C code profiling results of `coxph` in `survival` package does not show up in the final result

[dwuab]

I'm running Ubuntu 20.04.1 LTS with R 3.6.3 installed. I tried to profile the C code in coxph function of survival using the following commands (I used coxed solely to increase the running time of coxph):

library(survival)
library(jointprof)
library(coxed)

simdata = sim.survdata(N = 10000)

joint_pprof(coxph(Surv(y, failed) ~ X1+X2+X3, data=simdata$data))

The following the graph I got as a result. Before profiling, I recompiled the whole survival package with install.packages("survival", type="source", INSTALL_opts="--with-keep.source") and CFLAGS set to -g -O0 -mtune=native. It's clear that the C code profiling results are missing.

After looking into some intermediate results (the separate pprofile and rprofile files), it is clear that the C code was indeed profiled and the results were stored. However, in the rprofile file:

...
#File 3: /tmp/Rtmp5g7EGI/R.INSTALL235a67daae2bd/survival/R/coxph.fit.R
"aperm.default" "aperm" "apply" 3#55 "coxph.fit" 2#555 "coxph" "comingle_rprof" "comingle_pprof" "joint_pprof" 
"%in%" 3#55 "FUN" "apply" 3#55 "coxph.fit" 2#555 "coxph" "comingle_rprof" "comingle_pprof" "joint_pprof" 
"%in%" 3#55 "FUN" "apply" 3#55 "coxph.fit" 2#555 "coxph" "comingle_rprof" "comingle_pprof" "joint_pprof" 
"%in%" 3#55 "FUN" "apply" 3#55 "coxph.fit" 2#555 "coxph" "comingle_rprof" "comingle_pprof" "joint_pprof" 
3#59 "coxph.fit" 2#555 "coxph" "comingle_rprof" "comingle_pprof" "joint_pprof" 
3#59 "coxph.fit" 2#555 "coxph" "comingle_rprof" "comingle_pprof" "joint_pprof" 
3#59 "coxph.fit" 2#555 "coxph" "comingle_rprof" "comingle_pprof" "joint_pprof" 
3#59 "coxph.fit" 2#555 "coxph" "comingle_rprof" "comingle_pprof" "joint_pprof" 
3#59 "coxph.fit" 2#555 "coxph" "comingle_rprof" "comingle_pprof" "joint_pprof" 
...

In line 59 of coxph.fit.R:

    coxfit <- .Call(Ccoxfit6, ...

.Call is called but the function name is not registered in the rprofile result. This is perhaps the reason why the C code profiling results did not show up in the graph, because jointprof need to know where .Call is called inside R to locate the position where the two separate profiling results should be combined.
As I am not very familiar with profiling in general, I could not go any further on this issue.