[v3,09/11] c: Turn -Wreturn-mismatch into a permerror
Checks
Commit Message
gcc/
* doc/invoke.texi (Warning Options): Document changes.
gcc/c/
PR c/96284
* c-typeck.cc (c_finish_return): Use permerrors
for OPT_Wreturn_mismatch diagnostics.
gcc/testsuite/
* gcc.dg/permerror-default.c (return_mismatch_1)
(return_mismatch_2): Expect new permerror.
* gcc.dg/permerror-gnu89-nopermissive.c (return_mismatch_1):
Likewise.
* gcc.dg/permerror-system.c: Likewise.
* gcc.dg/20030906-1.c: Compile with -fpermissive due to
expected -Wreturn-mismatch error.
* gcc.dg/20030906-1a.c: New test. Copied from
gcc.dg/20030906-1.c. Expect the error.
* gcc.dg/20030906-2.c: Compile with -fpermissive due to
expected -Wreturn-mismatch error.
* gcc.dg/20030906-2a.c: New test. Copied from
gcc.dg/20030906-2.c. Expect the error.
* gcc.dg/Wreturn-mismatch-1.c: Compile with -fpermissive due to
expected -Wreturn-mismatch error.
* gcc.dg/Wreturn-mismatch-1a.c: New test. Copied from
gcc.dg/Wreturn-mismatch-1.c. Expect the error.
* gcc.dg/Wreturn-mismatch-2.c: Compile with -fpermissive due to
expected -Wreturn-mismatch error.
* gcc.dg/Wreturn-mismatch-2a.c: New test. Copied from
gcc.dg/Wreturn-mismatch-2.c. Expect the error.
* gcc.dg/diagnostic-range-bad-return.c: Compile with
-fpermissive due to expected -Wreturn-mismatch error.
* gcc.dg/diagnostic-range-bad-return-2.c: New test.
Copied from gcc.dg/diagnostic-range-bad-return.c. Expect the
error.
* gcc.dg/pr105635-2.c: Expect -Wreturn-mismatch error.
* gcc.dg/pr23075.c: Build with -fpermissive due to
expected -Wreturn-mismatch error.
* gcc.dg/pr23075-2.c: New test. Copied from gcc.dg/pr23075.c.
Expect the error.
* gcc.dg/pr29521.c: Compile with -fpermissive due to expected
-Wreturn-mismatch error.
* gcc.dg/pr29521-a.c: New test. Copied from gcc.dg/pr29521.c.
Expect error.
* gcc.dg/pr67730.c: Compile with -fpermissive due to expected
-Wreturn-mismatch error.
* gcc.dg/pr67730-a.c: New test. Copied from
gcc.dg/pr67730-a.c. Expect error.
* gcc.target/powerpc/conditional-return.c: Compile with
-fpermissive due to expected -Wreturn-mismatch error.
---
gcc/c/c-typeck.cc | 4 +-
gcc/doc/invoke.texi | 6 ++-
gcc/testsuite/gcc.dg/20030906-1.c | 2 +-
gcc/testsuite/gcc.dg/20030906-1a.c | 21 ++++++++
gcc/testsuite/gcc.dg/20030906-2.c | 2 +-
gcc/testsuite/gcc.dg/20030906-2a.c | 21 ++++++++
gcc/testsuite/gcc.dg/Wreturn-mismatch-1.c | 2 +-
gcc/testsuite/gcc.dg/Wreturn-mismatch-1a.c | 40 ++++++++++++++
gcc/testsuite/gcc.dg/Wreturn-mismatch-2.c | 2 +-
gcc/testsuite/gcc.dg/Wreturn-mismatch-2a.c | 41 +++++++++++++++
.../gcc.dg/diagnostic-range-bad-return-2.c | 52 +++++++++++++++++++
.../gcc.dg/diagnostic-range-bad-return.c | 2 +-
gcc/testsuite/gcc.dg/permerror-default.c | 4 +-
.../gcc.dg/permerror-gnu89-nopermissive.c | 2 +-
gcc/testsuite/gcc.dg/permerror-system.c | 3 ++
gcc/testsuite/gcc.dg/pr105635-2.c | 2 +-
gcc/testsuite/gcc.dg/pr23075-2.c | 14 +++++
gcc/testsuite/gcc.dg/pr23075.c | 2 +-
gcc/testsuite/gcc.dg/pr29521-a.c | 15 ++++++
