cmd/vet: improve asmdecl parameter handling

The asmdecl check had hand-rolled code that
calculated the size and offset of parameters
based only on the AST.
It included a list of known named types.

This CL changes asmdecl to use go/types instead.
This allows us to easily handle named types.
It also adds support for structs, arrays,
and complex parameters.

It improves the default names given to unnamed
parameters. Previously, all anonymous arguments were
called "unnamed", and the first anonymous return
argument was called "ret".
Anonymous arguments are now called arg, arg1, arg2,
etc., depending on the index in the argument list.
Return arguments are ret, ret1, ret2.

This CL also fixes a bug in the printing of
composite data type sizes.

Updates #11041

Change-Id: I1085116a26fe6199480b680eff659eb9ab31769b
Reviewed-on: https://go-review.googlesource.com/27150
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

src/cmd/vet/testdata/asm.go

@@ -8,6 +8,12 @@
 
 package testdata
 
+type S struct {
+	i int32
+	b bool
+	s string
+}
+
 func arg1(x int8, y uint8)
 func arg2(x int16, y uint16)
 func arg4(x int32, y uint32)
@@ -19,6 +25,9 @@ func argslice(x, y []string)
 func argiface(x interface{}, y interface {
 	m()
 })
+func argcomplex(x complex64, y complex128)
+func argstruct(x S, y struct{})
+func argarray(x [2]S)
 func returnint() int
 func returnbyte(x int) byte
 func returnnamed(x byte) (r1 int, r2 int16, r3 string, r4 byte)

