From: John Ericson <g...@johnericson.me> My goal is to be able to build libgcc cleanly in isolation --- today one needs to figure `make ...` misc things in the gcc subdir.
Following Andrew Pinski's suggestions in https://gcc.gnu.org/pipermail/gcc-patches/2025-July/689683.html, this commit moves the NO_PIE_CFLAGS logic. gcc/ChangeLog: * Makefile.in: Remove NO_PIE_CFLAGS logic, since it is now in libgcc. * configure.ac: Delete --enable-default-pie, because it no longer serves a purpose and would be dead code. libgcc/ChangeLog: * Makefile.in: Define NO_PIE_CFLAGS make variable via autoconf substitution. * configure.ac: New configure check to define NO_PIE_CFLAGS using the algorithm Andrew asked for in the linked mail. Suggested-by: Andrew Pinski <quic_apin...@quicinc.com> --- gcc/Makefile.in | 6 ------ gcc/configure.ac | 12 ------------ libgcc/Makefile.in | 2 ++ libgcc/configure.ac | 14 ++++++++++++++ 4 files changed, 16 insertions(+), 18 deletions(-) diff --git a/gcc/Makefile.in b/gcc/Makefile.in index 55b4cd7dbed..71d5dfb2ee9 100644 --- a/gcc/Makefile.in +++ b/gcc/Makefile.in @@ -2464,12 +2464,6 @@ libgcc.mvars: config.status Makefile specs xgcc$(exeext) echo GCC_CFLAGS = '$(GCC_CFLAGS)' >> tmp-libgcc.mvars echo INHIBIT_LIBC_CFLAGS = '$(INHIBIT_LIBC_CFLAGS)' >> tmp-libgcc.mvars echo TARGET_SYSTEM_ROOT = '$(TARGET_SYSTEM_ROOT)' >> tmp-libgcc.mvars - if test @enable_default_pie@ = yes; then \ - NO_PIE_CFLAGS="-fno-PIE"; \ - else \ - NO_PIE_CFLAGS=; \ - fi; \ - echo NO_PIE_CFLAGS = "$$NO_PIE_CFLAGS" >> tmp-libgcc.mvars mv tmp-libgcc.mvars libgcc.mvars diff --git a/gcc/configure.ac b/gcc/configure.ac index 9f67e62950a..fd7d05d73e2 100644 --- a/gcc/configure.ac +++ b/gcc/configure.ac @@ -7755,18 +7755,6 @@ else fi AC_SUBST([libgccjit_version]) -# Check whether --enable-default-pie was given. -AC_ARG_ENABLE(default-pie, -[AS_HELP_STRING([--enable-default-pie], - [enable Position Independent Executable as default])], -enable_default_pie=$enableval, -enable_default_pie=no) -if test x$enable_default_pie = xyes ; then - AC_DEFINE(ENABLE_DEFAULT_PIE, 1, - [Define if your target supports default PIE and it is enabled.]) -fi -AC_SUBST([enable_default_pie]) - # Check if -fno-PIE works. AC_CACHE_CHECK([for -fno-PIE option], [gcc_cv_c_no_fpie], diff --git a/libgcc/Makefile.in b/libgcc/Makefile.in index 0719fd0615d..12124d4a065 100644 --- a/libgcc/Makefile.in +++ b/libgcc/Makefile.in @@ -298,6 +298,8 @@ override CFLAGS := $(filter-out -fprofile-generate -fprofile-use,$(CFLAGS)) INTERNAL_CFLAGS = $(CFLAGS) $(LIBGCC2_CFLAGS) $(HOST_LIBGCC2_CFLAGS) \ $(INCLUDES) @set_have_cc_tls@ @set_use_emutls@ +NO_PIE_CFLAGS = @NO_PIE_CFLAGS@ + # Options to use when compiling crtbegin/end. CRTSTUFF_CFLAGS = -O2 $(GCC_CFLAGS) $(INCLUDES) $(MULTILIB_CFLAGS) -g0 \ $(NO_PIE_CFLAGS) -finhibit-size-directive -fno-inline -fno-exceptions \ diff --git a/libgcc/configure.ac b/libgcc/configure.ac index 85e4f1bc48b..bc084e0c2a3 100644 --- a/libgcc/configure.ac +++ b/libgcc/configure.ac @@ -258,6 +258,20 @@ AC_CACHE_CHECK([whether fixed-point is supported], [libgcc_cv_fixed_point], fixed_point=$libgcc_cv_fixed_point AC_SUBST(fixed_point) +# Check whether the compiler defines __PIE__ by default, so -fno-PIE is needed. +AC_CACHE_CHECK([whether the compiler defines __PIE__], [libgcc_cv_no_pie_cflags], + [AC_COMPILE_IFELSE( + [AC_LANG_PROGRAM([[ +#ifdef __PIE__ +#error __PIE__ defined +#endif + ]], [[]])], + [libgcc_cv_no_pie_cflags=''], + [libgcc_cv_no_pie_cflags='-fno-PIE'])]) + +NO_PIE_CFLAGS=$libgcc_cv_no_pie_cflags +AC_SUBST([NO_PIE_CFLAGS]) + # For platforms with the unwind ABI which includes an unwind library, # libunwind, we can choose to use the system libunwind. # config.gcc also contains tests of with_system_libunwind. -- 2.47.2
