compiler: permit compiler directives in parenthesized groups
The original compiler directive support was only for //line at the
start of a line and for //go: comments before function declarations.
When support was added for //go:notinheap for types and //go:embed for
variables the code did not adapt to permit spaces before the comment
or to permit the comments in var() or type() groups. This change
corrects those omissions.
Change-Id: I0d533a7f13d33115dca1eab842a24f6f294df09d
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/358699
Trust: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
diff --git a/go/lex.cc b/go/lex.cc
index dd66c02..d6909b8 100644
--- a/go/lex.cc
+++ b/go/lex.cc
@@ -1909,14 +1909,13 @@
if (saw_error)
return;
- // Recognize various magic comments at the start of a line.
+ // Recognize various magic comments at the start of a line, preceded
+ // only by spaces or tabs.
- if (lineoff != 2)
- {
- // Not at the start of the line. (lineoff == 2 because of the
- // two characters in "//").
+ // "- 2" for the "//" at the start of the comment.
+ for (const char* psp = this->linebuf_; psp < p - 2; psp++)
+ if (*psp != ' ' && *psp != '\t')
return;
- }
while (pend > p
&& (pend[-1] == ' ' || pend[-1] == '\t'
diff --git a/go/lex.h b/go/lex.h
index 75c8429..1c4cc5b 100644
--- a/go/lex.h
+++ b/go/lex.h
@@ -420,6 +420,12 @@
std::swap(*embeds, this->embeds_);
}
+ // Clear any go:embed patterns seen so far. This is used for
+ // erroneous cases.
+ void
+ clear_embeds()
+ { this->embeds_.clear(); }
+
// Return whether the identifier NAME should be exported. NAME is a
// mangled name which includes only ASCII characters.
static bool
diff --git a/go/parse.cc b/go/parse.cc
index e43b5f2..cc197e5 100644
--- a/go/parse.cc
+++ b/go/parse.cc
@@ -1307,46 +1307,14 @@
Parse::declaration()
{
const Token* token = this->peek_token();
-
- unsigned int pragmas = this->lex_->get_and_clear_pragmas();
- if (pragmas != 0
- && !token->is_keyword(KEYWORD_FUNC)
- && !token->is_keyword(KEYWORD_TYPE))
- go_warning_at(token->location(), 0,
- "ignoring magic comment before non-function");
-
- std::vector<std::string>* embeds = NULL;
- if (this->lex_->has_embeds())
- {
- embeds = new(std::vector<std::string>);
- this->lex_->get_and_clear_embeds(embeds);
-
- if (!this->gogo_->current_file_imported_embed())
- {
- go_error_at(token->location(),
- "invalid go:embed: missing import %<embed%>");
- delete embeds;
- embeds = NULL;
- }
- if (!token->is_keyword(KEYWORD_VAR))
- {
- go_error_at(token->location(), "misplaced go:embed directive");
- if (embeds != NULL)
- {
- delete embeds;
- embeds = NULL;
- }
- }
- }
-
if (token->is_keyword(KEYWORD_CONST))
this->const_decl();
else if (token->is_keyword(KEYWORD_TYPE))
- this->type_decl(pragmas);
+ this->type_decl();
else if (token->is_keyword(KEYWORD_VAR))
- this->var_decl(embeds);
+ this->var_decl();
else if (token->is_keyword(KEYWORD_FUNC))
- this->function_decl(pragmas);
+ this->function_decl();
else
{
go_error_at(this->location(), "expected declaration");
@@ -1367,8 +1335,7 @@
// Decl<P> = P | "(" [ List<P> ] ")" .
