X-Git-Url: https://git.draconx.ca/gitweb/cdecl99.git/blobdiff_plain/362559e5c1b4d138305f9edf2c2b7ee1a24a08f6..0c61f9637a469ac7a28b5a329551b03e6ad14d62:/src/parse.y

diff --git a/src/parse.y b/src/parse.y
index 70e1878..a14f909 100644
--- a/src/parse.y
+++ b/src/parse.y
@@ -1,6 +1,7 @@
+%code top {
 /*
  *  Parser for C declarations.
- *  Copyright © 2011 Nick Bowler
+ *  Copyright © 2011-2012, 2021 Nick Bowler
  *
  *  This program is free software: you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -15,29 +16,577 @@
  *  You should have received a copy of the GNU General Public License
  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
+}
 
+%name-prefix "cdecl__yy"
+%parse-param {void *scanner}
+%parse-param {struct cdecl **out}
+%lex-param {yyscan_t scanner}
 %define api.pure
 %error-verbose
 %locations
 
 %{
+#include <config.h>
+#include <assert.h>
+#include <stdbool.h>
+
 #include "scan.h"
+#include "cdecl.h"
+#include "cdecl-internal.h"
+
+#define FAIL(msg) do { \
+	yyerror(&yylloc, NULL, NULL, msg); \
+	YYERROR; \
+} while (0)
+
+#define ALLOC(ptr, size) do { \
+	(ptr) = malloc(size); \
+	if (!(ptr)) \
+		FAIL("failed to allocate memory"); \
+} while (0)
+
+#define ALLOC_STRUCT(ptr, type, ...) do { \
+	ALLOC(ptr, sizeof (type)); \
+	*(ptr) = (type) { __VA_ARGS__ }; \
+} while (0)
 %}
 
+%code requires {
+#include <inttypes.h>
+}
+
 %code provides {
-void yyerror(const char *);
+void cdecl__free(struct cdecl *);
+void cdecl__yyerror(YYLTYPE *, void *, struct cdecl **, const char *);
+int cdecl__yyparse(void *scanner, struct cdecl **out);
 }
 
 %union {
-	int foo;
+	uintmax_t uintval;
+	_Bool boolval;
+	char *strval;
+	struct cdecl_declspec *declspec;
+	struct cdecl_declarator *declarator;
+	struct cdecl *decl;
 }
 
+%{
+static void free_decl(struct cdecl *);
+
+static void free_declspec(struct cdecl_declspec *x)
+{
+	struct cdecl_declspec *p;
+	while (x) {
+		p = x->next;
+		free(x->ident);
+		free(x);
+		x = p;
+	}
+}
+
+static void free_declarator(struct cdecl_declarator *x)
+{
+	struct cdecl_declarator *p;
+
+	while (x) {
+		p = x->child;
+
+		switch (x->type) {
+		case CDECL_DECL_NULL:
+			break;
+		case CDECL_DECL_IDENT:
+			free(x->u.ident);
+			break;
+		case CDECL_DECL_POINTER:
+			free_declspec(x->u.pointer.qualifiers);
+			break;
+		case CDECL_DECL_ARRAY:
+			free(x->u.array.vla);
+			break;
+		case CDECL_DECL_FUNCTION:
+			free_decl(x->u.function.parameters);
+			break;
+		default:
+			assert(0);
+		}
+
+		free(x);
+		x = p;
+	}
+}
+
+static void free_decl(struct cdecl *x)
+{
+	struct cdecl *p;
+
+	while (x) {
+		p = x->next;
+
+		/* The specifiers may be shared by an entire chain. */
+		if (!p || p->specifiers != x->specifiers)
+			free_declspec(x->specifiers);
+
+		free_declarator(x->declarators);
+		free(x);
+		x = p;
+	}
+}
+
+void cdecl__free(struct cdecl *decl)
+{
+	free_decl(decl);
+}
+%}
+
+%destructor { free($$); }            <strval>
+%destructor { free_declspec($$); }   <declspec>
+%destructor { free_declarator($$); } <declarator>
+%destructor { free_decl($$); }       <decl>
+
+/* Magic tokens */
+%token T_LEX_ERROR
+%token T_ENGLISH
+
+%token <strval> T_IDENT "identifier"
+%token <uintval> T_UINT "integer constant"
+
+%token T_SEMICOLON ";"
+%token T_ASTERISK  "*"
+%token T_LPAREN    "("
+%token T_RPAREN    ")"
+%token T_LBRACKET  "["
+%token T_RBRACKET  "]"
+%token T_COMMA     ","
+%token T_ELLIPSIS  "..."
