How far back to you want to go? There is no definitive start point for C, as it grew fairly organically out of B and began as a living language. However, a rea

How far back to you want to go? There is no definitive start point for C, as it grew fairly organically out of B and began as a living language. However, a reasonable approximation for C 1.0 is The C Programming Language (Kernighan and Ritchie, 1978) [0], commonly known as K&R C. The language they describe is much simpler than modern C. Notably for this discussion, it contains no synchronization mechanisms. There is nothing in that book that suggests C was a macro assembler. On the contrary, its description of C precludes it from being a macro assembler for the reasons I talked about in a parent comment: > Although C matches the capabilities of many computers, it is independent of any particular machine architecture, and so with a little care it is easy to write "portable" programs, that is, programs which can be run without change on a variety of hardware. . It is now routine in our environment that software developed on UNIX is transported to the local Honeywell, IBM and Interdata systems. In fact, the C compilers and runtime support on these four machines are much more compatible than than the supposedly ANSI standard versions of Fortran. > Because the data types and control structures provided by C are supported directly by most existing computers, the runtime library required to implement self-contained programs is tiny. On the PDP-I1, for example, it contains only the routines to do 32-bit multiplication and division and to perform the subroutine entry and exit sequences. Notice the way this paragraph frames the issue. Since the features of C are supported by most machines, it can be implemented with a small runtime library. It does not say that C must use those features directly. In fact, it explicitly anticipates that C could provide some of its primitives in ways other then directly leveraging a corresponding capability of the hardware. The feature here is efficiency and a small runtime. [0] https://1lib.us/book/2660358/b1a4cf https://1lib.us/book/2660358/b1a4cf