Re: Lists and aliasing (Re: Freeze on 27 February)

[Lennart Sorensen]

On Tue, Feb 21, 2012 at 06:09:36PM +0100, Vladimir 'φ-coder/phcoder' Serbinenko 
wrote:
> Try attached patch
> 
> 
> -- 
> Regards
> Vladimir 'φ-coder/phcoder' Serbinenko
> 

> === modified file 'grub-core/kern/list.c'
> --- grub-core/kern/list.c     2012-02-12 02:52:17 +0000
> +++ grub-core/kern/list.c     2012-02-12 02:52:48 +0000
> @@ -32,3 +32,24 @@
>  
>    return NULL;
>  }
> +
> +void
> +grub_list_push (grub_list_t *head, grub_list_t item)
> +{
> +  item->prev = head;
> +  if (*head)
> +    (*head)->prev = &item->next;
> +  item->next = *head;
> +  *head = item;
> +}
> +
> +void
> +grub_list_remove (grub_list_t item)
> +{
> +  if (item->prev)
> +    *item->prev = item->next;
> +  if (item->next)
> +    item->next->prev = item->prev;
> +  item->next = 0;
> +  item->prev = 0;
> +}
> 
> === modified file 'include/grub/list.h'
> --- include/grub/list.h       2012-02-12 02:52:17 +0000
> +++ include/grub/list.h       2012-02-12 02:53:20 +0000
> @@ -31,26 +31,8 @@
>  };
>  typedef struct grub_list *grub_list_t;
>  
> -static inline void
> -grub_list_push (grub_list_t *head, grub_list_t item)
> -{
> -  item->prev = head;
> -  if (*head)
> -    (*head)->prev = &item->next;
> -  item->next = *head;
> -  *head = item;
> -}
> -
> -static inline void
> -grub_list_remove (grub_list_t item)
> -{
> -  if (item->prev)
> -    *item->prev = item->next;
> -  if (item->next)
> -    item->next->prev = item->prev;
> -  item->next = 0;
> -  item->prev = 0;
> -}
> +void EXPORT_FUNC(grub_list_push) (grub_list_t *head, grub_list_t item);
> +void EXPORT_FUNC(grub_list_remove) (grub_list_t item);
>  
>  #define FOR_LIST_ELEMENTS(var, list) for ((var) = (list); (var); (var) = 
> (var)->next)
>  

That actually seems to have done it.  I am still trying to wrap my head
around why that made a difference since it appears to be identical code
moved somewhere else.  It isn't inlined anymore, but should that make
a big difference?

Only 509 warnings left (down from 5000 or so).

Any patches for:

gcc-4.4 -DHAVE_CONFIG_H -I. -I../..  -Wall -W -I./include -DGRUB_UTIL=1 
-DGRUB_LIBDIR=\"/usr/lib/grub\" -DLOCALEDIR=\"/usr/share/locale\"  
-DGRUB_MACHINE_EMU=1 -DGRUB_MACHINE=POWERPC_EMU -DGRUB_TARGET_CPU_POWERPC=1 
-DGRUB_FILE=\"grub-core/lib/pbkdf2.c\" -I. -I../.. -I. -
I../.. -I../../include -I./include  -I./grub-core/gnulib 
-I../../grub-core/gnulib                -g -Wall -O2 -Wall -W -Wshadow 
-Wold-style-declaration -Wold-style-definition -Wpointer-arith -Wundef -Wextra 
-Waddress -Warray-bounds -Wattributes -Wbuiltin-macro-redefined 
-Wcast-align -Wchar-subscripts -Wclobbered -Wcomment -Wcoverage-mismatch 
-Wdeprecated -Wdeprecated-declarations -Wdisabled-optimization -Wdiv-by-zero 
-Wempty-body -Wendif-labels -Wfloat-equal -Wformat-contains-nul 
-Wformat-extra-args -Wformat-security -Wformat-y2k -Wigno
red-qualifiers -Wimplicit -Wimplicit-function-declaration -Wimplicit-int 
-Winit-self -Wint-to-pointer-cast -Winvalid-pch -Wunsafe-loop-optimizations 
-Wlogical-op -Wmain -Wmissing-braces -Wmissing-field-initializers 
-Wmissing-format-attribute -Wmissing-noreturn -Wmudflap 
-Wmultichar -Wnonnull -Woverflow -Wpacked-bitfield-compat -Wparentheses 
-Wpointer-arith -Wpointer-to-int-cast -Wreturn-type -Wsequence-point -Wshadow 
-Wsign-compare -Wstack-protector -Wstrict-aliasing -Wswitch -Wsync-nand 
-Wtrigraphs  -Wtype-limits -Wundef -Wuninitialize
d -Wunknown-pragmas -Wunreachable-code -Wunused -Wunused-function 
-Wunused-label -Wunused-parameter -Wunused-result -Wunused-value  
-Wunused-variable -Wvariadic-macros -Wvolatile-register-var -Wwrite-strings 
-Wmissing-declarations -Wmissing-parameter-type  -Wmissing-prot
otypes -Wnested-externs -Wstrict-prototypes -Wpointer-sign  -Wno-undef 
-Wno-sign-compare -Wno-unused -Wno-unused-parameter -Wno-redundant-decls 
-Wno-unreachable-code -Wno-conversion -Wno-old-style-definition                
-c -o grub-core/lib/libgrubkern_a-pbkdf2.o `test
 -f 'grub-core/lib/pbkdf2.c' || echo '../../'`grub-core/lib/pbkdf2.c
../../grub-core/lib/pbkdf2.c: In function 'grub_crypto_pbkdf2':
../../grub-core/lib/pbkdf2.c:77: warning: cannot optimize possibly infinite 
loops
../../grub-core/lib/pbkdf2.c:73: warning: cannot optimize possibly infinite 
loops

