Signal 11 Segfault in sta::Sta::delayCalcPreamble() during stage 2 floorplan final metrics

[sathwikrao0408]

Describe the bug

The flow crashes with a Segmentation Fault (Signal 11) at the end of the floorplan stage during metric reporting -

Signal 11 received
Stack trace:
 0# 0x00005622E142B3A6 in /foss/tools/bin/openroad
 1# 0x00007F79471F3330 in /lib/x86_64-linux-gnu/libc.so.6
 2# 0x00005622E410A73C in /foss/tools/bin/openroad
 3# 0x00005622E411C220 in /foss/tools/bin/openroad
 4# sta::Sta::delayCalcPreamble() in /foss/tools/bin/openroad
 5# sta::Sta::searchPreamble() in /foss/tools/bin/openroad
 6# 0x00005622E15B91DA in /foss/tools/bin/openroad
 7# TclNRRunCallbacks in /lib/x86_64-linux-gnu/libtcl8.6.so
 8# 0x00007F794AE536BC in /lib/x86_64-linux-gnu/libtcl8.6.so
 9# Tcl_EvalEx in /lib/x86_64-linux-gnu/libtcl8.6.so
10# Tcl_Eval in /lib/x86_64-linux-gnu/libtcl8.6.so
11# sta::sourceTclFile(char const*, bool, bool, Tcl_Interp*) in /foss/tools/bin/openroad
12# 0x00005622E4104E4C in /foss/tools/bin/openroad
13# ord::tclAppInit(Tcl_Interp*) in /foss/tools/bin/openroad
14# Tcl_MainEx in /lib/x86_64-linux-gnu/libtcl8.6.so
15# main in /foss/tools/bin/openroad
16# 0x00007F79471D81CA in /lib/x86_64-linux-gnu/libc.so.6
17# __libc_start_main in /lib/x86_64-linux-gnu/libc.so.6
18# _start in /foss/tools/bin/openroad
Elapsed time: 2:39.61[h:]min:sec. CPU time: user 312.70 sys 29.39 (214%). Peak memory: 5147896KB.
make: *** [Makefile:415: do-2_1_floorplan] Error 245

SKIP_REPORT_METRICS = 1, skips this and moves ahead with the rest of the flow, but the metrics are important for me.

Expected Behavior

report generation by default in the reports folder.

Environment

I am running openroad on podman iic-osic-tools - 
[WARNING] Your current OpenROAD version is outdated. (i am using an older version of openroad, however, the new versions too does not have a patch for this)
OpenROAD version: 26Q3-18-g5c5380c49a
OS: Ubuntu 24.04.4 LTS
Compiler: GNU 13.3.0

To Reproduce

run make DESIGN_CONFIG= do-floorplan.

make sure the SKIP_REPORT_METRICS is not equal to 1.

Relevant log output

"Report metrics stage 2, floorplan final...
Signal 11 received
Stack trace:
 0# 0x00005622E142B3A6 in /foss/tools/bin/openroad
 1# 0x00007F79471F3330 in /lib/x86_64-linux-gnu/libc.so.6
 2# 0x00005622E410A73C in /foss/tools/bin/openroad
 3# 0x00005622E411C220 in /foss/tools/bin/openroad
 4# sta::Sta::delayCalcPreamble() in /foss/tools/bin/openroad
 5# sta::Sta::searchPreamble() in /foss/tools/bin/openroad
 6# 0x00005622E15B91DA in /foss/tools/bin/openroad
 7# TclNRRunCallbacks in /lib/x86_64-linux-gnu/libtcl8.6.so
 8# 0x00007F794AE536BC in /lib/x86_64-linux-gnu/libtcl8.6.so
 9# Tcl_EvalEx in /lib/x86_64-linux-gnu/libtcl8.6.so
10# Tcl_Eval in /lib/x86_64-linux-gnu/libtcl8.6.so
11# sta::sourceTclFile(char const*, bool, bool, Tcl_Interp*) in /foss/tools/bin/openroad
12# 0x00005622E4104E4C in /foss/tools/bin/openroad
13# ord::tclAppInit(Tcl_Interp*) in /foss/tools/bin/openroad
14# Tcl_MainEx in /lib/x86_64-linux-gnu/libtcl8.6.so
15# main in /foss/tools/bin/openroad
16# 0x00007F79471D81CA in /lib/x86_64-linux-gnu/libc.so.6
17# __libc_start_main in /lib/x86_64-linux-gnu/libc.so.6
18# _start in /foss/tools/bin/openroad
Elapsed time: 2:39.61[h:]min:sec. CPU time: user 312.70 sys 29.39 (214%). Peak memory: 5147896KB.
make: *** [Makefile:415: do-2_1_floorplan] Error 245
"

