From c2d84563ddfcd9cd4947801d6078a9ddbe04703b Mon Sep 17 00:00:00 2001
From: Virgil Dupras <hsoft@hardcoded.net>
Date: Tue, 23 Jul 2019 16:01:23 -0400
Subject: [PATCH] zasm: allow duplicate const definition

This will allow interesting override scenarios, adding flexibility.
---
 apps/zasm/README.md                 |   4 ++++
 apps/zasm/directive.asm             |   7 +++++++
 tools/emul/zasm/zasm.bin            | Bin 4659 -> 4663 bytes
 tools/tests/zasm/errtests.sh        |   2 +-
 tools/tests/zasm/test7.asm          |   5 +++++
 tools/tests/zasm/test7.asm.expected |   1 +
 6 files changed, 18 insertions(+), 1 deletion(-)
 create mode 100644 tools/tests/zasm/test7.asm
 create mode 100644 tools/tests/zasm/test7.asm.expected

diff --git a/apps/zasm/README.md b/apps/zasm/README.md
index 335660b..ac678db 100644
--- a/apps/zasm/README.md
+++ b/apps/zasm/README.md
@@ -115,6 +115,10 @@ allowed. An included file cannot have an `#inc` directive.
 **.equ**: Binds a symbol named after the first parameter to the value of the
           expression written as the second parameter. Example:
           `.equ foo 0x42+'A'`
+          
+          If the symbol specified has already been defined, no error occur and
+          the first value defined stays intact. This allows for "user override"
+          of programs.
 
 **.fill**: Outputs the number of null bytes specified by its argument, an
            expression. Often used with `$` to fill our binary up to a certain
diff --git a/apps/zasm/directive.asm b/apps/zasm/directive.asm
index e25ab4d..4bf8afc 100644
--- a/apps/zasm/directive.asm
+++ b/apps/zasm/directive.asm
@@ -149,6 +149,13 @@ handleEQU:
 	ld	hl, DIREC_SCRATCHPAD
 	push	ix \ pop de
 	call	symRegisterConst	; A and Z set
+	jr	z, .end			; success
+	; register ended up in error. We need to figure which error. If it's
+	; a duplicate error, we ignore it and return success because, as per
+	; ".equ" policy, it's fine to define the same const twice. The first
+	; value has precedence.
+	cp	ERR_DUPSYM
+	; whatever the value of Z, it's the good one, return
 	jr	.end
 .badfmt:
 	ld	a, ERR_BAD_FMT
diff --git a/tools/emul/zasm/zasm.bin b/tools/emul/zasm/zasm.bin
index f74da551e3a493a0d8a133de77b333f872930f13..7a7a56f2f9818f6bad600c971b6c8f125d79a680 100644
GIT binary patch
delta 452
zcmdn2vR#GgFv~_Jc1Fgg$y|&Uj5V8`8J{vTp4+U+EXgRiD?)+o>fMJI_n*9YxF+)H
z*`Ce8EHaEhMFp(2OdK_l8s=9)f?wG)**Mk1ox}6PXM}H_oX%IP*A%H?`Sj}1vl(6r
zDuN{mj1CNMH-I?eiY5tXqkR;F6-yHCKD~HWFG7R&pV(wRer3jv$wvGRj5U*s`8(X-
zg`a&HaaZv(g!&PF_+^Bh-oBG}pWamjN?AqReF$a)<>BlfQ1;Wa-y$@O&uV%2pRJ$l
zBv7s<6rmvl(N`bwP=oWXB2Z<0go5DTIL5zWOcFo=pfUB6?+Yj~CQW7%G*<l^u9zBm
zR>sSY(WtQV?DR+l5yb)!e?5>3*8MW#?DWY|g0`6(BM(&k`=`Mq@%3y|qyp<%)hLPA
z`%j+b^{)8Gc<OZIKc-XXBmXgL2>knZ!cOooKSSkVkATX<cf&z}01P4Fvp~10gS`X{
zOX0J;Q4*41*8qjVhH(Q!H}dtvvsROYWW+y%Lg8$hr&e*Nl1c)|F-Aq5`%eM@S4+u|

delta 473
zcmdn4vRQ@cFvCVBc1Fg!$y|&Uj1`-m8J{vTp4zO*EXgRiEkc3q>fMJI_n*9YxFYiD
z*^bS@EHaEhMFp(2OdJ)F8s=9)f?wG)**KNM?ZdOfr-ZMcoX%IPRTrsY`t<72vl(6r
z3W6mGj1CNMH-I?8iY5tXqkR<k6-yHCKD~HWD`K(`zcORXWHWvT#)`@1{2lJE!p}a9
zxU2XcLVXE8{4~N&Z{NwgPwy%MrOYDkJ_NIY@^JPSDEsNzPZ1i%XSF>1&sI-%6DU{X
zi_nmP=&O!+sKI$x5vZ~{LP79v9OK_GCJCSb(3tAUj|G$%<0i8S8ms;cS4@mNE8}Iy
zXjIsFc5<YGh++<izaGd1>wX$>cJkynLEHMZkq0XN{nKEQ_<FW3Qi1iXVwA+|{U^`z
zdRP2oJas(sAJeJRk^h)A1pfUyVJCQ)pP}-wM?mG_o8h1U0EUk6S)kk0!CnG}qwrbI
zC<#fhYk<OF!?=MV8~OSn(31*G>rbBLXE=E_&{In#L8-VC<T%+*qavV--h+bYY?`N5
Pai@|>0?3s>;r%B8*ul{Q

diff --git a/tools/tests/zasm/errtests.sh b/tools/tests/zasm/errtests.sh
index 87537a9..dd4a76b 100755
--- a/tools/tests/zasm/errtests.sh
+++ b/tools/tests/zasm/errtests.sh
@@ -55,5 +55,5 @@ chkerr "#inc foo" 19
 chkerr "ld a, 0x100" 20
 chkerr ".db 0x100" 20
 chkerr "#inc \"doesnotexist\"" 21
-chkerr ".equ foo 42 \\ .equ foo 42" 22
+chkerr "foo:\\foo:" 22
 chkoom
diff --git a/tools/tests/zasm/test7.asm b/tools/tests/zasm/test7.asm
new file mode 100644
index 0000000..c5976ad
--- /dev/null
+++ b/tools/tests/zasm/test7.asm
@@ -0,0 +1,5 @@
+; It's fine to declare the same constant twice. Only the first value is
+; kept
+.equ	FOO	42
+.equ	FOO	22
+ld	a, FOO
diff --git a/tools/tests/zasm/test7.asm.expected b/tools/tests/zasm/test7.asm.expected
new file mode 100644
index 0000000..29cc4ea
--- /dev/null
+++ b/tools/tests/zasm/test7.asm.expected
@@ -0,0 +1 @@
+>*
\ No newline at end of file