From b5c39684d50deb95373541d46c4a5f0d0d48c613 Mon Sep 17 00:00:00 2001 From: Stefano Lattarini Date: Mon, 24 Oct 2011 23:18:34 +0200 Subject: [PATCH] tests: fix spurious failures due to missing 'yywrap()' function The AC_PROG_LEX Autoconf macro does not diagnose a failure to find the "lex library" expected to provide a `yywrap' function (function which is required to link most lex-generated programs). On the contrary, when all the link attempts (i.e., with `-ll' and `-lfl') fail, configure declares that no lex library is needed, and simply proceeds with the configuration process -- only for the build to possibly fail later, at make time. This behaviour is intended; the Autoconf manual reads: ``You are encouraged to use Flex in your sources, since it is both more pleasant to use than plain Lex and the C source it produces is portable. In order to ensure portability, however, you must either provide a function `yywrap' or, if you don't use it (e.g., your scanner has no `#include'-like feature), simply include a `%noyywrap' statement in the scanner's source.'' This AC_PROG_LEX behaviour is causing some spurious failures of the Automake testsuite in environments which lack a proper library providing `yywrap' (this happens for example on Fedora-based systems). The proper workaround is to simply provide a fall-back implementation of `yywrap' in our lexers. See also partially-overlapping commit `v1.11-871-geb147a1' (from the 'testsuite-work' branch), which was motivated by similar spurious failures experienced when cross-compiling. Reported by Jim Meyering: * tests/cond35.test: Provide a dummy `yywrap' function. * tests/lex3.test: Likewise. * tests/lexvpath.test: Likewise. * tests/silent-lex-generic.test: Likewise. * tests/silent-lex-gcc.test: Likewise. --- ChangeLog | 39 +++++++++++++++++++++++++++++++++++ tests/cond35.test | 6 ++++++ tests/lex3.test | 6 ++++++ tests/lexvpath.test | 5 +++++ tests/silent-lex-gcc.test | 3 +++ tests/silent-lex-generic.test | 3 +++ 6 files changed, 62 insertions(+) diff --git a/ChangeLog b/ChangeLog index 8dea9ebe2..a4b823fa0 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,42 @@ +2011-10-14 Stefano Lattarini + + tests: fix spurious failures due to missing 'yywrap()' function + + The AC_PROG_LEX Autoconf macro does not diagnose a failure to find + the "lex library" expected to provide a `yywrap' function (function + which is required to link most lex-generated programs). On the + contrary, when all the link attempts (i.e., with `-ll' and `-lfl') + fail, configure declares that no lex library is needed, and simply + proceeds with the configuration process -- only for the build to + possibly fail later, at make time. + + This behaviour is intended; the Autoconf manual reads: + ``You are encouraged to use Flex in your sources, since it is + both more pleasant to use than plain Lex and the C source it + produces is portable. In order to ensure portability, however, + you must either provide a function `yywrap' or, if you don't use + it (e.g., your scanner has no `#include'-like feature), simply + include a `%noyywrap' statement in the scanner's source.'' + + This AC_PROG_LEX behaviour is causing some spurious failures of + the Automake testsuite in environments which lack a proper library + providing `yywrap' (this happens for example on Fedora-based + systems). The proper workaround is to simply provide a fall-back + implementation of `yywrap' in our lexers. + + See also partially-overlapping commit `v1.11-871-geb147a1' (from + the 'testsuite-work' branch), which was motivated by similar + spurious failures experienced when cross-compiling. + + Reported by Jim Meyering: + + + * tests/cond35.test: Provide a dummy `yywrap' function. + * tests/lex3.test: Likewise. + * tests/lexvpath.test: Likewise. + * tests/silent-lex-generic.test: Likewise. + * tests/silent-lex-gcc.test: Likewise. + 2011-10-18 Stefano Lattarini tests: fix spurious failure with FreeBSD make and Yacc in VPATH diff --git a/tests/cond35.test b/tests/cond35.test index c3c5f0bb5..776c9e144 100755 --- a/tests/cond35.test +++ b/tests/cond35.test @@ -59,6 +59,12 @@ test `grep tparse.h: Makefile.in | wc -l` = 1 cat > tscan.l << 'END' %% "END" return EOF; +%% +/* Avoid possible link errors. */ +int yywrap (void) +{ + return 1; +} END cat > tparse.y << 'END' diff --git a/tests/lex3.test b/tests/lex3.test index f7028646d..4714472dc 100755 --- a/tests/lex3.test +++ b/tests/lex3.test @@ -53,6 +53,12 @@ main () else return 1; } + +/* Avoid possible link errors. */ +int yywrap (void) +{ + return 1; +} END $ACLOCAL diff --git a/tests/lexvpath.test b/tests/lexvpath.test index 300a476db..65565f676 100755 --- a/tests/lexvpath.test +++ b/tests/lexvpath.test @@ -53,6 +53,11 @@ END cat > foo.c << 'END' int main () { return 0; } +/* Avoid possible link errors. */ +int yywrap (void) +{ + return 1; +} END $ACLOCAL diff --git a/tests/silent-lex-gcc.test b/tests/silent-lex-gcc.test index a55f35802..5ab5ecd9e 100755 --- a/tests/silent-lex-gcc.test +++ b/tests/silent-lex-gcc.test @@ -55,6 +55,9 @@ cat > foo.l <<'EOF' "END" return EOF; . %% +/* Avoid possible link errors. */ +int yywrap (void) { return 1; } +int main (void) { return 0; } EOF cp foo.l sub/bar.l diff --git a/tests/silent-lex-generic.test b/tests/silent-lex-generic.test index a61969827..582f529ff 100755 --- a/tests/silent-lex-generic.test +++ b/tests/silent-lex-generic.test @@ -55,6 +55,9 @@ cat > foo.l <<'EOF' "END" return EOF; . %% +/* Avoid possible link errors. */ +int yywrap (void) { return 1; } +int main (void) { return 0; } EOF cp foo.l sub/bar.l -- 2.47.2