+
+%token T_TYPEDEF   "typedef"
+%token T_EXTERN    "extern"
+%token T_STATIC    "static"
+%token T_AUTO      "auto"
+%token T_REGISTER  "register"
+
+%token T_INLINE    "inline"
+
+%token T_RESTRICT  "restrict"
+%token T_VOLATILE  "volatile"
+%token T_CONST     "const"
+
+%token T_VOID      "void"
+%token T_CHAR      "char"
+%token T_SHORT     "short"
+%token T_INT       "int"
+%token T_LONG      "long"
+%token T_FLOAT     "float"
+%token T_DOUBLE    "double"
+%token T_SIGNED    "signed"
+%token T_UNSIGNED  "unsigned"
+%token T_BOOL      "_Bool"
+%token T_COMPLEX   "_Complex"
+%token T_IMAGINARY "_Imaginary"
+
+%token T_STRUCT    "struct"
+%token T_UNION     "union"
+%token T_ENUM      "enum"
+
+/*
+ * English keywords.
+ */
+%token T_TYPE      "type"
+%token T_DECLARE   "declare"
+%token T_POINTER   "pointer"
+%token T_FUNCTION  "function"
+%token T_RETURNING "returning"
+%token T_ARRAY     "array"
+%token T_TO        "to"
+%token T_OF        "of"
+%token T_AS        "as"
+%token T_VLA       "variable-length"
+
+%type <strval>     vla_ident
+%type <boolval>    varargs
+%type <uintval>    declspec_simple typespec_simple qualifier_simple
+%type <declspec>   declspec_notype declspec_noid typespec_noid typespec
+%type <declspec>   qualifier qualifiers
+%type <declspec>   declspecs declspecs_noid
+%type <declarator> direct_declarator declarator pointer array parens postfix
+%type <declarator> direct_declarator_ish declarator_ish parameter_type_list
+%type <decl>       declaration declarators declarator_wrap
+%type <decl>       parameter parameters
+
+%type <strval>     english_vla
+%type <declspec>   storage_func_specs post_specs
+%type <declspec>   type_qual_spec type_qual_specs typedef_name_qual
+%type <declarator> english_declarator english_array english_function
+%type <declarator> english_parameter_list null_decl
+%type <decl>       english_parameter english_parameters
+%type <decl>       english english_declaration
+
+/*
+ * Harmless shift/reduce conflicts in english_parameter.  See comments below
+ * for more details.
+ */
+%expect 2
+
 %%
 
-input: ;
+input: T_ENGLISH english {
+	*out = $2;
+} | declaration {
+	*out = $1;
+};
+
+semi: | T_SEMICOLON
+
+declaration: declspecs declarators semi {
+	$$ = $2;
+
+	for (struct cdecl *i = $$; i; i = i->next)
+		i->specifiers = $1;
+};
+
+declspecs: declspec_notype declspecs {
+	$$ = $1;
+	$$->next = $2;
+} | typespec declspecs_noid {
+	$$ = $1;
+	$$->next = $2;
+}
+
+declspecs_noid: { $$ = NULL; } | declspec_noid declspecs_noid {
+	$$ = $1;
+	$$->next = $2;
+}
+
+qualifiers: { $$ = NULL; } | qualifiers qualifier {
