Change in coreboot[master]: assert.h: Simplify dead_code()

[Nico Huber (Code Review)]

Hello Julius Werner, Felix Held,

I'd like you to do a code review. Please visit

https://review.coreboot.org/c/coreboot/+/40240

to review the following change.

Change subject: assert.h: Simplify dead_code()
......................................................................

assert.h: Simplify dead_code()

It turns out the linker's error message already includes the line
number of the dead_code() invocation. If we don't include the line
number in the identifier for our undefined reference, we don't need
individual identifiers at all and can work with a single, global
declaration.

Change-Id: Ib63868ce3114c3f839867a3bfb1b03bdb6facf16
Signed-off-by: Nico Huber 
---
M src/include/assert.h
1 file changed, 3 insertions(+), 8 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/40/40240/1

diff --git a/src/include/assert.h b/src/include/assert.h
index 492629d..7252ab6 100644
--- a/src/include/assert.h
+++ b/src/include/assert.h
@@ -52,15 +52,10 @@
  * The error message when this hits will look like this:
  *
  * ramstage/lib/bootmode.o: In function `display_init_required':
- * bootmode.c:42: undefined reference to `dead_code_assertion_failed_at_line_42'
+ * bootmode.c:42: undefined reference to `_dead_code_assertion_failed'
  */
-#define __dead_code(tag, line) do { \
-	extern void dead_code_assertion_failed##tag##_at_line_##line(void) \
-		__attribute__((noreturn)); \
-	dead_code_assertion_failed##tag##_at_line_##line(); \
-} while (0)
-#define _dead_code(tag, line) __dead_code(tag, line)
-#define dead_code(tag) _dead_code(tag, __LINE__)
+extern void _dead_code_assertion_failed(void) __attribute__((noreturn));
+#define dead_code() _dead_code_assertion_failed()

/* This can be used in the context of an expression of type 'type'. */
 #define dead_code_t(type) ({ \

[build bot (Jenkins) (Code Review)]

build bot (Jenkins) has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/40240 )

Change subject: assert.h: Simplify dead_code()
......................................................................

Patch Set 1:

(1 comment)

https://review.coreboot.org/c/coreboot/+/40240/1/src/include/assert.h 
File src/include/assert.h:

https://review.coreboot.org/c/coreboot/+/40240/1/src/include/assert.h@57 
PS1, Line 57: extern void _dead_code_assertion_failed(void) __attribute__((noreturn));
function definition argument 'void' should also have an identifier name

[Nico Huber (Code Review)]

Hello build bot (Jenkins), Julius Werner, Felix Held,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/40240

to look at the new patch set (#2).

Change subject: assert.h: Simplify dead_code()
......................................................................

assert.h: Simplify dead_code()

It turns out the linker's error message already includes the line
number of the dead_code() invocation. If we don't include the line
number in the identifier for our undefined reference, we don't need
individual identifiers at all and can work with a single, global
declaration.

Change-Id: Ib63868ce3114c3f839867a3bfb1b03bdb6facf16
Signed-off-by: Nico Huber 
---
M src/include/assert.h
M src/security/vboot/misc.h
2 files changed, 5 insertions(+), 10 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/40/40240/2

[build bot (Jenkins) (Code Review)]

build bot (Jenkins) has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/40240 )

Change subject: assert.h: Simplify dead_code()
......................................................................

Patch Set 2:

(1 comment)

https://review.coreboot.org/c/coreboot/+/40240/2/src/include/assert.h 
File src/include/assert.h:

https://review.coreboot.org/c/coreboot/+/40240/2/src/include/assert.h@57 
PS2, Line 57: extern void _dead_code_assertion_failed(void) __attribute__((noreturn));
function definition argument 'void' should also have an identifier name

[Nico Huber (Code Review)]

Nico Huber has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/40240 )

Change subject: assert.h: Simplify dead_code()
......................................................................

Patch Set 2:

(1 comment)

https://review.coreboot.org/c/coreboot/+/40240/2/src/include/assert.h 
File src/include/assert.h:

https://review.coreboot.org/c/coreboot/+/40240/2/src/include/assert.h@57 
PS2, Line 57: extern void _dead_code_assertion_failed(void) __attribute__((noreturn));
> function definition argument 'void' should also have an identifier name

Is that a weird way to tell me to put the attribute before the function name?

