[PATH] PR/49139 fix always_inline failures diagnostics

[Christian Bruel <christian dot bruel at st dot com>]

Hello,

The attached patch fixes a few diagnostic discrepancies for 
always_inline failures.

Illustrated by the fail_always_inline[12].c attached cases, the current 
behavior is one of:

- success (with and without -Winline), silently not honoring always_inline
   gcc fail_always_inline1.c -S -Winline -O0 -fpic
   gcc fail_always_inline1.c -S -O2 -fpic

- error: with -Winline but not without
   gcc fail_always_inline1.c -S -Winline -O2 -fpic

- error: without -Winline
   gcc fail_always_inline2.c -S -fno-early-inlining -O2
   or the original c++ attachment in this defect

note that -Winline never warns, as stated in the documentation

This simple patch consistently emits a warning (changing the sorry 
unimplemented message) whenever the attribute is not honored.

My first will was to generate and error instead of the warning, but 
since it is possible that inlines is only performed at LTO time, an 
error would be inapropriate (Note that today this is not possible with 
-Winline that would abort).

Another alternative I considered would be to emit the warning under 
-Winline rather than unconditionally, but this more a user misuse of the 
attribute, so should always be warned anyway. Or maybe a new 
-Winline-always that would be activated under -Wall ? Other opinion 
welcomed.

Tested with standard bootstrap and regression on x86.

Comments, and/or OK for trunk ?

Many thanks,

Christian

2010-05-25  Christian Bruel  <christian.bruel@st.com>
	
	PR 49139
	* ipa-inline-transform.c (inline_transform):force call to 
optimize_inline_calls error if function is always_inline.
	* tree-inline.c (tree_inlinable_function_p): always warn.
	(expand_call_inline): Likewise.
	
2010-05-25  Christian Bruel  <christian.bruel@st.com>
	
	* gcc.db/always_inline.c: Removed -Winline. Update checks
	* gcc.db/always_inline2.c: Likewise.
	* gcc.db/always_inline3.c: Likewise.
	* gcc.db/fail_always_inline1.c: New test.
	* gcc.db/fail_always_inline2.c: New test.

Attachment: fail_always_inline1.c
Description: Text document

Attachment: fail_always_inline2.c
Description: Text document

Attachment: always_inline_warn.patch
Description: Text document