MLton 20210117

# ShowProf

If an executable is compiled for profiling, then it accepts a special command-line runtime system argument, show-prof, that outputs information about the source functions that are profiled. Normally, this information is used by mlprof. This page documents the show-prof output format, and is intended for those working on the profiler internals.

The show-prof output is ASCII, and consists of a sequence of lines.

- The magic number of the executable.

- The number of source names in the executable.

- A line for each source name giving the name of the function, a tab, the filename of the file containing the function, a colon, a space, and the line number that the function starts on in that file.

- The number of (split) source functions.

- A line for each (split) source function, where each line consists of a source-name index (into the array of source names) and a successors index (into the array of split-source sequences, defined below).

- The number of split-source sequences.

- A line for each split-source sequence, where each line is a space separated list of (split) source functions.

The latter two arrays, split sources and split-source sequences, define a directed graph, which is the call-graph of the program.