From 6b3993b0bfaeb18ea93367006a9512ecc7f159b4 Mon Sep 17 00:00:00 2001 From: David Cole Date: Mon, 22 Aug 2011 15:48:26 -0400 Subject: [PATCH] CheckSymbolExists: Use IMMEDIATE flag for configure_file (#11333) The test "complex" sets the variable CMAKE_BACKWARDS_COMPATIBILITY to 1.4. When that variable is set, configure_file does not default to IMMEDIATE mode processing. And so, the output file likely does not exist yet by the time the next line in the CMakeLists.txt file is processed. When that next line is "try_compile" on that file, this is a problem. Fix the problem by explicitly using IMMEDIATE in the configure_file call. This problem was quite mysterious, as it only showed up on the "complex" test, when the previous commit introduced a CheckSymbolExists call into the FindThreads module. Which is not even explicitly included in the "complex" test... FindThreads gets included indirectly only as a side effect of setting CMAKE_BACKWARDS_COMPATIBILITY to 1.4 and even then it's included indirectly by auto-inclusion of CMakeBackwardCompatibilityC.cmake... Wow. Just wow. --- Modules/CheckSymbolExists.cmake | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Modules/CheckSymbolExists.cmake b/Modules/CheckSymbolExists.cmake index be7d65804..183b2bbe6 100644 --- a/Modules/CheckSymbolExists.cmake +++ b/Modules/CheckSymbolExists.cmake @@ -63,7 +63,7 @@ MACRO(_CHECK_SYMBOL_EXISTS SOURCEFILE SYMBOL FILES VARIABLE) "${CMAKE_CONFIGURABLE_FILE_CONTENT}\nvoid cmakeRequireSymbol(int dummy,...){(void)dummy;}\nint main()\n{\n#ifndef ${SYMBOL}\n cmakeRequireSymbol(0,&${SYMBOL});\n#endif\n return 0;\n}\n") CONFIGURE_FILE("${CMAKE_ROOT}/Modules/CMakeConfigurableFile.in" - "${SOURCEFILE}" @ONLY) + "${SOURCEFILE}" @ONLY IMMEDIATE) MESSAGE(STATUS "Looking for ${SYMBOL}") TRY_COMPILE(${VARIABLE}