VHDL Language Server/Support

VHDL Language Server and Support for Visual Studio Code.

Features

• Live syntax and type checking
• Finds missing and duplicate declarations
• Goto-definition/declaration (also in presence of overloading)
• Find-all-references (also in presence of overloading)
• Goto-implementation
  • From component declaration to matching entity by default binding
  • From entity to matching component declaration by default binding
• Hovering symbols reveals more information
• Renaming symbols
• Finding workspace symbols
• Viewing/finding document symbols

Configuration

The language server needs to know the library mapping of the VHDL files in the project, for this purpose it reads a configuration file in the TOML format named vhdl_ls.toml. The file contains the library mapping of all files within the project and should be located in the workspace root. Files outside of the project without library mapping are checked for syntax errors only.

vhdl_ls will load configuration files in the following order of priority (first to last):

1. A file named .vhdl_ls.toml in the user home folder.
2. A file name from the VHDL_LS_CONFIG environment variable.
3. A file named vhdl_ls.toml in the workspace root.

Library definitions in later files redefines those from previously loaded files.

Example vhdl_ls.toml

# File names are either absolute or relative to the parent folder of the
# vhdl_ls.toml file and supports glob-style patterns.

[libraries]

# Defines library lib2
lib2.files = [
  'pkg2.vhd',
  'src/**/*.vhd',
]

# Defines library lib1
lib1.files = [
  'pkg1.vhd',
  'tb_ent.vhd',
]

# Libraries can be marked as third-party to disable some analysis warnings, such as unused declarations
UNISIM.files = [
  'C:\Xilinx\Vivado\2023.1\data\vhdl\src\unisims\unisim_VCOMP.vhd',
]
UNISIM.is_third_party = true

Non-project files

By default, files that are not part of the project are added and analyzed as part of an anonymous library. You can disable this behaviour by changing the vhdlls.nonProjectFiles setting from analyze to ignore. Note that changing this setting requires a restart of the langauge server to become effective.

Technology under the hood

This extension is based on the VHDL-LS Language Server. Pre-compiled binaries for Linux and Windows are provided with the extension.

The server can also be loaded from either the system path or Docker depending on the value of the vhdlls.languageServer property.

• embedded: Use the embedded binary.
• user: Use path provided by user in vhdlls.languageServerUserPath property.
• systemPath: Run vhdl_ls from path.
• docker: Use docker image (Only supports files below workspace root)

NOTE: On Linux, it may be necessary to set -x on the vhdl_ls binary.

Issues

Issues related to the extension can be reported at VHDL LS - VSCode repository.

Issues related to the VHDL language support and language server featuresshould be reported directly to VHDL-LS

Syntax coloring

Syntax coloring is based on the textmate vhdl.tmbundle

Licenses

The VSCode extension is available under the MIT license.

The VHDL-LS VHDL language server is available under the Mozilla Public License, v. 2.0.