Re: [PATCH v2] lib: drop (replace) debug_build()

[Julien Grall]

Hi Jan,

On 23/12/2020 16:05, Jan Beulich wrote:

Its expansion shouldn't be tied to NDEBUG - down the road we may want to
allow enabling assertions independently of CONFIG_DEBUG. Replace the few
uses by a new xen_build_info() helper, subsuming gcov_string at the same
time (while replacing the stale CONFIG_GCOV used there) and also adding
CONFIG_UBSAN indication.

Signed-off-by: Jan Beulich <jbeul...@suse.com>

For the Arm code:

Acked-by: Julien Grall <jgr...@amazon.com>

Cheers,

---
v2: Introduce xen_build_info() including also gcov and ubsan info.

--- a/xen/arch/arm/traps.c
+++ b/xen/arch/arm/traps.c
@@ -175,14 +175,14 @@ static void print_xen_info(void)
  {
      char taint_str[TAINT_STRING_MAX_LEN];

- printk("----[ Xen-%d.%d%s %s debug=%c " gcov_string " %s ]----\n",

+    printk("----[ Xen-%d.%d%s  %s  %s  %s ]----\n",
             xen_major_version(), xen_minor_version(), xen_extra_version(),
  #ifdef CONFIG_ARM_32
             "arm32",
  #else
             "arm64",
  #endif
-           debug_build() ? 'y' : 'n', print_tainted(taint_str));
+           xen_build_info(), print_tainted(taint_str));
  }

#ifdef CONFIG_ARM_32

--- a/xen/arch/x86/x86_64/traps.c
+++ b/xen/arch/x86/x86_64/traps.c
@@ -29,9 +29,9 @@ static void print_xen_info(void)
  {
      char taint_str[TAINT_STRING_MAX_LEN];

- printk("----[ Xen-%d.%d%s x86_64 debug=%c " gcov_string " %s ]----\n",

+    printk("----[ Xen-%d.%d%s  x86_64  %s  %s ]----\n",
             xen_major_version(), xen_minor_version(), xen_extra_version(),
-           debug_build() ? 'y' : 'n', print_tainted(taint_str));
+           xen_build_info(), print_tainted(taint_str));
  }

enum context { CTXT_hypervisor, CTXT_pv_guest, CTXT_hvm_guest };

--- a/xen/common/version.c
+++ b/xen/common/version.c
@@ -70,6 +70,30 @@ const char *xen_deny(void)
      return "<denied>";
  }

+static const char build_info[] =

+    "debug="
+#ifdef CONFIG_DEBUG
+    "y"
+#else
+    "n"
+#endif
+#ifdef CONFIG_COVERAGE
+# ifdef __clang__
+    " llvmcov=y"
+# else
+    " gcov=y"
+# endif
+#endif
+#ifdef CONFIG_UBSAN
+    " ubsan=y"
+#endif
+    "";
+
+const char *xen_build_info(void)
+{
+    return build_info;
+}
+
  static const void *build_id_p __read_mostly;
  static unsigned int build_id_len __read_mostly;

--- a/xen/drivers/char/console.c

+++ b/xen/drivers/char/console.c
@@ -1002,10 +1002,10 @@ void __init console_init_preirq(void)
      spin_lock(&console_lock);
      __putstr(xen_banner());
      spin_unlock(&console_lock);
-    printk("Xen version %d.%d%s (%s@%s) (%s) debug=%c " gcov_string " %s\n",
+    printk("Xen version %d.%d%s (%s@%s) (%s) %s %s\n",
             xen_major_version(), xen_minor_version(), xen_extra_version(),
-           xen_compile_by(), xen_compile_domain(),
-           xen_compiler(), debug_build() ? 'y' : 'n', xen_compile_date());
+           xen_compile_by(), xen_compile_domain(), xen_compiler(),
+           xen_build_info(), xen_compile_date());
      printk("Latest ChangeSet: %s\n", xen_changeset());

/* Locate and print the buildid, if applicable. */

--- a/xen/include/xen/lib.h
+++ b/xen/include/xen/lib.h
@@ -48,21 +48,13 @@
  #define BUILD_BUG_ON(cond) ((void)BUILD_BUG_ON_ZERO(cond))
  #endif

-#ifdef CONFIG_GCOV

-#define gcov_string "gcov=y"
-#else
-#define gcov_string ""
-#endif
-
  #ifndef NDEBUG
  #define ASSERT(p) \
      do { if ( unlikely(!(p)) ) assert_failed(#p); } while (0)
  #define ASSERT_UNREACHABLE() assert_failed("unreachable")
-#define debug_build() 1
  #else
  #define ASSERT(p) do { if ( 0 && (p) ) {} } while (0)
  #define ASSERT_UNREACHABLE() do { } while (0)
-#define debug_build() 0
  #endif

#define ABS(_x) ({ \

--- a/xen/include/xen/version.h
+++ b/xen/include/xen/version.h
@@ -16,6 +16,7 @@ const char *xen_extra_version(void);
  const char *xen_changeset(void);
  const char *xen_banner(void);
  const char *xen_deny(void);
+const char *xen_build_info(void);
  int xen_build_id(const void **p, unsigned int *len);

#ifdef BUILD_ID

--
Julien Grall