gcc/testsuite/gcc.dg/pr29521.c | 2 +-
gcc/testsuite/gcc.dg/pr67730-a.c | 11 ++++
gcc/testsuite/gcc.dg/pr67730.c | 2 +-
.../gcc.target/powerpc/conditional-return.c | 2 +-
23 files changed, 238 insertions(+), 16 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/20030906-1a.c
create mode 100644 gcc/testsuite/gcc.dg/20030906-2a.c
create mode 100644 gcc/testsuite/gcc.dg/Wreturn-mismatch-1a.c
create mode 100644 gcc/testsuite/gcc.dg/Wreturn-mismatch-2a.c
create mode 100644 gcc/testsuite/gcc.dg/diagnostic-range-bad-return-2.c
create mode 100644 gcc/testsuite/gcc.dg/pr23075-2.c
create mode 100644 gcc/testsuite/gcc.dg/pr29521-a.c
create mode 100644 gcc/testsuite/gcc.dg/pr67730-a.c
Comments
On Mon, Nov 20, 2023 at 10:56:30AM +0100, Florian Weimer wrote:
> gcc/
>
> * doc/invoke.texi (Warning Options): Document changes.
That's pretty vague :). How about "Document that -Wreturn-mismatch is a
permerror in C99."?
> gcc/c/
>
> PR c/96284
> * c-typeck.cc (c_finish_return): Use permerrors
> for OPT_Wreturn_mismatch diagnostics.
>
> gcc/testsuite/
>
> * gcc.dg/permerror-default.c (return_mismatch_1)
> (return_mismatch_2): Expect new permerror.
> * gcc.dg/permerror-gnu89-nopermissive.c (return_mismatch_1):
> Likewise.
> * gcc.dg/permerror-system.c: Likewise.
> * gcc.dg/20030906-1.c: Compile with -fpermissive due to
> expected -Wreturn-mismatch error.
> * gcc.dg/20030906-1a.c: New test. Copied from
> gcc.dg/20030906-1.c. Expect the error.
> * gcc.dg/20030906-2.c: Compile with -fpermissive due to
> expected -Wreturn-mismatch error.
> * gcc.dg/20030906-2a.c: New test. Copied from
> gcc.dg/20030906-2.c. Expect the error.
> * gcc.dg/Wreturn-mismatch-1.c: Compile with -fpermissive due to
> expected -Wreturn-mismatch error.
> * gcc.dg/Wreturn-mismatch-1a.c: New test. Copied from
> gcc.dg/Wreturn-mismatch-1.c. Expect the error.
> * gcc.dg/Wreturn-mismatch-2.c: Compile with -fpermissive due to
> expected -Wreturn-mismatch error.
> * gcc.dg/Wreturn-mismatch-2a.c: New test. Copied from
> gcc.dg/Wreturn-mismatch-2.c. Expect the error.
> * gcc.dg/diagnostic-range-bad-return.c: Compile with
> -fpermissive due to expected -Wreturn-mismatch error.
> * gcc.dg/diagnostic-range-bad-return-2.c: New test.
> Copied from gcc.dg/diagnostic-range-bad-return.c. Expect the
> error.
> * gcc.dg/pr105635-2.c: Expect -Wreturn-mismatch error.
> * gcc.dg/pr23075.c: Build with -fpermissive due to
> expected -Wreturn-mismatch error.
> * gcc.dg/pr23075-2.c: New test. Copied from gcc.dg/pr23075.c.
> Expect the error.
> * gcc.dg/pr29521.c: Compile with -fpermissive due to expected
> -Wreturn-mismatch error.
> * gcc.dg/pr29521-a.c: New test. Copied from gcc.dg/pr29521.c.
> Expect error.
> * gcc.dg/pr67730.c: Compile with -fpermissive due to expected
> -Wreturn-mismatch error.
> * gcc.dg/pr67730-a.c: New test. Copied from
> gcc.dg/pr67730-a.c. Expect error.
> * gcc.target/powerpc/conditional-return.c: Compile with
> -fpermissive due to expected -Wreturn-mismatch error.
