virtestmock: Print invalid file accesses into a file

All the accesses to files outside our build or source directories
are now identified and appended into a file for later processing.
The location of the file that contains all the records can be
controlled via VIR_TEST_FILE_ACCESS env variable and defaults to
abs_builddir "/test_file_access.txt".

The script that will process the access file is to be added in
next commit.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>

.gitignore

@@ -169,6 +169,7 @@
 /tests/objectlocking.cm[ix]
 /tests/reconnect
 /tests/ssh
+/tests/test_file_access.txt
 /tests/test_conf
 /tools/libvirt-guests.sh
 /tools/virt-login-shell

HACKING

@@ -152,6 +152,17 @@ There is also a "./run" script at the top level, to make it easier to run
 programs that have not yet been installed, as well as to wrap invocations of
 various tests under gdb or Valgrind.
 
+When running our test suite it may happen that the test result is
+nondeterministic because of the test suite relying on a particular file in the
+system being accessible or having some specific value. To catch this kind of
+errors, the test suite has a module for that prints any path touched that
+fulfils constraints described above into a file. To enable it just set
+"VIR_TEST_FILE_ACCESS" environment variable. Then
+"VIR_TEST_FILE_ACCESS_OUTPUT" environment variable can alter location where
+the file is stored.
+
+  VIR_TEST_FILE_ACCESS=1 VIR_TEST_FILE_ACCESS_OUTPUT="/tmp/file_access.txt" ./qemuxml2argvtest
+
 
 
 (9) The Valgrind test should produce similar output to "make check". If the output

docs/hacking.html.in

@@ -189,6 +189,19 @@
           under gdb or Valgrind.
         </p>
 
+        <p>When running our test suite it may happen that the test result is
+        nondeterministic because of the test suite relying on a particular file
+        in the system being accessible or having some specific value. To catch
+        this kind of errors, the test suite has a module for that prints any
+        path touched that fulfils constraints described above
+        into a file. To enable it just set
+        <code>VIR_TEST_FILE_ACCESS</code> environment variable.
+        Then <code>VIR_TEST_FILE_ACCESS_OUTPUT</code> environment
+        variable can alter location where the file is stored.</p>
+<pre>
+  VIR_TEST_FILE_ACCESS=1 VIR_TEST_FILE_ACCESS_OUTPUT="/tmp/file_access.txt" ./qemuxml2argvtest
+</pre>
+
       </li>
       <li><p>The Valgrind test should produce similar output to
           <code>make check</code>. If the output has traces within libvirt

tests/Makefile.am

@@ -18,7 +18,9 @@
 
 # old automake does not provide abs_{src,build}dir variables
 abs_builddir = $(shell pwd)
+abs_topbuilddir = $(shell cd .. && pwd)
 abs_srcdir = $(shell cd $(srcdir) && pwd)
+abs_topsrcdir = $(shell cd $(top_srcdir) && pwd)
 
 SHELL = $(PREFERABLY_POSIX_SHELL)
 
@@ -33,7 +35,9 @@ INCLUDES = \
 
 AM_CFLAGS = \
 	-Dabs_builddir="\"$(abs_builddir)\"" \
+	-Dabs_topbuilddir="\"$(abs_topbuilddir)\"" \
 	-Dabs_srcdir="\"$(abs_srcdir)\"" \
+	-Dabs_topsrcdir="\"$(abs_topsrcdir)\"" \
 	$(LIBXML_CFLAGS) \
 	$(LIBNL_CFLAGS) \
 	$(GNUTLS_CFLAGS) \
@@ -1147,7 +1151,9 @@ virtestmock_la_SOURCES = \
 	virtestmock.c
 virtestmock_la_CFLAGS = $(AM_CFLAGS)
 virtestmock_la_LDFLAGS = $(MOCKLIBS_LDFLAGS)
-virtestmock_la_LIBADD = $(MOCKLIBS_LIBS)
+virtestmock_la_LIBADD = \
+	$(MOCKLIBS_LIBS) \
+	../src/libvirt_util.la
 else ! WITH_LINUX
 	EXTRA_DIST += virusbtest.c virusbmock.c \
 		virnetdevbandwidthtest.c virnetdevbandwidthmock.c \

tests/testutils.c

@@ -156,6 +156,11 @@ virtTestRun(const char *title,
 {
     int ret = 0;
 
+    /* Some test are fragile about environ settings.  If that's
+     * the case, don't poison it. */
+    if (getenv("VIR_TEST_MOCK_PROGNAME"))
+        setenv("VIR_TEST_MOCK_TESTNAME", title, 1);
+
     if (testCounter == 0 && !virTestGetVerbose())
         fprintf(stderr, "      ");
 
@@ -280,6 +285,7 @@ virtTestRun(const char *title,
     }
 #endif /* TEST_OOM */
 
+    unsetenv("VIR_TEST_MOCK_TESTNAME");
     return ret;
 }
 
@@ -832,8 +838,11 @@ virTestSetEnvPath(void)
     return ret;
 }
 
+#define TEST_MOCK (abs_builddir "/.libs/virtestmock.so")
+
 int virtTestMain(int argc,
                  char **argv,
+                 const char *lib,
                  int (*func)(void))
 {
     int ret;
@@ -842,6 +851,18 @@ int virtTestMain(int argc,
     char *oomstr;
 #endif
 
