From 0aec613a7870a929ba21de4fe97dbd2fdeada86c Mon Sep 17 00:00:00 2001 From: Nick Mathewson Date: Wed, 12 Sep 2018 10:10:29 -0400 Subject: [PATCH] Add an --enable-pic option for people who hack Tor into libraries Closes ticket 23846 --- changes/ticket23846 | 5 +++++ configure.ac | 10 +++++++++- 2 files changed, 14 insertions(+), 1 deletion(-) create mode 100644 changes/ticket23846 diff --git a/changes/ticket23846 b/changes/ticket23846 new file mode 100644 index 0000000000..73850482b1 --- /dev/null +++ b/changes/ticket23846 @@ -0,0 +1,5 @@ + o Minor features (build): + - If you pass the "--enable-pic" option to configure, Tor will try to + tell the compiler to build position-independent code suitable to + link into a library. (The default remains -fPIE, for code suitable for a + relocatable executable.) Closes ticket 23846. diff --git a/configure.ac b/configure.ac index 643068724e..bd300ba1b1 100644 --- a/configure.ac +++ b/configure.ac @@ -55,6 +55,8 @@ AC_ARG_ENABLE(zstd-advanced-apis, AS_HELP_STRING(--disable-zstd-advanced-apis, [Build without support for zstd's "static-only" APIs.])) AC_ARG_ENABLE(nss, AS_HELP_STRING(--enable-nss, [Use Mozilla's NSS TLS library. (EXPERIMENTAL)])) +AC_ARG_ENABLE(pic, + AS_HELP_STRING(--enable-pic, [Build Tor's binaries as position-independent code, suitable to link as a library.])) if test "x$enable_coverage" != "xyes" -a "x$enable_asserts_in_tests" = "xno" ; then AC_MSG_ERROR([Can't disable assertions outside of coverage build]) @@ -1138,6 +1140,10 @@ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([], [ #error #endif])], have_clang=yes, have_clang=no) +if test "x$enable_pic" = "xyes"; then + TOR_CHECK_CFLAGS(-fPIC) +fi + if test "x$enable_gcc_hardening" != "xno"; then CFLAGS="$CFLAGS -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2" if test "x$have_clang" = "xyes"; then @@ -1157,7 +1163,9 @@ m4_ifdef([AS_VAR_IF],[ TOR_CHECK_CFLAGS(-Wstack-protector) TOR_CHECK_CFLAGS(--param ssp-buffer-size=1) if test "$bwin32" = "false" && test "$enable_libfuzzer" != "yes" && test "$enable_oss_fuzz" != "yes"; then - TOR_CHECK_CFLAGS(-fPIE) + if test "$enable_pic" != "yes"; then + TOR_CHECK_CFLAGS(-fPIE) + fi TOR_CHECK_LDFLAGS(-pie, "$all_ldflags_for_check", "$all_libs_for_check") fi TOR_TRY_COMPILE_WITH_CFLAGS(-fwrapv, also_link, CFLAGS_FWRAPV="-fwrapv", true)