New --dump-macros option.

3 files changed, 17 insertions, 0 deletions

diff --git a/cppawk b/cppawk
index af17e5c..bf9ad2d 100755
--- a/cppawk
+++ b/cppawk
@@ -30,6 +30,7 @@
 # site configuration
 prepro=cpp
 incopt=-iquote # GNU extension: must be changed to -I for traditional cpp
+dumpopt=-dM # GNU cpp option to dump macros
 awk=gawk
 prepro_opts="-D__gawk__=1 -D__cppawk_ver=20220324"
 
@@ -137,6 +138,10 @@ while [ $# -gt 0 ] ; do
   --nobash )
     bash=
     ;;
+  --dump-macros )
+    prepro_opts="$prepro_opts $dumpopt"
+    prepro_only=y
+    ;;
   -U* | -D* | -I* | -iquote* )
     prepro_opts="$prepro_opts $(quote "$1")"
     ;;
diff --git a/cppawk.1 b/cppawk.1
index 9aed0b5..3253d09 100644
--- a/cppawk.1
+++ b/cppawk.1
@@ -90,6 +90,13 @@ Pretend that the shell which executes
 isn't GNU Bash, even if it is. This has the effect of disabling
 the use of process substitution in favor of the use of a temporary file.
 
+.IP "\fB\-\-dump-macros\fR"
+Instruct the preprocessor to dump all of the
+.BI #define
+directives instead of the preprocessed output. Since this is only useful with
+.BI --prepro-only
+that option is implied.
+
 .IP "\fB\-M\fR, \fB\--bignum\fR"
 These two equivalent GNU Awk options are passed through to
 .BR awk ,
diff --git a/testcases b/testcases
index 19d0c29..6e256ce 100644
--- a/testcases
+++ b/testcases
@@ -240,3 +240,8 @@ BEGIN { print __LINE__
 $cppawk -f testdir/name.cwk
 :
 testdir/name.cwk
+--
+42:
+$cppawk --dump-macros '#define foo_bar 42' | grep foo_bar
+:
+#define foo_bar 42