variables: cleanup, fix errors

Signed-off-by: Øyvind Harboe <[email protected]>

Author: oharboe

flow/scripts/synth.tcl

@@ -21,7 +21,7 @@ if {[env_var_exists_and_non_empty SYNTH_HIER_SEPARATOR]} {
   scratchpad -set flatten.separator $::env(SYNTH_HIER_SEPARATOR)
 }
 
-set synth_full_args $::env(SYNTH_ARGS)
+set synth_full_args [env_var_or_empty SYNTH_ARGS]
 if {[env_var_exists_and_non_empty SYNTH_OPERATIONS_ARGS]} {
   set synth_full_args [concat $synth_full_args $::env(SYNTH_OPERATIONS_ARGS)]
 } else {

flow/scripts/synth_canonicalize.tcl

@@ -1,7 +1,7 @@
 source $::env(SCRIPTS_DIR)/synth_preamble.tcl
 read_design_sources
 
-dict for {key value} $::env(VERILOG_TOP_PARAMS) {
+dict for {key value} [env_var_or_empty VERILOG_TOP_PARAMS] {
   # Apply toplevel parameters
   chparam -set $key $value $::env(DESIGN_NAME)
 }

flow/scripts/synth_preamble.tcl

@@ -48,20 +48,22 @@ proc read_design_sources {} {
     plugin -i slang
     yosys read_slang -D SYNTHESIS --keep-hierarchy --compat=vcs \
       --ignore-assertions --top $::env(DESIGN_NAME) \
-      {*}$vIdirsArgs {*}$::env(VERILOG_FILES) {*}$::env(VERILOG_DEFINES)
+      {*}$vIdirsArgs {*}$::env(VERILOG_FILES) {*}[env_var_or_empty VERILOG_DEFINES]
     # Workaround for yosys-slang#119
     setattr -unset init
   } elseif {[env_var_equals SYNTH_HDL_FRONTEND verific]} {
     if {[env_var_exists_and_non_empty VERILOG_INCLUDE_DIRS]} {
-	verific -vlog-incdir {*}$::env(VERILOG_INCLUDE_DIRS)
+	    verific -vlog-incdir {*}$::env(VERILOG_INCLUDE_DIRS)
     }
     if {[env_var_exists_and_non_empty VERILOG_DEFINES]} {
-	verific -vlog-define {*}$::env(VERILOG_DEFINES)
+	    verific -vlog-define {*}$::env(VERILOG_DEFINES)
     }
     verific -sv2012 {*}$::env(VERILOG_FILES)
   } elseif {![env_var_exists_and_non_empty SYNTH_HDL_FRONTEND]} {
     verilog_defaults -push
-    verilog_defaults -add {*}$::env(VERILOG_DEFINES)
+    if {[env_var_exists_and_non_empty VERILOG_DEFINES]} {
+      verilog_defaults -add {*}$::env(VERILOG_DEFINES)
+    }
     foreach file $::env(VERILOG_FILES) {
       read_verilog -defer -sv {*}$vIdirsArgs $file
     }

flow/scripts/util.tcl

@@ -124,6 +124,14 @@ proc append_env_var {list_name var_name prefix has_arg} {
   }
 }
 
+# Non-empty defaults should go into variables.yaml, generally
+proc env_var_or_empty {env_var} {
+  if {[env_var_exists_and_non_empty $env_var]} {
+    return $::env($env_var)
+  }
+  return ""
+}
+
 proc find_macros {} {
   set macros ""