From 1ab93a194e7242912929b08798447f91e831a090 Mon Sep 17 00:00:00 2001
From: Ben10do <Ben10do@users.noreply.github.com>
Date: Thu, 23 Feb 2017 15:00:57 +0000
Subject: [PATCH] Implement ALIGN keyword in rgbasm

The ALIGN keyword specifies the number of bits that should be zero at the start of a section. It works in a simliar fashion to BANK.
---
 src/asm/asmy.y    | 14 +++++++++++++-
 src/asm/globlex.c |  1 +
 src/asm/output.c  |  5 ++++-
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/src/asm/asmy.y b/src/asm/asmy.y
index a8b96f50..8d9f7e7a 100644
--- a/src/asm/asmy.y
+++ b/src/asm/asmy.y
@@ -442,7 +442,7 @@ void	if_skip_to_endc( void )
 %left	T_OP_MUL T_OP_DIV T_OP_MOD
 %left	T_OP_NOT
 %left	T_OP_DEF
-%left	T_OP_BANK
+%left	T_OP_BANK T_OP_ALIGN
 %left	T_OP_SIN
 %left	T_OP_COS
 %left	T_OP_TAN
@@ -1095,6 +1095,10 @@ section:
 			else
 				yyerror("Address $%x not 16-bit", $6);
 		}
+	|	T_POP_SECTION string ',' sectiontype ',' T_OP_ALIGN '[' const ']'
+		{
+			out_NewAlignedSection($2, $4, $8, -1);
+		}
 	|	T_POP_SECTION string ',' sectiontype ',' T_OP_BANK '[' const ']'
 		{
 			bankrangecheck($2, $4, -1, $8);
@@ -1106,6 +1110,14 @@ section:
 			}
 			bankrangecheck($2, $4, $6, $11);
 		}
+	|	T_POP_SECTION string ',' sectiontype ',' T_OP_ALIGN '[' const ']' ',' T_OP_BANK '[' const ']'
+		{
+			out_NewAlignedSection($2, $4, $8, $13);
+		}
+	|	T_POP_SECTION string ',' sectiontype ',' T_OP_BANK '[' const ']' ',' T_OP_ALIGN '[' const ']'
+		{
+			out_NewAlignedSection($2, $4, $13, $8);
+		}
 ;
 
 sectiontype:
diff --git a/src/asm/globlex.c b/src/asm/globlex.c
index 9f9523a8..dd379277 100644
--- a/src/asm/globlex.c
+++ b/src/asm/globlex.c
@@ -267,6 +267,7 @@ struct sLexInitString staticstrings[] = {
 	{"def", T_OP_DEF},
 
 	{"bank", T_OP_BANK},
+	{"align", T_OP_ALIGN},
 
 	{"round", T_OP_ROUND},
 	{"ceil", T_OP_CEIL},
diff --git a/src/asm/output.c b/src/asm/output.c
index 601dff76..e40f92c8 100644
--- a/src/asm/output.c
+++ b/src/asm/output.c
@@ -631,7 +631,10 @@ out_NewAbsSection(char *pzName, ULONG secttype, SLONG org, SLONG bank)
 void 
 out_NewAlignedSection(char *pzName, ULONG secttype, SLONG alignment, SLONG bank)
 {
-	out_SetCurrentSection(out_FindSection(pzName, secttype, -1, bank, alignment));
+	if (alignment < 0) {
+		yyerror("Alignment must not be negative.");
+	}
+	out_SetCurrentSection(out_FindSection(pzName, secttype, -1, bank, 1 << alignment));
 }
 
 /*