verilator

zig-based build system and setup for verilator

version compatibility

tested range: v5.018 - v5.044 (and likely newer)

quick start

zig build -Doptimize=ReleaseFast

./zig-out/bin/verilator --version
./zig-out/bin/verilator --lint-only your_design.v

requirements

build dependencies

runtime dependencies

build options

compiler selection

by default, verilated designs use zig c++ as the compiler. this provides:

• cross-platform builds without msvc/mingw on windows
• consistent c++20/coroutines support
• single toolchain

to use system compiler:

zig build -Duse-zig-cc=false    # uses system c++ and ar

to use a specific compiler:

zig build -Dcxx=clang++ -Dar=llvm-ar
zig build -Dcxx=g++ -Dar=ar

[!NOTE] -Dcxx/-Dar take precedence over -Duse-zig-cc

runtime compiler override

the generated verilated.mk defaults to zig c++ but supports runtime override:

# override when building verilated designs
VERILATOR_CXX=g++ VERILATOR_AR=ar make -f Vdesign.mk

# or export for the session
export VERILATOR_CXX=clang++
export VERILATOR_AR=llvm-ar
make -f Vdesign.mk

the makefile automatically detects compiler type (zig/clang/gcc) and adjusts:

• coroutine flags (-fcoroutines for gcc)
• precompiled header suffix (.gch for clang)
• macos linker flags (-undefined dynamic_lookup for zig)

building

zig build

switch verilator version

zig fetch --save=verilator "git+https://github.com/verilator/verilator#v5.042"
zig build

cross-compilation

zig build -Dtarget=aarch64-linux-gnu -Doptimize=ReleaseFast
zig build -Dtarget=x86_64-windows-gnu -Doptimize=ReleaseFast

supported targets:

• x86_64-linux-gnu, aarch64-linux-gnu
• x86_64-macos, aarch64-macos
• x86_64-windows-gnu, aarch64-windows-gnu

output structure

zig-out/
├── bin/
│   ├── verilator              # perl wrapper (entry point)
│   ├── verilator_bin          # main compiler binary
│   ├── verilator_coverage     # coverage tool wrapper
│   └── ...
└── include/
    ├── verilated.h            # runtime headers
    ├── verilated.mk           # makefile for verilated designs
    └── vltstd/                # standard library