iocsh on vxWorks broken

The reason is in iocsh.cpp line 363:
        if (quote != EOF) {

Here, quote is 0xff but EOF is -1.

quote is initialized in line 265:
        char quote = EOF;

The problem is the usage of EOF in function split().

On any architecture, where char is unsigned (e.g. VxWorks on PPC), the initialization
        char quote = EOF;
sets quote to (char)-1 = 255.

Later, the comparison (quote != EOF) compares an unsigned char with the signed int literal -1. Thus the unsigned char gets promoted to a signed int with the same value 255 which is then then compared to -1. That is of course not equal.

The possible fixes are:
1. use signed char quote
2. use int quote
3. use 0 instead of EOF

I prefer solution 3. The attached patch has been created with commit 60128ee but can be applied to the current HEAD (bc54524) as well.

I suggest to add at least one architecture with unsigned char to the automated tests. Maybe building EPICS on Linux with -funsigned-char will do?

> ... building EPICS on Linux with -funsigned-char ...

Adding this as a CI job seems an interesting idea. Have you tried it locally?

Not yet...

Core Group 2/1/2023: Thanks!

This change is still in unreleased Base branch.

We agree with Dirk's analysis, and would prefer to run the tests on an architecture that has unsigned char, if necessary the use of -funsigned-char should work.

Compiling base on my Linux host with CMD_CFLAGS=-funsigned-char and CMD_CXXFLAGS=-funsigned char builds an ioc that shows the same buggy behavior (complaining about any command with "Unbalanced quote" error).

And it fails iocshTest.t:
Test Summary Report
-------------------
iocshTest.t (Wstat: 256 Tests: 19 Failed: 8)
  Failed tests: 2, 4-5, 9, 14-17

And in database/test/std/rec/:
Unbalanced quote.
iocsh Error: Break
dbAllocRecord(rec0) with ao rec_size = 0
Can't create record "rec0" of type "ao"
Error at or before ')' in path ".." file "asTest.db" line 1
Error: syntax error
Bailout called. Further testing stopped: Failed to load test database
FAILED--Further testing stopped: Failed to load test database

After applying the patch iocsh works and all tests succeed.

The regression in https://github.com/epics-base/epics-base/pull/274 is the change from

> int quote, inword, backslash;

to

> bool inword = false;
> bool backslash = false;
> char quote = EOF;

Which in retrospect is an issue because the EOF macro is meant to be stored/compared with 'int' (eg. with 'getc()' and friends).

> 3. use 0 instead of EOF
>
> I prefer solution 3. ...

I agree.

> The attached patch ...

Applied as 3dbc9ea26491dc676888fca091e78cddf9a8760c

I've also added a GHA job with -funsigned-char