[Bug macros/24291] Incorrect/Partial Macro Expansion

[Bug macros/24291] Incorrect/Partial Macro Expansion

[tromey at sourceware dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=24291

Tom Tromey <tromey at sourceware dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tromey at sourceware dot org
   Last reconfirmed|                            |2021-05-10
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1

--- Comment #1 from Tom Tromey <tromey at sourceware dot org> ---
Confirmed:

(gdb) macro define IIF(cond) IIF_ ## cond
(gdb) macro define IIF_0(t, f) f
(gdb) macro define IIF_1(t, f) t
(gdb) macro expand IIF(1)(true,false)
expands to: IIF_1(true,false)


Also:

murgatroyd. cat q.c
#define IIF(cond) IIF_ ## cond
#define IIF_0(t, f) f
#define IIF_1(t, f) t
IIF(1)(true,false)
murgatroyd. gcc -E q.c
# 1 "q.c"
# 1 "<built-in>"
# 1 "<command-line>"
# 31 "<command-line>"
# 1 "/usr/include/stdc-predef.h" 1 3 4
# 32 "<command-line>" 2
# 1 "q.c"



true

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[Bug macros/24291] Incorrect/Partial Macro Expansion

[tromey at sourceware dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=24291

--- Comment #2 from Tom Tromey <tromey at sourceware dot org> ---
The code in expand does:

      shared_macro_buffer substituted_src (substituted.text, substituted.len);
      scan (dest, &substituted_src, &new_no_loop, scope);

However this just tries to re-scan "IIF_1" -- it doesn't
concatenate the rest of the un-processed input.
This is why the function-like invocation isn't expanded.

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