diff options
| -rw-r--r-- | ChangeLog | 5 | ||||
| -rw-r--r-- | configure.ac | 29 |
2 files changed, 31 insertions, 3 deletions
@@ -1,3 +1,8 @@ +2015-04-14 Mark Wielaard <[email protected]> + + * configure.ac (ac_cv_c99): Add explicit checks for all GNU99 + extensions used. + 2015-03-13 Mark Wielaard <[email protected]> * configure.ac (ac_cv_c99): Add explicit return. diff --git a/configure.ac b/configure.ac index c4b818d0..ed2c9644 100644 --- a/configure.ac +++ b/configure.ac @@ -79,15 +79,38 @@ m4_ifdef([AM_PROG_AR], [AM_PROG_AR]) AC_CHECK_TOOL([READELF], [readelf]) AC_CHECK_TOOL([NM], [nm]) -AC_CACHE_CHECK([for gcc with C99 support], ac_cv_c99, [dnl +# We use -std=gnu99 but have explicit checks for some language constructs +# and GNU extensions since some compilers claim GNU99 support, but don't +# really support all language extensions. In particular we need +# Mixed Declarations and Code +# https://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html +# Nested Functions +# https://gcc.gnu.org/onlinedocs/gcc/Nested-Functions.html +# Arrays of Variable Length +# https://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html +AC_CACHE_CHECK([for gcc with GNU99 support], ac_cv_c99, [dnl old_CFLAGS="$CFLAGS" CFLAGS="$CFLAGS -std=gnu99" AC_COMPILE_IFELSE([AC_LANG_SOURCE([dnl -int foo (int a) { for (int i = 0; i < a; ++i) if (i % 4) break; int s = a; return s;}])], +int foo (int a) +{ + for (int i = 0; i < a; ++i) if (i % 4) break; int s = a; return s; +} + +double bar (double a, double b) +{ + double square (double z) { return z * z; } + return square (a) + square (b); +} + +void baz (int n) +{ + struct S { int x[[n]]; }; +}])], ac_cv_c99=yes, ac_cv_c99=no) CFLAGS="$old_CFLAGS"]) AS_IF([test "x$ac_cv_c99" != xyes], - AC_MSG_ERROR([gcc with C99 support required])) + AC_MSG_ERROR([gcc with GNU99 support required])) AC_CACHE_CHECK([for __thread support], ac_cv_tls, [dnl # Use the same flags that we use for our DSOs, so the test is representative. |