GNU Assembler .print expression instead of string

Question

According this https://sourceware.org/binutils/docs/as/Print.html#Print, I only can print string instead of expression.

I tried this one line assembler

.print "Hello" //No Error
.print 1+2 //Error: missing string

How do I make assembler recognize that expression 1+2 is a string? I expect it will print:

Hello
3

UPDATE: I found something strange after using .altmacro https://sourceware.org/binutils/docs/as/Altmacro.html#Altmacro

.altmacro

.macro myMacro
  LOCAL myLabel
  .set myLabel, 1+2
  .print "myLabel"
.endm

myMacro

It said I can use %expr: You can write ‘%expr’ to evaluate the expression expr and use the result as a string.

But my console shown:

.LL0001

Answer 1

According your both refference:

• Enable .altmacro which has more feature than legacy as such as LOCAL labeling.

• Define macro with name .printPlusPlus, name inspired from C++ that upgraded version of C but this context is version of .print

• Since .print only accept double quote string then put the parameter a to the double-quoted argument.

• Use pair of angle bracket <my string> for print string, use %(expr) to print string expression. Note, you must use escaped character hexadecimal to use hell character like double-quoted. \x22 means Character number 22 in hexadecimal form in ascii table which it's a ".

Usage

.altmacro

.macro .printPlusPlus a
  .print "\a"
.endm

.printPlusPlus <\x22\Hello World\x22>
.printPlusPlus %(1 +2)

Output

$ as temp.m
"Hello World"
3

EDIT

.altmacro

.macro .printPlusPlus a
  .print "\a"
.endm

.macro summation a,b
  .printPlusPlus %(\a + \b)
.endm

summation 3,4 //will show 7, i just tested it works fine