Hi autoconf team. During testing of tcc 0.9.28rc, I found a strange bug in autoconf 2.71 with `AC_CHECK_DEFINE` for `__unix__`. For comparsion, i added checks for "__unix" and "__linux__": Overview: * [__unix__] always found, but the log text is crippled * __unix__ never found and the log text is crippled * The second check does not use the cached result from the first check * When i duplicate the tests, the duplicate test used the cached result from the previous check, but all other failures remain. (1: first result: see above, 2: cached result from 1, 3: different result: see above, 4: cached result from 3) I am using tcc 0.9.28rc on linux and gcc 12.3.0 produces the same results. Please test this snipped with the current 2.72rc: ``` AC_CHECK_DEFINE(__unix, CFLAGS="-DFOUND__unix $CFLAGS") AC_CHECK_DEFINE(__unix__, CFLAGS="-DFOUND__unix__ $CFLAGS") AC_CHECK_DEFINE(__linux__, CFLAGS="-DFOUND__linux__ $CFLAGS") AC_CHECK_DEFINE([__unix], CFLAGS="-DFOUNDxx__unix $CFLAGS") AC_CHECK_DEFINE([__unix__], CFLAGS="-DFOUNDxx__unix__ $CFLAGS") AC_CHECK_DEFINE([__linux__], CFLAGS="-DFOUNDxx__linux__ $CFLAGS") ``` buggy results: ``` checking for __unix defined... yes checking for defined... no checking for __linux__ defined... yes checking for __unix defined... (cached) yes checking for defined... yes checking for __linux__ defined... (cached) yes ``` And yes, when the checks are reordered, .... ``` AC_CHECK_DEFINE([__unix], CFLAGS="-DFOUNDxx__unix $CFLAGS") AC_CHECK_DEFINE([__unix__], CFLAGS="-DFOUNDxx__unix__ $CFLAGS") AC_CHECK_DEFINE([__linux__], CFLAGS="-DFOUNDxx__linux__ $CFLAGS") AC_CHECK_DEFINE(__unix, CFLAGS="-DFOUND__unix $CFLAGS") AC_CHECK_DEFINE(__unix__, CFLAGS="-DFOUND__unix__ $CFLAGS") AC_CHECK_DEFINE(__linux__, CFLAGS="-DFOUND__linux__ $CFLAGS") ``` ... the results are different: ``` checking for __unix defined... yes checking for defined... yes checking for __linux__ defined... yes checking for __unix defined... (cached) yes checking for defined... no checking for __linux__ defined... (cached) yes ``` * What is 2.72rc doing? * Should i add a bug report for 2.71 to document this bug? -- Bye bye ... Detlef