[Julius Werner (Code Review)]

Julius Werner has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/40240 )

Change subject: assert.h: Simplify dead_code()
......................................................................

Patch Set 2: Code-Review+2

[Felix Held (Code Review)]

Felix Held has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/40240 )

Change subject: assert.h: Simplify dead_code()
......................................................................

Patch Set 2: Code-Review+1

this looks much cleaner to me

[Angel Pons (Code Review)]

Angel Pons has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/40240 )

Change subject: assert.h: Simplify dead_code()
......................................................................

Patch Set 2: Code-Review+2

[Angel Pons (Code Review)]

Angel Pons has submitted this change. ( https://review.coreboot.org/c/coreboot/+/40240 )

Change subject: assert.h: Simplify dead_code()
......................................................................

assert.h: Simplify dead_code()

It turns out the linker's error message already includes the line
number of the dead_code() invocation. If we don't include the line
number in the identifier for our undefined reference, we don't need
individual identifiers at all and can work with a single, global
declaration.

Change-Id: Ib63868ce3114c3f839867a3bfb1b03bdb6facf16
Signed-off-by: Nico Huber 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/40240
Tested-by: build bot (Jenkins) 
Reviewed-by: Julius Werner 
Reviewed-by: Felix Held 
Reviewed-by: Angel Pons 
---
M src/include/assert.h
M src/security/vboot/misc.h
2 files changed, 5 insertions(+), 10 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Felix Held: Looks good to me, but someone else must approve
  Julius Werner: Looks good to me, approved
  Angel Pons: Looks good to me, approved

diff --git a/src/include/assert.h b/src/include/assert.h
index 492629d..7252ab6 100644
--- a/src/include/assert.h
+++ b/src/include/assert.h
@@ -52,15 +52,10 @@
  * The error message when this hits will look like this:
  *
  * ramstage/lib/bootmode.o: In function `display_init_required':
- * bootmode.c:42: undefined reference to `dead_code_assertion_failed_at_line_42'
+ * bootmode.c:42: undefined reference to `_dead_code_assertion_failed'
  */
-#define __dead_code(tag, line) do { \
-	extern void dead_code_assertion_failed##tag##_at_line_##line(void) \
-		__attribute__((noreturn)); \
-	dead_code_assertion_failed##tag##_at_line_##line(); \
-} while (0)
-#define _dead_code(tag, line) __dead_code(tag, line)
-#define dead_code(tag) _dead_code(tag, __LINE__)
+extern void _dead_code_assertion_failed(void) __attribute__((noreturn));
+#define dead_code() _dead_code_assertion_failed()

/* This can be used in the context of an expression of type 'type'. */
 #define dead_code_t(type) ({ \
diff --git a/src/security/vboot/misc.h b/src/security/vboot/misc.h
index 22cc750..fd422b2 100644
--- a/src/security/vboot/misc.h
+++ b/src/security/vboot/misc.h
@@ -53,7 +53,7 @@
    else if (CONFIG(VBOOT_STARTS_IN_BOOTBLOCK))
    	return ENV_BOOTBLOCK;
    else
-		dead_code(_in_vboot_misc_h);
+		dead_code();
 }

static inline int verstage_should_load(void)
@@ -82,7 +82,7 @@
    	/* Post-RAM stages are "after the romstage" */
    	return !ENV_ROMSTAGE_OR_BEFORE;
    } else {
-		dead_code(_in_vboot_misc_h);
+		dead_code();
    }
 }

[9elements QA (Code Review)]

9elements QA has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/40240 )

Change subject: assert.h: Simplify dead_code()
......................................................................

Patch Set 3:

Automatic boot test returned (PASS/FAIL/TOTAL): 3/0/3
Emulation targets:
EMULATION_QEMU_X86_Q35 using payload TianoCore : SUCCESS : https://lava.9esec.io/r/2222
EMULATION_QEMU_X86_Q35 using payload SeaBIOS : SUCCESS : https://lava.9esec.io/r/2221
EMULATION_QEMU_X86_I440FX using payload SeaBIOS : SUCCESS : https://lava.9esec.io/r/2220

Please note: This test is under development and might not be accurate at all!