+	$$ = $2;
+	$$->next = $1;
+}
+
+declarators: declarator_wrap | declarator_wrap T_COMMA declarators {
+	$$ = $1;
+	$$->next = $3;
+}
+
+declarator_wrap: declarator {
+	ALLOC_STRUCT($$, struct cdecl, .declarators = $1);
+}
+
+declspec_simple: T_AUTO { $$ = CDECL_STOR_AUTO;     }
+	| T_TYPEDEF     { $$ = CDECL_STOR_TYPEDEF;  }
+	| T_EXTERN      { $$ = CDECL_STOR_EXTERN;   }
+	| T_STATIC      { $$ = CDECL_STOR_STATIC;   }
+	| T_REGISTER    { $$ = CDECL_STOR_REGISTER; }
+	| T_INLINE      { $$ = CDECL_FUNC_INLINE;   }
+
+typespec_simple: T_VOID { $$ = CDECL_TYPE_VOID;      }
+	| T_CHAR        { $$ = CDECL_TYPE_CHAR;      }
+	| T_SHORT       { $$ = CDECL_TYPE_SHORT;     }
+	| T_INT         { $$ = CDECL_TYPE_INT;       }
+	| T_LONG        { $$ = CDECL_TYPE_LONG;      }
+	| T_FLOAT       { $$ = CDECL_TYPE_FLOAT;     }
+	| T_DOUBLE      { $$ = CDECL_TYPE_DOUBLE;    }
+	| T_SIGNED      { $$ = CDECL_TYPE_SIGNED;    }
+	| T_UNSIGNED    { $$ = CDECL_TYPE_UNSIGNED;  }
+	| T_BOOL        { $$ = CDECL_TYPE_BOOL;      }
+	| T_COMPLEX     { $$ = CDECL_TYPE_COMPLEX;   }
+	| T_IMAGINARY   { $$ = CDECL_TYPE_IMAGINARY; }
+
+qualifier_simple: T_CONST { $$ = CDECL_QUAL_CONST;    }
+	| T_RESTRICT      { $$ = CDECL_QUAL_RESTRICT; }
+	| T_VOLATILE      { $$ = CDECL_QUAL_VOLATILE; }
+
+declspec_notype: qualifier | declspec_simple {
+	ALLOC_STRUCT($$, struct cdecl_declspec, .type = $1);
+}
+
+typespec_noid: typespec_simple {
+	ALLOC_STRUCT($$, struct cdecl_declspec, .type = $1);
+}
+
+qualifier: qualifier_simple {
+	ALLOC_STRUCT($$, struct cdecl_declspec, .type = $1);
+}
+
+typespec: typespec_noid | T_STRUCT T_IDENT {
+	ALLOC_STRUCT($$, struct cdecl_declspec,
+		.type = CDECL_TYPE_STRUCT,
+		.ident = $2);
+} | T_UNION T_IDENT {
+	ALLOC_STRUCT($$, struct cdecl_declspec,
+		.type = CDECL_TYPE_UNION,
+		.ident = $2);
+} | T_ENUM T_IDENT {
+	ALLOC_STRUCT($$, struct cdecl_declspec,
+		.type = CDECL_TYPE_ENUM,
+		.ident = $2);
+} | T_IDENT {
+	ALLOC_STRUCT($$, struct cdecl_declspec,
+		.type = CDECL_TYPE_IDENT,
+		.ident = $1);
+}
+
+declspec_noid: declspec_notype | typespec_noid
+
+vla_ident: T_IDENT | T_ASTERISK {
+	ALLOC($$, sizeof "");
+	strcpy($$, "");
+}
+
+array: T_LBRACKET T_UINT T_RBRACKET {
+	if ($2 == 0)
+		FAIL("array length must be positive");
+
+	ALLOC_STRUCT($$, struct cdecl_declarator,
+		.type = CDECL_DECL_ARRAY,
+		.u.array.length = $2);
+} | T_LBRACKET vla_ident T_RBRACKET {
+	ALLOC_STRUCT($$, struct cdecl_declarator,
+		.type = CDECL_DECL_ARRAY,
+		.u.array.vla = $2);
+} | T_LBRACKET T_RBRACKET {
+	ALLOC_STRUCT($$, struct cdecl_declarator,
