libctf, tests: do not assume host and target have identical field offsets

The newly-introduced libctf-lookup unnamed-field-info test checks
C compiler-observed field offsets against libctf-computed ones
by #including the testcase in the lookup runner as well as
generating CTF for it.  This only works if the host, on which
the lookup runner is compiled and executed, is the same architecture as
the target, for which the CTF is generated: when crossing, the trick
may fail.

So pass down an indication of whether this is a cross into the
testsuite, and add a new no_cross flag to .lk files that is used to
suppress test execution when a cross-compiler is being tested.

libctf/
	* Makefile.am (check_DEJAGNU): Pass down TEST_CROSS.
	* Makefile.in: Regenerated.
	* testsuite/lib/ctf-lib.exp (run_lookup_test): Use it to
	implement the new no_cross option.
	* testsuite/libctf-lookup/unnamed-field-info.lk: Mark as
	no_cross.

4 files changed, 24 insertions, 3 deletions

diff --git a/libctf/Makefile.am b/libctf/Makefile.am
index c959b09..b1dbc2f 100644
--- a/libctf/Makefile.am
+++ b/libctf/Makefile.am
@@ -92,10 +92,15 @@ check-DEJAGNU: site.exp development.exp
 	r=`pwd`; export r; \
 	LC_ALL=C; export LC_ALL; \
 	EXPECT=$(EXPECT); export EXPECT; \
+	if [ "@host@" = "@target@" ] ; then \
+	  TEST_CROSS=no; \
+	else \
+	  TEST_CROSS=yes; \
+	fi; \
 	runtest=$(RUNTEST); \
 	if $(SHELL) -c "$$runtest --version" > /dev/null 2>&1; then \
 	  $$runtest --tool $(DEJATOOL) --srcdir $${srcroot}/testsuite \
-		CC="$(CC)" CC_FOR_TARGET="$(CC_FOR_TARGET)" \
+		CC="$(CC)" CC_FOR_TARGET="$(CC_FOR_TARGET)" TEST_CROSS="$${TEST_CROSS}" \
 		CFLAGS="$(CFLAGS) -I$(INCDIR) -I$(srcdir) -I$(builddir) -I$(builddir)/../bfd $(ZLIBINC)" \
 		LIBS="$(libctf_nobfd_la_LIBADD) $(LIBS)" $(RUNTESTFLAGS); \
 	else echo "WARNING: could not find \`runtest'" 1>&2; :;\
diff --git a/libctf/Makefile.in b/libctf/Makefile.in
index c6cb55c..3d2696b 100644
--- a/libctf/Makefile.in
+++ b/libctf/Makefile.in
@@ -1678,10 +1678,15 @@ check-DEJAGNU: site.exp development.exp
 	r=`pwd`; export r; \
 	LC_ALL=C; export LC_ALL; \
 	EXPECT=$(EXPECT); export EXPECT; \
+	if [ "@host@" = "@target@" ] ; then \
+	  TEST_CROSS=no; \
+	else \
+	  TEST_CROSS=yes; \
+	fi; \
 	runtest=$(RUNTEST); \
 	if $(SHELL) -c "$$runtest --version" > /dev/null 2>&1; then \
 	  $$runtest --tool $(DEJATOOL) --srcdir $${srcroot}/testsuite \
-		CC="$(CC)" CC_FOR_TARGET="$(CC_FOR_TARGET)" \
+		CC="$(CC)" CC_FOR_TARGET="$(CC_FOR_TARGET)" TEST_CROSS="$${TEST_CROSS}" \
 		CFLAGS="$(CFLAGS) -I$(INCDIR) -I$(srcdir) -I$(builddir) -I$(builddir)/../bfd $(ZLIBINC)" \
 		LIBS="$(libctf_nobfd_la_LIBADD) $(LIBS)" $(RUNTESTFLAGS); \
 	else echo "WARNING: could not find \`runtest'" 1>&2; :;\
diff --git a/libctf/testsuite/lib/ctf-lib.exp b/libctf/testsuite/lib/ctf-lib.exp
index 3ee82a0..73b67b4 100644
--- a/libctf/testsuite/lib/ctf-lib.exp
+++ b/libctf/testsuite/lib/ctf-lib.exp
@@ -103,6 +103,9 @@ proc compile_link_one_host_cc { src output additional_args } {
 #   xfail: GLOB|PROC ...
 #	This test is expected to fail on a specified list of targets.
 #
+#   no_cross:
+#       If set, do not run this test when host != target.
+#
 # Each option may occur at most once unless otherwise mentioned.
 #
 # After the option lines come regexp lines.  run_lookup_test calls
@@ -110,7 +113,7 @@ proc compile_link_one_host_cc { src output additional_args } {
 # regexps in FILE.d.
 #
 proc run_lookup_test { name } {
-    global CC_FOR_TARGET CFLAGS_FOR_TARGET LIBS
+    global CC_FOR_TARGET CFLAGS_FOR_TARGET LIBS TEST_CROSS
     global copyfile env runtests srcdir subdir verbose
 
     if ![runtest_file_p $runtests $name] then {
@@ -139,6 +142,7 @@ proc run_lookup_test { name } {
     set opts(name) {}
     set opts(source) {}
     set opts(xfail) {}
+    set opts(no_cross) {}
 
     foreach i $opt_array {
 	set opt_name [lindex $i 0]
@@ -156,6 +160,12 @@ proc run_lookup_test { name } {
 	set opts($opt_name) [concat $opts($opt_name) $opt_val]
     }
 
+    if { [llength $opts(no_cross)] != 0
+	 && "$TEST_CROSS" eq "yes" } {
+	untested "$subdir/$name not tested when cross-compiling"
+	return
+    }
+
     if { [llength $opts(lookup)] == 0 } {
 	set opts(lookup) "$file.c"
     } else {
diff --git a/libctf/testsuite/libctf-lookup/unnamed-field-info.lk b/libctf/testsuite/libctf-lookup/unnamed-field-info.lk
index eae6a51..680b8e0 100644
--- a/libctf/testsuite/libctf-lookup/unnamed-field-info.lk
+++ b/libctf/testsuite/libctf-lookup/unnamed-field-info.lk
@@ -1,2 +1,3 @@
 # source: unnamed-field-info-ctf.c
+# no_cross: yes
 Offset validation complete.