diff options
Diffstat (limited to 'src/liblink')
| -rw-r--r-- | src/liblink/go.c | 2 | ||||
| -rw-r--r-- | src/liblink/obj6.c | 52 |
2 files changed, 50 insertions, 4 deletions
diff --git a/src/liblink/go.c b/src/liblink/go.c index e31c71ab92..3bc780b852 100644 --- a/src/liblink/go.c +++ b/src/liblink/go.c @@ -21,7 +21,7 @@ static struct { int *val; } exper[] = { {"fieldtrack", &fieldtrack_enabled}, - {"basepointer", &framepointer_enabled}, + {"framepointer", &framepointer_enabled}, }; static void diff --git a/src/liblink/obj6.c b/src/liblink/obj6.c index 696026300c..0ccb03924f 100644 --- a/src/liblink/obj6.c +++ b/src/liblink/obj6.c @@ -379,7 +379,7 @@ preprocess(Link *ctxt, LSym *cursym) { Prog *p, *q, *p1, *p2; int32 autoffset, deltasp; - int a, pcsize; + int a, pcsize, bpsize; vlong textstksiz, textarg; if(ctxt->tlsg == nil) @@ -403,6 +403,18 @@ preprocess(Link *ctxt, LSym *cursym) if(autoffset < 0) autoffset = 0; + if(framepointer_enabled && autoffset > 0) { + // Make room for to save a base pointer. If autoffset == 0, + // this might do something special like a tail jump to + // another function, so in that case we omit this. + bpsize = ctxt->arch->ptrsize; + autoffset += bpsize; + textstksiz += bpsize; + p->to.offset = ((uint64)p->to.offset & (0xffffffffull<<32)) | (uint32)autoffset; + } else { + bpsize = 0; + } + cursym->args = p->to.offset>>32; cursym->locals = textstksiz; @@ -447,6 +459,28 @@ preprocess(Link *ctxt, LSym *cursym) if(q != nil) q->pcond = p; deltasp = autoffset; + + if(bpsize > 0) { + // Save caller's BP + p = appendp(ctxt, p); + p->as = AMOVQ; + p->from.type = TYPE_REG; + p->from.reg = REG_BP; + p->to.type = TYPE_MEM; + p->to.reg = REG_SP; + p->to.scale = 1; + p->to.offset = autoffset - bpsize; + + // Move current frame to BP + p = appendp(ctxt, p); + p->as = ALEAQ; + p->from.type = TYPE_MEM; + p->from.reg = REG_SP; + p->from.scale = 1; + p->from.offset = autoffset - bpsize; + p->to.type = TYPE_REG; + p->to.reg = REG_BP; + } if(cursym->text->from.scale & WRAPPER) { // if(g->panic != nil && g->panic->argp == FP) g->panic->argp = bottom-of-frame @@ -580,12 +614,12 @@ preprocess(Link *ctxt, LSym *cursym) pcsize = p->mode/8; a = p->from.name; if(a == NAME_AUTO) - p->from.offset += deltasp; + p->from.offset += deltasp - bpsize; if(a == NAME_PARAM) p->from.offset += deltasp + pcsize; a = p->to.name; if(a == NAME_AUTO) - p->to.offset += deltasp; + p->to.offset += deltasp - bpsize; if(a == NAME_PARAM) p->to.offset += deltasp + pcsize; @@ -630,6 +664,18 @@ preprocess(Link *ctxt, LSym *cursym) ctxt->diag("unbalanced PUSH/POP"); if(autoffset) { + if(bpsize > 0) { + // Restore caller's BP + p->as = AMOVQ; + p->from.type = TYPE_MEM; + p->from.reg = REG_SP; + p->from.scale = 1; + p->from.offset = autoffset - bpsize; + p->to.type = TYPE_REG; + p->to.reg = REG_BP; + p = appendp(ctxt, p); + } + p->as = AADJSP; p->from.type = TYPE_CONST; p->from.offset = -autoffset; |