| Message ID | 20180521233411.GD3122@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | C++ PATCH to implement P0614R1, Range-based for statements with initializer (take 2) | expand |
On Mon, May 21, 2018 at 7:34 PM, Marek Polacek <polacek@redhat.com> wrote: > The previous version of this patch got confused by > > for (int i = 0; n > 0 ? true : false; i++) > // ... > > because even though we see a ; followed by a :, it's not a range-based for with > an initializer. I find it very strange that this didn't show up during the > regtest. > > To fix this, I had to uglify range_based_for_with_init_p to also check for a ?. > Yuck. Perhaps cp_parser_skip_to_closing_parenthesis_1 should handle balanced ?: like ()/[]/{}. Jason
On Mon, May 21, 2018 at 09:51:44PM -0400, Jason Merrill wrote: > On Mon, May 21, 2018 at 7:34 PM, Marek Polacek <polacek@redhat.com> wrote: > > The previous version of this patch got confused by > > > > for (int i = 0; n > 0 ? true : false; i++) > > // ... > > > > because even though we see a ; followed by a :, it's not a range-based for with > > an initializer. I find it very strange that this didn't show up during the > > regtest. > > > > To fix this, I had to uglify range_based_for_with_init_p to also check for a ?. > > Yuck. > > Perhaps cp_parser_skip_to_closing_parenthesis_1 should handle balanced > ?: like ()/[]/{}. Good point. Clearly there's a difference between ?: and e.g. () because : can stand alone--e.g. in asm (: "whatever"), labels, goacc arrays like a[0:N], and so on. The following seems to work well, and is certainly less ugly than the previous version. Bootstrapped/regtested on x86_64-linux, ok for trunk? 2018-05-22 Marek Polacek <polacek@redhat.com> Implement P0614R1, Range-based for statements with initializer. * parser.c (cp_parser_range_based_for_with_init_p): New. (cp_parser_init_statement): Use it. Parse the optional init-statement for a range-based for loop. (cp_parser_skip_to_closing_parenthesis_1): Handle balancing ?:. * g++.dg/cpp2a/range-for1.C: New test. * g++.dg/cpp2a/range-for2.C: New test. * g++.dg/cpp2a/range-for3.C: New test. * g++.dg/cpp2a/range-for4.C: New test. * g++.dg/cpp2a/range-for5.C: New test. * g++.dg/cpp2a/range-for6.C: New test. * g++.dg/cpp2a/range-for7.C: New test. diff --git gcc/cp/parser.c gcc/cp/parser.c index 6f51f03f47c..8e4c66d8503 100644 --- gcc/cp/parser.c +++ gcc/cp/parser.c @@ -3493,6 +3493,7 @@ cp_parser_skip_to_closing_parenthesis_1 (cp_parser *parser, unsigned paren_depth = 0; unsigned brace_depth = 0; unsigned square_depth = 0; + unsigned condop_depth = 0; if (recovering && or_ttype == CPP_EOF && cp_parser_uncommitted_to_tentative_parse_p (parser)) @@ -3504,7 +3505,7 @@ cp_parser_skip_to_closing_parenthesis_1 (cp_parser *parser, /* Have we found what we're looking for before the closing paren? */ if (token->type == or_ttype && or_ttype != CPP_EOF - && !brace_depth && !paren_depth && !square_depth) + && !brace_depth && !paren_depth && !square_depth && !condop_depth) return -1; switch (token->type) @@ -3551,6 +3552,16 @@ cp_parser_skip_to_closing_parenthesis_1 (cp_parser *parser, } break; + case CPP_QUERY: + if (!brace_depth) + ++condop_depth; + break; + + case CPP_COLON: + if (!brace_depth && condop_depth > 0) + condop_depth--; + break; + default: break; } @@ -11255,6 +11266,40 @@ cp_parser_statement_seq_opt (cp_parser* parser, tree in_statement_expr) } } +/* Return true if this is the C++20 version of range-based-for with + init-statement. */ + +static bool +cp_parser_range_based_for_with_init_p (cp_parser *parser) +{ + bool r = false; + + /* Save tokens so that we can put them back. */ + cp_lexer_save_tokens (parser->lexer); + + /* There has to be an unnested ; followed by an unnested :. */ + if (cp_parser_skip_to_closing_parenthesis_1 (parser, + /*recovering=*/false, + CPP_SEMICOLON, + /*consume_paren=*/false) != -1) + goto out; + + /* We found the semicolon, eat it now. */ + cp_lexer_consume_token (parser->lexer); + + /* Now look for ':' that is not nested in () or {}. */ + r = (cp_parser_skip_to_closing_parenthesis_1 (parser, + /*recovering=*/false, + CPP_COLON, + /*consume_paren=*/false) == -1); + +out: + /* Roll back the tokens we skipped. */ + cp_lexer_rollback_tokens (parser->lexer); + + return r; +} + /* Return true if we're looking at (init; cond), false otherwise. */ static bool @@ -12299,7 +12344,7 @@ cp_parser_iteration_statement (cp_parser* parser, bool *if_p, bool ivdep, simple-declaration */ static bool -cp_parser_init_statement (cp_parser* parser, tree *decl) +cp_parser_init_statement (cp_parser *parser, tree *decl) { /* If the next token is a `;', then we have an empty expression-statement. Grammatically, this is also a @@ -12312,6 +12357,29 @@ cp_parser_init_statement (cp_parser* parser, tree *decl) bool is_range_for = false; bool saved_colon_corrects_to_scope_p = parser->colon_corrects_to_scope_p; + /* Try to parse the init-statement. */ + if (cp_parser_range_based_for_with_init_p (parser)) + { + tree dummy; + cp_parser_parse_tentatively (parser); + /* Parse the declaration. */ + cp_parser_simple_declaration (parser, + /*function_definition_allowed_p=*/false, + &dummy); + cp_parser_require (parser, CPP_SEMICOLON, RT_SEMICOLON); + if (!cp_parser_parse_definitely (parser)) + /* That didn't work, try to parse it as an expression-statement. */ + cp_parser_expression_statement (parser, NULL_TREE); + + if (cxx_dialect < cxx2a) + { + pedwarn (cp_lexer_peek_token (parser->lexer)->location, 0, + "range-based %<for%> loops with initializer only " + "available with -std=c++2a or -std=gnu++2a"); + *decl = error_mark_node; + } + } + /* A colon is used in range-based for. */ parser->colon_corrects_to_scope_p = false; @@ -12325,7 +12393,7 @@ cp_parser_init_statement (cp_parser* parser, tree *decl) parser->colon_corrects_to_scope_p = saved_colon_corrects_to_scope_p; if (cp_lexer_next_token_is (parser->lexer, CPP_COLON)) { - /* It is a range-for, consume the ':' */ + /* It is a range-for, consume the ':'. */ cp_lexer_consume_token (parser->lexer); is_range_for = true; if (cxx_dialect < cxx11) @@ -12337,9 +12405,9 @@ cp_parser_init_statement (cp_parser* parser, tree *decl) } } else - /* The ';' is not consumed yet because we told - cp_parser_simple_declaration not to. */ - cp_parser_require (parser, CPP_SEMICOLON, RT_SEMICOLON); + /* The ';' is not consumed yet because we told + cp_parser_simple_declaration not to. */ + cp_parser_require (parser, CPP_SEMICOLON, RT_SEMICOLON); if (cp_parser_parse_definitely (parser)) return is_range_for; diff --git gcc/testsuite/g++.dg/cpp2a/range-for1.C gcc/testsuite/g++.dg/cpp2a/range-for1.C