[PATCH] ld: Add an LTO test for common symbol override

[PATCH] ld: Add an LTO test for common symbol override

[H.J. Lu]

Linker checks if a symbol in an archive member is a real definition, not
common, before including the archive member in the link output so that
only a real definition in archive will override the common symbol in
object file.  Add an LTO test to verify that a real definition in archive
overrides the common symbol in object file.

	* testsuite/ld-plugin/common-1.c: New file.
	* testsuite/ld-plugin/definition-1.c: Likewise.
	* testsuite/ld-plugin/lto.exp: Run common tests.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
---
 ld/testsuite/ld-plugin/common-1.c     | 11 +++++++++++
 ld/testsuite/ld-plugin/definition-1.c |  6 ++++++
 ld/testsuite/ld-plugin/lto.exp        | 18 ++++++++++++++++++
 3 files changed, 35 insertions(+)
 create mode 100644 ld/testsuite/ld-plugin/common-1.c
 create mode 100644 ld/testsuite/ld-plugin/definition-1.c

diff --git a/ld/testsuite/ld-plugin/common-1.c b/ld/testsuite/ld-plugin/common-1.c
new file mode 100644
index 00000000000..b4f616aeea2
--- /dev/null
+++ b/ld/testsuite/ld-plugin/common-1.c
@@ -0,0 +1,11 @@
+#include <stdio.h>
+
+int foo;
+
+int main()
+{
+  if (foo == 1)
+    printf ("PASS\n");
+
+  return 0;
+}
diff --git a/ld/testsuite/ld-plugin/definition-1.c b/ld/testsuite/ld-plugin/definition-1.c
new file mode 100644
index 00000000000..8eb90e849d2
--- /dev/null
+++ b/ld/testsuite/ld-plugin/definition-1.c
@@ -0,0 +1,6 @@
+int foo = 1;
+
+void
+func (void)
+{
+}
diff --git a/ld/testsuite/ld-plugin/lto.exp b/ld/testsuite/ld-plugin/lto.exp
index 1a8c3736307..bbd68407edc 100644
--- a/ld/testsuite/ld-plugin/lto.exp
+++ b/ld/testsuite/ld-plugin/lto.exp
@@ -231,6 +231,13 @@ set lto_link_tests [list \
    "$plug_opt" "-flto $lto_no_fat -fcommon" \
    {pr26389.c} \
    [list [list "nm" "$plug_opt" "pr26389.d"]]] \
+  [list "Build libdefinition-1.a" \
+   "$plug_opt" \
+   "-O2 -fcommon -flto $lto_no_fat" \
+   {definition-1.c} \
+   {} \
+   "libdefinition-1.a" \
+  ] \
 ]
 
 if { [at_least_gcc_version 10 0] && [check_lto_shared_available] } {
@@ -763,6 +770,17 @@ set lto_run_tests [list \
    {pr26262a.c} "pr26262b" "pass.out" \
    "-flto -O2" "c" "" \
    ""] \
+  [list "Run common-1" \
+   "-O2 -flto" \
+   "" \
+   {common-1.c} \
+   "common-1" \
+   "pass.out" \
+   "-O2 -fcommon -flto $lto_no_fat" \
+   "c" \
+   "" \
+   "tmpdir/libdefinition-1.a" \
+  ] \
 ]
 
 if { [at_least_gcc_version 4 7] } {
-- 
2.46.0