gcc-4.4 -DHAVE_CONFIG_H -I. -I../..  -Wall -W -I./include -DGRUB_UTIL=1 
-DGRUB_LIBDIR=\"/usr/lib/grub\" -DLOCALEDIR=\"/usr/share/locale\"  
-DGRUB_MACHINE_EMU=1 -DGRUB_MACHINE=POWERPC_EMU -DGRUB_TARGET_CPU_POWERPC=1 
-DGRUB_FILE=\"grub-core/disk/ldm.c\" -I. -I../.. -I. -I../.. -I../../include 
-I./include  -I./grub-core/gnulib -I../../grub-core/gnulib                -g 
-Wall -O2 -Wall -W -Wshadow -Wold-style-declaration -Wold-style-definition 
-Wpointer-arith -Wundef -Wextra -Waddress -Warray-bounds -Wattributes 
-Wbuiltin-macro-redefined -Wcast-align -Wchar-subscripts -Wclobbered -Wcomment 
-Wcoverage-mismatch -Wdeprecated -Wdeprecated-declarations 
-Wdisabled-optimization -Wdiv-by-zero -Wempty-body -Wendif-labels -Wfloat-equal 
-Wformat-contains-nul -Wformat-extra-args -Wformat-security -Wformat-y2k 
-Wignored-qualifiers -Wimplicit -Wimplicit-function-declaration -Wimplicit-int 
-Winit-self -Wint-to-pointer-cast -Winvalid-pch -Wunsafe-loop-optimizations 
-Wlogical-op -Wmain -Wmissing-braces -Wmissing-field-initializers 
-Wmissing-format-attribute -Wmissing-noreturn -Wmudflap -Wmultichar -Wnonnull 
-Woverflow -Wpacked-bitfield-compat -Wparentheses -Wpointer-arith 
-Wpointer-to-int-cast -Wreturn-type -Wsequence-point -Wshadow -Wsign-compare 
-Wstack-protector -Wstrict-aliasing -Wswitch -Wsync-nand -Wtrigraphs  
-Wtype-limits -Wundef -Wuninitialized -Wunknown-pragmas -Wunreachable-code 
-Wunused -Wunused-function -Wunused-label -Wunused-parameter -Wunused-result 
-Wunused-value  -Wunused-variable -Wvariadic-macros -Wvolatile-register-var 
-Wwrite-strings -Wmissing-declarations -Wmissing-parameter-type  
-Wmissing-prototypes -Wnested-externs -Wstrict-prototypes -Wpointer-sign  
-Wno-undef -Wno-sign-compare -Wno-unused -Wno-unused-parameter 
-Wno-redundant-decls -Wno-unreachable-code -Wno-conversion 
-Wno-old-style-definition                -c -o 
grub-core/disk/libgrubkern_a-ldm.o `test -f 'grub-core/disk/ldm.c' || echo 
'../../'`grub-core/disk/ldm.c
../../grub-core/disk/ldm.c: In function 'grub_util_get_ldm':
../../grub-core/disk/ldm.c:834: warning: 'res' may be used uninitialized in 
this function

