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| author | Rolf Eike Beer <eike@sf-mail.de> | 2012-01-03 19:54:43 +0100 |
|---|---|---|
| committer | Rolf Eike Beer <eike@sf-mail.de> | 2012-01-16 20:27:40 +0100 |
| commit | 813eca64160509465c0e557aa98c9b0f828e47a9 (patch) | |
| tree | eb75fba2beee4f070734f599b130f02ef497435d /Modules/CheckSymbolExists.cmake | |
| parent | 9a20abf04a7fc11b53beb545f1555fe9815ae09c (diff) | |
| download | cmake-813eca64160509465c0e557aa98c9b0f828e47a9.tar.gz | |
CheckSymbolExists: force the compiler to keep the referenced symbol
Otherwise the compiler may optimize out the reference to the symbol as the
previous version was not really using this. This leads to symbols that are
only in a header but not in the given libraries to be reported as present.
This came up on the first try to fix bug 11333 as "gcc -O3" would optimize
out the reference to pthread_create() so the correct library the symbol is in
was not detected.
The new test code was suggested by Brad King.
Diffstat (limited to 'Modules/CheckSymbolExists.cmake')
| -rw-r--r-- | Modules/CheckSymbolExists.cmake | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/Modules/CheckSymbolExists.cmake b/Modules/CheckSymbolExists.cmake index 183b2bbe6b..515319dd6c 100644 --- a/Modules/CheckSymbolExists.cmake +++ b/Modules/CheckSymbolExists.cmake @@ -60,7 +60,7 @@ MACRO(_CHECK_SYMBOL_EXISTS SOURCEFILE SYMBOL FILES VARIABLE) "${CMAKE_CONFIGURABLE_FILE_CONTENT}#include <${FILE}>\n") ENDFOREACH(FILE) SET(CMAKE_CONFIGURABLE_FILE_CONTENT - "${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") + "${CMAKE_CONFIGURABLE_FILE_CONTENT}\nint main(int argc, char** argv)\n{\n (void)argv;\n#ifndef ${SYMBOL}\n return ((int*)(&${SYMBOL}))[argc];\n#else\n (void)argc;\n return 0;\n#endif\n}\n") CONFIGURE_FILE("${CMAKE_ROOT}/Modules/CMakeConfigurableFile.in" "${SOURCEFILE}" @ONLY IMMEDIATE) |