Screenshots

No response

Additional Context

No response

[maliberty]

This doesn't reproduce:

make DESIGN_CONFIG= do-floorplan
/workspace/w3/flow/scripts/variables.mk:23: *** PLATFORM variable not set.. Stop.

Setting DESIGN_CONFIG to nothing means there is no design to run so I don't see how this could be meaningful

[sathwikrao0408]

I have set it to this - make DESIGN_CONFIG=./designs/custom_pdk/my_design/config.mk do-floorplan

i left it empty so your design can be run.

My file has this -

export NUM_CORES = 10                                                                                                                                                                                                                                                                                                                                                                        
export DESIGN_NAME = <design name here>                                                                                                                                                                                                                                                                                                                                                       
export DESIGN_NICKNAME = <nickname here>                                                                                                                                                                                                                                                                                                                                                               
export PLATFORM = custom_pdk                                                                                                                                                                                                                                                                                                                                                                 
export YOSYS_EXE = /foss/tools/bin/yosys                                                                                                                                                                                                                                                                                                                                                     
export OPENROAD_EXE = /foss/tools/bin/openroad                                                                                                                                                                                                                                                                                                                                               
export FLOW_VARIANT = normal_run                                                                                                                                                                                                                                                                                                                                                             
                                                                                                                                                                                                                                                                                                                                                                                             
# Netlist and sdc                                                                                                                                                                                                                                                                                                                                                                            
export SYNTH_NETLIST_FILES = <netlist>                                                                                                                                                                                                                                                                                                                    
export SDC_FILE = <sdc>                                                                                                                                                                                                                                                                                                                             
                                                                                                                                                                                                                                                                                                                                                                                             
# Floorplan                                                                                                                                                                                                                                                                                                                                                                                  
# below command useful only for yosys, hence set to 1 as i am using genus netlist.                                                                                                                                                                                                                                                                                                           
export REMOVE_ABC_BUFFERS = 1                                                                                                                                                                                                                                                                                                                                                                
export PDN_TCL = $(PLATFORM_DIR)/pdn_noring.tcl                                                                                                                                                                                                                                                                                                                                              
export TAPCELL_TCL = $(PLATFORM_DIR)/tapcell_1.tcl                                                                                                                                                                                                                                                                                                                                           
export DIE_AREA  = 0 0 2000 2000                                                                                                                                                                                                                                                                                                                                                             
export CORE_AREA = 10 10 1990 1990                                                                                                                                                                                                                                                                                                                                                           
                                                                                                                                                                                                                                                                                                                                                                                             
export OPENROAD_HIERARCHICAL = 1                                                                                                                                                                                                                                                                                                                                                             
                                                                                                                                                                                                                                                                                                                                                                                             
# Placement                                                                                                                                                                                                                                                                                                                                                                                  
export PLACE_DENSITY = 0.5                                                                                                                                                                                                                                                                                                                                                                   
export CELL_PAD_IN_SITES_GLOBAL_PLACEMENT = 4                                                                                                                                                                                                                                                                                                                                                
export CELL_PAD_IN_SITES_DETAIL_PLACEMENT = 4                                                                                                                                                                                                                                                                                                                                                
export MACRO_PLACE_HALO = 40 40                                                                                                                                                                                                                                                                                                                                                              
export MACRO_BLOCKAGE_HALO = 15                                                                                                                                                                                                                                                                                                                                                              
export GPL_ROUTABILITY_DRIVEN = 1                                                                                                                                                                                                                                                                                                                                                            
export DETAIL_PLACEMENT_ARGS = -max_displacement 500                                                                                                                                                                                                                                                                                                                                         
#optimized detailed placement turned of as multiheight heights were throwing an error here, normal detailed placement works here                                                                                                                                                                                                                                                             
export ENABLE_DPO = 0                                                                                                                                                                                                                                                                                                                                                                        
                                                                                                                                                                                                                                                                                                                                                                                             
