From e533756d253c13b538c0744f57e98f08056d970f Mon Sep 17 00:00:00 2001
From: Jesse McDonald <nybble41@gmail.com>
Date: Mon, 9 Nov 2020 13:55:55 -0600
Subject: [PATCH] replace global variables holding local data with ALLOCA

---
 startup.4th | 64 ++++++++++++++++++++++++++++-------------------------
 1 file changed, 34 insertions(+), 30 deletions(-)

diff --git a/startup.4th b/startup.4th
index ef352a8..f7ba181 100644
--- a/startup.4th
+++ b/startup.4th
@@ -2226,12 +2226,10 @@ ENDSTRUCT termios%
 
 SYSTEM DEFINITIONS
 
-termios% %VARIABLE SCRATCH-TERMIOS
-
 FORTH DEFINITIONS
 
 : TTY?  ( fd -- flag )
-   IOCTL_TCGETS SCRATCH-TERMIOS SYS_IOCTL SYSCALL3 0= ;
+   IOCTL_TCGETS termios% %ALLOCA SYS_IOCTL SYSCALL3 UNALLOCA 0= ;
 
 STDIN TTY? CONSTANT INTERACTIVE?
 
@@ -2788,9 +2786,7 @@ ENDSTRUCT FILE%
 
 { CONTAINEROF FILE>NODE ▪ FILE>FD @ } ' <=> NEW-AA-TREE CONSTANT FILES
 
-open_how% %VARIABLE OPEN-HOW
 stat64% %VARIABLE STAT64-RESULT
-signed-long-long% %VARIABLE LLSEEK-RESULT
 
 : FD>FILE  ( fileid -- file-addr )
    FILES AA-LOOKUP ?DUP 0= "unknown file ID" ?FAIL ;
@@ -2818,36 +2814,44 @@ O_RDWR   CONSTANT R/W  ( -- fam )
 : BIN  ( fam1 -- fam2 )  IMMEDIATE ;
 
 : OPEN-FILE  ( c-addr u fam -- fileid )
-   FILE% %ALLOCATE >R
-   NULL R@ FILE>BUFFER !
-   R@ CLEAR-LEFTOVER
-   0# R@ FILE>POSITION 2!
-   [ NULL 0 ] 2LITERAL R@ FILE>SOURCE 2!
-   OPEN-HOW SIZEOF open_how% 0 FILL
-   DUP 0 SWAP OPEN-HOW open_how>flags 2!
-   [[ O_CREAT __O_TMPFILE OR ]] AND IF
-      0 0666 OPEN-HOW open_how>mode 2!
-   THEN
-   AT_FDCWD ▪ -ROT MAKE-CSTRING DUP >R ▪ OPEN-HOW ▪ SIZEOF open_how%
-      SYS_OPENAT2 SYSCALL4-RETRY
-   R> FREE
-   DUP ERRNO_ENOENT = OR-ELSE DUP ERRNO_ENOTDIR = THEN IF
-      DROP EXCP-NON-EXISTENT-FILE THROW THEN
-   DUP 0< IF DROP EXCP-FILE-IO THROW THEN
-   DUP R@ FILE>FD !
-   R@ FILES AA-LOOKUP 0<> "internal error - duplicate key in FILES" ?FAIL
-   R> FILES AA-INSERT ;
+   -ROT MAKE-CSTRING
+   open_how% %ALLOCA
+      FILE% %ALLOCATE
+      LOCALS| fam name open-how file |
+         NULL file FILE>BUFFER !
+         file CLEAR-LEFTOVER
+         0# file FILE>POSITION 2!
+         [ NULL 0 ] 2LITERAL file FILE>SOURCE 2!
+         open-how SIZEOF open_how% 0 FILL
+         0 fam open-how open_how>flags 2!
+         fam [[ O_CREAT __O_TMPFILE OR ]] AND IF
+            0 0666 open-how open_how>mode 2!
+         THEN
+         AT_FDCWD ▪ name ▪ open-how ▪ SIZEOF open_how%
+            SYS_OPENAT2 SYSCALL4-RETRY
+         name FREE
+         DUP ERRNO_ENOENT = OR-ELSE DUP ERRNO_ENOTDIR = THEN IF
+            DROP file FREE EXCP-NON-EXISTENT-FILE THROW THEN
+         DUP 0< IF DROP file FREE EXCP-FILE-IO THROW THEN
+         DUP file FILE>FD !
+         file FILES AA-LOOKUP NULL<> "internal error - duplicate key in FILES" ?FAIL
+         file FILES AA-INSERT
+      ENDLOCALS
+   UNALLOCA ;
 
 : CREATE-FILE  ( c-addr u fam -- fileid )
    [[ O_CREAT O_TRUNC OR ]] OR OPEN-FILE ;
 
 : REPOSITION-FILE  ( ud fileid -- )
-   DUP ▪ FD>FILE >R ▪ -ROT SWAP ▪ LLSEEK-RESULT ▪ SEEK_SET
-      SYS__LLSEEK SYSCALL5-RETRY
-   R@ CLEAR-LEFTOVER
-   0<> IF RDROP EXCP-FILE-IO THROW THEN
-   LLSEEK-RESULT 2@ SWAP R@ FILE>POSITION 2!
-   RDROP ;
+   DUP FD>FILE ▪ signed-long-long% %ALLOCA
+      LOCALS| file llseek-result |
+         -ROT SWAP ▪ llseek-result ▪ SEEK_SET
+            SYS__LLSEEK SYSCALL5-RETRY
+         file CLEAR-LEFTOVER
+         0<> IF RDROP EXCP-FILE-IO THROW THEN
+         llseek-result 2@ SWAP file FILE>POSITION 2!
+      ENDLOCALS
+   UNALLOCA ;
 
 : FILE-POSITION  ( fileid -- ud )  FD>FILE FILE>POSITION 2@ ;