tests: Redirect to real I/O to support coverage run

Implement a check that redirects mock io functions to the real
implementations. Real I/O functions are needed for the coverage tool to
be able to create and write files.

BUG=None
BRANCH=None
TEST=None

Change-Id: I0817fce6ea0f53a4c127794a0d8246504675f805
Signed-off-by: Evan Benn <evanbenn@chromium.org>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/69539
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Anastasia Klimchuk <aklm@chromium.org>

tests/io_real.c

@@ -0,0 +1,63 @@
+/*
+ * This file is part of the flashrom project.
+ *
+ * Copyright 2022 Google LLC
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include "io_mock.h"
+#include "wraps.h"
+
+#include "io_real.h"
+#include <string.h>
+
+static int io_real_open(void *state, const char *pathname, int flags, mode_t mode)
+{
+	LOG_ME;
+	return __real_open(pathname, flags, mode);
+}
+
+static FILE *io_real_fdopen(void *state, int fd, const char *mode)
+{
+	LOG_ME;
+	return __real_fdopen(fd, mode);
+}
+
+static size_t io_real_fwrite(void *state, const void *ptr, size_t size, size_t nmemb, FILE *fp)
+{
+	return __real_fwrite(ptr, size, nmemb, fp);
+}
+
+/* Mock ios that defer to the real io functions.
+ * These exist so that code coverage can print to real files on disk.
+ */
+static const struct io_mock real_io = {
+	.iom_open = io_real_open,
+	.iom_fwrite = io_real_fwrite,
+	.iom_fdopen = io_real_fdopen,
+};
+
+/* Return 0 if string ends with suffix. */
+static int check_suffix(const char *string, const char *suffix)
+{
+	int len_l = strlen(string);
+	int len_r = strlen(suffix);
+	if (len_l > len_r)
+		return strcmp(string + len_l - len_r, suffix);
+	return 1;
+}
+
+void maybe_unmock_io(const char *pathname)
+{
+	const char *gcov_suffix = ".gcda";
+	if (!check_suffix(pathname, gcov_suffix))
+		io_mock_register(&real_io);
+}

tests/io_real.h

@@ -0,0 +1,24 @@
+/*
+ * This file is part of the flashrom project.
+ *
+ * Copyright 2022 Google LLC
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef IO_REAL_H
+#define IO_REAL_H
+
+/* Detect file io that should not be mocked, for example code coverage writing
+ * gcda files. Call io_mock_register with functions that defer to real io.
+ */
+void maybe_unmock_io(const char* pathname);
+
+#endif /* IO_REAL_H */

tests/meson.build

@@ -23,6 +23,7 @@ test_srcs = files(
   'chip.c',
   'chip_wp.c',
   'selfcheck.c',
+  'io_real.c',
 )
 
 if not programmer.get('dummy').get('active')

tests/wraps.h

@@ -29,6 +29,7 @@ uintptr_t __wrap_pcidev_readbar(void *dev, int bar);
 void __wrap_sio_write(uint16_t port, uint8_t reg, uint8_t data);
 uint8_t __wrap_sio_read(uint16_t port, uint8_t reg);
 int __wrap_open(const char *pathname, int flags, ...);
+int __real_open(const char *pathname, int flags, ...);
 int __wrap_open64(const char *pathname, int flags, ...);
 int __wrap___open64_2(const char *pathname, int flags, ...);
 int __wrap_ioctl(int fd, unsigned long int request, ...);
@@ -37,6 +38,7 @@ int __wrap_read(int fd, void *buf, size_t sz);
 FILE *__wrap_fopen(const char *pathname, const char *mode);
 FILE *__wrap_fopen64(const char *pathname, const char *mode);
 FILE *__wrap_fdopen(int fd, const char *mode);
+FILE *__real_fdopen(int fd, const char *mode);
 int __wrap_stat(const char *path, void *buf);
 int __wrap_stat64(const char *path, void *buf);
 int __wrap___xstat(const char *path, void *buf);
@@ -49,6 +51,7 @@ char *__wrap_fgets(char *buf, int len, FILE *fp);
 char *__wrap___fgets_chk(char *buf, int len, FILE *fp);
 size_t __wrap_fread(void *ptr, size_t size, size_t nmemb, FILE *fp);
 size_t __wrap_fwrite(const void *ptr, size_t size, size_t nmemb, FILE *fp);
+size_t __real_fwrite(const void *ptr, size_t size, size_t nmemb, FILE *fp);
 int __wrap_fflush(FILE *fp);
 int __wrap_fileno(FILE *fp);
 int __wrap_fsync(int fd);