src/cmd/vet/testdata/asm1.s

@@ -221,6 +221,49 @@ TEXT ·argiface(SB),0,$0-32
 	MOVQ	y_data+24(FP), AX
 	RET
 
+TEXT ·argcomplex(SB),0,$24 // ERROR "wrong argument size 0; expected \$\.\.\.-24"
+	MOVSS	x+0(FP), X0 // ERROR "invalid MOVSS of x\+0\(FP\); complex64 is 8-byte value containing x_real\+0\(FP\) and x_imag\+4\(FP\)"
+	MOVSD	x+0(FP), X0 // ERROR "invalid MOVSD of x\+0\(FP\); complex64 is 8-byte value containing x_real\+0\(FP\) and x_imag\+4\(FP\)"
+	MOVSS	x_real+0(FP), X0
+	MOVSD	x_real+0(FP), X0 // ERROR "invalid MOVSD of x_real\+0\(FP\); real\(complex64\) is 4-byte value"
+	MOVSS	x_real+4(FP), X0 // ERROR "invalid offset x_real\+4\(FP\); expected x_real\+0\(FP\)"
+	MOVSS	x_imag+4(FP), X0
+	MOVSD	x_imag+4(FP), X0 // ERROR "invalid MOVSD of x_imag\+4\(FP\); imag\(complex64\) is 4-byte value"
+	MOVSS	x_imag+8(FP), X0 // ERROR "invalid offset x_imag\+8\(FP\); expected x_imag\+4\(FP\)"
+	MOVSD	y+8(FP), X0 // ERROR "invalid MOVSD of y\+8\(FP\); complex128 is 16-byte value containing y_real\+8\(FP\) and y_imag\+16\(FP\)"
+	MOVSS	y_real+8(FP), X0 // ERROR "invalid MOVSS of y_real\+8\(FP\); real\(complex128\) is 8-byte value"
+	MOVSD	y_real+8(FP), X0
+	MOVSS	y_real+16(FP), X0 // ERROR "invalid offset y_real\+16\(FP\); expected y_real\+8\(FP\)"
+	MOVSS	y_imag+16(FP), X0 // ERROR "invalid MOVSS of y_imag\+16\(FP\); imag\(complex128\) is 8-byte value"
+	MOVSD	y_imag+16(FP), X0
+	MOVSS	y_imag+24(FP), X0 // ERROR "invalid offset y_imag\+24\(FP\); expected y_imag\+16\(FP\)"
+	RET
+
+TEXT ·argstruct(SB),0,$64 // ERROR "wrong argument size 0; expected \$\.\.\.-24"
+	MOVQ	x+0(FP), AX // ERROR "invalid MOVQ of x\+0\(FP\); testdata.S is 24-byte value"
+	MOVQ	x_i+0(FP), AX // ERROR "invalid MOVQ of x_i\+0\(FP\); int32 is 4-byte value"
+	MOVQ	x_b+0(FP), AX // ERROR "invalid offset x_b\+0\(FP\); expected x_b\+4\(FP\)"
+	MOVQ	x_s+8(FP), AX
+	MOVQ	x_s_base+8(FP), AX
+	MOVQ	x_s+16(FP), AX // ERROR "invalid offset x_s\+16\(FP\); expected x_s\+8\(FP\), x_s_base\+8\(FP\), or x_s_len\+16\(FP\)"
+	MOVQ	x_s_len+16(FP), AX
+	RET
+
+TEXT ·argarray(SB),0,$64 // ERROR "wrong argument size 0; expected \$\.\.\.-48"
+	MOVQ	x+0(FP), AX // ERROR "invalid MOVQ of x\+0\(FP\); \[2\]testdata.S is 48-byte value"
+	MOVQ	x_0_i+0(FP), AX // ERROR "invalid MOVQ of x_0_i\+0\(FP\); int32 is 4-byte value"
+	MOVQ	x_0_b+0(FP), AX // ERROR "invalid offset x_0_b\+0\(FP\); expected x_0_b\+4\(FP\)"
+	MOVQ	x_0_s+8(FP), AX
+	MOVQ	x_0_s_base+8(FP), AX
+	MOVQ	x_0_s+16(FP), AX // ERROR "invalid offset x_0_s\+16\(FP\); expected x_0_s\+8\(FP\), x_0_s_base\+8\(FP\), or x_0_s_len\+16\(FP\)"
+	MOVQ	x_0_s_len+16(FP), AX
+	MOVB	foo+25(FP), AX // ERROR "unknown variable foo; offset 25 is x_1_i\+24\(FP\)"
+	MOVQ	x_1_s+32(FP), AX
+	MOVQ	x_1_s_base+32(FP), AX
+	MOVQ	x_1_s+40(FP), AX // ERROR "invalid offset x_1_s\+40\(FP\); expected x_1_s\+32\(FP\), x_1_s_base\+32\(FP\), or x_1_s_len\+40\(FP\)"
+	MOVQ	x_1_s_len+40(FP), AX
+	RET
+
 TEXT ·returnint(SB),0,$0-8
 	MOVB	AX, ret+0(FP) // ERROR "invalid MOVB of ret\+0\(FP\); int is 8-byte value"
 	MOVW	AX, ret+0(FP) // ERROR "invalid MOVW of ret\+0\(FP\); int is 8-byte value"

src/runtime/sys_darwin_arm.s

@@ -106,7 +106,7 @@ TEXT runtime·raiseproc(SB),NOSPLIT,$24
 	MOVW	$SYS_getpid, R12
 	SWI	$0x80
 	// arg 1 pid already in R0 from getpid
-	MOVW	unnamed+0(FP), R1	// arg 2 - signal
+	MOVW	arg+0(FP), R1	// arg 2 - signal
 	MOVW	$1, R2	// arg 3 - posix
 	MOVW	$SYS_kill, R12
 	SWI $0x80

src/runtime/sys_plan9_arm.s

@@ -131,7 +131,7 @@ TEXT runtime·plan9_tsemacquire(SB),NOSPLIT,$0-12
 TEXT runtime·nsec(SB),NOSPLIT,$-4-12
 	MOVW	$SYS_NSEC, R0
 	SWI	0
-	MOVW	unnamed+0(FP), R1
+	MOVW	arg+0(FP), R1
 	MOVW	0(R1), R0
 	MOVW	R0, ret_lo+4(FP)
 	MOVW	4(R1), R0