[dev.cc] cmd/asm: the text flag argument to TEXT psudo-op is optional
Allow TEXT to have two or three operands.
In
TEXT foo(SB),flag,$0
the flag can be missing, in which case we take it to be zero.
Change-Id: I7b88543b52019f7890baac4b95f9e63884d43c83
Reviewed-on: https://go-review.googlesource.com/3440
Reviewed-by: Russ Cox <rsc@golang.org>
diff --git a/src/cmd/asm/internal/asm/asm.go b/src/cmd/asm/internal/asm/asm.go
index 82846d0..dfb7ad1 100644
--- a/src/cmd/asm/internal/asm/asm.go
+++ b/src/cmd/asm/internal/asm/asm.go
@@ -146,8 +146,8 @@
// asmText assembles a TEXT pseudo-op.
// TEXT runtime·sigtramp(SB),4,$0-0
func (p *Parser) asmText(word string, operands [][]lex.Token) {
- if len(operands) != 3 {
- p.errorf("expect three operands for TEXT")
+ if len(operands) != 2 && len(operands) != 3 {
+ p.errorf("expect two or three operands for TEXT")
}
// Operand 0 is the symbol name in the form foo(SB).
@@ -157,22 +157,26 @@
p.errorf("TEXT symbol %q must be an offset from SB", nameAddr.Symbol)
}
name := nameAddr.Symbol
+ next := 1
- // Operand 1 is the text flag, a literal integer.
- // TODO: This is optional but this parser takes it as required.
- flagAddr := p.address(operands[1])
- if !flagAddr.Is(addr.Offset) {
- p.errorf("TEXT flag for %s must be an integer", name)
+ // Next operand is the optional text flag, a literal integer.
+ flag := int8(0)
+ if len(operands) == 3 {
+ flagAddr := p.address(operands[next])
+ if !flagAddr.Is(addr.Offset) {
+ p.errorf("TEXT flag for %s must be an integer", name)
+ }
+ flag = int8(flagAddr.Offset)
+ next++
}
- flag := int8(flagAddr.Offset)
- // Operand 2 is the frame and arg size.
+ // Next operand is the frame and arg size.
// Bizarre syntax: $frameSize-argSize is two words, not subtraction.
// Both frameSize and argSize must be simple integers; only frameSize
// can be negative.
// The "-argSize" may be missing; if so, set it to obj.ArgsSizeUnknown.
// Parse left to right.
- op := operands[2]
+ op := operands[next]
if len(op) < 2 || op[0].ScanToken != '$' {
p.errorf("TEXT %s: frame size must be an immediate constant", name)
}