void
-Parse::decl(void (Parse::*pfn)(unsigned int, std::vector<std::string>*),
- unsigned int pragmas, std::vector<std::string>* embeds)
+Parse::decl(void (Parse::*pfn)())
{
if (this->peek_token()->is_eof())
{
@@ -1378,15 +1345,18 @@
}
if (!this->peek_token()->is_op(OPERATOR_LPAREN))
- (this->*pfn)(pragmas, embeds);
+ (this->*pfn)();
else
{
- if (pragmas != 0)
- go_warning_at(this->location(), 0,
- "ignoring magic %<//go:...%> comment before group");
- if (embeds != NULL)
+ if (this->lex_->get_and_clear_pragmas() != 0)
go_error_at(this->location(),
- "ignoring %<//go:embed%> comment before group");
+ "ignoring compiler directive before group");
+ if (this->lex_->has_embeds())
+ {
+ this->lex_->clear_embeds();
+ go_error_at(this->location(),
+ "ignoring %<//go:embed%> comment before group");
+ }
if (!this->advance_token()->is_op(OPERATOR_RPAREN))
{
this->list(pfn, true);
@@ -1410,10 +1380,9 @@
// might follow. This is either a '}' or a ')'.
void
-Parse::list(void (Parse::*pfn)(unsigned int, std::vector<std::string>*),
- bool follow_is_paren)
+Parse::list(void (Parse::*pfn)(), bool follow_is_paren)
{
- (this->*pfn)(0, NULL);
+ (this->*pfn)();
Operator follow = follow_is_paren ? OPERATOR_RPAREN : OPERATOR_RCURLY;
while (this->peek_token()->is_op(OPERATOR_SEMICOLON)
|| this->peek_token()->is_op(OPERATOR_COMMA))
@@ -1422,7 +1391,7 @@
go_error_at(this->location(), "unexpected comma");
if (this->advance_token()->is_op(follow))
break;
- (this->*pfn)(0, NULL);
+ (this->*pfn)();
}
}
@@ -1469,6 +1438,8 @@
void
Parse::const_spec(int iota, Type** last_type, Expression_list** last_expr_list)
{
+ this->check_directives();
+
Location loc = this->location();
Typed_identifier_list til;
this->identifier_list(&til);
@@ -1545,18 +1516,21 @@
// TypeDecl = "type" Decl<TypeSpec> .
void
-Parse::type_decl(unsigned int pragmas)
+Parse::type_decl()
{
go_assert(this->peek_token()->is_keyword(KEYWORD_TYPE));
this->advance_token();
- this->decl(&Parse::type_spec, pragmas, NULL);
+ this->decl(&Parse::type_spec);
}
// TypeSpec = identifier ["="] Type .
void
-Parse::type_spec(unsigned int pragmas, std::vector<std::string>*)
+Parse::type_spec()
{
+ unsigned int pragmas = this->lex_->get_and_clear_pragmas();
+ this->check_directives();
+
const Token* token = this->peek_token();
if (!token->is_identifier())
{
@@ -1649,23 +1623,34 @@
// VarDecl = "var" Decl<VarSpec> .
void
-Parse::var_decl(std::vector<std::string>* embeds)
+Parse::var_decl()
{
go_assert(this->peek_token()->is_keyword(KEYWORD_VAR));
this->advance_token();
- this->decl(&Parse::var_spec, 0, embeds);
+ this->decl(&Parse::var_spec);
}
// VarSpec = IdentifierList
// ( CompleteType [ "=" ExpressionList ] | "=" ExpressionList ) .
void
-Parse::var_spec(unsigned int pragmas, std::vector<std::string>* embeds)
+Parse::var_spec()
{
Location loc = this->location();
- if (pragmas != 0)
- go_warning_at(loc, 0, "ignoring magic %<//go:...%> comment before var");
+ std::vector<std::string>* embeds = NULL;
+ if (this->lex_->has_embeds())
+ {
+ if (!this->gogo_->current_file_imported_embed())
+ go_error_at(loc, "invalid go:embed: missing import %<embed%>");
+ else
+ {
+ embeds = new(std::vector<std::string>);
+ this->lex_->get_and_clear_embeds(embeds);
+ }
+ }
+
+ this->check_directives();
// Get the variable names.
