Implement [[ inline code blocks ]]

Fixes gbdev#500
Rangi42 · Jan 24, 2021 · 7db4cc1 · 7db4cc1
1 parent 6623b1d
commit 7db4cc1
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Showing 4 changed files with 54 additions and 6 deletions.
diff --git 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
@@ -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
@@ -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 +407,11 @@ enum {
 		int32_t step;
 	} forArgs;
 	struct StrFmtArgList strfmtArgs;
+	struct {
+		int32_t nPCOffset;
+		uint32_t nListCountEmpty;
+		struct Section *sect;
+	} inlineBlock;
 }
 
 %type	<sVal>		relocexpr
@@ -429,12 +435,15 @@ 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"
 
@@ -1179,22 +1188,47 @@ reloc_8bit_no_str : relocexpr_no_str {
 		}
 ;
 
-reloc_16bit	: relocexpr {
+reloc_16bit	: inline_block { rpn_Symbol(&$$, $1.sect->name); }
+		| relocexpr {
 			if (rpn_isKnown(&$1)
 			 && ($1.nVal < -32768 || $1.nVal > 65535))
 				warning(WARNING_TRUNCATION, "Expression must be 16-bit\n");
 			$$ = $1;
 		}
 ;
 
-reloc_16bit_no_str : relocexpr_no_str {
+reloc_16bit_no_str : inline_block { rpn_Symbol(&$$, $1.sect->name); }
+		| relocexpr_no_str {
 			if (rpn_isKnown(&$1)
 			 && ($1.nVal < -32768 || $1.nVal > 65535))
 				warning(WARNING_TRUNCATION, "Expression must be 16-bit\n");
 			$$ = $1;
 		}
 ;
 
+inline_block	: T_2LBRACK T_NEWLINE {
+			struct Section *sect = sect_GetCurrentSection();
+			struct SectionSpec attrs;
+			char name[24]; // space for "inline_block$4294967295" + '\0'
+
+			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(name, "inline_block$%" PRIu32, inlineBlockID++);
+			out_NewSection(name, sect->type, sect->org, &attrs, sect->modifier);
+			sym_AddLabel(name);
+			$<inlineBlock>$.sect = sect_GetCurrentSection();
+		} lines T_2RBRACK {
+			out_PopSection();
+			nPCOffset = $<inlineBlock>3.nPCOffset;
+			nListCountEmpty = $<inlineBlock>3.nListCountEmpty;
+			$$.sect = $<inlineBlock>3.sect;
+		}
+;
 
 relocexpr	: relocexpr_no_str
 		| string {

diff --git 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;