在默认参数百分号气体altmacro宏观失败＆QUOT;％运营商需要绝对EX pression＆QUOT; [英] Gas altmacro macro with a percent sign in a default parameter fails with "% operator needs absolute expression"

问题描述

我要创建如下所示的宏：

I want to create a macro like the following:

.altmacro

.macro assert_eq a, b=%eax
    LOCAL ok
    #...
.endm

要作为：

assert_eq $1
assert_eq $1, %eax

我想 .altmacro 为本地（我看到使用的另一种可能性 \\ @ ，但我想本地）。

I want .altmacro for LOCAL (I see the other possibility of using \@, but I want LOCAL).

但是当我尝试编译此我得到：

But when I try to compile this I get:

Error: % operator needs absolute expression

我猜测，这个问题是由一个事实，即 B =％EAX 正在尝试使用由 .altmacro ：前pression结果字符串，
因为没有 .altmacro 我可以写这个没有问题。

I am guessing that this problem is created by the fact that b=%eax is attempting to use another feature enabled by .altmacro: Expression results as strings, since without .altmacro I could write this without problem.

如果这是真的，我怎么逃，对于我的宏来工作？如果不是，有什么不对我的code？

If this is true, how do I escape that for my macro to work? If not, what is wrong with my code?

奖金的问题：如何使用％

Bonus question: how to use %?

GAS版本：52年2月23日

GAS version: 2.23.52

推荐答案

我遇到了，我想寄存器作为参数传递给需要使用.altmacro宏非常类似的问题。该工作定盘附上上述＆lt寄存器;>和地点！之前％。因此，尝试改变你的宏为

I have run into a very similar problem where I wanted to pass registers as arguments to a macro that required the use .altmacro. The fix that worked was to enclose the registers in <> and place ! before %. So try changing your macro to be

.macro assert_eq a, b=<%eax>

如果你想打电话给你的宏与寄存器作为参数做

and if you ever want to call your macro with a register as an argument do

assert_eq <%eax>, <%ecx>

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