Undocumented variables set in SYSEDIT

[masinter]

          In SYSEDIT:

Apart from the copyright, what do the following do:

GLOBALVARFLG
CROSSCOMPILING
MSRECORDTRANFLG

IRM and man don’t appear to know about these.

[masinter]

I think we need a "modern medley" developers guide that explains or at least gives some clues about otherwise undocumented features -- or else, when appropriate, removes those features.

The variables @rmkaplan noted are set in SYSEDIT (recommended loading when editing system code) which in turn loads EXPORTS.ALL and sets some variables.

GLOBALVARFLG set to T: This flag, if set to NIL, will basically ignore any "global variable" declaration when compiling (during the BYTECOMPILER phase). It is initialized to T. The use of spaghetti stack primitives to add the multi-threading features of Interlisp aren't well documented. Using the "FVAR" opcode to reference a "free" variable is much slower than using the "GVAR" opcode -- GVAR is a single memory reference, while FVAR has to search up the stack the first time (the memory location of FVAR opcodes is cached in the stack frame).
GLOBALVARFLG isn't itself a global.

CROSSCOMPILING set to T: Initialized in the file LLDATATYPE to NIL.
Looking at the code (I don't remember it), it controls whether it should ask the user "OK TO REDECLARE DATATYPE" when compiling a file with a different DATATYPE declaration than what is defined in the file. (this is in the function \ASSIGNDATATYPE1 in the file LLDATATYPE). There's also a use in the file LLCODE with something testing (AND CROSSCOMPILING (FMEMB :3-BYTE COMPILER::TARGET-ARCHITECTURE)). The RENAMEFNS part of MAKEINIT also sets (RESETVARS) the CROSSCOMPILING variable to T. So CROSSCOMPILING seems to bundle a couple of uses.

MSRECORDTRANFLG is a global var initialized to NIL in the file MSANALYZE and reset to T (using RESETVARS) when using CALLS on an expr. MSRECORDTRANFLG is used both to control (in a way I might have understood in 1988) whether a record expression (fetch, replace, change, create) should also analyze the translated expression and also (in the function CHANGERECORD) some of the (faulty IMO) logic around updating functions with record expressions.