CL65: --no-rtl option for disabling default runtime library

doc/cl65.sgml

@@ -103,6 +103,7 @@ Long options:
   --memory-model model          Set the memory model
   --module                      Link as a module
   --module-id id                Specify a module id for the linker
+  --no-rtl                      Don't link default runtime library
   --o65-model model             Override the o65 model
   --obj file                    Link this object file
   --obj-path path               Specify an object file search path
@@ -185,6 +186,11 @@ There are a few remaining options that control the behaviour of cl65:
   seem to use cc65 to develop for the C64.
 
 
+  <tag><tt>--no-rtl</tt></tag>
+
+  This option disables default runtime library of target system.
+
+
   <tag><tt>-Wa options, --asm-args options</tt></tag>
 
   Pass options directly to the assembler. This may be used to pass options

src/cl65/main.c

@@ -139,6 +139,7 @@ static int Module = 0;
 
 /* Name of the target specific runtime library */
 static char* TargetLib  = 0;
+static int   NoRTL      = 0;
 
 
 
@@ -414,6 +415,12 @@ static void SetTargetFiles (void)
     const char* TargetName = GetTargetName (Target);
     unsigned    TargetNameLen = strlen (TargetName);
 
+    if (NoRTL)
+    {
+        /* Default RunTime Library is disabled */
+        return;
+    }
+
     /* Set the library file */
     TargetLib = xmalloc (TargetNameLen + 4 + 1);
     memcpy (TargetLib, TargetName, TargetNameLen);
@@ -812,6 +819,7 @@ static void Usage (void)
             "  --memory-model model\t\tSet the memory model\n"
             "  --module\t\t\tLink as a module\n"
             "  --module-id id\t\tSpecify a module ID for the linker\n"
+            "  --no-rtl\t\t\tDon't link default runtime library\n"
             "  --o65-model model\t\tOverride the o65 model\n"
             "  --obj file\t\t\tLink this object file\n"
             "  --obj-path path\t\tSpecify an object file search path\n"
@@ -1167,6 +1175,15 @@ static void OptModuleId (const char* Opt attribute ((unused)), const char* Arg)
 
 
 
+static void OptNoRTL (const char* Opt attribute ((unused)),
+                      const char* Arg attribute ((unused)))
+/* Disable default runtime library */
+{
+    NoRTL = 1;
+}
+
+
+
 static void OptO65Model (const char* Opt attribute ((unused)), const char* Arg)
 /* Handle the --o65-model option */
 {
@@ -1369,6 +1386,7 @@ int main (int argc, char* argv [])
         { "--memory-model",      1, OptMemoryModel    },
         { "--module",            0, OptModule         },
         { "--module-id",         1, OptModuleId       },
+        { "--no-rtl",            0, OptNoRTL          },
         { "--o65-model",         1, OptO65Model       },
         { "--obj",               1, OptObj            },
         { "--obj-path",          1, OptObjPath        },