+		.type = CDECL_DECL_ARRAY);
+}
+
+parameter: declspecs declarator {
+	ALLOC_STRUCT($$, struct cdecl,
+		.specifiers = $1,
+		.declarators = $2);
+}
+
+parameters: parameter | parameters T_COMMA parameter {
+	$$ = $3;
+	$$->next = $1;
+}
+
+varargs: { $$ = false; } | T_COMMA T_ELLIPSIS { $$ = true; }
+
+parameter_type_list: parameters varargs {
+	struct cdecl *p, *c, *n;
+
+	/* Parameters were accumulated in reverse order. */
+	for (p = NULL, c = $1; c; p = c, c = n) {
+		n = c->next;
+		c->next = p;
+	}
+
+	ALLOC_STRUCT($$, struct cdecl_declarator,
+		.type = CDECL_DECL_FUNCTION,
+		.u.function.parameters = p,
+		.u.function.variadic = $2);
+}
+
+parens: T_LPAREN parameter_type_list T_RPAREN {
+	$$ = $2;
+} | T_LPAREN declarator_ish T_RPAREN {
+	ALLOC_STRUCT($$, struct cdecl_declarator,
+		.type = CDECL_DECL_FUNCTION);
+	ALLOC_STRUCT($$->u.function.parameters, struct cdecl,
+		.declarators = $2);
+}
+
+pointer: T_ASTERISK qualifiers direct_declarator {
+	ALLOC_STRUCT($$, struct cdecl_declarator,
+		.type = CDECL_DECL_POINTER,
+		.u.pointer.qualifiers = $2,
+		.child = $3);
+} | T_ASTERISK qualifiers pointer {
+	ALLOC_STRUCT($$, struct cdecl_declarator,
+		.type = CDECL_DECL_POINTER,
+		.u.pointer.qualifiers = $2,
+		.child = $3);
+}
+
+declarator: direct_declarator | pointer
+declarator_ish: direct_declarator_ish | pointer
+postfix: array | parens
+
+direct_declarator_ish: {
+	ALLOC_STRUCT($$, struct cdecl_declarator,
+		.type = CDECL_DECL_NULL);
+} | direct_declarator_ish postfix {
+	$$ = $2;
+	$$->child = $1;
+}
+
+direct_declarator: {
+	ALLOC_STRUCT($$, struct cdecl_declarator,
+		.type = CDECL_DECL_NULL);
+} | T_IDENT {
+	ALLOC_STRUCT($$, struct cdecl_declarator,
+		.type = CDECL_DECL_IDENT,
+		.u.ident = $1);
+} | direct_declarator postfix {
+	$$ = $2;
+	$$->child = $1;
+}
+
+english: T_DECLARE T_IDENT T_AS english_declaration {
+	$$ = $4;
+	for (struct cdecl_declarator *d = $$->declarators; d; d = d->child) {
+		if (d->type == CDECL_DECL_NULL) {
+			d->type = CDECL_DECL_IDENT;
+			d->u.ident = $2;
+		}
+	}
+} | T_TYPE english_declaration {
+	$$ = $2;
+}
+
+storage_func_specs: { $$ = NULL; } | declspec_simple storage_func_specs {
+	ALLOC_STRUCT($$, struct cdecl_declspec,
+		.type = $1,
+		.next = $2);
+}
+
+type_qual_spec: typespec_noid | qualifier
+
+type_qual_specs: { $$ = NULL; } | type_qual_spec type_qual_specs {
+	$$ = $1;
+	$$->next = $2;
+}
+
+/*
+ * The "qualifiers" nonterminal needs to be used here to avoid shift/reduce
+ * conflicts with pointer declarators.  So we end up needing to stitch
+ * together three different specifiers lists.
