From 5a8d69ea869636e29807955d621fa45d8a21a8d8 Mon Sep 17 00:00:00 2001
From: Jakob Kaivo <jkk@ung.org>
Date: Mon, 2 Sep 2019 16:57:47 -0400
Subject: flesh out skeleton of process

---
 cpp.y | 174 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 174 insertions(+)
 create mode 100644 cpp.y

(limited to 'cpp.y')

diff --git a/cpp.y b/cpp.y
new file mode 100644
index 0000000..798e976
--- /dev/null
+++ b/cpp.y
@@ -0,0 +1,174 @@
+%{
+#define _XOPEN_SOURCE 700
+#include <errno.h>
+#include <search.h>
+#include <stdio.h>
+#include <string.h>
+#include "version.h"
+
+#define HASHSIZE 1024
+
+int cpplex(void);
+int cpperror(const char *s);
+%}
+
+%token IDENTIFIER
+%token LPAREN
+%token H_CHAR Q_CHAR
+%token DIGIT
+%token IF IFDEF IFNDEF ELIF ELSE ENDIF
+%token INCLUDE DEFINE UNDEF LINE ERROR PRAGMA
+%token OPERATOR PUNCTUATOR
+%token CHARACTER_CONSTANT STRING_LITERAL
+%token sign identifier_list constant_expression
+
+%start preprocessing_file
+
+%%
+
+preprocessing_file	: /* empty */
+			| group
+			;
+
+group	: group_part
+	| group group_part;
+
+group_part	: new_line
+		| pp_tokens new_line
+		| if_section
+		| control_line
+		;
+
+if_section	: if_group endif_line
+		| if_group elif_groups endif_line
+		| if_group else_group endif_line
+		| if_group elif_groups else_group endif_line
+		;
+
+if_group	: '#' IF constant_expression new_line
+		| '#' IF constant_expression new_line group
+		| '#' IFDEF IDENTIFIER new_line
+		| '#' IFDEF IDENTIFIER new_line group
+		| '#' IFNDEF IDENTIFIER new_line
+		| '#' IFNDEF IDENTIFIER new_line group
+		;
+
+elif_groups	: elif_group
+		| elif_groups elif_group
+		;
+
+elif_group	: '#' ELIF constant_expression new_line
+		| '#' ELIF constant_expression new_line group
+		;
+
+else_group	: '#' ELSE new_line
+		| '#' ELSE new_line group
+		;
+
+endif_line	: '#' ENDIF new_line
+		;
+
+control_line	: '#' INCLUDE pp_tokens new_line
+		| '#' DEFINE IDENTIFIER replacement_list new_line
+		| '#' DEFINE IDENTIFIER LPAREN ')' replacement_list new_line
+		| '#' DEFINE IDENTIFIER LPAREN identifier_list ')' replacement_list new_line
+		| '#' UNDEF IDENTIFIER new_line
+		| '#' LINE pp_tokens new_line
+		| '#' ERROR new_line
+		| '#' ERROR pp_tokens new_line
+		| '#' PRAGMA new_line
+		| '#' PRAGMA pp_tokens new_line
+		| '#' new_line
+		;
+
+/* LPAREN: '(' without preceding whitespace */
+
+replacement_list	: /* empty */
+			| pp_tokens
+			;
+
+pp_tokens	: preprocessing_token
+		| pp_tokens preprocessing_token
+		;
+
+new_line	: '\n'
+		;
+
+preprocessing_token	: header_name
+			| IDENTIFIER
+			| pp_number
+			| CHARACTER_CONSTANT 
+			| STRING_LITERAL 
+			| OPERATOR
+			| PUNCTUATOR
+			;
+
+header_name	: '<' h_char_sequence '>'
+		| '"' q_char_sequence '"'
+		;
+
+h_char_sequence	: H_CHAR
+		| h_char_sequence H_CHAR
+		;
+
+q_char_sequence	: Q_CHAR
+		| q_char_sequence Q_CHAR
+		;
+
+pp_number	: DIGIT
+		| '.' DIGIT
+		| pp_number DIGIT
+		/* | pp_number nondigit */
+		| pp_number 'e' sign
+		| pp_number 'E' sign
+		| pp_number '.'
+		;
+
+%%
+
+int cpplex(void)
+{
+	return 0;
+}
+
+int cpperror(const char *s)
+{
+	(void)s;
+	return 0;
+}
+
+void define(const char *macro, const char *replacement)
+{
+	static int created = 0;
+	if (!created) {
+		hcreate(HASHSIZE);
+	}
+	ENTRY e = {
+		.key = strdup(macro),
+		.data = strdup(replacement)
+	};
+	ENTRY *p = hsearch(e, ENTER);
+	if (p == NULL) {
+		cpperror(strerror(ENOMEM));
+	}
+	printf("replacing '%s' with '%s'\n", macro, replacement == (char*)-1 ? "INTERNAL" : replacement);
+}
+
+void undef(const char *macro)
+{
+	printf("undefining '%s'\n", macro);
+}
+
+void include(const char *path)
+{
+	printf("adding '%s' to INCLUDE path\n", path);
+}
+
+int preprocess(FILE *in, FILE *out, long int version)
+{
+	printf("preprocessing\n");
+	int c = 0;
+	while ((c = fgetc(in)) != EOF) {
+		fputc(c, out);
+	}
+}
-- 
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