index e69de29bb2d..3a5523585a1 100644 --- gcc/testsuite/g++.dg/cpp2a/range-for1.C +++ gcc/testsuite/g++.dg/cpp2a/range-for1.C @@ -0,0 +1,16 @@ +// P0614R1 +// { dg-do compile { target c++11 } } +// { dg-options "" } + +void +fn1 () +{ + int a[] = { 1, 2, 3, 4, 5 }; + + for (int i = 0; auto x : a) // { dg-warning "range-based .for. loops with initializer only available with" "" { target c++17_down } } + ++i; + + int i; + for (i = 0; auto x : a) // { dg-warning "range-based .for. loops with initializer only available with" "" { target c++17_down } } + ++i; +} diff --git gcc/testsuite/g++.dg/cpp2a/range-for2.C gcc/testsuite/g++.dg/cpp2a/range-for2.C index e69de29bb2d..acb16c57d1c 100644 --- gcc/testsuite/g++.dg/cpp2a/range-for2.C +++ gcc/testsuite/g++.dg/cpp2a/range-for2.C @@ -0,0 +1,16 @@ +// P0614R1 +// { dg-do compile } +// { dg-options "-std=c++2a" } + +void +fn1 () +{ + int a[] = { 1, 2, 3, 4, 5 }; + + for (int i = 0; auto x : a) + ++i; + + int i; + for (i = 0; auto x : a) + ++i; +} diff --git gcc/testsuite/g++.dg/cpp2a/range-for3.C gcc/testsuite/g++.dg/cpp2a/range-for3.C index e69de29bb2d..291e605b92f 100644 --- gcc/testsuite/g++.dg/cpp2a/range-for3.C +++ gcc/testsuite/g++.dg/cpp2a/range-for3.C @@ -0,0 +1,26 @@ +// P0614R1 +// { dg-do compile } +// { dg-options "-std=c++2a" } + +static const int a[] = { 1, 2, 3, 4, 5 }; +extern void foo (int); +extern void bar (int, int); + +constexpr int +baz () +{ + return 6; +} + +void +fn1 (int i) +{ + for ((i += 2); auto x : a) + foo (i); + + for (auto j = 0, k = 0; auto x : a) + bar (j + k, x); + + for (constexpr int j = baz (); auto x : a) + bar (x, j); +} diff --git gcc/testsuite/g++.dg/cpp2a/range-for4.C gcc/testsuite/g++.dg/cpp2a/range-for4.C index e69de29bb2d..6ba783f46cb 100644 --- gcc/testsuite/g++.dg/cpp2a/range-for4.C +++ gcc/testsuite/g++.dg/cpp2a/range-for4.C @@ -0,0 +1,27 @@ +// P0614R1 +// { dg-do run } +// { dg-options "-std=c++2a" } + +int +main () +{ + int a[] = { 1, 2, 3, 4, 5 }; + + for (int i = 1; auto x : a) + if (i++ != x) + __builtin_abort (); + + int i; + for (i = 1; auto x : a) + if (i++ != x) + __builtin_abort (); + + i = 0; + for (i++; auto x : a) + if (i != 1) + __builtin_abort (); + + for (int s[] = { 1, 1, 1 }; auto x : s) + if (x != 1) + __builtin_abort (); +} diff --git gcc/testsuite/g++.dg/cpp2a/range-for5.C gcc/testsuite/g++.dg/cpp2a/range-for5.C index e69de29bb2d..62f1c2f04e1 100644 --- gcc/testsuite/g++.dg/cpp2a/range-for5.C +++ gcc/testsuite/g++.dg/cpp2a/range-for5.C @@ -0,0 +1,46 @@ +// P0614R1 +// { dg-do compile } +// { dg-options "-std=c++2a" } + +void +fn1 () +{ + int a[] = { 1, 2, 3, 4, 5 }; + + for (int i = 0; auto x : a) + ++i; + + i = 0; // { dg-error "not declared" } + + for (int i = 0; auto x : a) + { + for (int j = 0; auto x : a) + { + for (int k = 0; auto x : a) + k++; + k++; // { dg-error "not declared" } + } + j++; // { dg-error "not declared" } + } +} + +void +fn2 () +{ + int a[] = { 1, 2, 3, 4, 5 }; + for (int i = 0; auto x : a) + int i = 3; // { dg-error "redeclaration" } +} +void +fn3 () +{ + int a[] = { 1, 2, 3, 4, 5 }; + + for (;:) // { dg-error "expected" } + { + } + + for (;;:) // { dg-error "expected" } + { + } +} diff --git gcc/testsuite/g++.dg/cpp2a/range-for6.C gcc/testsuite/g++.dg/cpp2a/range-for6.C index e69de29bb2d..4cee60a839e 100644 --- gcc/testsuite/g++.dg/cpp2a/range-for6.C +++ gcc/testsuite/g++.dg/cpp2a/range-for6.C @@ -0,0 +1,17 @@ +// P0614R1 +// { dg-do run } +// { dg-options "-std=c++2a" } + +int +main () +{ + int a[] = { 1, 2, 3, 4, 5 }; + + for (int i = []{ return 3; }(); auto x : a) + if (i != 3) + __builtin_abort (); + + for (int i = ({ 3; }); auto x : a) + if (i != 3) + __builtin_abort (); +} diff --git gcc/testsuite/g++.dg/cpp2a/range-for7.C gcc/testsuite/g++.dg/cpp2a/range-for7.C index e69de29bb2d..5a3a89c1c25 100644 --- gcc/testsuite/g++.dg/cpp2a/range-for7.C +++ gcc/testsuite/g++.dg/cpp2a/range-for7.C @@ -0,0 +1,45 @@ +// P0614R1 +// { dg-do compile } +// { dg-options "-std=c++2a" } + +extern void bar (int); + +void +fn0 (int n) +{ + int a[] = { 1, 2, 3, 4, 5 }; + + /* Don't get confused by the colon here. */ + for (int i = 0; n > 0 ? true : false; i++) + bar (i); + + for (int i = n ? 3 : 4; auto x : a) + bar (x); + + for (int i = n ? ({ a: 3; }) : 4; i < 10; i++) + bar (i); + + for (int i = n ? ({ L: 3; }) : 4; auto x : a) + bar (x); + + for (int i = n; auto x : a) + bar (x); + + for (int i = n ? n ? n : 3 : 3; auto x : a) + bar (x); + + for (int i = n ? n ? 3 : n ? 3 : 3 : 3; auto x : a) + bar (x); + + for (int i = [=]{ return n ? 1 : 2; }(); auto x : a) + bar (x); + + for (int i = [=]{ L2: if (!n) goto L2; else return 2; }(); auto x : a) + bar (x); + + for (auto x = n ? 1 : 2 : a) // { dg-error "initializer" } + bar (x); + + for (int i = 1; auto x = n ? 1 : 2 : a) // { dg-error "initializer" } + bar (x); +}
On Tue, May 22, 2018 at 7:25 PM, Marek Polacek <polacek@redhat.com> wrote: > On Mon, May 21, 2018 at 09:51:44PM -0400, Jason Merrill wrote: >> On Mon, May 21, 2018 at 7:34 PM, Marek Polacek <polacek@redhat.com> wrote: >> > The previous version of this patch got confused by >> > >> > for (int i = 0; n > 0 ? true : false; i++) >> > // ... >> > >> > because even though we see a ; followed by a :, it's not a range-based for with >> > an initializer. I find it very strange that this didn't show up during the >> > regtest. >> > >> > To fix this, I had to uglify range_based_for_with_init_p to also check for a ?. >> > Yuck. >> >> Perhaps cp_parser_skip_to_closing_parenthesis_1 should handle balanced >> ?: like ()/[]/{}. > > Good point. Clearly there's a difference between ?: and e.g. () because : can > stand alone--e.g. in asm (: "whatever"), labels, goacc arrays like a[0:N], and > so on. The following seems to work well, and is certainly less ugly than the > previous version. > > + case CPP_QUERY: > + if (!brace_depth) > + ++condop_depth; > + break; > + > + case CPP_COLON: > + if (!brace_depth && condop_depth > 0) > + condop_depth--; > + break; Since, as you say, colons can appear in more places, maybe we only want to adjust condop_depth when all the other depths are 0, not just brace_depth. Jason
