test: Add a test for auto-args in dlopen library

The Parent and Child classes are in a library which is loaded by dlopen.

  $ uftrace -a t-dlopen2
              [1358278] | main(1, 0xADDR) {
     1.004  s [1358278] |   dlopen("./libbaz.so", RTLD_LAZY) = 0xADDR;
    11.847 us [1358278] |   dlsym(0xADDR, "create") = &create;
              [1358278] |   create() {
              [1358278] |     Child::Child(0xADDR) {
     7.422 us [1358278] |       Parent::Parent(0xADDR);
     8.859 us [1358278] |     } /* Child::Child */
    10.168 us [1358278] |   } = 0xADDR; /* create */
    99.308 us [1358278] |   Child::func(0xADDR, 1) = 100;
    36.109 us [1358278] |   dlclose(0xADDR) = 0;
     2.012  s [1358278] | } = 0; /* main */

Signed-off-by: Namhyung Kim <namhyung@gmail.com>

tests/t291_arg_dlopen.py

@@ -0,0 +1,62 @@
+#!/usr/bin/env python3
+
+import os
+import re
+
+from runtest import TestBase
+
+class TestCase(TestBase):
+    def __init__(self):
+        TestBase.__init__(self, 'dlopen2', lang="C++", cflags='-g', result="""
+# DURATION     TID      FUNCTION
+            [1358278] | main(1, 0xADDR) {
+   1.004  s [1358278] |   dlopen("./libbaz.so", RTLD_LAZY) = 0xADDR;
+  11.847 us [1358278] |   dlsym(0xADDR, "create") = &create;
+            [1358278] |   create() {
+            [1358278] |     Child::Child(0xADDR) {
+   7.422 us [1358278] |       Parent::Parent(0xADDR);
+   8.859 us [1358278] |     } /* Child::Child */
+  10.168 us [1358278] |   } = 0xADDR; /* create */
+  99.308 us [1358278] |   Child::func(0xADDR, 1) = 100;
+  36.109 us [1358278] |   dlclose(0xADDR) = 0;
+   2.012  s [1358278] | } = 0; /* main */
+""")
+        os.environ['LD_LIBRARY_PATH'] = "."
+
+    def build(self, name, cflags='', ldflags=''):
+        # cygprof doesn't support arguments now
+        if cflags.find('-finstrument-functions') >= 0:
+            return TestBase.TEST_SKIP
+        # we want to test auto-args from DWARF
+        if not 'dwarf' in self.feature:
+            return TestBase.TEST_SKIP
+
+        if TestBase.build_libfoo(self, 'bar', cflags, ldflags) != 0:
+            return TestBase.TEST_BUILD_FAIL
+        if TestBase.build_libfoo(self, 'baz', cflags, ldflags + ' -L. -lbar') != 0:
+            return TestBase.TEST_BUILD_FAIL
+        return TestBase.build_libmain(self, name, 's-dlopen2.cpp', ['libdl.so'],
+                                      cflags, ldflags)
+
+    def setup(self):
+        self.option = '-F main -a'
+
+    def sort(self, output):
+        result = []
+        for ln in output.split('\n'):
+            # ignore blank lines and comments
+            if ln.strip() == '' or ln.startswith('#'):
+                continue
+            line = ln.split('|', 1)[-1]
+            func = re.sub(r'0x[0-9a-f]+', '0xADDR', line)
+            result.append(func)
+
+        return '\n'.join(result)
+
+    def fixup(self, cflags, result):
+        # GCC seems to optimize out the empty Parent::Parent().
+        return result.replace("""
+            [1358278] |     Child::Child(0xADDR) {
+   7.422 us [1358278] |       Parent::Parent(0xADDR);
+   8.859 us [1358278] |     } /* Child::Child */""", """
+            [1358278] |     Child::Child(0xADDR);""")