+    if (getenv("VIR_TEST_FILE_ACCESS"))
+        VIRT_TEST_PRELOAD(TEST_MOCK);
+
+    if (lib)
+        VIRT_TEST_PRELOAD(lib);
+
+    progname = last_component(argv[0]);
+    if (STRPREFIX(progname, "lt-"))
+        progname += 3;
+
+    setenv("VIR_TEST_MOCK_PROGNAME", progname, 1);
+
     virFileActivateDirOverride(argv[0]);
 
     if (virTestSetEnvPath() < 0)
@@ -850,9 +871,6 @@ int virtTestMain(int argc,
     if (!virFileExists(abs_srcdir))
         return EXIT_AM_HARDFAIL;
 
-    progname = last_component(argv[0]);
-    if (STRPREFIX(progname, "lt-"))
-        progname += 3;
     if (argc > 1) {
         fprintf(stderr, "Usage: %s\n", argv[0]);
         fputs("effective environment variables:\n"

tests/testutils.h

@@ -102,12 +102,13 @@ const char *virtTestCounterNext(void);
 
 int virtTestMain(int argc,
                  char **argv,
+                 const char *lib,
                  int (*func)(void));
 
 /* Setup, then call func() */
-# define VIRT_TEST_MAIN(func)                   \
-    int main(int argc, char **argv) {           \
-        return virtTestMain(argc, argv, func);  \
+# define VIRT_TEST_MAIN(func)                           \
+    int main(int argc, char **argv) {                   \
+        return virtTestMain(argc, argv, NULL, func);    \
     }
 
 # define VIRT_TEST_PRELOAD(lib)                                         \
@@ -132,8 +133,7 @@ int virtTestMain(int argc,
 
 # define VIRT_TEST_MAIN_PRELOAD(func, lib)                              \
     int main(int argc, char **argv) {                                   \
-        VIRT_TEST_PRELOAD(lib);                                         \
-        return virtTestMain(argc, argv, func);                          \
+        return virtTestMain(argc, argv, lib, func);                     \
     }
 
 virCapsPtr virTestGenericCapsInit(void);

tests/virtestmock.c

@@ -24,9 +24,14 @@
 #include <unistd.h>
 #include <sys/types.h>
 #include <fcntl.h>
+#include <execinfo.h>
+#include <sys/file.h>
 
 #include "internal.h"
 #include "configmake.h"
+#include "virstring.h"
+#include "viralloc.h"
+#include "virfile.h"
 
 static int (*real_open)(const char *path, int flags, ...);
 static FILE *(*real_fopen)(const char *path, const char *mode);
@@ -36,6 +41,11 @@ static int (*real___xstat)(int ver, const char *path, struct stat *sb);
 static int (*real_lstat)(const char *path, struct stat *sb);
 static int (*real___lxstat)(int ver, const char *path, struct stat *sb);
 
+static const char *progname;
+const char *output;
+
+#define VIR_FILE_ACCESS_DEFAULT abs_builddir "/test_file_access.txt"
+
 static void init_syms(void)
 {
     if (real_open)
@@ -49,9 +59,90 @@ static void init_syms(void)
 }
 
 static void
-checkPath(const char *path ATTRIBUTE_UNUSED)
+printFile(const char *file)
 {
-    /* Nada */
+    FILE *fp;
+    const char *testname = getenv("VIR_TEST_MOCK_TESTNAME");
+
+    if (!progname) {
+        progname = getenv("VIR_TEST_MOCK_PROGNAME");
+
+        if (!progname)
+            return;
+
+        output = getenv("VIR_TEST_FILE_ACCESS_OUTPUT");
+        if (!output)
+            output = VIR_FILE_ACCESS_DEFAULT;
+    }
+
+    if (!(fp = real_fopen(output, "a"))) {
+        fprintf(stderr, "Unable to open %s: %s\n", output, strerror(errno));
+        abort();
+    }
+
+    if (flock(fileno(fp), LOCK_EX) < 0) {
+        fprintf(stderr, "Unable to lock %s: %s\n", output, strerror(errno));
+        fclose(fp);
+        abort();
+    }
+
+    /* Now append the following line into the output file:
+     * $file: $progname $testname */
+
+    fprintf(fp, "%s: %s", file, progname);
+    if (testname)
+        fprintf(fp, ": %s", testname);
+
+    fputc('\n', fp);
+
+    flock(fileno(fp), LOCK_UN);
+    fclose(fp);
+}
+
+static void
+checkPath(const char *path)
+{
+    char *fullPath = NULL;
+    char *relPath = NULL;
+    char *crippledPath = NULL;
+
+    if (path[0] != '/' &&
+        virAsprintfQuiet(&relPath, "./%s", path) < 0)
+        goto error;
+
+    /* Le sigh. Both canonicalize_file_name() and realpath()
+     * expect @path to exist otherwise they return an error. So
+     * if we are called over an non-existent file, this could
+     * return an error. In that case do our best and hope we will
+     * catch possible error. */
+    if ((fullPath = canonicalize_file_name(relPath ? relPath : path))) {
+        path = fullPath;
+    } else {
+        /* Yeah, our worst nightmares just became true. Path does
+         * not exist. Cut off the last component and retry. */
+        if (VIR_STRDUP_QUIET(crippledPath, relPath ? relPath : path) < 0)
+            goto error;
+
+        virFileRemoveLastComponent(crippledPath);
+
+        if ((fullPath = canonicalize_file_name(crippledPath)))
+            path = fullPath;
+    }
+
+
+    if (!STRPREFIX(path, abs_topsrcdir) &&
+        !STRPREFIX(path, abs_topbuilddir)) {
+        printFile(path);
+    }
+
+    VIR_FREE(crippledPath);
+    VIR_FREE(relPath);
+    VIR_FREE(fullPath);
+
+    return;
+ error:
+    fprintf(stderr, "Out of memory\n");
+    abort();
 }