On Thu, Sep 8, 2022 at 8:45 PM Sathyanarayanan Kuppuswamy sathyanarayanan.kuppuswamy@linux.intel.com wrote:
On 9/8/22 7:16 AM, Wander Lairson Costa wrote:
+#ifdef DEBUG +static void print_array_hex(const char *title, const char *prefix_str,
const void *buf, int len)+{
- const __u8 *ptr = buf;
- int i, rowsize = HEX_DUMP_SIZE;
- if (!len || !buf)
return;- printf("\t\t%s", title);
- for (i = 0; i < len; i++) {
if (!(i % rowsize))printf("\n%s%.8x:", prefix_str, i);printf(" %.2x", ptr[i]);- }
- printf("\n");
+} +#endif
+TEST(verify_report) +{
- __u8 reportdata[TDX_REPORTDATA_LEN];
- struct tdreport tdreport;
- struct tdx_report_req req;
- int devfd, i;
- devfd = open(TDX_GUEST_DEVNAME, O_RDWR | O_SYNC);
- ASSERT_LT(0, devfd);
- /* Generate sample report data */
- for (i = 0; i < TDX_REPORTDATA_LEN; i++)
reportdata[i] = i;- /* Initialize IOCTL request */
- req.subtype = 0;
- req.reportdata = (__u64)reportdata;
- req.rpd_len = TDX_REPORTDATA_LEN;
- req.tdreport = (__u64)&tdreport;
- req.tdr_len = sizeof(tdreport);
- /* Get TDREPORT */
- ASSERT_EQ(0, ioctl(devfd, TDX_CMD_GET_REPORT, &req));
+#ifdef DEBUG
- print_array_hex("\n\t\tTDX report data\n", "",
reportdata, sizeof(reportdata));- print_array_hex("\n\t\tTDX tdreport data\n", "",
&tdreport, sizeof(tdreport));+#endif
You can unconditionally define print_array_hex, and use `if (DEBUG)` instead of #ifdef `DEBUG here`. The compiler will get rid of the unused code when DEBUG is not defined as expected, but you get the parser to validate it independent of the definition of DEBUG.
Currently, DEBUG is a macro, so we cannot use if (DEBUG) directly. You are suggesting to change DEBUG to a variable? Any reason to make this change? I think both changes are functionally similar. So I am wondering why to make this change?
My thought is always to define DEBUG. If in debug mode it is defined to 1; otherwise to 0. Then, you can use `if (DEBUG)` instead of `#ifdef DEBUG`. But the former will always check the syntax of the debug code, independent of the value of DEBUG, and the compiler will generate the same code. The GNU coding standard [1] explains that better than I do.
[1] https://www.gnu.org/prep/standards/standards.html#Conditional-Compilation
-- Sathyanarayanan Kuppuswamy Linux Kernel Developer