> Honza, > > For example g++.dg/abi/vcall1.C fails at a call in a "localalias" > function, which jumps to a bad location: > > > (gdb) up > #1 0x100004c0 in B::B() [clone .localalias.2] () > (gdb) x/16i $pc-32 > 0x100004a0 <_ZN1BC2Ev+156>: add r10,r10,r8 > 0x100004a4 <_ZN1BC2Ev+160>: mr r3,r10 > 0x100004a8 <_ZN1BC2Ev+164>: stw r2,20(r1) > 0x100004ac <_ZN1BC2Ev+168>: lwz r10,0(r9) > 0x100004b0 <_ZN1BC2Ev+172>: lwz r11,8(r9) > 0x100004b4 <_ZN1BC2Ev+176>: mtctr r10 > 0x100004b8 <_ZN1BC2Ev.localalias.2+180>: lwz r2,4(r9) > 0x100004bc <_ZN1BC2Ev.localalias.2+184>: bctrl > => 0x100004c0 <_ZN1BC2Ev.localalias.2+188>: lwz r2,20(r1) > 0x100004c4 <_ZN1BC2Ev.localalias.2+192>: addi r1,r31,64 > 0x100004c8 <_ZN1BC2Ev.localalias.2+196>: lwz r0,8(r1) > 0x100004cc <_ZN1BC2Ev.localalias.2+200>: mtlr r0 > 0x100004d0 <_ZN1BC2Ev.localalias.2+204>: lwz r31,-4(r1) > 0x100004d4 <_ZN1BC2Ev.localalias.2+208>: blr
I suppose this is the problem Richard mentioned - the offsets are not computed by DECL_RTL callback but by place_block. > >>> is SYMBOL_REF_BLOCK_OFFSET (target) guaranteed to be valid at this point? > >>> It looked at face value like you'd need a recursive call to > >>> place_block_symbol > >>> on the target before the copy. > >> > >> My reading was that SYMBOL_REF_BLOCK_OFFSET is computed at DECL_RTL > >> calculation time. But you are right - it is done by validize_mem that > >> is not done by DECL_RTL. Shall I just call it on target first? > > > > Yeah, sounds like calling place_block_symbol would be safer. I will test: Index: varasm.c =================================================================== --- varasm.c (revision 211096) +++ varasm.c (working copy) @@ -7094,6 +7094,7 @@ if (snode->alias) { rtx target = DECL_RTL (symtab_alias_ultimate_target (snode)->decl); + place_block_symbol (symbol); SYMBOL_REF_BLOCK_OFFSET (symbol) = SYMBOL_REF_BLOCK_OFFSET (target); return; } Honza > > > > IIRC, the reason I didn't do it at SET_DECL_RTL time is that some frontends > > tended to create placeholder decls that for whatever reason ended up with > > an initial DECL_RTL, then changed the properties of the decl later once > > more information was known. (This was all many years ago.) > > > > Thanks, > > Richard