GCC Assembly

[Nach]

Does anyone know if GCC defines anything when in Intel or ATT mode?
I've tried searching online and have been unsuccessful.

Thanks to Jonas Quinn, I know about the .att_syntax and .intel_syntax inline assembly instructions, but I have no way of knowing what the default was.

[grinvader]

From the GCC 3.3.6 manpage:

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-masm=dialect
           Output asm instructions using selected dialect. Supported choices
           are intel or att (the default one).

[mozz]

From the GCC 3.3.6 manpage:

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-masm=dialect
           Output asm instructions using selected dialect. Supported choices
           are intel or att (the default one).

I think that is for generating listings, but Nach is asking about the compiler's mode for *parsing* inline assembly. It sounds like he can force it to one mode or the other with .att_syntax or .intel_syntax, but he is looking for a way to detect the original state first, so he can set it back after the inline assembly.

I don't know the answer unfortunately. You might be able to find out using the -dM option:

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-dCHARS
    CHARS is a sequence of one or more of the following characters, and must not be preceded by a space. Other characters are interpreted by the compiler proper, or reserved for future versions of GCC, and so are silently ignored. If you specify characters whose behavior conflicts, the result is undefined.

    M
        Instead of the normal output, generate a list of #define directives for all the macros defined during the execution of the preprocessor, including predefined macros. This gives you a way of finding out what is predefined in your version of the preprocessor. Assuming you have no file foo.h, the command

               touch foo.h; cpp -dM foo.h
          

        will show all the predefined macros.

[grinvader]

Personally, if I make a compiler that outputs AT&T asm natively, I'll make it eat inline AT&T asm natively.

LOGIC

[Nach]

mozz is correct.

However the -dM option doesn't seem to specify anything special for intel or att mode.

And as far as I know there is no .original_syntax option :/

[mozz]

These [three] pages both imply that .att_syntax is the default. Maybe you could safely assume that to be the case.
http://gcc.gnu.org/ml/gcc/2003-07/msg01390.html
http://www.ugcs.caltech.edu/info/binutils/c-i386_1.html
http://www.cygwin.com/ml/binutils/2000-10/msg00268.html

[Nach]

.att_syntax is the default, but I can't assume that's the case because someone can use -masm=intel.

I think I can chalk this up as another one of GCCs major assembly weaknesses.