Question

I would like something like the following gperf input file:

%{
#include <keywords.h>
// the contents of which contain
// #define KEYWORD1_MACRO "keyword1"
// #define KEYWORD2_MACRO "keyword2"
%}
%%
KEYWORD1_MACRO
KEYWORD2_MACRO
%%

Unfortunately, gperf will interpret those as the stings “KEYWORD1_MACRO”, etc.

The reason for this is that I have a protocol spec provided by another party as a header file, containing such #defines. So I don’t have control over how they are defined, and I’d rather not have to write another preprocessing tool to #include the header and output the expansion of the macros as quoted strings, only then for use as a gperf input file.

Answer 1

I made the following experiment which uses gcc -E to deal with those #includes.

keywords.h:

#define KEYWORD1_MACRO "keyword1"
#define KEYWORD2_MACRO "keyword2"

test.c:

%{
#include "keywords.h"
%}
%%
KEYWORD1_MACRO
KEYWORD2_MACRO
%%

Command: gcc -E -o test.out.txt test.c.
Then, the content in test.out.txt:

# 1 "test.c"
# 1 "<built-in>"
# 1 "<command line>"
# 1 "test.c"
%{
# 1 "keywords.h" 1
# 3 "test.c" 2
%}
%%
"keyword1"
"keyword2"
%%

The #includes are handled automatically. You can then do some text processing and feed into gperf.