[Bug libgomp/60670] New: omp.h may differ between multilibs

[ro at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60670

            Bug ID: 60670
           Summary: omp.h may differ between multilibs
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libgomp
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ro at gcc dot gnu.org
                CC: jakub at gcc dot gnu.org
              Host: *-*-solaris2.*, x86_64-unknown-linux-gnu
            Target: *-*-solaris2.*, x86_64-unknown-linux-gnu
             Build: *-*-solaris2.*, x86_64-unknown-linux-gnu

It has been noticed that the libgomp omp.h header that is generated at build
time
may differ between different multilibs.  E.g. 

* i386-pc-solaris2.11:

--- omp.h       2014-03-21 14:27:34.522529041 +0100
+++ ../amd64/libgomp/omp.h      2014-03-21 14:27:56.903263206 +0100
@@ -34,13 +34,13 @@
 typedef struct
 {
   unsigned char _x[48] 
-    __attribute__((__aligned__(4)));
+    __attribute__((__aligned__(8)));
 } omp_lock_t;

 typedef struct
 {
-  unsigned char _x[56] 
-    __attribute__((__aligned__(4)));
+  unsigned char _x[64] 
+    __attribute__((__aligned__(8)));
 } omp_nest_lock_t;
 #endif

* sparc-sun-solaris2.11:

--- omp.h       2014-03-21 15:26:13.738263000 +0100
+++ ../sparcv9/libgomp/omp.h    2014-03-21 15:26:49.743545700 +0100
@@ -39,7 +39,7 @@

 typedef struct
 {
-  unsigned char _x[56] 
+  unsigned char _x[64] 
     __attribute__((__aligned__(8)));
 } omp_nest_lock_t;
 #endif

* x86_64-unknown-linux-gnu:

--- omp.h       2014-03-21 19:02:19.351059178 +0100
+++ ../32/libgomp/omp.h 2014-03-21 19:02:30.432588699 +0100
@@ -39,8 +39,8 @@

 typedef struct
 {
-  unsigned char _x[16] 
-    __attribute__((__aligned__(8)));
+  unsigned char _x[12] 
+    __attribute__((__aligned__(4)));
 } omp_nest_lock_t;
 #endif

Unfortunately, only the version for the default multilib is installed.  Given
that variables of those types can be allocated by user code and size and/or
alignment can differ between different multilibs, this can lead to all sorts
of errors when the allocations performed are smaller than what libgomp assumes.

It seems like different per-multilib headers need to be installed into separate
hierarchies to handle this.

  Rainer