# mandatory variable, left empty                                                                                                                                                                                                                                                                                                                                                             
export DONT_USE_CELLS =                                                                                                                                                                                                                                                                                                                                                                      
                                                                                                                                                                                                                                                                                                                                                                                             
# Routing                                                                                                                                                                                                                                                                                                                                                                                    
export MIN_ROUTING_LAYER = ME3                                                                                                                                                                                                                                                                                                                                                                
export MAX_ROUTING_LAYER = ME6                                                                                                                                                                                                                                                                                                                                                                
export GLOBAL_ROUTE_ARGS = -congestion_iterations 50 -verbose                                                                                                                                                                                                                                                                                                                                
export BALANCE_ROWS = 1                                                                                                                                                                                                                                                                                                                                                                      
                                                                                                                                                                                                                                                                                                                                                                                             
# pre cts for scan_en fixing. fix power nets to mark power pins as special pins so global route doesnt error out.                                                                                                                                                                                                                                                                            
export PRE_GLOBAL_ROUTE_TCL = /foss/designs/OpenROAD-flow-scripts/flow/designs/custom_pdk/my_design/fix_power_nets.tcl                                                                                                                                                                                                                                                                       
export PRE_CTS_TCL = /foss/designs/OpenROAD-flow-scripts/flow/designs/custom_pdk/my_design/pre_cts.tcl                                                                                                                                                                                                                                                                                       
                                                                                                                                                                                                                                                                                                                                                                                             
# without this for some reason openroad crashes.                                                                                                                                                                                                                                                                                                                                             
export SKIP_REPORT_METRICS = 1                                                                                                                                                                                                                                                                                                                                                               
# export TNS_END_PERCENT = 100  use when u wanna fix timing errors                                                                                                                                                                                                                                                                                                                          
                                                                                                                                                                                                                                                                                                                                                                                             
#only speedup steps, remove all this once dewarp works                                                                                                                                                                                                                                                                                                                                       
export DETAILED_ROUTE_END_ITERATION = 5                                                                                                                                                                                                                                                                                                                                                      
export MAX_REPAIR_ANTENNAS_ITER_GRT = 1                                                                                                                                                                                                                                                                                                                                                      
export MAX_REPAIR_ANTENNAS_ITER_DRT = 1                                                                                                                                                                                                                                                                                                                                                      
export MAX_REPAIR_TIMING_ITER = 1                                                                                                                                                                                                                                                                                                                                                            
export TNS_END_PERCENT = 20                                                                                                                                                                                                                                                                                                                                                                  
export SKIP_GATE_CLONING = 1                                                                                                                                                                                                                                                                                                                                                                 
export SKIP_LAST_GASP = 1                                                                                                                                                                                                                                                                                                                                                                    
export SKIP_PIN_SWAP = 1                                                                                                                                                                                                                                                                                                                                                                     
export SKIP_VT_SWAP = 1                                                                                                                                                                                                                                                                                                                                                                      
export SKIP_CRIT_VT_SWAP = 1                                                                                                                                                                                                                                                                                                                                                                 
export REPORT_CLOCK_SKEW = 0                                                                                                                                                                                                                                                                                                                                                                 
export SKIP_CTS_REPAIR_TIMING = 1                                                                                                                                                                                                                                                                                                                                                            
                                                                                                                                                                                                                                                                                                                                                                                             
# to ease up timing, remove this later                                                                                                                                                                                                                                                                                                                                                       
export SETUP_SLACK_MARGIN = -500                                                                                                                                                                                                                                                                                                                                                             
export HOLD_SLACK_MARGIN = -300                                                                                                                                                                                                                                                                                     

my platform config file has all the platform related variables.

