Re: Various build failures in current bzr tree

[Lennart Sorensen]

On Mon, Feb 13, 2012 at 10:39:17AM -0500, Lennart Sorensen wrote:
> Well that doesn't really seem to be helping.  I just checked out the
> latest tree from bzr and applied this one patch, and I am still getting
> close to 5000 warnings.

Doing this instead does seem to reduce it from 5000 to 1500 warnings:

--- ../grub/include/grub/list.h 2012-02-09 13:54:20.181305000 -0500
+++ include/grub/list.h 2012-02-15 11:40:27.513949443 -0500
@@ -28,7 +28,7 @@
 {
   struct grub_list *next;
   struct grub_list **prev;
-};
+} __attribute__ ((may_alias));
 typedef struct grub_list *grub_list_t;
 
 static inline void
@@ -84,7 +84,7 @@
   struct grub_named_list *next;
   struct grub_named_list **prev;
   char *name;
-};
+} __attribute__ ((may_alias));
 typedef struct grub_named_list *grub_named_list_t;
 
 void * EXPORT_FUNC(grub_named_list_find) (grub_named_list_t head,
@@ -111,7 +111,7 @@
   struct grub_prio_list **prev;
   char *name;
   int prio;
-};
+} __attribute__ ((may_alias));
 typedef struct grub_prio_list *grub_prio_list_t;
 
 void EXPORT_FUNC(grub_prio_list_insert) (grub_prio_list_t *head,

Doing this drops it to 1100 warnings:

--- ../grub/include/grub/list.h 2012-02-09 13:54:20.181305000 -0500
+++ include/grub/list.h 2012-02-15 11:52:30.729949590 -0500
@@ -28,8 +28,8 @@
 {
   struct grub_list *next;
   struct grub_list **prev;
-};
-typedef struct grub_list *grub_list_t;
+} __attribute__ ((may_alias));
+typedef struct grub_list __attribute__ ((may_alias)) *grub_list_t;
 
 static inline void
 grub_list_push (grub_list_t *head, grub_list_t item)
@@ -84,8 +84,8 @@
   struct grub_named_list *next;
   struct grub_named_list **prev;
   char *name;
-};
-typedef struct grub_named_list *grub_named_list_t;
+} __attribute__ ((may_alias));
+typedef struct grub_named_list __attribute__ ((may_alias)) *grub_named_list_t;
 
 void * EXPORT_FUNC(grub_named_list_find) (grub_named_list_t head,
                                          const char *name);
@@ -111,8 +111,8 @@
   struct grub_prio_list **prev;
   char *name;
   int prio;
-};
-typedef struct grub_prio_list *grub_prio_list_t;
+} __attribute__ ((may_alias));
+typedef struct grub_prio_list __attribute__ ((may_alias)) *grub_prio_list_t;
 
 void EXPORT_FUNC(grub_prio_list_insert) (grub_prio_list_t *head,
                                         grub_prio_list_t item);

At that point there doesn't appear to be any more strict aliasing
compliants about list.h.  There are 'imcompatible pointer type warnings
though, as well as a with alising issues in other files.

For example:

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=\"util/misc.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-alig
n -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-qualifi
ers -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 -Wne
sted-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 
util/libgrubkern_a-misc.o `test -f 'util/misc.c' || e
cho '../../'`util/misc.c
In file included from ../../include/grub/term.h:68,
                 from ../../util/misc.c:41:
../../include/grub/list.h: In function 'grub_list_push':
../../include/grub/list.h:37: warning: assignment from incompatible pointer type

happens very frequently.

-- 
Len Sorensen