On Tue, May 22, 2018 at 09:46:10PM -0400, Jason Merrill wrote: > On Tue, May 22, 2018 at 7:25 PM, Marek Polacek <polacek@redhat.com> wrote: > > On Mon, May 21, 2018 at 09:51:44PM -0400, Jason Merrill wrote: > >> On Mon, May 21, 2018 at 7:34 PM, Marek Polacek <polacek@redhat.com> wrote: > >> > The previous version of this patch got confused by > >> > > >> > for (int i = 0; n > 0 ? true : false; i++) > >> > // ... > >> > > >> > because even though we see a ; followed by a :, it's not a range-based for with > >> > an initializer. I find it very strange that this didn't show up during the > >> > regtest. > >> > > >> > To fix this, I had to uglify range_based_for_with_init_p to also check for a ?. > >> > Yuck. > >> > >> Perhaps cp_parser_skip_to_closing_parenthesis_1 should handle balanced > >> ?: like ()/[]/{}. > > > > Good point. Clearly there's a difference between ?: and e.g. () because : can > > stand alone--e.g. in asm (: "whatever"), labels, goacc arrays like a[0:N], and > > so on. The following seems to work well, and is certainly less ugly than the > > previous version. > > > > + case CPP_QUERY: > > + if (!brace_depth) > > + ++condop_depth; > > + break; > > + > > + case CPP_COLON: > > + if (!brace_depth && condop_depth > 0) > > + condop_depth--; > > + break; > > Since, as you say, colons can appear in more places, maybe we only > want to adjust condop_depth when all the other depths are 0, not just > brace_depth. Yeah, I meant to do it but apparently I didn't :(. Fixed below. Bootstrapped/regtested on x86_64-linux, ok for trunk? 2018-05-23 Marek Polacek <polacek@redhat.com> Implement P0614R1, Range-based for statements with initializer. * parser.c (cp_parser_range_based_for_with_init_p): New. (cp_parser_init_statement): Use it. Parse the optional init-statement for a range-based for loop. (cp_parser_skip_to_closing_parenthesis_1): Handle balancing ?:. * g++.dg/cpp2a/range-for1.C: New test. * g++.dg/cpp2a/range-for2.C: New test. * g++.dg/cpp2a/range-for3.C: New test. * g++.dg/cpp2a/range-for4.C: New test. * g++.dg/cpp2a/range-for5.C: New test. * g++.dg/cpp2a/range-for6.C: New test. * g++.dg/cpp2a/range-for7.C: New test. diff --git gcc/cp/parser.c gcc/cp/parser.c index 6f51f03f47c..d3e73488e84 100644 --- gcc/cp/parser.c +++ gcc/cp/parser.c @@ -3493,6 +3493,7 @@ cp_parser_skip_to_closing_parenthesis_1 (cp_parser *parser, unsigned paren_depth = 0; unsigned brace_depth = 0; unsigned square_depth = 0; + unsigned condop_depth = 0; if (recovering && or_ttype == CPP_EOF && cp_parser_uncommitted_to_tentative_parse_p (parser)) @@ -3504,7 +3505,7 @@ cp_parser_skip_to_closing_parenthesis_1 (cp_parser *parser, /* Have we found what we're looking for before the closing paren? */ if (token->type == or_ttype && or_ttype != CPP_EOF - && !brace_depth && !paren_depth && !square_depth) + && !brace_depth && !paren_depth && !square_depth && !condop_depth) return -1; switch (token->type) @@ -3551,6 +3552,16 @@ cp_parser_skip_to_closing_parenthesis_1 (cp_parser *parser, } break; + case CPP_QUERY: + if (!brace_depth && !paren_depth && !square_depth) + ++condop_depth; + break; + + case CPP_COLON: + if (!brace_depth && !paren_depth && !square_depth && condop_depth > 0) + condop_depth--; + break; + default: break; } @@ -11255,6 +11266,40 @@ cp_parser_statement_seq_opt (cp_parser* parser, tree in_statement_expr) } } +/* Return true if this is the C++20 version of range-based-for with + init-statement. */ + +static bool +cp_parser_range_based_for_with_init_p (cp_parser *parser) +{ + bool r = false; + + /* Save tokens so that we can put them back. */ + cp_lexer_save_tokens (parser->lexer); + + /* There has to be an unnested ; followed by an unnested :. */ + if (cp_parser_skip_to_closing_parenthesis_1 (parser, + /*recovering=*/false, + CPP_SEMICOLON, + /*consume_paren=*/false) != -1) + goto out; + + /* We found the semicolon, eat it now. */ + cp_lexer_consume_token (parser->lexer); + + /* Now look for ':' that is not nested in () or {}. */ + r = (cp_parser_skip_to_closing_parenthesis_1 (parser, + /*recovering=*/false, + CPP_COLON, + /*consume_paren=*/false) == -1); + +out: + /* Roll back the tokens we skipped. */ + cp_lexer_rollback_tokens (parser->lexer); + + return r; +} + /* Return true if we're looking at (init; cond), false otherwise. */ static bool @@ -12299,7 +12344,7 @@ cp_parser_iteration_statement (cp_parser* parser, bool *if_p, bool ivdep, simple-declaration */ static bool -cp_parser_init_statement (cp_parser* parser, tree *decl) +cp_parser_init_statement (cp_parser *parser, tree *decl) { /* If the next token is a `;', then we have an empty expression-statement. Grammatically, this is also a @@ -12312,6 +12357,29 @@ cp_parser_init_statement (cp_parser* parser, tree *decl) bool is_range_for = false; bool saved_colon_corrects_to_scope_p = parser->colon_corrects_to_scope_p; + /* Try to parse the init-statement. */ + if (cp_parser_range_based_for_with_init_p (parser)) + { + tree dummy; + cp_parser_parse_tentatively (parser); + /* Parse the declaration. */ + cp_parser_simple_declaration (parser, + /*function_definition_allowed_p=*/false, + &dummy); + cp_parser_require (parser, CPP_SEMICOLON, RT_SEMICOLON); + if (!cp_parser_parse_definitely (parser)) + /* That didn't work, try to parse it as an expression-statement. */ + cp_parser_expression_statement (parser, NULL_TREE); + + if (cxx_dialect < cxx2a) + { + pedwarn (cp_lexer_peek_token (parser->lexer)->location, 0, + "range-based %<for%> loops with initializer only " + "available with -std=c++2a or -std=gnu++2a"); + *decl = error_mark_node; + } + } + /* A colon is used in range-based for. */ parser->colon_corrects_to_scope_p = false; @@ -12325,7 +12393,7 @@ cp_parser_init_statement (cp_parser* parser, tree *decl) parser->colon_corrects_to_scope_p = saved_colon_corrects_to_scope_p; if (cp_lexer_next_token_is (parser->lexer, CPP_COLON)) { - /* It is a range-for, consume the ':' */ + /* It is a range-for, consume the ':'. */ cp_lexer_consume_token (parser->lexer); is_range_for = true; if (cxx_dialect < cxx11) @@ -12337,9 +12405,9 @@ cp_parser_init_statement (cp_parser* parser, tree *decl) } } else - /* The ';' is not consumed yet because we told - cp_parser_simple_declaration not to. */ - cp_parser_require (parser, CPP_SEMICOLON, RT_SEMICOLON); + /* The ';' is not consumed yet because we told + cp_parser_simple_declaration not to. */ + cp_parser_require (parser, CPP_SEMICOLON, RT_SEMICOLON); if (cp_parser_parse_definitely (parser)) return is_range_for; diff --git gcc/testsuite/g++.dg/cpp2a/range-for1.C gcc/testsuite/g++.dg/cpp2a/range-for1.C index e69de29bb2d..3a5523585a1 100644 --- gcc/testsuite/g++.dg/cpp2a/range-for1.C +++ gcc/testsuite/g++.dg/cpp2a/range-for1.C @@ -0,0 +1,16 @@ +// P0614R1 +// { dg-do compile { target c++11 } } +// { dg-options "" } + +void +fn1 () +{ + int a[] = { 1, 2, 3, 4, 5 }; + + for (int i = 0; auto x : a) // { dg-warning "range-based .for. loops with initializer only available with" "" { target c++17_down } } + ++i; + + int i; + for (i = 0; auto x : a) // { dg-warning "range-based .for. loops with initializer only available with" "" { target