From 18205c74c571af97f8f8106698fc9b70ce0c1c0f Mon Sep 17 00:00:00 2001
From: Rangi <remy.oukaour+rangi42@gmail.com>
Date: Sat, 23 Jan 2021 22:20:35 -0500
Subject: [PATCH] Implement [[ inline code blocks ]]

Fixes #500
---
 include/asm/section.h |  1 +
 src/asm/lexer.c       | 16 +++++++++++----
 src/asm/parser.y      | 45 +++++++++++++++++++++++++++++++++++++++++--
 src/asm/section.c     |  5 +++++
 4 files changed, 61 insertions(+), 6 deletions(-)

diff --git a/include/asm/section.h b/include/asm/section.h
index d8c7855a44..74700f4451 100644
--- a/include/asm/section.h
+++ b/include/asm/section.h
@@ -46,6 +46,7 @@ void out_SetLoadSection(char const *name, uint32_t secttype, uint32_t org,
 			struct SectionSpec const *attributes);
 void out_EndLoadSection(void);
 
+struct Section *sect_GetCurrentSection(void);
 struct Section *sect_GetSymbolSection(void);
 uint32_t sect_GetSymbolOffset(void);
 uint32_t sect_GetOutputOffset(void);
diff --git a/src/asm/lexer.c b/src/asm/lexer.c
index 706363f619..7d44da2a86 100644
--- a/src/asm/lexer.c
+++ b/src/asm/lexer.c
@@ -1650,10 +1650,6 @@ static int yylex_NORMAL(void)
 			yylval.tzSym[1] = '\0';
 			return T_ID;
 
-		case '[':
-			return T_LBRACK;
-		case ']':
-			return T_RBRACK;
 		case '(':
 			return T_LPAREN;
 		case ')':
@@ -1663,6 +1659,18 @@ static int yylex_NORMAL(void)
 
 		/* Handle ambiguous 1- or 2-char tokens */
 
+		case '[': /* Either [ or [[ */
+			if (peek(0) == '[') {
+				shiftChars(1);
+				return T_2LBRACK;
+			}
+			return T_LBRACK;
+		case ']': /* Either ] or ]] */
+			if (peek(0) == ']') {
+				shiftChars(1);
+				return T_2RBRACK;
+			}
+			return T_RBRACK;
 		case '*': /* Either MUL or EXP */
 			if (peek(0) == '*') {
 				shiftChars(1);
diff --git a/src/asm/parser.y b/src/asm/parser.y
index 0ae82123c6..5cc8aacacc 100644
--- a/src/asm/parser.y
+++ b/src/asm/parser.y
@@ -41,6 +41,7 @@ int32_t nPCOffset; /* Read by rpn_Symbol */
 static uint32_t nListCountEmpty;
 static bool executeElseBlock; /* If this is set, ELIFs cannot be executed anymore */
 static struct CaptureBody captureBody; /* Captures a REPT/FOR or MACRO */
+static uint32_t inlineBlockID = 0; /* Incrementing unique ID for inline block labels */
 
 static void upperstring(char *dest, char const *src)
 {
@@ -406,6 +407,12 @@ enum {
 		int32_t step;
 	} forArgs;
 	struct StrFmtArgList strfmtArgs;
+	struct {
+		int32_t nPCOffset;
+		uint32_t nListCountEmpty;
+		struct Section *sect;
+		char name[24]; // space for "inline_block$4294967295" + '\0'
+	} inlineBlock;
 }
 
 %type	<sVal>		relocexpr
@@ -429,12 +436,15 @@ enum {
 %type	<nConstValue>	sectorg
 %type	<sectSpec>	sectattrs
 
+%type	<inlineBlock>	inline_block
+
 %token	<nConstValue>	T_NUMBER "number"
 %token	<tzString>	T_STRING "string"
 
 %token	T_COMMA ","
 %token	T_COLON ":"
 %token	T_LBRACK "[" T_RBRACK "]"
+%token	T_2LBRACK "[[" T_2RBRACK "]]"
 %token	T_LPAREN "(" T_RPAREN ")"
 %token	T_NEWLINE "newline"
 
@@ -1179,7 +1189,8 @@ reloc_8bit_no_str : relocexpr_no_str {
 		}
 ;
 
-reloc_16bit	: relocexpr {
+reloc_16bit	: inline_block { rpn_Symbol(&$$, $1.name); }
+		| relocexpr {
 			if (rpn_isKnown(&$1)
 			 && ($1.nVal < -32768 || $1.nVal > 65535))
 				warning(WARNING_TRUNCATION, "Expression must be 16-bit\n");
@@ -1187,7 +1198,8 @@ reloc_16bit	: relocexpr {
 		}
 ;
 
-reloc_16bit_no_str : relocexpr_no_str {
+reloc_16bit_no_str : inline_block { rpn_Symbol(&$$, $1.name); }
+		| relocexpr_no_str {
 			if (rpn_isKnown(&$1)
 			 && ($1.nVal < -32768 || $1.nVal > 65535))
 				warning(WARNING_TRUNCATION, "Expression must be 16-bit\n");
@@ -1195,6 +1207,35 @@ reloc_16bit_no_str : relocexpr_no_str {
 		}
 ;
 
+inline_block	: T_2LBRACK T_NEWLINE {
+			struct Section *sect = sect_GetCurrentSection();
+			struct SectionSpec attrs;
+
+			attrs.bank = sect->bank == 0 ? -1 : sect->bank; // BANK[0] not allowed
+			attrs.alignment = sect->align;
+			attrs.alignOfs = sect->alignOfs;
+			sect->modifier = SECTION_FRAGMENT;
+			$<inlineBlock>$.nPCOffset = nPCOffset;
+			$<inlineBlock>$.nListCountEmpty = nListCountEmpty;
+			out_PushSection();
+			sprintf($<inlineBlock>$.name, "inline_block$%" PRIu32, inlineBlockID++);
+			out_NewSection($<inlineBlock>$.name, sect->type, sect->org, &attrs, sect->modifier);
+			sym_AddLabel($<inlineBlock>$.name);
+			$<inlineBlock>$.sect = sect_GetCurrentSection();
+		} lines T_2RBRACK {
+			out_PopSection();
+			struct Section *sect = sect_GetCurrentSection();
+
+			free($<inlineBlock>3.sect->name);
+			$<inlineBlock>3.sect->name = strdup(sect->name);
+			if ($<inlineBlock>3.sect->name == NULL)
+				fatalerror("Not enough memory for section name: %s\n", strerror(errno));
+			nPCOffset = $<inlineBlock>3.nPCOffset;
+			nListCountEmpty = $<inlineBlock>3.nListCountEmpty;
+			$$.sect = $<inlineBlock>3.sect;
+			strcpy($$.name, $<inlineBlock>3.name);
+		}
+;
 
 relocexpr	: relocexpr_no_str
 		| string {
diff --git a/src/asm/section.c b/src/asm/section.c
index f96de32a59..4ba0d623a7 100644
--- a/src/asm/section.c
+++ b/src/asm/section.c
@@ -364,6 +364,11 @@ void out_EndLoadSection(void)
 	loadOffset = 0;
 }
 
+struct Section *sect_GetCurrentSection(void)
+{
+	return pCurrentSection;
+}
+
 struct Section *sect_GetSymbolSection(void)
 {
 	return currentLoadSection ? currentLoadSection : pCurrentSection;