There seem to be some extra whitespaces after "expected".
> ---
> gcc/c/c-typeck.cc | 4 +-
> gcc/doc/invoke.texi | 6 ++-
> gcc/testsuite/gcc.dg/20030906-1.c | 2 +-
> gcc/testsuite/gcc.dg/20030906-1a.c | 21 ++++++++
> gcc/testsuite/gcc.dg/20030906-2.c | 2 +-
> gcc/testsuite/gcc.dg/20030906-2a.c | 21 ++++++++
> gcc/testsuite/gcc.dg/Wreturn-mismatch-1.c | 2 +-
> gcc/testsuite/gcc.dg/Wreturn-mismatch-1a.c | 40 ++++++++++++++
> gcc/testsuite/gcc.dg/Wreturn-mismatch-2.c | 2 +-
> gcc/testsuite/gcc.dg/Wreturn-mismatch-2a.c | 41 +++++++++++++++
> .../gcc.dg/diagnostic-range-bad-return-2.c | 52 +++++++++++++++++++
> .../gcc.dg/diagnostic-range-bad-return.c | 2 +-
> gcc/testsuite/gcc.dg/permerror-default.c | 4 +-
> .../gcc.dg/permerror-gnu89-nopermissive.c | 2 +-
> gcc/testsuite/gcc.dg/permerror-system.c | 3 ++
> gcc/testsuite/gcc.dg/pr105635-2.c | 2 +-
> gcc/testsuite/gcc.dg/pr23075-2.c | 14 +++++
> gcc/testsuite/gcc.dg/pr23075.c | 2 +-
> gcc/testsuite/gcc.dg/pr29521-a.c | 15 ++++++
> gcc/testsuite/gcc.dg/pr29521.c | 2 +-
> gcc/testsuite/gcc.dg/pr67730-a.c | 11 ++++
> gcc/testsuite/gcc.dg/pr67730.c | 2 +-
> .../gcc.target/powerpc/conditional-return.c | 2 +-
> 23 files changed, 238 insertions(+), 16 deletions(-)
> create mode 100644 gcc/testsuite/gcc.dg/20030906-1a.c
> create mode 100644 gcc/testsuite/gcc.dg/20030906-2a.c
> create mode 100644 gcc/testsuite/gcc.dg/Wreturn-mismatch-1a.c
> create mode 100644 gcc/testsuite/gcc.dg/Wreturn-mismatch-2a.c
> create mode 100644 gcc/testsuite/gcc.dg/diagnostic-range-bad-return-2.c
> create mode 100644 gcc/testsuite/gcc.dg/pr23075-2.c
> create mode 100644 gcc/testsuite/gcc.dg/pr29521-a.c
> create mode 100644 gcc/testsuite/gcc.dg/pr67730-a.c
>
> diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
> index c7b35a27e3f..f4b700117ff 100644
> --- a/gcc/c/c-typeck.cc
> +++ b/gcc/c/c-typeck.cc
> @@ -11205,7 +11205,7 @@ c_finish_return (location_t loc, tree retval, tree origtype)
> && valtype != NULL_TREE && TREE_CODE (valtype) != VOID_TYPE)
> {
> no_warning = true;
> - if (emit_diagnostic (flag_isoc99 ? DK_PEDWARN : DK_WARNING,
> + if (emit_diagnostic (flag_isoc99 ? DK_PERMERROR : DK_WARNING,
> loc, OPT_Wreturn_mismatch,
> "%<return%> with no value,"
> " in function returning non-void"))
> @@ -11218,7 +11218,7 @@ c_finish_return (location_t loc, tree retval, tree origtype)
> current_function_returns_null = 1;
> bool warned_here;
> if (TREE_CODE (TREE_TYPE (retval)) != VOID_TYPE)
> - warned_here = pedwarn
> + warned_here = permerror_opt
> (xloc, OPT_Wreturn_mismatch,
> "%<return%> with a value, in function returning void");
> else
> diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
> index eb7417fd9be..831242d134b 100644
> --- a/gcc/doc/invoke.texi
> +++ b/gcc/doc/invoke.texi
> @@ -6185,6 +6185,7 @@ that have their own flag:
> -Wimplicit-int @r{(C)}
> -Wint-conversion @r{(C)}
> -Wnarrowing @r{(C++)}
> +-Wreturn-mismatch @r{(C)}
> }
>
> The @option{-fpermissive} option is the default for historic C language
> @@ -7375,7 +7376,10 @@ Attempting to use the return value of a non-@code{void} function other
> than @code{main} that flows off the end by reaching the closing curly
> brace that terminates the function is undefined.