c++17_down } } + ++i; +} diff --git gcc/testsuite/g++.dg/cpp2a/range-for2.C gcc/testsuite/g++.dg/cpp2a/range-for2.C index e69de29bb2d..acb16c57d1c 100644 --- gcc/testsuite/g++.dg/cpp2a/range-for2.C +++ gcc/testsuite/g++.dg/cpp2a/range-for2.C @@ -0,0 +1,16 @@ +// P0614R1 +// { dg-do compile } +// { dg-options "-std=c++2a" } + +void +fn1 () +{ + int a[] = { 1, 2, 3, 4, 5 }; + + for (int i = 0; auto x : a) + ++i; + + int i; + for (i = 0; auto x : a) + ++i; +} diff --git gcc/testsuite/g++.dg/cpp2a/range-for3.C gcc/testsuite/g++.dg/cpp2a/range-for3.C index e69de29bb2d..291e605b92f 100644 --- gcc/testsuite/g++.dg/cpp2a/range-for3.C +++ gcc/testsuite/g++.dg/cpp2a/range-for3.C @@ -0,0 +1,26 @@ +// P0614R1 +// { dg-do compile } +// { dg-options "-std=c++2a" } + +static const int a[] = { 1, 2, 3, 4, 5 }; +extern void foo (int); +extern void bar (int, int); + +constexpr int +baz () +{ + return 6; +} + +void +fn1 (int i) +{ + for ((i += 2); auto x : a) + foo (i); + + for (auto j = 0, k = 0; auto x : a) + bar (j + k, x); + + for (constexpr int j = baz (); auto x : a) + bar (x, j); +} diff --git gcc/testsuite/g++.dg/cpp2a/range-for4.C gcc/testsuite/g++.dg/cpp2a/range-for4.C index e69de29bb2d..6ba783f46cb 100644 --- gcc/testsuite/g++.dg/cpp2a/range-for4.C +++ gcc/testsuite/g++.dg/cpp2a/range-for4.C @@ -0,0 +1,27 @@ +// P0614R1 +// { dg-do run } +// { dg-options "-std=c++2a" } + +int +main () +{ + int a[] = { 1, 2, 3, 4, 5 }; + + for (int i = 1; auto x : a) + if (i++ != x) + __builtin_abort (); + + int i; + for (i = 1; auto x : a) + if (i++ != x) + __builtin_abort (); + + i = 0; + for (i++; auto x : a) + if (i != 1) + __builtin_abort (); + + for (int s[] = { 1, 1, 1 }; auto x : s) + if (x != 1) + __builtin_abort (); +} diff --git gcc/testsuite/g++.dg/cpp2a/range-for5.C gcc/testsuite/g++.dg/cpp2a/range-for5.C index e69de29bb2d..62f1c2f04e1 100644 --- gcc/testsuite/g++.dg/cpp2a/range-for5.C +++ gcc/testsuite/g++.dg/cpp2a/range-for5.C @@ -0,0 +1,46 @@ +// P0614R1 +// { dg-do compile } +// { dg-options "-std=c++2a" } + +void +fn1 () +{ + int a[] = { 1, 2, 3, 4, 5 }; + + for (int i = 0; auto x : a) + ++i; + + i = 0; // { dg-error "not declared" } + + for (int i = 0; auto x : a) + { + for (int j = 0; auto x : a) + { + for (int k = 0; auto x : a) + k++; + k++; // { dg-error "not declared" } + } + j++; // { dg-error "not declared" } + } +} + +void +fn2 () +{ + int a[] = { 1, 2, 3, 4, 5 }; + for (int i = 0; auto x : a) + int i = 3; // { dg-error "redeclaration" } +} +void +fn3 () +{ + int a[] = { 1, 2, 3, 4, 5 }; + + for (;:) // { dg-error "expected" } + { + } + + for (;;:) // { dg-error "expected" } + { + } +} diff --git gcc/testsuite/g++.dg/cpp2a/range-for6.C gcc/testsuite/g++.dg/cpp2a/range-for6.C index e69de29bb2d..4cee60a839e 100644 --- gcc/testsuite/g++.dg/cpp2a/range-for6.C +++ gcc/testsuite/g++.dg/cpp2a/range-for6.C @@ -0,0 +1,17 @@ +// P0614R1 +// { dg-do run } +// { dg-options "-std=c++2a" } + +int +main () +{ + int a[] = { 1, 2, 3, 4, 5 }; + + for (int i = []{ return 3; }(); auto x : a) + if (i != 3) + __builtin_abort (); + + for (int i = ({ 3; }); auto x : a) + if (i != 3) + __builtin_abort (); +} diff --git gcc/testsuite/g++.dg/cpp2a/range-for7.C gcc/testsuite/g++.dg/cpp2a/range-for7.C index e69de29bb2d..5a3a89c1c25 100644 --- gcc/testsuite/g++.dg/cpp2a/range-for7.C +++ gcc/testsuite/g++.dg/cpp2a/range-for7.C @@ -0,0 +1,45 @@ +// P0614R1 +// { dg-do compile } +// { dg-options "-std=c++2a" } + +extern void bar (int); + +void +fn0 (int n) +{ + int a[] = { 1, 2, 3, 4, 5 }; + + /* Don't get confused by the colon here. */ + for (int i = 0; n > 0 ? true : false; i++) + bar (i); + + for (int i = n ? 3 : 4; auto x : a) + bar (x); + + for (int i = n ? ({ a: 3; }) : 4; i < 10; i++) + bar (i); + + for (int i = n ? ({ L: 3; }) : 4; auto x : a) + bar (x); + + for (int i = n; auto x : a) + bar (x); + + for (int i = n ? n ? n : 3 : 3; auto x : a) + bar (x); + + for (int i = n ? n ? 3 : n ? 3 : 3 : 3; auto x : a) + bar (x); + + for (int i = [=]{ return n ? 1 : 2; }(); auto x : a) + bar (x); + + for (int i = [=]{ L2: if (!n) goto L2; else return 2; }(); auto x : a) + bar (x); + + for (auto x = n ? 1 : 2 : a) // { dg-error "initializer" } + bar (x); + + for (int i = 1; auto x = n ? 1 : 2 : a) // { dg-error "initializer" } + bar (x); +}
OK. On Wed, May 23, 2018 at 10:45 AM, Marek Polacek <polacek@redhat.com> wrote: > On Tue, May 22, 2018 at 09:46:10PM -0400, Jason Merrill wrote: >> On Tue, May 22, 2018 at 7:25 PM, Marek Polacek <polacek@redhat.com> wrote: >> > On Mon, May 21, 2018 at 09:51:44PM -0400, Jason Merrill wrote: >> >> On Mon, May 21, 2018 at 7:34 PM, Marek Polacek <polacek@redhat.com> wrote: >> >> > The previous version of this patch got confused by >> >> > >> >> > for (int i = 0; n > 0 ? true : false; i++) >> >> > // ... >> >> > >> >> > because even though we see a ; followed by a :, it's not a range-based for with >> >> > an initializer. I find it very strange that this didn't show up during the >> >> > regtest. >> >> > >> >> > To fix this, I had to uglify range_based_for_with_init_p to also check for a ?. >> >> > Yuck. >> >> >> >> Perhaps cp_parser_skip_to_closing_parenthesis_1 should handle balanced >> >> ?: like ()/[]/{}. >> > >> > Good point. Clearly there's a difference between ?: and e.g. () because : can >> > stand alone--e.g. in asm (: "whatever"), labels, goacc arrays like a[0:N], and >> > so on. The following seems to work well, and is certainly less ugly than the >> > previous version. >> > >> > + case CPP_QUERY: >> > + if (!brace_depth) >> > + ++condop_depth; >> > + break; >> > + >> > + case CPP_COLON: >> > + if (!brace_depth && condop_depth > 0) >> > + condop_depth--; >> > + break; >> >> Since, as you say, colons can appear in more places, maybe we only >> want to adjust condop_depth when all the other depths are 0, not just >> brace_depth. > > Yeah, I meant to do it but apparently I didn't :(. Fixed below. > > Bootstrapped/regtested on x86_64-linux, ok for trunk? > > 2018-05-23 Marek Polacek <polacek@redhat.com> > > Implement P0614R1, Range-based for statements with initializer. > * parser.c (cp_parser_range_based_for_with_init_p): New. > (cp_parser_init_statement): Use it. Parse the optional init-statement > for a range-based for loop. > (cp_parser_skip_to_closing_parenthesis_1): Handle balancing ?:. > > * g++.dg/cpp2a/range-for1.C: New test. > * g++.dg/cpp2a/range-for2.C: New test. > * g++.dg/cpp2a/range-for3.C: New test. > * g++.dg/cpp2a/range-for4.C: New test. > * g++.dg/cpp2a/range-for5.C: New test. > * g++.dg/cpp2a/range-for6.C: New test. > * g++.dg/cpp2a/range-for7.C: New test. > > diff --git