Add debugging output to VHDL target

Prints progress when -pdebug=1 specified.

Adds a new debug_msg function to print progress messages.

tgt-vhdl/process.cc

@@ -81,6 +81,10 @@ int draw_process(ivl_process_t proc, void *cd)
 {
    ivl_scope_t scope = ivl_process_scope(proc);
 
+   debug_msg("Translating process in %s (%s:%d)",
+             ivl_scope_name(scope), ivl_process_file(proc),
+             ivl_process_lineno(proc));
+
    // A process should occur in a module scope, therefore it
    // should have already been assigned a VHDL entity
    assert(ivl_scope_type(scope) == IVL_SCT_MODULE);

tgt-vhdl/scope.cc

@@ -129,7 +129,7 @@ static string visible_nexus_signal_name(nexus_private_t *priv, vhdl_scope *scope
  * Generates VHDL code to fully represent a nexus.
  */
 void draw_nexus(ivl_nexus_t nexus)
-{
+{   
    nexus_private_t *priv = new nexus_private_t;
    int nexus_signal_width = -1;
    priv->const_driver = NULL;
@@ -275,6 +275,8 @@ vhdl_var_ref *nexus_to_var_ref(vhdl_scope *scope, ivl_nexus_t nexus)
  */
 static void declare_logic(vhdl_arch *arch, ivl_scope_t scope)
 {
+   debug_msg("Declaring logic in scope %s", ivl_scope_name(scope));
+
    int nlogs = ivl_scope_logs(scope);
    for (int i = 0; i < nlogs; i++)
       draw_logic(arch, ivl_scope_log(scope, i)); 
@@ -321,6 +323,8 @@ static string make_safe_name(ivl_signal_t sig)
  */
 static void declare_signals(vhdl_entity *ent, ivl_scope_t scope)
 {
+   debug_msg("Declaring signals in scope %s", ivl_scope_name(scope));
+
    int nsigs = ivl_scope_sigs(scope);
    for (int i = 0; i < nsigs; i++) {
       ivl_signal_t sig = ivl_scope_sig(scope, i);      
@@ -518,6 +522,9 @@ static int draw_function(ivl_scope_t scope, ivl_scope_t parent)
 {
    assert(ivl_scope_type(scope) == IVL_SCT_FUNCTION);
 
+   debug_msg("Generating function %s (%s)", ivl_scope_tname(scope),
+             ivl_scope_name(scope));
+
    // Find the containing entity
    vhdl_entity *ent = find_entity(ivl_scope_name(parent));
    assert(ent);
@@ -663,6 +670,8 @@ static void create_skeleton_entity_for(ivl_scope_t scope)
  */
 static int draw_skeleton_scope(ivl_scope_t scope, void *_parent)
 {
+   debug_msg("Initial visit to scope %s", ivl_scope_name(scope));
+
    switch (ivl_scope_type(scope)) {
    case IVL_SCT_MODULE:
       create_skeleton_entity_for(scope);

tgt-vhdl/vhdl.cc

@@ -87,6 +87,24 @@ void error(const char *fmt, ...)
    g_errors++;
 }
 
+/*
+ * Print a message only if -pdebug was specified.
+ */
+void debug_msg(const char *fmt, ...)
+{
+   std::va_list args;
+
+   va_start(args, fmt);
+
+   if (std::strcmp(ivl_design_flag(g_design, "debug"), "")) {
+      std::fputs("[DEBUG] ", stdout);  
+      std::vprintf(fmt, args);
+      std::putchar('\n');
+   }
+
+   va_end(args);
+}
+
 /*
  * Find an entity given a scope name.
  */

tgt-vhdl/vhdl_target.h

@@ -14,6 +14,7 @@
 using namespace std;
 
 void error(const char *fmt, ...);
+void debug_msg(const char *fmt, ...);
 
 int draw_scope(ivl_scope_t scope, void *_parent);
 int draw_process(ivl_process_t net, void *cd);