Tombstone diagram

In computing, tombstone diagrams (or T-diagrams) consist of a set of “puzzle pieces” representing compilers and other related language processing programs. They are used to illustrate and reason about transformations from a source language (left of T) to a target language (right of T) realised in an implementation language (bottom of T). They are most commonly found describing complicated processes for bootstrapping, porting, and self-compiling of compilers, interpreters, and macro-processors.^[1]

Tombstone diagram representing an Ada compiler written in C that produces machine code.

Representation of the process of bootstrapping a C compiler written in C, by compiling it using another compiler written in machine code. To explain, the lefthand T is a C compiler written in C that produces machine code. The righthand T is a C compiler written in machine code that also produces machine code. The diagram illustrates that this can be used to bootstrap the left T by using it to compile the compiler written in C.

T-diagrams were first used for describing bootstrapping and cross-compiling compilers by Harvey Bratman in 1961,^[2] who reshaped the diagrams originally introduced by Strong et al. (1958) to illustrate UNCOL. ^[3] Later on, others, including McKeeman et al. ^[4] and P.D. Terry,^[1] explained the usage of T-diagrams with further detail. T-diagrams are also now used to describe client-server interconnectivity on the World Wide Web.^[5] A teaching tool TDiag has been implemented at Leipzig University, Germany.^[6]

See also

• Bootstrapping (compilers)