gcc/cp/parser.c gcc/cp/parser.c > index 6f51f03f47c..d3e73488e84 100644 > --- gcc/cp/parser.c > +++ gcc/cp/parser.c > @@ -3493,6 +3493,7 @@ cp_parser_skip_to_closing_parenthesis_1 (cp_parser *parser, > unsigned paren_depth = 0; > unsigned brace_depth = 0; > unsigned square_depth = 0; > + unsigned condop_depth = 0; > > if (recovering && or_ttype == CPP_EOF > && cp_parser_uncommitted_to_tentative_parse_p (parser)) > @@ -3504,7 +3505,7 @@ cp_parser_skip_to_closing_parenthesis_1 (cp_parser *parser, > > /* Have we found what we're looking for before the closing paren? */ > if (token->type == or_ttype && or_ttype != CPP_EOF > - && !brace_depth && !paren_depth && !square_depth) > + && !brace_depth && !paren_depth && !square_depth && !condop_depth) > return -1; > > switch (token->type) > @@ -3551,6 +3552,16 @@ cp_parser_skip_to_closing_parenthesis_1 (cp_parser *parser, > } > break; > > + case CPP_QUERY: > + if (!brace_depth && !paren_depth && !square_depth) > + ++condop_depth; > + break; > + > + case CPP_COLON: > + if (!brace_depth && !paren_depth && !square_depth && condop_depth > 0) > + condop_depth--; > + break; > + > default: > break; > } > @@ -11255,6 +11266,40 @@ cp_parser_statement_seq_opt (cp_parser* parser, tree in_statement_expr) > } > } > > +/* Return true if this is the C++20 version of range-based-for with > + init-statement. */ > + > +static bool > +cp_parser_range_based_for_with_init_p (cp_parser *parser) > +{ > + bool r = false; > + > + /* Save tokens so that we can put them back. */ > + cp_lexer_save_tokens (parser->lexer); > + > + /* There has to be an unnested ; followed by an unnested :. */ > + if (cp_parser_skip_to_closing_parenthesis_1 (parser, > + /*recovering=*/false, > + CPP_SEMICOLON, > + /*consume_paren=*/false) != -1) > + goto out; > + > + /* We found the semicolon, eat it now. */ > + cp_lexer_consume_token (parser->lexer); > + > + /* Now look for ':' that is not nested in () or {}. */ > + r = (cp_parser_skip_to_closing_parenthesis_1 (parser, > + /*recovering=*/false, > + CPP_COLON, > + /*consume_paren=*/false) == -1); > + > +out: > + /* Roll back the tokens we skipped. */ > + cp_lexer_rollback_tokens (parser->lexer); > + > + return r; > +} > + > /* Return true if we're looking at (init; cond), false otherwise. */ > > static bool > @@ -12299,7 +12344,7 @@ cp_parser_iteration_statement (cp_parser* parser, bool *if_p, bool ivdep, > simple-declaration */ > > static bool > -cp_parser_init_statement (cp_parser* parser, tree *decl) > +cp_parser_init_statement (cp_parser *parser, tree *decl) > { > /* If the next token is a `;', then we have an empty > expression-statement. Grammatically, this is also a > @@ -12312,6 +12357,29 @@ cp_parser_init_statement (cp_parser* parser, tree *decl) > bool is_range_for = false; > bool saved_colon_corrects_to_scope_p = parser->colon_corrects_to_scope_p; > > + /* Try to parse the init-statement. */ > + if (cp_parser_range_based_for_with_init_p (parser)) > + { > + tree dummy; > + cp_parser_parse_tentatively (parser); > + /* Parse the declaration. */ > + cp_parser_simple_declaration (parser, > + /*function_definition_allowed_p=*/false, > + &dummy); > + cp_parser_require (parser, CPP_SEMICOLON, RT_SEMICOLON); > + if (!cp_parser_parse_definitely (parser)) > + /* That didn't work, try to parse it as an expression-statement. */ > + cp_parser_expression_statement (parser, NULL_TREE); > + > + if (cxx_dialect < cxx2a) > + { > + pedwarn (cp_lexer_peek_token (parser->lexer)->location, 0, > + "range-based %<for%> loops with initializer only " > + "available with -std=c++2a or -std=gnu++2a"); > + *decl = error_mark_node; > + } > + } > + > /* A colon is used in range-based for. */ > parser->colon_corrects_to_scope_p = false; > > @@ -12325,7 +12393,7 @@ cp_parser_init_statement (cp_parser* parser, tree *decl) > parser->colon_corrects_to_scope_p = saved_colon_corrects_to_scope_p; > if (cp_lexer_next_token_is (parser->lexer, CPP_COLON)) > { > - /* It is a range-for, consume the ':' */ > + /* It is a range-for, consume the ':'. */ > cp_lexer_consume_token (parser->lexer); > is_range_for = true; > if (cxx_dialect < cxx11) > @@ -12337,9 +12405,9 @@ cp_parser_init_statement (cp_parser* parser, tree *decl) > } > } > else > - /* The ';' is not consumed yet because we told > - cp_parser_simple_declaration not to. */ > - cp_parser_require (parser, CPP_SEMICOLON, RT_SEMICOLON); > + /* The ';' is not consumed yet because we told > + cp_parser_simple_declaration not to. */ > + cp_parser_require (parser, CPP_SEMICOLON, RT_SEMICOLON); > > if (cp_parser_parse_definitely (parser)) > return is_range_for; > diff --git gcc/testsuite/g++.dg/cpp2a/range-for1.C gcc/testsuite/g++.dg/cpp2a/range-for1.C > index e69de29bb2d..3a5523585a1 100644 > --- gcc/testsuite/g++.dg/cpp2a/range-for1.C > +++ gcc/testsuite/g++.dg/cpp2a/range-for1.C > @@ -0,0 +1,16 @@ > +// P0614R1 > +// { dg-do compile { target c++11 } } > +// { dg-options "" } > + > +void > +fn1 () > +{ > + int a[] = { 1, 2, 3, 4, 5 }; > + > + for (int i = 0; auto x : a) // { dg-warning "range-based .for. loops with initializer only available with" "" { target c++17_down } } > + ++i; > + > + int i; > + for (i = 0; auto x : a) // { dg-warning "range-based .for. loops with initializer only available with" "" { target c++17_down } } > + ++i; > +} > diff --git gcc/testsuite/g++.dg/cpp2a/range-for2.C gcc/testsuite/g++.dg/cpp2a/range-for2.C > index e69de29bb2d..acb16c57d1c 100644 > --- gcc/testsuite/g++.dg/cpp2a/range-for2.C > +++ gcc/testsuite/g++.dg/cpp2a/range-for2.C > @@ -0,0 +1,16 @@ > +// P0614R1 > +// { dg-do compile } > +// { dg-options "-std=c++2a" } > + > +void > +fn1 () > +{ > + int a[] = { 1, 2, 3, 4, 5 }; > + > + for (int i = 0; auto x : a) > + ++i; > + > + int i; > + for (i = 0; auto x : a) > + ++i; > +} > diff --git gcc/testsuite/g++.dg/cpp2a/range-for3.C gcc/testsuite/g++.dg/cpp2a/range-for3.C > index e69de29bb2d..291e605b92f 100644 > --- gcc/testsuite/g++.dg/cpp2a/range-for3.C > +++ gcc/testsuite/g++.dg/cpp2a/range-for3.C > @@ -0,0 +1,26 @@ > +// P0614R1 > +// { dg-do compile } > +// { dg-options "-std=c++2a" } > + > +static const int a[] = { 1, 2, 3, 4, 5 }; > +extern void foo (int); > +extern void bar (int, int); > + > +constexpr int > +baz () > +{ > + return 6; > +} > + > +void > +fn1 (int i) > +{ > + for ((i += 2); auto x : a) > + foo (i); > + > + for (auto j = 0, k = 0; auto x : a) > + bar (j + k, x); > + > + for (constexpr int j = baz (); auto x : a) > + bar (x, j); > +} > diff --git gcc/testsuite/g++.dg/cpp2a/range-for4.C gcc/testsuite/g++.dg/cpp2a/range-for4.C > index e69de29bb2d..6ba783f46cb 100644 > --- gcc/testsuite/g++.dg/cpp2a/range-for4.C > +++ gcc/testsuite/g++.dg/cpp2a/range-for4.C > @@ -0,0 +1,27 @@ > +// P0614R1 > +// { dg-do run } > +// { dg-options "-std=c++2a" } > + > +int > +main () > +{ > + int a[] = { 1, 2, 3, 4, 5 }; > + > + for (int i = 1; auto x : a) > + if (i++ != x) > + __builtin_abort (); > + > + int i; > + for (i = 1; auto x : a) > + if (i++ != x) > + __builtin_abort (); > + > + i = 0; > + for (i++; auto x : a) > + if (i != 1) > + __builtin_abort (); > + > + for (int s[] = { 1, 1, 1 }; auto x : s) > + if (x != 1) > + __builtin_abort (); > +} > diff --git gcc/testsuite/g++.dg/cpp2a/range-for5.C gcc/testsuite/g++.dg/cpp2a/range-for5.C > index e69de29bb2d..62f1c2f04e1 100644 > --- gcc/testsuite/g++.dg/cpp2a/range-for5.C > +++ gcc/testsuite/g++.dg/cpp2a/range-for5.C > @@ -0,0 +1,46 @@ > +// P0614R1 > +// { dg-do compile } > +// { dg-options "-std=c++2a" } > + > +void > +fn1 () > +{ > + int a[] = { 1, 2, 3, 4, 5 }; > + > + for (int i = 0; auto x : a) > + ++i; > + > + i = 0; // { dg-error "not declared" } > + > + for (int i = 0; auto x : a) > + { > + for (int j = 0; auto x : a) > + { > + for (int k = 0; auto x : a) > + k++; > + k++; // { dg-error "not declared" } > + } > + j++; // { dg-error "not declared" } > + } > +} > + > +void > +fn2 () > +{ > + int a[] = { 1, 2, 3, 4, 5 }; > + for (int i = 0; auto x : a) > + int i = 3; // { dg-error "redeclaration" } > +} > +void > +fn3 () > +{ > + int a[] = { 1, 2, 3, 4, 5 }; > + > + for (;:) // { dg-error "expected" } > + { > + } > + > + for (;;:) // { dg-error "expected" } > + { > + } > +} > diff --git gcc/testsuite/g++.dg/cpp2a/range-for6.C gcc/testsuite/g++.dg/cpp2a/range-for6.C > index e69de29bb2d..4cee60a839e 100644 > --- gcc/testsuite/g++.dg/cpp2a/range-for6.C > +++ gcc/testsuite/g++.dg/cpp2a/range-for6.C > @@ -0,0 +1,17 @@ > +// P0614R1 > +// { dg-do run } > +// { dg-options "-std=c++2a" } > + > +int > +main () > +{ > + int a[] = { 1, 2, 3, 4, 5 }; > + > + for (int i = []{ return 3; }(); auto x : a) > + if (i != 3) > + __builtin_abort (); > + > + for (int i = ({ 3; }); auto x : a) > + if (i != 3) > + __builtin_abort (); > +} > diff --git gcc/testsuite/g++.dg/cpp2a/range-for7.C gcc/testsuite/g++.dg/cpp2a/range-for7.C > index e69de29bb2d..5a3a89c1c25 100644 > --- gcc/testsuite/g++.dg/cpp2a/range-for7.C > +++ gcc/testsuite/g++.dg/cpp2a/range-for7.C > @@ -0,0 +1,45 @@ > +// P0614R1 > +// { dg-do compile } > +// { dg-options "-std=c++2a" } > + > +extern void bar (int); > + > +void > +fn0 (int n) > +{ > + int a[] = { 1, 2, 3, 4, 5 }; > + > + /* Don't get confused by the colon here. */ > + for (int i = 0; n > 0 ? true : false; i++) > + bar (i); > + > + for (int i = n ? 3 : 4; auto x : a) > + bar (x); > + > + for (int i = n ? ({ a: 3; }) : 4; i < 10; i++) > + bar (i); > + > + for (int i = n ? ({ L: 3; }) : 4; auto x : a) > + bar (x); > + > + for (int i = n; auto x : a) > + bar (x); > + > + for (int i = n ? n ? n : 3 : 3; auto x : a) > + bar (x); > + > + for (int i = n ? n ? 3 : n ? 3 : 3 : 3; auto x : a) > + bar (x); > + > + for (int i = [=]{ return n ? 1 : 2; }(); auto x : a) > + bar (x); > + > + for (int i = [=]{ L2: if (!n) goto L2; else return 2; }(); auto x : a) > + bar (x); > + > + for (auto x = n ? 1 : 2 : a) // { dg-error "initializer" } > + bar (x); > + > + for (int i = 1; auto x = n ? 1 : 2 : a) // { dg-error "initializer" } > + bar (x); > +}
On Wed, May 23, 2018 at 10:45:43AM -0400, Marek Polacek wrote: > 2018-05-23 Marek Polacek <polacek@redhat.com> > > Implement P0614R1, Range-based for statements with initializer. > * parser.c (cp_parser_range_based_for_with_init_p): New. > (cp_parser_init_statement): Use it. Parse the optional init-statement > for a range-based for loop. > (cp_parser_skip_to_closing_parenthesis_1): Handle balancing ?:. > > * g++.dg/cpp2a/range-for1.C: New test. > * g++.dg/cpp2a/range-for2.C: New test. > * g++.dg/cpp2a/range-for3.C: New test. > * g++.dg/cpp2a/range-for4.C: New test. > * g++.dg/cpp2a/range-for5.C: New test. > * g++.dg/cpp2a/range-for6.C: New test. > * g++.dg/cpp2a/range-for7.C: New test. Could you please add some testcases that would test the handling of structured bindings in these new forms of range for, like: for (int i = 0; auto [ x, y ] : z) but perhaps for completeness also in the init-stmt and perhaps both spots too? Jakub
On Wed, May 23, 2018 at 06:45:41PM +0200, Jakub Jelinek wrote: > On Wed, May 23, 2018 at 10:45:43AM -0400, Marek Polacek wrote: > > 2018-05-23 Marek Polacek <polacek@redhat.com> > > > > Implement P0614R1, Range-based for statements with initializer. > > * parser.c (cp_parser_range_based_for_with_init_p): New. > > (cp_parser_init_statement): Use it. Parse the optional init-statement > > for a range-based for loop. > > (cp_parser_skip_to_closing_parenthesis_1): Handle balancing ?:. > > > > * g++.dg/cpp2a/range-for1.C: New test. > > * g++.dg/cpp2a/range-for2.C: New test. > > * g++.dg/cpp2a/range-for3.C: New test. > > * g++.dg/cpp2a/range-for4.C: New test. > > * g++.dg/cpp2a/range-for5.C: New test. > > * g++.dg/cpp2a/range-for6.C: New test. > > * g++.dg/cpp2a/range-for7.C: New test. > > Could you please add some testcases that would test the handling of > structured bindings in these new forms of range for, like: > for (int i = 0; auto [ x, y ] : z) > but perhaps for completeness also in the init-stmt and perhaps both spots > too? Sure. Tested on x86_64-linux, ok for trunk? 2018-05-23 Marek Polacek <polacek@redhat.com> * g++.dg/cpp2a/range-for8.C: New test. * g++.dg/cpp2a/range-for9.C: New test. * g++.dg/cpp2a/range-for10.C: New test. diff --git gcc/testsuite/g++.dg/cpp2a/range-for10.C gcc/testsuite/g++.dg/cpp2a/range-for10.C index e69de29bb2d..a0d0e6d085e 100644 --- gcc/testsuite/g++.dg/cpp2a/range-for10.C +++ gcc/testsuite/g++.dg/cpp2a/range-for10.C @@ -0,0 +1,24 @@ +// P0614R1 +// { dg-do run } +// { dg-options "-std=c++2a" } + +struct A { int i; long long j; } a[64]; + +int +main () +{ + A b = { 1, 2 }; + for (auto & [ u, v ] : a) + { + u = 2; + v = 3; + } + + for (auto [x, y] = b; auto [ u, v ] : a) + if (y + u != x + v) + __builtin_abort (); + + for (auto [x, y] = b; auto & [ u, v ] : a) + if (y + u != x + v) + __builtin_abort (); +} diff --git gcc/testsuite/g++.dg/cpp2a/range-for8.C gcc/testsuite/g++.dg/cpp2a/range-for8.C index e69de29bb2d..204a63204ca 100644 --- gcc/testsuite/g++.dg/cpp2a/range-for8.C +++ gcc/testsuite/g++.dg/cpp2a/range-for8.C @@ -0,0 +1,37 @@ +// P0614R1 +// { dg-do run } +// { dg-options "-std=c++2a" } + +struct A { int i; long long j; } a[64]; + +int +main () +{ + for (int i = 0; auto &x : a) + { + x.i = i; + x.j = 2 * i++; + } + for (auto & [ x, y ] : a) + { + x += 2; + y += 