Clang Func Completion

Clang Func Completion fills in the half of a C function you have not written yet: it suggests only functions whose declaration or definition is missing, and inserts the missing one for you.

Features

• Completes the missing counterpart. Where a definition belongs, you are offered the functions that are declared but never defined, inserted as a full signature with a { } body and the cursor placed inside. Where a declaration belongs — a header, or the prototype block at the top of a .c file — you are offered the functions that are defined but never declared, inserted as a signature ending in ;.
• Never suggests what already exists. A function that has both a declaration and a definition is filtered out, so the list stays short instead of duplicating ordinary token-match completion.
• A lower-priority tier for functions you called before writing them. A name that is called somewhere in the workspace but declared and defined nowhere is offered too. Only the bare name is inserted: a call site shows argument expressions, never their types, so any signature built from one would be a guess.
• Replaces the type tokens you already typed. Typing static void fun and accepting a candidate produces static void fun(...), not a duplicated return type. extern is dropped when inserting a definition, since it only means something on a declaration.
• Whole-workspace scan kept warm in the background. The scan runs at startup, re-runs when you save a supported file, and is cleared when files are deleted or renamed.
• Respects static linkage. A static definition is offered as a declaration candidate only inside the file that defines it.

Usage

Works automatically in c and cpp files (.c .C .cpp .cxx .h .hpp .hxx). Start typing a function name where a declaration or a definition would go and the candidates appear in the normal completion list. Inside a function body, where neither can be written, nothing is offered.

If the workspace scan has to stop early — more than 5000 files, a file over 4 MB, directories nested deeper than 12 levels, or an unreadable file — a warning is shown once per scan. A file that was skipped makes an already-defined function look undefined, so check the signature before accepting an insertion.

Requirements

VS Code 1.104.0 or later. No compiler or language server is required; signatures are extracted by text analysis. Because that analysis is regex-based rather than a real C parser, unusual declaration forms (a pointer return type written as char *get_buf(void), CC-RL __far / __near / __callt qualifiers, or a function returning a function pointer) may go unrecognized, which again shows up as an offer to insert a duplicate definition.