+ */
+post_specs: qualifiers typespec type_qual_specs {
+	$$ = $2;
+	$$->next = $1;
+	for (struct cdecl_declspec *s = $$; s; s = s->next) {
+		if (!s->next) {
+			s->next = $3;
+			break;
+		}
+	}
+}
+
+english_declaration: storage_func_specs english_declarator post_specs {
+	ALLOC_STRUCT($$, struct cdecl,
+		.specifiers = $3,
+		.declarators = $2);
+
+	for (struct cdecl_declspec *s = $$->specifiers; s; s = s->next) {
+		if (!s->next) {
+			s->next = $1;
+			break;
+		}
+	}
+}
+
+english_declarator: {
+	ALLOC_STRUCT($$, struct cdecl_declarator,
+		.type = CDECL_DECL_NULL);
+} | english_declarator qualifiers T_POINTER T_TO {
+	ALLOC_STRUCT($$, struct cdecl_declarator,
+		.type = CDECL_DECL_POINTER,
+		.child = $1,
+		.u.pointer.qualifiers = $2);
+} | english_declarator english_array {
+	$$ = $2;
+	$$->child = $1;
+} | english_declarator english_function {
+	$$ = $2;
+	$$->child = $1;
+}
+
+english_function: T_FUNCTION T_RETURNING {
+	ALLOC_STRUCT($$, struct cdecl_declarator,
+		.type = CDECL_DECL_FUNCTION,
+		.u.function.parameters = NULL);
+} | T_FUNCTION T_LPAREN english_parameter_list T_RPAREN T_RETURNING {
+	$$ = $3;
+}
+
+english_parameter_list: english_parameters varargs {
+	struct cdecl *p, *c, *n;
+
+	/* Parameters were accumulated in reverse order. */
+	for (p = NULL, c = $1; c; p = c, c = n) {
+		n = c->next;
+		c->next = p;
+	}
+
+	ALLOC_STRUCT($$, struct cdecl_declarator,
+		.type = CDECL_DECL_FUNCTION,
+		.u.function.parameters = p,
+		.u.function.variadic = $2);
+}
+
+english_parameters: english_parameters T_COMMA english_parameter {
+	$$ = $3;
+	$$->next = $1;
+} | english_parameter
+
+typedef_name_qual: T_IDENT qualifiers {
+	ALLOC_STRUCT($$, struct cdecl_declspec,
+		.type = CDECL_TYPE_IDENT,
+		.ident = $1,
+		.next = $2);
+}
+
+null_decl: {
+	ALLOC_STRUCT($$, struct cdecl_declarator,
+		.type = CDECL_DECL_NULL);
+}
+
+/*
+ * There is a small shift/reduce conflict here.  An unadorned identifier
+ * as the first thing in the parameter might be a typedef name deep in the
+ * first english_declaration (thus empty storage_func_specs and empty
+ * english_declarator need to be reduced) or it might be the identifier
+ * before the "as" (thus the identifier should be shifted).
+ *
+ * The typedef name conflict is the only issue, so treating it as a special
+ * case makes the shift harmless.
+ */
+english_parameter: english_declaration | typedef_name_qual null_decl {
+	ALLOC_STRUCT($$, struct cdecl,
+		.specifiers = $1,
+		.declarators = $2);
+} | T_IDENT T_AS english_declaration {
+	$$ = $3;
+	for (struct cdecl_declarator *d = $$->declarators; d; d = d->child) {
+		if (d->type == CDECL_DECL_NULL) {
+			d->type = CDECL_DECL_IDENT;
+			d->u.ident = $1;
+		}
+	}
+}
+
+english_array: T_VLA T_ARRAY english_vla T_OF {
+	ALLOC_STRUCT($$, struct cdecl_declarator,
+		.type = CDECL_DECL_ARRAY,
+		.u.array.vla = $3);
+} | T_ARRAY T_UINT T_OF {
+	if ($2 == 0)
+		FAIL("array length must be positive");
+
+	ALLOC_STRUCT($$, struct cdecl_declarator,
+		.type = CDECL_DECL_ARRAY,
+		.u.array.length = $2);
+} | T_ARRAY T_OF {
+	ALLOC_STRUCT($$, struct cdecl_declarator,
+		.type = CDECL_DECL_ARRAY,
+		.u.array.length = 0);
+}
+
+english_vla: T_IDENT | {
+	ALLOC($$, sizeof "");
+	strcpy($$, "");
+}
 
 %%
-void yyerror(const char *err)
+void
+yyerror(YYLTYPE *loc, yyscan_t scanner, struct cdecl **out, const char *err)
 {
-	fprintf(stderr, "%s\n", err);
+	if (strstr(err, "T_LEX_ERROR"))
+		return;
+
+	cdecl__set_error(&(const struct cdecl_error){
+		.code = CDECL_ENOPARSE,
+		.str  = err,
+	});
 }