because
we would run the trap handler but then not stop. (It is possible
to get the trap handler semantics right but it is convoluted largely
because of bugs in dash, so it is simpler to just avoid it.)

Note that "temporary files go in the build directory, not /tmp" is
the way autoconf behaves.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2 files changed
tree: 05b83733766e2de26962810c82553767d95240f5
  1. audio/
  2. backends/
  3. block/
  4. bsd-user/
  5. default-configs/
  6. disas/
  7. docs/
  8. fpu/
  9. fsdev/
  10. gdb-xml/
  11. hw/
  12. include/
  13. libcacard/
  14. linux-headers/
  15. linux-user/
  16. net/
  17. pc-bios/
  18. po/
  19. qapi/
  20. qga/
  21. qobject/
  22. qom/
  23. roms/
  24. scripts/
  25. slirp/
  26. stubs/
  27. sysconfigs/
  28. target-alpha/
  29. target-arm/
  30. target-cris/
  31. target-i386/
  32. target-lm32/
  33. target-m68k/
  34. target-microblaze/
  35. target-mips/
  36. target-moxie/
  37. target-openrisc/
  38. target-ppc/
  39. target-s390x/
  40. target-sh4/
  41. target-sparc/
  42. target-unicore32/
  43. target-xtensa/
  44. tcg/
  45. tests/
  46. trace/
  47. ui/
  48. util/
  49. .exrc
  50. .gitignore
  51. .gitmodules
  52. .mailmap
  53. .travis.yml
  54. aio-posix.c
  55. aio-win32.c
  56. arch_init.c
  57. async.c
  58. balloon.c
  59. block-migration.c
  60. block.c
  61. blockdev-nbd.c
  62. blockdev.c
  63. blockjob.c
  64. bt-host.c
  65. bt-vhci.c
  66. Changelog
  67. CODING_STYLE
  68. configure
  69. COPYING
  70. COPYING.LIB
  71. coroutine-gthread.c
  72. coroutine-sigaltstack.c
  73. coroutine-ucontext.c
  74. coroutine-win32.c
  75. cpu-exec.c
  76. cpus.c
  77. cputlb.c
  78. device-hotplug.c
  79. device_tree.c
  80. disas.c
  81. dma-helpers.c
  82. dump.c
  83. exec.c
  84. gdbstub.c
  85. HACKING
  86. hmp-commands.hx
  87. hmp.c
  88. hmp.h
  89. iohandler.c
  90. ioport.c
  91. iothread.c
  92. kvm-all.c
  93. kvm-stub.c
  94. LICENSE
  95. main-loop.c
  96. MAINTAINERS
  97. Makefile
  98. Makefile.objs
  99. Makefile.target
  100. memory.c
  101. memory_mapping.c
  102. migration-exec.c
  103. migration-fd.c
  104. migration-rdma.c
  105. migration-tcp.c
  106. migration-unix.c
  107. migration.c
  108. module-common.c
  109. monitor.c
  110. nbd.c
  111. os-posix.c
  112. os-win32.c
  113. page_cache.c
  114. qapi-schema.json
  115. qdev-monitor.c
  116. qdict-test-data.txt
  117. qemu-bridge-helper.c
  118. qemu-char.c
  119. qemu-coroutine-io.c
  120. qemu-coroutine-lock.c
  121. qemu-coroutine-sleep.c
  122. qemu-coroutine.c
  123. qemu-doc.texi
  124. qemu-file.c
  125. qemu-img-cmds.hx
  126. qemu-img.c
  127. qemu-img.texi
  128. qemu-io-cmds.c
  129. qemu-io.c
  130. qemu-log.c
  131. qemu-nbd.c
  132. qemu-nbd.texi
  133. qemu-options-wrapper.h
  134. qemu-options.h
  135. qemu-options.hx
  136. qemu-seccomp.c
  137. qemu-tech.texi
  138. qemu-timer.c
  139. qemu.nsi
  140. qemu.sasl
  141. qmp-commands.hx
  142. qmp.c
  143. qtest.c
  144. README
  145. rules.mak
  146. savevm.c
  147. spice-qemu-char.c
  148. tcg-runtime.c
  149. tci.c
  150. thread-pool.c
  151. thunk.c
  152. tpm.c
  153. trace-events
  154. translate-all.c
  155. translate-all.h
  156. user-exec.c
  157. VERSION
  158. version.rc
  159. vl.c
  160. vmstate.c
  161. xbzrle.c
  162. xen-common-stub.c
  163. xen-common.c
  164. xen-hvm-stub.c
  165. xen-hvm.c
  166. xen-mapcache.c