C99 mode warns about defaulting to int by default, but without the possibility to suppress the warning with -Wno-implicit-int. This is likely to arouse the ire of the users, especially with the new default.
Therefore the following patch tweaks warn_implicit_int in such a way that -Wimplicit and -Wimplicit-int should work as intended (following the rule that more specific option takes precedence over the less specific). There should be no changes in GNU89 mode. Bootstrapped/regtested on x86_64-linux, ok for trunk? 2014-10-17 Marek Polacek <pola...@redhat.com> c-family/ * c-opts.c (c_common_post_options): Set warn_implicit_int. * c.opt (Wimplicit-int): Initialize to -1. c/ * c-decl.c (grokdeclarator): Use OPT_Wimplicit_int unconditionally. (start_function): Use OPT_Wimplicit_int instead of 0. (store_parm_decls_oldstyle): Likewise. testsuite/ * gcc.dg/Wimplicit-int-1.c: New test. * gcc.dg/Wimplicit-int-2.c: New test. * gcc.dg/Wimplicit-int-3.c: New test. * gcc.dg/Wimplicit-int-4.c: New test. diff --git gcc/c-family/c-opts.c gcc/c-family/c-opts.c index eb078e3..448eb3e 100644 --- gcc/c-family/c-opts.c +++ gcc/c-family/c-opts.c @@ -864,6 +864,10 @@ c_common_post_options (const char **pfilename) if (warn_implicit_function_declaration == -1) warn_implicit_function_declaration = flag_isoc99; + /* -Wimplicit-int is enabled by default for C99. */ + if (warn_implicit_int == -1) + warn_implicit_int = flag_isoc99; + /* Declone C++ 'structors if -Os. */ if (flag_declone_ctor_dtor == -1) flag_declone_ctor_dtor = optimize_size; diff --git gcc/c-family/c.opt gcc/c-family/c.opt index 72ac2ed..4f96cf8 100644 --- gcc/c-family/c.opt +++ gcc/c-family/c.opt @@ -488,7 +488,7 @@ C ObjC Var(warn_implicit_function_declaration) Init(-1) Warning LangEnabledBy(C Warn about implicit function declarations Wimplicit-int -C ObjC Var(warn_implicit_int) Warning LangEnabledBy(C ObjC,Wimplicit) +C ObjC Var(warn_implicit_int) Init(-1) Warning LangEnabledBy(C ObjC,Wimplicit) Warn when a declaration does not specify a type Wimport diff --git gcc/c/c-decl.c gcc/c/c-decl.c index 839c67b..b18da48 100644 --- gcc/c/c-decl.c +++ gcc/c/c-decl.c @@ -5330,11 +5330,11 @@ grokdeclarator (const struct c_declarator *declarator, else { if (name) - warn_defaults_to (loc, flag_isoc99 ? 0 : OPT_Wimplicit_int, + warn_defaults_to (loc, OPT_Wimplicit_int, "type defaults to %<int%> in declaration " "of %qE", name); else - warn_defaults_to (loc, flag_isoc99 ? 0 : OPT_Wimplicit_int, + warn_defaults_to (loc, OPT_Wimplicit_int, "type defaults to %<int%> in type name"); } } @@ -8120,7 +8120,7 @@ start_function (struct c_declspecs *declspecs, struct c_declarator *declarator, } if (warn_about_return_type) - warn_defaults_to (loc, flag_isoc99 ? 0 + warn_defaults_to (loc, flag_isoc99 ? OPT_Wimplicit_int : (warn_return_type ? OPT_Wreturn_type : OPT_Wimplicit_int), "return type defaults to %<int%>"); @@ -8429,7 +8429,8 @@ store_parm_decls_oldstyle (tree fndecl, const struct c_arg_info *arg_info) if (flag_isoc99) pedwarn (DECL_SOURCE_LOCATION (decl), - 0, "type of %qD defaults to %<int%>", decl); + OPT_Wimplicit_int, "type of %qD defaults to %<int%>", + decl); else warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wmissing_parameter_type, diff --git gcc/testsuite/gcc.dg/Wimplicit-int-1.c gcc/testsuite/gcc.dg/Wimplicit-int-1.c index e69de29..0c89caf 100644 --- gcc/testsuite/gcc.dg/Wimplicit-int-1.c +++ gcc/testsuite/gcc.dg/Wimplicit-int-1.c @@ -0,0 +1,11 @@ +/* { dg-do compile } */ +/* { dg-options "" } */ + +static l; /* { dg-warning "type defaults to" } */ + +foo (a) /* { dg-warning "return type defaults to" } */ +/* { dg-warning "type of .a. defaults to .int." "type" { target *-*-* } 6 } */ +{ + auto p; /* { dg-warning "type defaults to" } */ + typedef bar; /* { dg-warning "type defaults to" } */ +} diff --git gcc/testsuite/gcc.dg/Wimplicit-int-2.c gcc/testsuite/gcc.dg/Wimplicit-int-2.c index e69de29..158b61c 100644 --- gcc/testsuite/gcc.dg/Wimplicit-int-2.c +++ gcc/testsuite/gcc.dg/Wimplicit-int-2.c @@ -0,0 +1,11 @@ +/* { dg-do compile } */ +/* { dg-options "-pedantic-errors" } */ + +static l; /* { dg-error "type defaults to" } */ + +foo (a) /* { dg-error "return type defaults to" } */ +/* { dg-error "type of .a. defaults to .int." "type" { target *-*-* } 6 } */ +{ + auto p; /* { dg-error "type defaults to" } */ + typedef bar; /* { dg-error "type defaults to" } */ +} diff --git gcc/testsuite/gcc.dg/Wimplicit-int-3.c gcc/testsuite/gcc.dg/Wimplicit-int-3.c index e69de29..654ce73 100644 --- gcc/testsuite/gcc.dg/Wimplicit-int-3.c +++ gcc/testsuite/gcc.dg/Wimplicit-int-3.c @@ -0,0 +1,10 @@ +/* { dg-do compile } */ +/* { dg-options "-pedantic-errors -Wno-implicit-int" } */ + +static l; + +foo (a) +{ + auto p; + typedef bar; +} diff --git gcc/testsuite/gcc.dg/Wimplicit-int-4.c gcc/testsuite/gcc.dg/Wimplicit-int-4.c index e69de29..b2528356 100644 --- gcc/testsuite/gcc.dg/Wimplicit-int-4.c +++ gcc/testsuite/gcc.dg/Wimplicit-int-4.c @@ -0,0 +1,11 @@ +/* { dg-do compile } */ +/* { dg-options "-Wno-implicit -Wimplicit-int" } */ + +static l; /* { dg-warning "type defaults to" } */ + +foo (a) /* { dg-warning "return type defaults to" } */ +/* { dg-warning "type of .a. defaults to .int." "type" { target *-*-* } 6 } */ +{ + auto p; /* { dg-warning "type defaults to" } */ + typedef bar; /* { dg-warning "type defaults to" } */ +} Marek