dc: conditionalize parts which require libm

2 files changed, 12 insertions, 0 deletions

diff --git a/miscutils/Config.in b/miscutils/Config.in
index 0c80ae6e9..15f677a73 100644
--- a/miscutils/Config.in
+++ b/miscutils/Config.in
@@ -138,6 +138,14 @@ config DC
           Dc is a reverse-polish desk calculator which supports unlimited
           precision arithmetic.
 
+config FEATURE_DC_LIBM
+        bool "Enable power and exp functions (requires libm)"
+        default n
+        depends on DC
+        help
+          Enable power and exp functions.
+          NOTE: This will require libm to be present for linking.
+
 config DEVFSD
         bool "devfsd (obsolete)"
         default n
diff --git a/miscutils/dc.c b/miscutils/dc.c
index 47ec060c8..7d5886eb2 100644
--- a/miscutils/dc.c
+++ b/miscutils/dc.c
@@ -53,12 +53,14 @@ static void mul(void)
         push(pop() * pop());
 }
 
+#if ENABLE_FEATURE_DC_LIBM
 static void power(void)
 {
         double topower = pop();
 
         push(pow(pop(), topower));
 }
+#endif
 
 static void divide(void)
 {
@@ -137,9 +139,11 @@ static const struct op operators[] = {
         {"mul", mul},
         {"/",   divide},
         {"div", divide},
+#if ENABLE_FEATURE_DC_LIBM
         {"**",  power},
         {"exp", power},
         {"pow", power},
+#endif
         {"%",   mod},
         {"mod", mod},
         {"and", and},