All path groups (#215)

* All path groups

* Fixes

* Use c++17 iteration

README.md

@@ -210,11 +210,13 @@ Use Homebrew to install them.
 
 Set these variables before using cmake to cirumvent the Xcode versions.
 
+```
   # flex/bison override apple version
   export PATH="$(brew --prefix bison)/bin:${PATH}"
   export PATH="$(brew --prefix flex)/bin:${PATH}"
   export CMAKE_INCLUDE_PATH="$(brew --prefix flex)/include"
   export CMAKE_LIBRARY_PATH="$(brew --prefix flex)/lib;$(brew --prefix bison)/lib"
+```
 
 Homebrew does not support tclreadline, but the macports system does
 (see https://www.macports.org). 

sdc/Sdc.i

@@ -1323,6 +1323,17 @@ filter_timing_arcs(const char *property,
 
 ////////////////////////////////////////////////////////////////
 
+StringSeq
+path_group_names()
+{
+  StringSeq pg_names;
+  for (auto const& [name, group] : Sta::sta()->sdc()->groupPaths())
+    pg_names.push_back(name);
+  return pg_names;
+}
+
+////////////////////////////////////////////////////////////////
+
 void
 set_voltage_global(const MinMax *min_max,
                    float voltage)

test/path_group_names.ok

@@ -0,0 +1,2 @@
+Initial path groups: 
+Final path groups: In2Out In2Reg Reg2Out Reg2Reg

test/path_group_names.tcl

@@ -0,0 +1,14 @@
+# path_group_names
+
+read_liberty asap7_small.lib.gz
+read_verilog reg1_asap7.v
+link_design top
+create_clock -name clk -period 500 {clk1 clk2 clk3}
+set_input_delay -clock clk 0 [all_inputs -no_clocks]
+set_output_delay -clock clk 0 [all_outputs]
+puts "Initial path groups: [sta::path_group_names]"
+group_path -name In2Reg -from [all_inputs] -to [all_registers -data_pins]
+group_path -name In2Out -from [all_inputs] -to [all_outputs]
+group_path -name Reg2Out -from [all_registers -clock_pins] -to [all_outputs]
+group_path -name Reg2Reg -from [all_registers -clock_pins] -to [all_registers -data_pins]
+puts "Final path groups: [sta::path_group_names]"

test/regression_vars.tcl

@@ -147,6 +147,7 @@ record_sta_tests {
   liberty_arcs_one2one_2
   liberty_ccsn
   liberty_latch3
+  path_group_names
   prima3
   report_checks_src_attr
   report_json1