gcc-4.4 -DHAVE_CONFIG_H -I. -I../..  -Wall -W -I./include -DGRUB_UTIL=1 
-DGRUB_LIBDIR=\"/usr/lib/grub\" -DLOCALEDIR=\"/usr/share/locale\"  
-DGRUB_MACHINE_EMU=1 -DGRUB_MACHINE=POWERPC_EMU -DGRUB_TARGET_CPU_POWERPC=1 
-DGRUB_FILE=\"grub-core/commands/testload.c\" -I. -I../.. -I. -I../.. 
-I../../include -I./include  -I../../grub-core/lib/minilzo 
-I../../grub-core/lib/xzembed -DMINILZO_HAVE_CONFIG_H                -g -Wall 
-O2 -Wall -W -Wshadow -Wold-style-declaration -Wold-style-definition 
-Wpointer-arith -Wundef -Wextra -Waddress -Warray-bounds -Wattributes 
-Wbuiltin-macro-redefined -Wcast-align -Wchar-subscripts -Wclobbered -Wcomment 
-Wcoverage-mismatch -Wdeprecated -Wdeprecated-declarations 
-Wdisabled-optimization -Wdiv-by-zero -Wempty-body -Wendif-labels -Wfloat-equal 
-Wformat-contains-nul -Wformat-extra-args -Wformat-security -Wformat-y2k 
-Wignored-qualifiers -Wimplicit -Wimplicit-function-declaration -Wimplicit-int 
-Winit-self -Wint-to-pointer-cast -Winvalid-pch -Wunsafe-loop-optimizations 
-Wlogical-op -Wmain -Wmissing-braces -Wmissing-field-initializers 
-Wmissing-format-attribute -Wmissing-noreturn -Wmudflap -Wmultichar -Wnonnull 
-Woverflow -Wpacked-bitfield-compat -Wparentheses -Wpointer-arith 
-Wpointer-to-int-cast -Wreturn-type -Wsequence-point -Wshadow -Wsign-compare 
-Wstack-protector -Wstrict-aliasing -Wswitch -Wsync-nand -Wtrigraphs  
-Wtype-limits -Wundef -Wuninitialized -Wunknown-pragmas -Wunreachable-code 
-Wunused -Wunused-function -Wunused-label -Wunused-parameter -Wunused-result 
-Wunused-value  -Wunused-variable -Wvariadic-macros -Wvolatile-register-var 
-Wwrite-strings -Wmissing-declarations -Wmissing-parameter-type  
-Wmissing-prototypes -Wnested-externs -Wstrict-prototypes -Wpointer-sign  
-fno-builtin -Wno-undef                -c -o 
grub-core/commands/libgrubmods_a-testload.o `test -f 
'grub-core/commands/testload.c' || echo '../../'`grub-core/commands/testload.c
../../grub-core/commands/testload.c: In function 'grub_cmd_testload':
../../grub-core/commands/testload.c:99: warning: cannot optimize loop, the loop 
counter may overflow
../../grub-core/commands/testload.c:80: warning: cannot optimize loop, the loop 
counter may overflow

gcc-4.4 -DHAVE_CONFIG_H -I. -I../..  -Wall -W -I./include -DGRUB_UTIL=1 
-DGRUB_LIBDIR=\"/usr/lib/grub\" -DLOCALEDIR=\"/usr/share/locale\"  
-DGRUB_MACHINE_EMU=1 -DGRUB_MACHINE=POWERPC_EMU -DGRUB_TARGET_CPU_POWERPC=1 
-DGRUB_FILE=\"grub-core/fs/affs.c\" -I. -I../.. -I. -I../.. -I../../include 
-I./include  -I../../grub-core/lib/minilzo -I../../grub-core/lib/xzembed 
-DMINILZO_HAVE_CONFIG_H                -g -Wall -O2 -Wall -W -Wshadow 
-Wold-style-declaration -Wold-style-definition -Wpointer-arith -Wundef -Wextra 
-Waddress -Warray-bounds -Wattributes -Wbuiltin-macro-redefined -Wcast-align 
-Wchar-subscripts -Wclobbered -Wcomment -Wcoverage-mismatch -Wdeprecated 
-Wdeprecated-declarations -Wdisabled-optimization -Wdiv-by-zero -Wempty-body 
-Wendif-labels -Wfloat-equal -Wformat-contains-nul -Wformat-extra-args 
-Wformat-security -Wformat-y2k -Wignored-qualifiers -Wimplicit 
-Wimplicit-function-declaration -Wimplicit-int -Winit-self 
-Wint-to-pointer-cast -Winvalid-pch -Wunsafe-loop-optimizations -Wlogical-op 
-Wmain -Wmissing-braces -Wmissing-field-initializers -Wmissing-format-attribute 
-Wmissing-noreturn -Wmudflap -Wmultichar -Wnonnull -Woverflow 
-Wpacked-bitfield-compat -Wparentheses -Wpointer-arith -Wpointer-to-int-cast 
-Wreturn-type -Wsequence-point -Wshadow -Wsign-compare -Wstack-protector 
-Wstrict-aliasing -Wswitch -Wsync-nand -Wtrigraphs  -Wtype-limits -Wundef 
-Wuninitialized -Wunknown-pragmas -Wunreachable-code -Wunused -Wunused-function 
-Wunused-label -Wunused-parameter -Wunused-result -Wunused-value  
-Wunused-variable -Wvariadic-macros -Wvolatile-register-var -Wwrite-strings 
-Wmissing-declarations -Wmissing-parameter-type  -Wmissing-prototypes 
-Wnested-externs -Wstrict-prototypes -Wpointer-sign  -fno-builtin -Wno-undef    
            -c -o grub-core/fs/libgrubmods_a-affs.o `test -f 
'grub-core/fs/affs.c' || echo '../../'`grub-core/fs/affs.c
../../grub-core/fs/affs.c: In function 'grub_affs_read_block':
../../grub-core/fs/affs.c:146: warning: cannot optimize possibly infinite loops

