Hello, There was an issue with paths returned by llvm-config, discussed upstream on https://reviews.llvm.org/D53557 , I'd like to NMU the fix commited upstream attached here, may I proceed?
Samuel
[hurd] Make getMainExecutable get the real binary path On GNU/Hurd, llvm-config is returning bogus value, such as: $ llvm-config-6.0 --includedir /usr/include while it should be: $ llvm-config-6.0 --includedir /usr/lib/llvm-6.0/include This is because getMainExecutable does not get the actual installation path. On GNU/Hurd, /proc/self/exe is indeed a symlink to the path that was used to start the program, and not the eventual binary file. Llvm's getMainExecutable thus needs to run realpath over it to get the actual place where llvm was installed (/usr/lib/llvm-6.0/bin/llvm-config), and not /usr/bin/llvm-config-6.0. This will not change the result on Linux, where /proc/self/exe already points to the eventual file. Patch by Samuel Thibault! While making changes here, I reformatted this block a bit to reduce indentation and match 2 space indent style. Differential Revision: https://reviews.llvm.org/D53557 Index: llvm/trunk/lib/Support/Unix/Path.inc =================================================================== --- llvm/trunk/lib/Support/Unix/Path.inc +++ llvm/trunk/lib/Support/Unix/Path.inc @@ -179,14 +179,34 @@ char exe_path[MAXPATHLEN]; StringRef aPath("/proc/self/exe"); if (sys::fs::exists(aPath)) { - // /proc is not always mounted under Linux (chroot for example). - ssize_t len = readlink(aPath.str().c_str(), exe_path, sizeof(exe_path)); - if (len >= 0) - return std::string(exe_path, len); + // /proc is not always mounted under Linux (chroot for example). + ssize_t len = readlink(aPath.str().c_str(), exe_path, sizeof(exe_path)); + if (len < 0) + return ""; + + // Null terminate the string for realpath. readlink never null + // terminates its output. + len = std::min(len, long(sizeof(exe_path) - 1)); + exe_path[len] = '\0'; + + // At least on GNU/Hurd, /proc/self/exe is a symlink to the path that + // was used to start the program, and not the eventual binary file. + // We thus needs to run realpath over it to get the actual place + // where llvm was installed. +#if _POSIX_VERSION >= 200112 || defined(__GLIBC__) + char *real_path = realpath(exe_path, NULL); + std::string ret = std::string(real_path); + free(real_path); + return ret; +#else + char real_path[MAXPATHLEN]; + realpath(exe_path, real_path); + return std::string(real_path); +#endif } else { - // Fall back to the classical detection. - if (getprogpath(exe_path, argv0)) - return exe_path; + // Fall back to the classical detection. + if (getprogpath(exe_path, argv0)) + return exe_path; } #elif defined(HAVE_DLFCN_H) && defined(HAVE_DLADDR) // Use dladdr to get executable path if available.
