[This patch assumes the two patches here: https://gcc.gnu.org/ml/gcc-patches/2017-10/msg00274.html ]
c_parser_declaration_or_fndef has logic for parsing what might be either a declaration or a function definition. This patch adds a test to detect cases where a semicolon would have terminated the decls as a declaration, where the token that follows would start a new declaration specifier, and updates the error message accordingly, with a fix-it hint. This addresses PR c/7356, fixing the case of a stray token before a #include which previously gave inscrutable output, and improving e.g.: int i int j; from: t.c:2:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'int' int j; ^~~ to: t.c:1:6: error: expected ';' before 'int' int i ^ ; int j; ~~~ The patch also adds a test for PR c/44515 as a baseline. gcc.dg/noncompile/920923-1.c needs a slight update, as the output for the first line changes from: 920923-1.c:2:14: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'unsigned' typedef BYTE unsigned char; /* { dg-error "expected" } */ ^~~~~~~~ to: 920923-1.c:2:13: error: expected ';' before 'unsigned' typedef BYTE unsigned char; /* { dg-error "expected" } */ ^~~~~~~~~ ; 920923-1.c:2:1: warning: useless type name in empty declaration typedef BYTE unsigned char; /* { dg-error "expected" } */ ^~~~~~~ Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu. OK for trunk? Thanks Dave gcc/c/ChangeLog: PR c/7356 * c-parser.c (c_parser_declaration_or_fndef): Detect missing semicolons. gcc/testsuite/ChangeLog: PR c/7356 PR c/44515 * c-c++-common/pr44515.c: New test case. * gcc.dg/pr7356-2.c: New test case. * gcc.dg/pr7356.c: New test case. * gcc.dg/spellcheck-typenames.c: Update the "singed" char "TODO" case to reflect changes to output. * gcc.dg/noncompile/920923-1.c: Add dg-warning to reflect changes to output. --- gcc/c/c-parser.c | 36 +++++++++++++++++++++++++---- gcc/testsuite/c-c++-common/pr44515.c | 14 +++++++++++ gcc/testsuite/gcc.dg/noncompile/920923-1.c | 1 + gcc/testsuite/gcc.dg/pr7356-2.c | 33 ++++++++++++++++++++++++++ gcc/testsuite/gcc.dg/pr7356.c | 17 ++++++++++++++ gcc/testsuite/gcc.dg/spellcheck-typenames.c | 5 ++-- 6 files changed, 99 insertions(+), 7 deletions(-) create mode 100644 gcc/testsuite/c-c++-common/pr44515.c create mode 100644 gcc/testsuite/gcc.dg/pr7356-2.c create mode 100644 gcc/testsuite/gcc.dg/pr7356.c diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c index a5e3ec4..7c3b834 100644 --- a/gcc/c/c-parser.c +++ b/gcc/c/c-parser.c @@ -2241,11 +2241,37 @@ c_parser_declaration_or_fndef (c_parser *parser, bool fndef_ok, } if (!start_function (specs, declarator, all_prefix_attrs)) { - /* This can appear in many cases looking nothing like a - function definition, so we don't give a more specific - error suggesting there was one. */ - c_parser_error (parser, "expected %<=%>, %<,%>, %<;%>, %<asm%> " - "or %<__attribute__%>"); + /* At this point we've consumed: + declaration-specifiers declarator + and the next token isn't CPP_EQ, CPP_COMMA, CPP_SEMICOLON, + RID_ASM, RID_ATTRIBUTE, or RID_IN, + but the + declaration-specifiers declarator + aren't grokkable as a function definition, so we have + an error. */ + gcc_assert (!c_parser_next_token_is (parser, CPP_SEMICOLON)); + if (c_parser_next_token_starts_declspecs (parser)) + { + /* If we have + declaration-specifiers declarator decl-specs + then assume we have a missing semicolon, which would + give us: + declaration-specifiers declarator decl-specs + ^ + ; + <~~~~~~~~~ declaration ~~~~~~~~~~> + Use c_parser_require to get an error with a fix-it hint. */ + c_parser_require (parser, CPP_SEMICOLON, "expected %<;%>"); + parser->error = false; + } + else + { + /* This can appear in many cases looking nothing like a + function definition, so we don't give a more specific + error suggesting there was one. */ + c_parser_error (parser, "expected %<=%>, %<,%>, %<;%>, %<asm%> " + "or %<__attribute__%>"); + } if (nested) c_pop_function_context (); break; diff --git a/gcc/testsuite/c-c++-common/pr44515.c b/gcc/testsuite/c-c++-common/pr44515.c new file mode 100644 index 0000000..dbb77509 --- /dev/null +++ b/gcc/testsuite/c-c++-common/pr44515.c @@ -0,0 +1,14 @@ +/* { dg-options "-fdiagnostics-show-caret" } */ + +void bar(void); +void foo(void) +{ + bar() /* { dg-error "expected ';' before '.' token" } */ +} +/* { dg-begin-multiline-output "" } + bar() + ^ + ; + } + ~ + { dg-end-multiline-output "" } */ diff --git a/gcc/testsuite/gcc.dg/noncompile/920923-1.c b/gcc/testsuite/gcc.dg/noncompile/920923-1.c index 1cb140e..006a071 100644 --- a/gcc/testsuite/gcc.dg/noncompile/920923-1.c +++ b/gcc/testsuite/gcc.dg/noncompile/920923-1.c @@ -1,5 +1,6 @@ /* { dg-message "undeclared identifier is reported only once" "reminder for mmu_base" { target *-*-* } 0 } */ typedef BYTE unsigned char; /* { dg-error "expected" } */ +/* { dg-warning "useless type name in empty declaration" "" { target *-*-* } .-1 } */ typedef int item_n; typedef int perm_set; struct PENT { caddr_t v_addr; };/* { dg-error "unknown type name" } */ diff --git a/gcc/testsuite/gcc.dg/pr7356-2.c b/gcc/testsuite/gcc.dg/pr7356-2.c new file mode 100644 index 0000000..ad67975 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr7356-2.c @@ -0,0 +1,33 @@ +/* { dg-options "-fdiagnostics-show-caret" } */ + +int i /* { dg-error "6: expected ';' before 'int'" } */ +int j; +/* { dg-begin-multiline-output "" } + int i + ^ + ; + int j; + ~~~ + { dg-end-multiline-output "" } */ + + +void test (void) +{ + int i /* { dg-error "8: expected ';' before 'int'" } */ + int j; + + /* { dg-begin-multiline-output "" } + int i + ^ + ; + int j; + ~~~ + { dg-end-multiline-output "" } */ +} + +int old_style_params (first, second) + int first; + int second; +{ + return first + second; +} diff --git a/gcc/testsuite/gcc.dg/pr7356.c b/gcc/testsuite/gcc.dg/pr7356.c new file mode 100644 index 0000000..84baf07 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr7356.c @@ -0,0 +1,17 @@ +/* { dg-options "-fdiagnostics-show-caret" } */ + +a /* { dg-line stray_token } */ +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +int main(int argc, char** argv) +{ + return 0; +} + +/* { dg-error "expected ';' before '.*'" "" { target *-*-* } stray_token } */ +/* { dg-begin-multiline-output "" } + a + ^ + ; + { dg-end-multiline-output "" } */ diff --git a/gcc/testsuite/gcc.dg/spellcheck-typenames.c b/gcc/testsuite/gcc.dg/spellcheck-typenames.c index f3b8102..3717ad8 100644 --- a/gcc/testsuite/gcc.dg/spellcheck-typenames.c +++ b/gcc/testsuite/gcc.dg/spellcheck-typenames.c @@ -100,8 +100,9 @@ baz value; /* { dg-error "1: unknown type name .baz.; use .enum. keyword to refe { dg-end-multiline-output "" } */ /* TODO: it would be better to detect the "singed" vs "signed" typo here. */ -singed char ch; /* { dg-error "8: before .char." } */ +singed char ch; /* { dg-error "7: before .char." } */ /* { dg-begin-multiline-output "" } singed char ch; - ^~~~ + ^~~~~ + ; { dg-end-multiline-output "" } */ -- 1.8.5.3