gcc-4.4 -DHAVE_CONFIG_H -I. -I../..  -Wall -W -I./include -DGRUB_UTIL=1 
-DGRUB_LIBDIR=\"/usr/lib/grub\" -DLOCALEDIR=\"/usr/share/locale\"  
-DGRUB_MACHINE_EMU=1 -DGRUB_MACHINE=POWERPC_EMU -DGRUB_TARGET_CPU_POWERPC=1 
-DGRUB_FILE=\"grub-core/fs/cpio_be.c\" -I. -I../.. -I. -I../.. -I../../include 
-I./include  -I../../grub-core/lib/minilzo -I../../grub-core/lib/xzembed 
-DMINILZO_HAVE_CONFIG_H                -g -Wall -O2 -Wall -W -Wshadow 
-Wold-style-declaration -Wold-style-definition -Wpointer-arith -Wundef -Wextra 
-Waddress -Warray-bounds -Wattributes -Wbuiltin-macro-redefined -Wcast-align 
-Wchar-subscripts -Wclobbered -Wcomment -Wcoverage-mismatch -Wdeprecated 
-Wdeprecated-declarations -Wdisabled-optimization -Wdiv-by-zero -Wempty-body 
-Wendif-labels -Wfloat-equal -Wformat-contains-nul -Wformat-extra-args 
-Wformat-security -Wformat-y2k -Wignored-qualifiers -Wimplicit 
-Wimplicit-function-declaration -Wimplicit-int -Winit-self 
-Wint-to-pointer-cast -Winvalid-pch -Wunsafe-loop-optimizations -Wlogical-op 
-Wmain -Wmissing-braces -Wmissing-field-initializers -Wmissing-format-attribute 
-Wmissing-noreturn -Wmudflap -Wmultichar -Wnonnull -Woverflow 
-Wpacked-bitfield-compat -Wparentheses -Wpointer-arith -Wpointer-to-int-cast 
-Wreturn-type -Wsequence-point -Wshadow -Wsign-compare -Wstack-protector 
-Wstrict-aliasing -Wswitch -Wsync-nand -Wtrigraphs  -Wtype-limits -Wundef 
-Wuninitialized -Wunknown-pragmas -Wunreachable-code -Wunused -Wunused-function 
-Wunused-label -Wunused-parameter -Wunused-result -Wunused-value  
-Wunused-variable -Wvariadic-macros -Wvolatile-register-var -Wwrite-strings 
-Wmissing-declarations -Wmissing-parameter-type  -Wmissing-prototypes 
-Wnested-externs -Wstrict-prototypes -Wpointer-sign  -fno-builtin -Wno-undef    
            -c -o grub-core/fs/libgrubmods_a-cpio_be.o `test -f 
'grub-core/fs/cpio_be.c' || echo '../../'`grub-core/fs/cpio_be.c
In file included from ../../grub-core/fs/cpio_be.c:2:
../../grub-core/fs/cpio.c: In function 'grub_cpio_find_file':
../../grub-core/fs/cpio.c:187: warning: will never be executed
../../grub-core/fs/cpio.c:187: warning: will never be executed
../../grub-core/fs/cpio.c:187: warning: will never be executed
../../grub-core/fs/cpio.c:187: warning: will never be executed

and many more.

I can include a complete build log again if you want.

-- 
Len Sorensen