From 67803f6cb5c013fca15d409e540cd83f4e84e547 Mon Sep 17 00:00:00 2001
From: Virgil Dupras <hsoft@hardcoded.net>
Date: Tue, 14 May 2019 15:42:15 -0400
Subject: [PATCH] zasm: don't upcase char literals

---
 apps/zasm/instr.asm       |  2 +-
 apps/zasm/tests/test4.asm |  1 +
 apps/zasm/tok.asm         |  1 -
 apps/zasm/util.asm        | 41 +++++++++++++++++++++++++++++++++++++--
 4 files changed, 41 insertions(+), 4 deletions(-)

diff --git a/apps/zasm/instr.asm b/apps/zasm/instr.asm
index 0f60f65..0ffd33d 100644
--- a/apps/zasm/instr.asm
+++ b/apps/zasm/instr.asm
@@ -143,7 +143,7 @@ parseArg:
 	ld	b, ARGSPEC_TBL_CNT
 .loop1:
 	ld	a, 4
-	call	JUMP_STRNCMP
+	call	strncmpI
 	jr	z, .found		; got it!
 	ld	a, 5
 	call	JUMP_ADDDE
diff --git a/apps/zasm/tests/test4.asm b/apps/zasm/tests/test4.asm
index c1dcf45..b04228f 100644
--- a/apps/zasm/tests/test4.asm
+++ b/apps/zasm/tests/test4.asm
@@ -5,3 +5,4 @@ ld	a, 0x42
 ld	hl, 0x4234
 ld	hl, (0x4234)
 ld	a, 'X'
+ld	a, 'a'	; don't upcase!
diff --git a/apps/zasm/tok.asm b/apps/zasm/tok.asm
index 02e15c8..76f06bd 100644
--- a/apps/zasm/tok.asm
+++ b/apps/zasm/tok.asm
@@ -75,7 +75,6 @@ readWord:
 	ld	a, (hl)
 	call	isSepOrLineEnd
 	jr	z, .success
-	call	JUMP_UPCASE
 	ld	(de), a
 	inc	hl
 	inc	de
diff --git a/apps/zasm/util.asm b/apps/zasm/util.asm
index 74a9938..1366985 100644
--- a/apps/zasm/util.asm
+++ b/apps/zasm/util.asm
@@ -55,6 +55,42 @@ strlen:
 	pop	bc
 	ret
 
+; Compares strings pointed to by HL and DE up to A count of characters in a
+; case-insensitive manner.
+; If equal, Z is set. If not equal, Z is reset.
+strncmpI:
+	push	bc
+	push	hl
+	push	de
+
+	ld	b, a
+.loop:
+	ld	a, (de)
+	call	JUMP_UPCASE
+	ld	c, a
+	ld	a, (hl)
+	call	JUMP_UPCASE
+	cp	c
+	jr	nz, .end	; not equal? break early. NZ is carried out
+				; to the called
+	or	a		; cp 0. If our chars are null, stop the cmp
+	jr	z, .end		; The positive result will be carried to the
+	                        ; caller
+	inc	hl
+	inc	de
+	djnz	.loop
+	; Success
+	; We went through all chars with success. Ensure Z
+	cp	a
+.end:
+	pop	de
+	pop	hl
+	pop	bc
+	; Because we don't call anything else than CP that modify the Z flag,
+	; our Z value will be that of the last cp (reset if we broke the loop
+	; early, set otherwise)
+	ret
+
 ; If string at (HL) starts with ( and ends with ), "enter" into the parens
 ; (advance HL and put a null char at the end of the string) and set Z.
 ; Otherwise, do nothing and reset Z.
@@ -87,14 +123,15 @@ enterParens:
 	call	JUMP_UNSETZ
 	ret
 
-; Find string (HL) in string list (DE) of size B. Each string is C bytes wide.
+; Find string (HL) in string list (DE) of size B, in a case-insensitive manner.
+; Each string is C bytes wide.
 ; Returns the index of the found string. Sets Z if found, unsets Z if not found.
 findStringInList:
 	push	de
 	push	bc
 .loop:
 	ld	a, c
-	call	JUMP_STRNCMP
+	call	strncmpI
 	ld	a, c
 	call	JUMP_ADDDE
 	jr	z, .match