Profiling

A program is slower than it should be, or it still holds memory you thought you had given back. echoc run --profile records a real run and tells you which functions took the time, which paths allocated, and which still hold memory when the program exits.

echoc run --profile app.eco

That writes an .ecoprof file and prints a short summary. A build without --profile is unchanged. The profiled build is otherwise a release build: same optimization, plus enough DWARF and frame pointers that a sample can be named.

function work() : void
{
    array<int32> $n;
    for (int32 $i = 0; $i < 1000; $i = $i + 1) {
        $n[] = $i;
    }
}

work();

You will see allocation paths through work and array<int32>::push. On a terminal the heading is a PROFILE chip. In a pipe it is [profile] plus the path.

The summary

Three parts, each a handful of rows.

Time is sampled (1000 Hz). Self-time is where the CPU is. Inclusive time is that function plus everything it called. The hottest paths are the stacks that showed up most. Allocator thunks fold into the first user-visible frame, so you see main -> work -> array::push rather than __eco_alloc.

Allocations are counted, not sampled: allocs, reallocs, frees, the top paths by count and by bytes. Live at exit is the leak column. A path that still holds memory after the program is done is a path you did not free.

Copies split into bytewise and constructor. A type with a destructor that is being copied in a loop shows up here.

echoc profile --text app.ecoprof is the same report with more rows. The file is already symbolized: names and file:line, inlined frames included. Later tools need neither the binary nor the dSYM.

echoc profile app.ecoprof
echoc profile --text app.ecoprof
echoc profile --folded time app.ecoprof

--folded writes collapsed stacks for speedscope or flamegraph.pl. time, self, allocs, alloc-bytes, live-bytes, copies, copy-bytes, calls.

A loose .eco writes ./<stem>.ecoprof. A project writes <build dir>/profile/<stem>.ecoprof.

Exact calls

Time is statistical unless you ask:

echoc run --profile-calls app.eco

That instruments function entry and exit. --profile-stdlib includes the standard library. Both imply --profile. Use it when a sampled stack is too coarse, not as the default: it is slower to compile and heavier to run.

External tools (samply, perf, Instruments) remain first-class. Profiled builds carry frame pointers and line-table DWARF, so they work with those too.

What it will not do

Time is sampled unless --profile-calls is given. A C library without frame pointers truncates the stack there. Threads still running at exit are read racily. echoc test, a foreign --target-os, wasi, iOS and Windows are refused: on Windows, use the external tools. --check-refcounts poisons class boxes and never frees them, so they show as live at exit.

Next

• Debugging for -g and dprint.
• CLI reference for the flags.