3; + } + for (int i = 0; const auto [ u, v ] : a) + { + if (u != i + 2 || v != 2 * i++ + 3) + __builtin_abort (); + } + for (int i = 0; auto [ x, y ] : a) + { + x += 4; + y += 5; + if (x != i + 6 || y != 2 * i++ + 8) + __builtin_abort (); + } + for (int i = 0; const auto x : a) + { + if (x.i != i + 2 || x.j != 2 * i++ + 3) + __builtin_abort (); + } +} diff --git gcc/testsuite/g++.dg/cpp2a/range-for9.C gcc/testsuite/g++.dg/cpp2a/range-for9.C index e69de29bb2d..74d71b67213 100644 --- gcc/testsuite/g++.dg/cpp2a/range-for9.C +++ gcc/testsuite/g++.dg/cpp2a/range-for9.C @@ -0,0 +1,30 @@ +// P0614R1 +// { dg-do run } +// { dg-options "-std=c++2a" } + +struct A { int i, j; }; + +int +main () +{ + A a = { .i = 2, .j = 3 }; + int arr[] = { 1, 1, 1 }; + + for (auto & [ x, y ] = a; auto z : arr) + if (x + z != 3 || y + z != 4) + __builtin_abort (); + + for (int d = 1; auto &z : arr) + z += d; + + for (const auto [ x, y ] = a; auto z : arr) + if (x + z != 4 || y + z != 5) + __builtin_abort (); + + for (int d = 1; auto &z : arr) + z += d; + + for (auto [ x, y ] = a; auto z : arr) + if (x + z != 5 || y + z != 6) + __builtin_abort (); +}
On Wed, May 23, 2018 at 02:49:09PM -0400, Marek Polacek wrote: > > Could you please add some testcases that would test the handling of > > structured bindings in these new forms of range for, like: > > for (int i = 0; auto [ x, y ] : z) > > but perhaps for completeness also in the init-stmt and perhaps both spots > > too? > > Sure. > > Tested on x86_64-linux, ok for trunk? > > 2018-05-23 Marek Polacek <polacek@redhat.com> > > * g++.dg/cpp2a/range-for8.C: New test. > * g++.dg/cpp2a/range-for9.C: New test. > * g++.dg/cpp2a/range-for10.C: New test. LGTM, thanks. > diff --git gcc/testsuite/g++.dg/cpp2a/range-for10.C gcc/testsuite/g++.dg/cpp2a/range-for10.C > index e69de29bb2d..a0d0e6d085e 100644 > --- gcc/testsuite/g++.dg/cpp2a/range-for10.C > +++ gcc/testsuite/g++.dg/cpp2a/range-for10.C > @@ -0,0 +1,24 @@ > +// P0614R1 > +// { dg-do run } > +// { dg-options "-std=c++2a" } > + > +struct A { int i; long long j; } a[64]; > + > +int > +main () > +{ > + A b = { 1, 2 }; > + for (auto & [ u, v ] : a) > + { > + u = 2; > + v = 3; > + } > + > + for (auto [x, y] = b; auto [ u, v ] : a) > + if (y + u != x + v) > + __builtin_abort (); > + > + for (auto [x, y] = b; auto & [ u, v ] : a) > + if (y + u != x + v) > + __builtin_abort (); > +} > diff --git gcc/testsuite/g++.dg/cpp2a/range-for8.C gcc/testsuite/g++.dg/cpp2a/range-for8.C > index e69de29bb2d..204a63204ca 100644 > --- gcc/testsuite/g++.dg/cpp2a/range-for8.C > +++ gcc/testsuite/g++.dg/cpp2a/range-for8.C > @@ -0,0 +1,37 @@ > +// P0614R1 > +// { dg-do run } > +// { dg-options "-std=c++2a" } > + > +struct A { int i; long long j; } a[64]; > + > +int > +main () > +{ > + for (int i = 0; auto &x : a) > + { > + x.i = i; > + x.j = 2 * i++; > + } > + for (auto & [ x, y ] : a) > + { > + x += 2; > + y += 3; > + } > + for (int i = 0; const auto [ u, v ] : a) > + { > + if (u != i + 2 || v != 2 * i++ + 3) > + __builtin_abort (); > + } > + for (int i = 0; auto [ x, y ] : a) > + { > + x += 4; > + y += 5; > + if (x != i + 6 || y != 2 * i++ + 8) > + __builtin_abort (); > + } > + for (int i = 0; const auto x : a) > + { > + if (x.i != i + 2 || x.j != 2 * i++ + 3) > + __builtin_abort (); > + } > +} > diff --git gcc/testsuite/g++.dg/cpp2a/range-for9.C gcc/testsuite/g++.dg/cpp2a/range-for9.C > index e69de29bb2d..74d71b67213 100644 > --- gcc/testsuite/g++.dg/cpp2a/range-for9.C > +++ gcc/testsuite/g++.dg/cpp2a/range-for9.C > @@ -0,0 +1,30 @@ > +// P0614R1 > +// { dg-do run } > +// { dg-options "-std=c++2a" } > + > +struct A { int i, j; }; > + > +int > +main () > +{ > + A a = { .i = 2, .j = 3 }; > + int arr[] = { 1, 1, 1 }; > + > + for (auto & [ x, y ] = a; auto z : arr) > + if (x + z != 3 || y + z != 4) > + __builtin_abort (); > + > + for (int d = 1; auto &z : arr) > + z += d; > + > + for (const auto [ x, y ] = a; auto z : arr) > + if (x + z != 4 || y + z != 5) > + __builtin_abort (); > + > + for (int d = 1; auto &z : arr) > + z += d; > + > + for (auto [ x, y ] = a; auto z : arr) > + if (x + z != 5 || y + z != 6) > + __builtin_abort (); > +} Jakub
diff --git gcc/cp/parser.c gcc/cp/parser.c index 3f621911f12..2693cf37a3e 100644 --- gcc/cp/parser.c +++ gcc/cp/parser.c @@ -11255,6 +11255,52 @@ cp_parser_statement_seq_opt (cp_parser* parser, tree in_statement_expr) } } +/* Return true if this is the C++20 version of range-based-for with + init-statement. */ + +static bool +cp_parser_range_based_for_with_init_p (cp_parser *parser) +{ + bool r = false; + bool saw_query; + + /* Save tokens so that we can put them back. */ + cp_lexer_save_tokens (parser->lexer); + + /* There has to be an unnested ; followed by an unnested :. */ + if (cp_parser_skip_to_closing_parenthesis_1 (parser, + /*recovering=*/false, + CPP_SEMICOLON, + /*consume_paren=*/false) != -1) + goto out; + + /* We found the semicolon, eat it now. */ + cp_lexer_consume_token (parser->lexer); + + /* Don't get confused by an unnested "?:" operator. This requires a nested + stashing of tokens. */ + cp_lexer_save_tokens (parser->lexer); + saw_query + = cp_parser_skip_to_closing_parenthesis_1 (parser, /*recovering=*/false, + CPP_QUERY, + /*consume_paren=*/false) == -1; + cp_lexer_rollback_tokens (parser->lexer); + if (saw_query) + goto out; + + /* Now look for ':' that is not nested in () or {}. */ + r = (cp_parser_skip_to_closing_parenthesis_1 (parser, + /*recovering=*/false, + CPP_COLON, + /*consume_paren=*/false) == -1); + +out: + /* Roll back the tokens we skipped. */ + cp_lexer_rollback_tokens (parser->lexer); + + return r; +} + /* Return true if we're looking at (init; cond), false otherwise. */ static bool @@ -12299,7 +12345,7 @@ cp_parser_iteration_statement (cp_parser* parser, bool *if_p, bool ivdep, simple-declaration */ static bool -cp_parser_init_statement (cp_parser* parser, tree *decl) +cp_parser_init_statement (cp_parser *parser, tree *decl) { /* If the next token is a `;', then we have an empty expression-statement. Grammatically, this is also a @@ -12312,6 +12358,29 @@ cp_parser_init_statement (cp_parser* parser, tree *decl) bool is_range_for = false; bool saved_colon_corrects_to_scope_p = parser->colon_corrects_to_scope_p; + /* Try to parse the init-statement. */ + if (cp_parser_range_based_for_with_init_p (parser)) + { + tree dummy; + cp_parser_parse_tentatively (parser); + /* Parse the declaration. */ + cp_parser_simple_declaration (parser, + /*function_definition_allowed_p=*/false, + &dummy); + cp_parser_require (parser, CPP_SEMICOLON, RT_SEMICOLON); + if (!cp_parser_parse_definitely (parser)) + /* That