summaryrefslogtreecommitdiffstats
path: root/src/cmd/internal/obj/pass.go
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-16 19:23:18 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-16 19:23:18 +0000
commit43a123c1ae6613b3efeed291fa552ecd909d3acf (patch)
treefd92518b7024bc74031f78a1cf9e454b65e73665 /src/cmd/internal/obj/pass.go
parentInitial commit. (diff)
downloadgolang-1.20-43a123c1ae6613b3efeed291fa552ecd909d3acf.tar.xz
golang-1.20-43a123c1ae6613b3efeed291fa552ecd909d3acf.zip
Adding upstream version 1.20.14.upstream/1.20.14upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/cmd/internal/obj/pass.go')
-rw-r--r--src/cmd/internal/obj/pass.go181
1 files changed, 181 insertions, 0 deletions
diff --git a/src/cmd/internal/obj/pass.go b/src/cmd/internal/obj/pass.go
new file mode 100644
index 0000000..b91a15d
--- /dev/null
+++ b/src/cmd/internal/obj/pass.go
@@ -0,0 +1,181 @@
+// Inferno utils/6l/pass.c
+// https://bitbucket.org/inferno-os/inferno-os/src/master/utils/6l/pass.c
+//
+// Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved.
+// Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
+// Portions Copyright © 1997-1999 Vita Nuova Limited
+// Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
+// Portions Copyright © 2004,2006 Bruce Ellis
+// Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
+// Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
+// Portions Copyright © 2009 The Go Authors. All rights reserved.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package obj
+
+// Code and data passes.
+
+// brloop returns the ultimate destination of the series of unconditional jumps beginning at p.
+// In the case of an infinite loop, brloop returns nil.
+func brloop(p *Prog) *Prog {
+ c := 0
+ for q := p; q != nil; q = q.To.Target() {
+ if q.As != AJMP || q.To.Target() == nil {
+ return q
+ }
+ c++
+ if c >= 5000 {
+ // infinite loop
+ return nil
+ }
+ }
+ panic("unreachable")
+}
+
+// checkaddr checks that a has an expected encoding, especially TYPE_CONST vs TYPE_ADDR.
+func checkaddr(ctxt *Link, p *Prog, a *Addr) {
+ switch a.Type {
+ case TYPE_NONE, TYPE_REGREG2, TYPE_REGLIST:
+ return
+
+ case TYPE_BRANCH, TYPE_TEXTSIZE:
+ if a.Reg != 0 || a.Index != 0 || a.Scale != 0 || a.Name != 0 {
+ break
+ }
+ return
+
+ case TYPE_MEM:
+ return
+
+ case TYPE_CONST:
+ // TODO(rsc): After fixing SHRQ, check a.Index != 0 too.
+ if a.Name != 0 || a.Sym != nil || a.Reg != 0 {
+ ctxt.Diag("argument is TYPE_CONST, should be TYPE_ADDR, in %v", p)
+ return
+ }
+
+ if a.Reg != 0 || a.Scale != 0 || a.Name != 0 || a.Sym != nil || a.Val != nil {
+ break
+ }
+ return
+
+ case TYPE_FCONST, TYPE_SCONST:
+ if a.Reg != 0 || a.Index != 0 || a.Scale != 0 || a.Name != 0 || a.Offset != 0 || a.Sym != nil {
+ break
+ }
+ return
+
+ case TYPE_REG:
+ // TODO(rsc): After fixing PINSRQ, check a.Offset != 0 too.
+ // TODO(rsc): After fixing SHRQ, check a.Index != 0 too.
+ if a.Scale != 0 || a.Name != 0 || a.Sym != nil {
+ break
+ }
+ return
+
+ case TYPE_ADDR:
+ if a.Val != nil {
+ break
+ }
+ if a.Reg == 0 && a.Index == 0 && a.Scale == 0 && a.Name == 0 && a.Sym == nil {
+ ctxt.Diag("argument is TYPE_ADDR, should be TYPE_CONST, in %v", p)
+ }
+ return
+
+ case TYPE_SHIFT, TYPE_REGREG:
+ if a.Index != 0 || a.Scale != 0 || a.Name != 0 || a.Sym != nil || a.Val != nil {
+ break
+ }
+ return
+
+ case TYPE_INDIR:
+ // Expect sym and name to be set, nothing else.
+ // Technically more is allowed, but this is only used for *name(SB).
+ if a.Reg != 0 || a.Index != 0 || a.Scale != 0 || a.Name == 0 || a.Offset != 0 || a.Sym == nil || a.Val != nil {
+ break
+ }
+ return
+ case TYPE_SPECIAL:
+ if a.Reg != 0 || a.Index != 0 || a.Scale != 0 || a.Name != 0 || a.Class != 0 || a.Sym != nil {
+ break
+ }
+ return
+ }
+
+ ctxt.Diag("invalid encoding for argument %v", p)
+}
+
+func linkpatch(ctxt *Link, sym *LSym, newprog ProgAlloc) {
+ for p := sym.Func().Text; p != nil; p = p.Link {
+ checkaddr(ctxt, p, &p.From)
+ if p.GetFrom3() != nil {
+ checkaddr(ctxt, p, p.GetFrom3())
+ }
+ checkaddr(ctxt, p, &p.To)
+
+ if ctxt.Arch.Progedit != nil {
+ ctxt.Arch.Progedit(ctxt, p, newprog)
+ }
+ if p.To.Type != TYPE_BRANCH {
+ continue
+ }
+ if p.To.Val != nil {
+ continue
+ }
+
+ if p.To.Sym != nil {
+ continue
+ }
+ q := sym.Func().Text
+ for q != nil && p.To.Offset != q.Pc {
+ if q.Forwd != nil && p.To.Offset >= q.Forwd.Pc {
+ q = q.Forwd
+ } else {
+ q = q.Link
+ }
+ }
+
+ if q == nil {
+ name := "<nil>"
+ if p.To.Sym != nil {
+ name = p.To.Sym.Name
+ }
+ ctxt.Diag("branch out of range (%#x)\n%v [%s]", uint32(p.To.Offset), p, name)
+ p.To.Type = TYPE_NONE
+ }
+
+ p.To.SetTarget(q)
+ }
+
+ if !ctxt.Flag_optimize {
+ return
+ }
+
+ // Collapse series of jumps to jumps.
+ for p := sym.Func().Text; p != nil; p = p.Link {
+ if p.To.Target() == nil {
+ continue
+ }
+ p.To.SetTarget(brloop(p.To.Target()))
+ if p.To.Target() != nil && p.To.Type == TYPE_BRANCH {
+ p.To.Offset = p.To.Target().Pc
+ }
+ }
+}