[maliberty]

I don't get a crash on any design we test with.

[sathwikrao0408]

remove_buffers appears to leave the design/timing-graph in an inconsistent state on large, macro-heavy hierarchical designs (synthesized with Genus using -hier read-in). The corruption doesn't crash remove_buffers itself — it only surfaces as a SIGSEGV the next time any command forces a full STA graph/search rebuild (sta::Sta::searchPreamble() → sta::Sta::delayCalcPreamble()), regardless of which specific command triggers that rebuild.

I am also not able to replicate this issue on any other designs of mine with my PDK (proprietary), only the one design that has macros is erroring out like this.

Reproduction pattern (isolated across two independent flow stages)
Floorplan stage:

The remove_buffers when REMOVE_ABC_BUFFERS is set to 1, followed by the next reports.

Global placement stage:

if { $::env(GPL_TIMING_DRIVEN) } {
remove_buffers
}
post this remove_buffers too. if i comment this out, the run follows as normal.

global_placement crash -

read_db -hier ./results/custom_pdk/dw200/smaller_design/3_2_place_iop.odb  
[WARNING ORD-0012] Hierarchical flow (-hier) is currently in development and may cause multiple issues. Do not use in production environments.  
read_sdc ./results/custom_pdk/dw200/smaller_design/2_floorplan.sdc  
Took 18 seconds: read_sdc ./results/custom_pdk/dw200/smaller_design/2_floorplan.sdc  
source /foss/designs/OpenROAD-flow-scripts/flow/platforms/custom_pdk/setRC.tcl  
[INFO RSZ-0026] Removed 16475 buffers.  
Perform port buffering...  
Signal 11 received  
Stack trace:  
 0# 0x00005634B3E4B3A6 in /foss/tools/bin/openroad  
 1# 0x00007FF2A1B0C330 in /lib/x86_64-linux-gnu/libc.so.6  
 2# 0x00005634B6B2A73C in /foss/tools/bin/openroad  
 3# 0x00005634B6B3C220 in /foss/tools/bin/openroad  
 4# rsz::Resizer::bufferInputs(sta::LibertyCell*, bool) in /foss/tools/bin/openroad  
 5# 0x00005634B3F39C27 in /foss/tools/bin/openroad  
 6# TclNRRunCallbacks in /lib/x86_64-linux-gnu/libtcl8.6.so  
 7# 0x00007FF2A576C6BC in /lib/x86_64-linux-gnu/libtcl8.6.so  
 8# Tcl_EvalEx in /lib/x86_64-linux-gnu/libtcl8.6.so  
 9# Tcl_Eval in /lib/x86_64-linux-gnu/libtcl8.6.so  
10# sta::sourceTclFile(char const*, bool, bool, Tcl_Interp*) in /foss/tools/bin/openroad  
11# 0x00005634B6B24E4C in /foss/tools/bin/openroad  
12# ord::tclAppInit(Tcl_Interp*) in /foss/tools/bin/openroad  
13# Tcl_MainEx in /lib/x86_64-linux-gnu/libtcl8.6.so  
14# main in /foss/tools/bin/openroad  
15# 0x00007FF2A1AF11CA in /lib/x86_64-linux-gnu/libc.so.6  
16# __libc_start_main in /lib/x86_64-linux-gnu/libc.so.6  
17# _start in /foss/tools/bin/openroad  
Elapsed time: 1:14.88[h:]min:sec. CPU time: user 70.74 sys 2.66 (98%). Peak memory: 3554756KB.  
make[1]: *** [Makefile:464: do-3_3_place_gp] Error 245  
make: *** [Makefile:464: results/custom_pdk/dw200/smaller_design/3_3_place_gp.odb] Error 2  

does remove buffers behave differently for macros ? As of now, I have a workaround as the netlist has been extracted from genus, hence removal of the buffers is not entirely necessary, but I would like to get to the bottom of this. Thank you