The new command marks the target window as a scratch window -- a window
whose state cannot be "dirtied" by changes made to its body, therefore
avoiding warnings about unsaved changes when deleting the window or
exiting acme.
Existing examples of scratch windows are error, directory, and guide
windows, whose scratchness is set internally.
With the new command users and programs alike can create their own
scratch windows. This is put to use in acme's own win(1).
basically, we want the following commands to print
the same pid twice:
rc -c 'cat /dev/pid &;echo $apid'
vs:
rc -c 'a=1 cat /dev/pid &;echo $apid'
basically, Xsimple() calls exitnext() to determine if
a simple command should be promoted to exec, by peeking
ahead into the code and searching for Xexit instruction.
Xexit might not follow immediately after the Xsimple
instruction because of redirections, which exitnext()
would skip.
but it would not skip the Xunlocal instructions that
where added by the variable assignment.
the maketab helper program was generated in parallel, which
had a dependency to y.tab.h which lead to yacc running
twice in parallel.
this removes the dependency to y.tab.h in the virtual
maketab.$objtype target to prevent this race condition.
the dependency to y.tab.h is resolved in the main mk at the
$cputype.maketab target which serializes with the other
targets.
the page attribute table was initialized in mmuinit(), which is
too late for bootscreen(). So now we check for PAT support and
insert the write-combine entry early in cpuidentify().
this might have been the cause of some slow EFI framebuffers on
machines with overlapping or insufficient MTRR entries.
at the _cas0 label, the linker would generate spurious stack
adjustment before the return:
atexitdont+0x84 0x000000000003614c CLREX $0xf
atexitdont+0x88 0x0000000000036150 MOVW R31,R0
atexitdont+0x8c 0x0000000000036154 MOV (SP)16!,R30 <- ????????????
atexitdont+0x90 0x0000000000036158 RETURN
the work arround is to move the code into its own cas0
text symbol.
this fixes impossible cwfs crashes in srvi().
