From 6ce6f76cc1b60aaa5461e17e3d21e31b4baa3254 Mon Sep 17 00:00:00 2001
From: pommicket <pommicket@gmail.com>
Date: Sun, 9 Jan 2022 19:53:18 -0500
Subject: preprocessor fixes

---
 05/main.c       |  6 +++---
 05/preprocess.b | 40 +++++++++++++++++++++++++---------------
 2 files changed, 28 insertions(+), 18 deletions(-)

(limited to '05')

diff --git a/05/main.c b/05/main.c
index ee2e51b..f591edc 100644
--- a/05/main.c
+++ b/05/main.c
@@ -4,17 +4,17 @@
 #define JOIN(x,y) JOIN2(x, y)
 #define X 22
 
-JOIN2(X, X)
+JOIN(X, X)
 
 STRINGIFY(X)
 
-#define E 5
+   #define E 5
 #define D E
 #define C D
 #define B C
 #define A B
 
-int x = E;
+  int x = E;
 
 main(void) {
 }
diff --git a/05/preprocess.b b/05/preprocess.b
index 6103454..0f58676 100644
--- a/05/preprocess.b
+++ b/05/preprocess.b
@@ -1,7 +1,7 @@
 ; returns a string of null character-separated preprocessing tokens and space characters
 ; this corresponds to translation phases 1-3 in the C89 standard
 ; each sequence of two or more spaces is replaced with a single space
-; spaces following # and around ## are removed
+; spaces around # and ## are removed
 function split_into_preprocessing_tokens
 	argument filename
 	local fd
@@ -338,31 +338,30 @@ function split_into_preprocessing_tokens
 	:join_spaces_loop_end
 	*1out = 0
 	
-	; delete space surrounding ## and following #
+	; delete space surrounding ## and #
+	; we want to delete spaces before # so that all preprocessor directives are at the start of the line
+	;   (this makes recognizing them slightly easier)
 	in = pptokens2
 	out = pptokens
 	:delete_hash_spaces_loop
 		c = *1in
 		if c == 0 goto delete_hash_spaces_loop_end
-		pptoken_copy_and_advance(&in, &out)
 		if c == '# goto delete_hash_spaces_hash
+		pptoken_copy_and_advance(&in, &out)
+		goto delete_hash_spaces_loop
 		
 		:delete_hash_spaces_hash
-			p = in + 1
-			if *1p == '# goto delete_surrounding_space
-			:delete_hash_spaces_skip_spaces
-			pptoken_skip_spaces(&in)
-			goto delete_hash_spaces_loop
-			
-		:delete_surrounding_space
-			p = out - 2 ; ## can't appear at start of file
-			if *1p != 32 goto delete_hash_spaces_skip_spaces ; no space before ##
-			; space before ##
+			if out == pptokens goto copy_and_delete_spaces_after_hash ; little edge case
+			p = out - 2
+			if *1p != 32 goto copy_and_delete_spaces_after_hash ; no space before ##
+			; space before #/##
 			; remove it
 			out -= 2
 			*1out = 0
-			goto delete_hash_spaces_skip_spaces
-			
+			:copy_and_delete_spaces_after_hash
+			pptoken_copy_and_advance(&in, &out)
+			pptoken_skip_spaces(&in)
+			goto delete_hash_spaces_loop		
 	:delete_hash_spaces_loop_end
 	*1out = 0
 	
@@ -829,6 +828,10 @@ function macro_replacement
 		goto done_replacement
 		
 	:fmacro_argument
+		q = p + 3 ; skip these characters: arg idx, null separator, first '#'
+		if *1q == '# goto fmacro_argument_no_rescan ; this argument is immediately followed by ## so it shouldn't be scanned for replacements
+		q = p - 2 ; skip these characters: null separator, second '#'
+		if *1q == '# goto fmacro_argument_no_rescan ; this argument is immediately preceded by ##
 		; write argument to *fmacro_out, performing any necessary macro substitutions
 		q = fmacro_get_arg(filename, line_number, arguments, *1p)
 		:fmacro_arg_replace_loop
@@ -837,6 +840,13 @@ function macro_replacement
 		p += 2 ; skip arg idx & null separator
 		goto freplace_loop
 		
+		:fmacro_argument_no_rescan
+			q = fmacro_get_arg(filename, line_number, arguments, *1p)
+			fmacro_out = memccpy(fmacro_out, q, 255)
+			*1fmacro_out = 0
+			p += 2 ; skip arg idx & null separator
+			goto freplace_loop
+			
 	:no_replacement
 		pptoken_copy_and_advance(&in, &out)
 		; (fallthrough)
-- 
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