380998 - StackGrowthDirection is not reliable with Sun Studio 11

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Ginn Chen]

StackGrowthDirection in jscpucfg.c is not reliable with Sun Studio 11 on Solaris x86.

Sun Studio doesn't support "__attribute__((noinline))"
Compile it with optimization will get JS_STACK_GROWTH_DIRECTION (1)
should be JS_STACK_GROWTH_DIRECTION (-1)

It may cause problems with some javascripts.

Comment 1

[Ginn Chen]

some options we may use,

1) don't call StackGrowthDirection(), hardcode JS_STACK_GROWTH_DIRECTION for Solaris
2) use "-g" to compile jscpucfg.c, it will avoid inline for Sun Studio.
3) put StackGrowthDirection() into another C file, maybe we can avoid it be inlined for all/most compilers
4) use a function pointer for StackGrowthDirection(), maybe we can avoid it be inlined for all/most compilers

Comment 2

[Boying Lu]

Attachment: Add "-g" to prevent StackGrowthDirection from being inlined

Comment 3

[Ginn Chen]

at least we should use MOZ_DEBUG_FLAGS instead of "-g"

Comment 4

[Boying Lu]

Attachment: Use more general "MOZ_DEBUG_FLAGS" instead of "-g"

Comment 5

[Brendan Eich [:brendan]]

It would be better to define NS_NEVER_INLINE to something that your compiler respects -- is there such a pragma?

$ grep NS_NEVER_INLINE *.[ch]
jscpucfg.c:#define NS_NEVER_INLINE __attribute__((noinline))
jscpucfg.c:#define NS_NEVER_INLINE
jscpucfg.c:static int NS_NEVER_INLINE StackGrowthDirection(int *dummy1addr)

/be

Comment 6

[Ginn Chen]

Attachment: patch that uses #pragma for Sun Studio

I forgot Sun Studio C does have no_inline pragma.
But it's not as same as gcc.
I've to declare the function first.

Sun Studio 12 will have same attributes ability as gcc.

Comment 7

[Brendan Eich [:brendan]]

Comment on attachment 265477 [details] [diff] [review]
patch that uses #pragma for Sun Studio

r=me, thanks.

/be

Comment 8

[Ginn Chen]

Comment on attachment 265477 [details] [diff] [review]
patch that uses #pragma for Sun Studio

brendan, can you commit this for me?

Also, I think it's important for 1.5.x and 2.0.x.

BTW:
#pragma no_inline only works for Sun Studio C compiler not C++.
"-g" option only disables inlining for Sun Studio C++ compiler.
So this approach is the correct one.

Comment 9

[Brian Crowder]

jscpucfg.c: 3.26

Comment 10

[Brian Crowder]

This should certainly not block a branch release, in my opinion.

Comment 11

[Daniel Veditz [:dveditz]]

Not blocking _us_, but Sun (and other vendors) are committed to longer branch support than Mozilla.

Comment 12

[Daniel Veditz [:dveditz]]

Comment on attachment 265477 [details] [diff] [review]
patch that uses #pragma for Sun Studio

Approved for 1.8.1.5 and 1.8.0.13, a=dveditz for release-drivers

Comment 13

[Brendan Eich [:brendan]]

Probably this should be assigned to crowder, who did the checkin, rather than to ginn.chen.

/be

Comment 14

[Brian Crowder]

MOZILLA_1_8_BRANCH: jscpucfg.c: 3.25.2.1
MOZILLA_1_8_0_BRANCH: jscpucfg.c: 3.25.10.1