[dev.link] cmd/link/internal/loader: add Loader plt/got access methods

Add accessor methods to get at the symbol {plt,got} value for
PE symbols. Fix a bug in the loaders SetPlt/SetGot methods.

Change-Id: I975bd6b86122622b206487c8798f8290ecd25a57
Reviewed-on: https://go-review.googlesource.com/c/go/+/225199
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

diff --git a/src/cmd/link/internal/loader/loader.go b/src/cmd/link/internal/loader/loader.go
index e342fbe680a890ccd2c21baab442423e899223d6..3b77a4bff3372c8848e22d5ae778e5278d2cfdd1 100644 (file)
--- a/src/cmd/link/internal/loader/loader.go
+++ b/src/cmd/link/internal/loader/loader.go
@@ -1133,24 +1133,40 @@ func (l *Loader) SetSymElfType(i Sym, et elf.SymType) {
        }
 }
 
+// SymPlt returns the plt value for pe symbols.
+func (l *Loader) SymPlt(s Sym) int32 {
+       if v, ok := l.plt[s]; ok {
+               return v
+       }
+       return -1
+}
+
 // SetPlt sets the plt value for pe symbols.
 func (l *Loader) SetPlt(i Sym, v int32) {
        if i >= Sym(len(l.objSyms)) || i == 0 {
                panic("bad symbol for SetPlt")
        }
-       if v == 0 {
+       if v == -1 {
                delete(l.plt, i)
        } else {
                l.plt[i] = v
        }
 }
 
+// SymGot returns the got value for pe symbols.
+func (l *Loader) SymGot(s Sym) int32 {
+       if v, ok := l.got[s]; ok {
+               return v
+       }
+       return -1
+}
+
 // SetGot sets the got value for pe symbols.
 func (l *Loader) SetGot(i Sym, v int32) {
        if i >= Sym(len(l.objSyms)) || i == 0 {
                panic("bad symbol for SetGot")
        }
-       if v == 0 {
+       if v == -1 {
                delete(l.got, i)
        } else {
                l.got[i] = v
@@ -1257,11 +1273,11 @@ func (l *Loader) SymLocalentry(i Sym) uint8 {
        return l.localentry[i]
 }
 
-// SetSymExtname sets the "extname" attribute for a symbol.
+// SetSymLocalentry sets the "local entry" attribute for a symbol.
 func (l *Loader) SetSymLocalentry(i Sym, value uint8) {
        // reject bad symbols
        if i >= Sym(len(l.objSyms)) || i == 0 {
-               panic("bad symbol index in SetExtname")
+               panic("bad symbol index in SetSymLocalentry")
        }
        if value == 0 {
                delete(l.localentry, i)