Typed_identifier_list til;
@@ -2339,9 +2324,13 @@
// PRAGMAS is a bitset of magic comments.
void
-Parse::function_decl(unsigned int pragmas)
+Parse::function_decl()
{
go_assert(this->peek_token()->is_keyword(KEYWORD_FUNC));
+
+ unsigned int pragmas = this->lex_->get_and_clear_pragmas();
+ this->check_directives();
+
Location location = this->location();
std::string extern_name = this->lex_->extern_name();
const Token* token = this->advance_token();
@@ -5370,7 +5359,7 @@
{
go_error_at(this->location(),
"var declaration not allowed in for initializer");
- this->var_decl(NULL);
+ this->var_decl();
}
if (token->is_op(OPERATOR_SEMICOLON))
@@ -5815,17 +5804,15 @@
{
go_assert(this->peek_token()->is_keyword(KEYWORD_IMPORT));
this->advance_token();
- this->decl(&Parse::import_spec, 0, NULL);
+ this->decl(&Parse::import_spec);
}
// ImportSpec = [ "." | PackageName ] PackageFileName .
void
-Parse::import_spec(unsigned int pragmas, std::vector<std::string>*)
+Parse::import_spec()
{
- if (pragmas != 0)
- go_warning_at(this->location(), 0,
- "ignoring magic %<//go:...%> comment before import");
+ this->check_directives();
const Token* token = this->peek_token();
Location location = token->location();
@@ -5916,6 +5903,23 @@
this->skip_past_error(OPERATOR_INVALID);
}
}
+
+ this->check_directives();
+}
+
+// If there are any pending compiler directives, clear them and give
+// an error. This is called when directives are not permitted.
+
+void
+Parse::check_directives()
+{
+ if (this->lex_->get_and_clear_pragmas() != 0)
+ go_error_at(this->location(), "misplaced compiler directive");
+ if (this->lex_->has_embeds())
+ {
+ this->lex_->clear_embeds();
+ go_error_at(this->location(), "misplaced go:embed directive");
+ }
}
// Skip forward to a semicolon or OP. OP will normally be
diff --git a/go/parse.h b/go/parse.h
index 2c3c505..6e300ef 100644
--- a/go/parse.h
+++ b/go/parse.h
@@ -181,15 +181,14 @@
void method_spec(Typed_identifier_list*);
void declaration();
bool declaration_may_start_here();
- void decl(void (Parse::*)(unsigned int, std::vector<std::string>*),
- unsigned int pragmas, std::vector<std::string>* embeds);
- void list(void (Parse::*)(unsigned int, std::vector<std::string>*), bool);
+ void decl(void (Parse::*)());
+ void list(void (Parse::*)(), bool);
void const_decl();
void const_spec(int, Type**, Expression_list**);
- void type_decl(unsigned int pragmas);
- void type_spec(unsigned int pragmas, std::vector<std::string>*);
- void var_decl(std::vector<std::string>* embeds);
- void var_spec(unsigned int pragmas, std::vector<std::string>*);
+ void type_decl();
+ void type_spec();
+ void var_decl();
+ void var_spec();
void init_vars(const Typed_identifier_list*, Type*, Expression_list*,
bool is_coloneq, std::vector<std::string>*, Location);
bool init_vars_from_call(const Typed_identifier_list*, Type*, Expression*,
@@ -210,7 +209,7 @@
void simple_var_decl_or_assignment(const std::string&, Location,
bool may_be_composite_lit,
Range_clause*, Type_switch*);
- void function_decl(unsigned int pragmas);
+ void function_decl();
Typed_identifier* receiver();
Expression* operand(bool may_be_sink, bool *is_parenthesized);
Expression* enclosing_var_reference(Named_object*, Named_object*,
@@ -278,7 +277,10 @@
void goto_stat();
void package_clause();
void import_decl();
- void import_spec(unsigned int pragmas, std::vector<std::string>*);
+ void import_spec();
+
+ // Check for unused compiler directives.
+ void check_directives();
// Skip past an error looking for a semicolon or OP. Return true if
// all is well, false if we found EOF.