didn't work, try to parse it as an expression-statement. */ + cp_parser_expression_statement (parser, NULL_TREE); + + if (cxx_dialect < cxx2a) + { + pedwarn (cp_lexer_peek_token (parser->lexer)->location, 0, + "range-based %<for%> loops with initializer only " + "available with -std=c++2a or -std=gnu++2a"); + *decl = error_mark_node; + } + } + /* A colon is used in range-based for. */ parser->colon_corrects_to_scope_p = false; @@ -12325,7 +12394,7 @@ cp_parser_init_statement (cp_parser* parser, tree *decl) parser->colon_corrects_to_scope_p = saved_colon_corrects_to_scope_p; if (cp_lexer_next_token_is (parser->lexer, CPP_COLON)) { - /* It is a range-for, consume the ':' */ + /* It is a range-for, consume the ':'. */ cp_lexer_consume_token (parser->lexer); is_range_for = true; if (cxx_dialect < cxx11) @@ -12337,9 +12406,9 @@ cp_parser_init_statement (cp_parser* parser, tree *decl) } } else - /* The ';' is not consumed yet because we told - cp_parser_simple_declaration not to. */ - cp_parser_require (parser, CPP_SEMICOLON, RT_SEMICOLON); + /* The ';' is not consumed yet because we told + cp_parser_simple_declaration not to. */ + cp_parser_require (parser, CPP_SEMICOLON, RT_SEMICOLON); if (cp_parser_parse_definitely (parser)) return is_range_for; diff --git gcc/testsuite/g++.dg/cpp2a/range-for1.C gcc/testsuite/g++.dg/cpp2a/range-for1.C index e69de29bb2d..3a5523585a1 100644 --- gcc/testsuite/g++.dg/cpp2a/range-for1.C +++ gcc/testsuite/g++.dg/cpp2a/range-for1.C @@ -0,0 +1,16 @@ +// P0614R1 +// { dg-do compile { target c++11 } } +// { dg-options "" } + +void +fn1 () +{ + int a[] = { 1, 2, 3, 4, 5 }; + + for (int i = 0; auto x : a) // { dg-warning "range-based .for. loops with initializer only available with" "" { target c++17_down } } + ++i; + + int i; + for (i = 0; auto x : a) // { dg-warning "range-based .for. loops with initializer only available with" "" { target c++17_down } } + ++i; +} diff --git gcc/testsuite/g++.dg/cpp2a/range-for2.C gcc/testsuite/g++.dg/cpp2a/range-for2.C index e69de29bb2d..acb16c57d1c 100644 --- gcc/testsuite/g++.dg/cpp2a/range-for2.C +++ gcc/testsuite/g++.dg/cpp2a/range-for2.C @@ -0,0 +1,16 @@ +// P0614R1 +// { dg-do compile } +// { dg-options "-std=c++2a" } + +void +fn1 () +{ + int a[] = { 1, 2, 3, 4, 5 }; + + for (int i = 0; auto x : a) + ++i; + + int i; + for (i = 0; auto x : a) + ++i; +} diff --git gcc/testsuite/g++.dg/cpp2a/range-for3.C gcc/testsuite/g++.dg/cpp2a/range-for3.C index e69de29bb2d..291e605b92f 100644 --- gcc/testsuite/g++.dg/cpp2a/range-for3.C +++ gcc/testsuite/g++.dg/cpp2a/range-for3.C @@ -0,0 +1,26 @@ +// P0614R1 +// { dg-do compile } +// { dg-options "-std=c++2a" } + +static const int a[] = { 1, 2, 3, 4, 5 }; +extern void foo (int); +extern void bar (int, int); + +constexpr int +baz () +{ + return 6; +} + +void +fn1 (int i) +{ + for ((i += 2); auto x : a) + foo (i); + + for (auto j = 0, k = 0; auto x : a) + bar (j + k, x); + + for (constexpr int j = baz (); auto x : a) + bar (x, j); +} diff --git gcc/testsuite/g++.dg/cpp2a/range-for4.C gcc/testsuite/g++.dg/cpp2a/range-for4.C index e69de29bb2d..6ba783f46cb 100644 --- gcc/testsuite/g++.dg/cpp2a/range-for4.C +++ gcc/testsuite/g++.dg/cpp2a/range-for4.C @@ -0,0 +1,27 @@ +// P0614R1 +// { dg-do run } +// { dg-options "-std=c++2a" } + +int +main () +{ + int a[] = { 1, 2, 3, 4, 5 }; + + for (int i = 1; auto x : a) + if (i++ != x) + __builtin_abort (); + + int i; + for (i = 1; auto x : a) + if (i++ != x) + __builtin_abort (); + + i = 0; + for (i++; auto x : a) + if (i != 1) + __builtin_abort (); + + for (int s[] = { 1, 1, 1 }; auto x : s) + if (x != 1) + __builtin_abort (); +} diff --git gcc/testsuite/g++.dg/cpp2a/range-for5.C gcc/testsuite/g++.dg/cpp2a/range-for5.C index e69de29bb2d..62f1c2f04e1 100644 --- gcc/testsuite/g++.dg/cpp2a/range-for5.C +++ gcc/testsuite/g++.dg/cpp2a/range-for5.C @@ -0,0 +1,46 @@ +// P0614R1 +// { dg-do compile } +// { dg-options "-std=c++2a" } + +void +fn1 () +{ + int a[] = { 1, 2, 3, 4, 5 }; + + for (int i = 0; auto x : a) + ++i; + + i = 0; // { dg-error "not declared" } + + for (int i = 0; auto x : a) + { + for (int j = 0; auto x : a) + { + for (int k = 0; auto x : a) + k++; + k++; // { dg-error "not declared" } + } + j++; // { dg-error "not declared" } + } +} + +void +fn2 () +{ + int a[] = { 1, 2, 3, 4, 5 }; + for (int i = 0; auto x : a) + int i = 3; // { dg-error "redeclaration" } +} +void +fn3 () +{ + int a[] = { 1, 2, 3, 4, 5 }; + + for (;:) // { dg-error "expected" } + { + } + + for (;;:) // { dg-error "expected" } + { + } +} diff --git gcc/testsuite/g++.dg/cpp2a/range-for6.C gcc/testsuite/g++.dg/cpp2a/range-for6.C index e69de29bb2d..4cee60a839e 100644 --- gcc/testsuite/g++.dg/cpp2a/range-for6.C +++ gcc/testsuite/g++.dg/cpp2a/range-for6.C @@ -0,0 +1,17 @@ +// P0614R1 +// { dg-do run } +// { dg-options "-std=c++2a" } + +int +main () +{ + int a[] = { 1, 2, 3, 4, 5 }; + + for (int i = []{ return 3; }(); auto x : a) + if (i != 3) + __builtin_abort (); + + for (int i = ({ 3; }); auto x : a) + if (i != 3) + __builtin_abort (); +} diff --git gcc/testsuite/g++.dg/cpp2a/range-for7.C gcc/testsuite/g++.dg/cpp2a/range-for7.C index e69de29bb2d..3c23a77b15e 100644 --- gcc/testsuite/g++.dg/cpp2a/range-for7.C +++ gcc/testsuite/g++.dg/cpp2a/range-for7.C @@ -0,0 +1,23 @@ +// P0614R1 +// { dg-do compile } +// { dg-options "-std=c++2a" } + +extern void bar (int); + +void +fn0 (int n) +{ + int a[] = { 1, 2, 3, 4, 5 }; + + for (int i = 0; n > 0 ? true : false; i++) + bar (i); + + for (int i = n ? 3 : 4; auto x : a) + bar (x); + + for (auto x = n ? 1 : 2 : a) // { dg-error "initializer" } + bar (x); + + for (int i = 1; auto x = n ? 1 : 2 : a) // { dg-error "expected" } + bar (x); +}
The previous version of this patch got confused by for (int i = 0; n > 0 ? true : false; i++) // ... because even though we see a ; followed by a :, it's not a range-based for with an initializer. I find it very strange that this didn't show up during the regtest. To fix this, I had to uglify range_based_for_with_init_p to also check for a ?. Yuck. Bootstrapped/regtested on x86_64-linux, ok for trunk? 2018-05-21 Marek Polacek <polacek@redhat.com> Implement P0614R1, Range-based for statements with initializer. * parser.c (cp_parser_range_based_for_with_init_p): New. (cp_parser_init_statement): Use it. Parse the optional init-statement for a range-based for loop. * g++.dg/cpp2a/range-for1.C: New test. * g++.dg/cpp2a/range-for2.C: New test. * g++.dg/cpp2a/range-for3.C: New test. * g++.dg/cpp2a/range-for4.C: New test. * g++.dg/cpp2a/range-for5.C: New test. * g++.dg/cpp2a/range-for6.C: New test. * g++.dg/cpp2a/range-for7.C: New test. Marek