>
> -This warning is specific to C and enabled by default.
> +This warning is specific to C and enabled by default. In C99 and later
> +language dialects, it is treated as an error. It an be downgraded
an -> can
> +to a warning using @option{-fpermissive} (along with other warnings),
> +or for just this warning, with @option{-Wno-error=return-mismatch}.
>
> @opindex Wreturn-type
> @opindex Wno-return-type
> diff --git a/gcc/testsuite/gcc.dg/20030906-1.c b/gcc/testsuite/gcc.dg/20030906-1.c
> index c416f55ee75..6ba5b3d770a 100644
> --- a/gcc/testsuite/gcc.dg/20030906-1.c
> +++ b/gcc/testsuite/gcc.dg/20030906-1.c
> @@ -2,7 +2,7 @@
> Copyright (C) 2003 Free Software Foundation Inc. */
>
> /* { dg-do compile } */
> -/* { dg-options "-O -finline-functions -Wreturn-type" } */
> +/* { dg-options "-fpermissive -O -finline-functions -Wreturn-type" } */
>
> extern int i;
> extern int foo (void);
> diff --git a/gcc/testsuite/gcc.dg/20030906-1a.c b/gcc/testsuite/gcc.dg/20030906-1a.c
> new file mode 100644
> index 00000000000..46ca1771a4d
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/20030906-1a.c
> @@ -0,0 +1,21 @@
> +/* Bug 9862 -- Spurious warnings with -finline-functions.
> + Copyright (C) 2003 Free Software Foundation Inc. */
> +
> +/* { dg-do compile } */
> +/* { dg-options "-O -finline-functions -Wreturn-type" } */
> +
> +extern int i;
> +extern int foo (void);
> +extern int bar (void);
> +
> +int foo (void)
> +{
> + if( i ) return 0;
> + else return 1;
> +}
> +
> +int bar (void)
> +{
> + if( i ) return; /* { dg-error "'return' with no value, in function returning non-void" } */
> + else return 1;
> +}
> diff --git a/gcc/testsuite/gcc.dg/20030906-2.c b/gcc/testsuite/gcc.dg/20030906-2.c
> index 1191133e6a0..a85d91f46f3 100644
> --- a/gcc/testsuite/gcc.dg/20030906-2.c
> +++ b/gcc/testsuite/gcc.dg/20030906-2.c
> @@ -2,7 +2,7 @@
> Copyright (C) 2003 Free Software Foundation Inc. */
>
> /* { dg-do compile } */
> -/* { dg-options "-O -finline-functions -Wreturn-type" } */
> +/* { dg-options "-fpermissive -O -finline-functions -Wreturn-type" } */
>
> extern int i;
> extern int foo (void);
> diff --git a/gcc/testsuite/gcc.dg/20030906-2a.c b/gcc/testsuite/gcc.dg/20030906-2a.c
> new file mode 100644
> index 00000000000..a6ffbacb46d
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/20030906-2a.c
> @@ -0,0 +1,21 @@
> +/* Bug 9862 -- Spurious warnings with -finline-functions.
> + Copyright (C) 2003 Free Software Foundation Inc. */
> +
> +/* { dg-do compile } */
> +/* { dg-options "-O -finline-functions -Wreturn-type" } */
> +
> +extern int i;
> +extern int foo (void);
> +extern int bar (void);
> +
> +int foo (void)
> +{
> + if( i ) return; /* { dg-error "'return' with no value, in function returning non-void" } */
> + else return 1;
> +}
> +
> +int bar (void)
> +{
> + if( i ) return 0;
> + else return 1;
> +}
> diff --git a/gcc/testsuite/gcc.dg/Wreturn-mismatch-1.c b/gcc/testsuite/gcc.dg/Wreturn-mismatch-1.c
> index 3bad847ecf7..aef6782cbeb 100644
> --- a/gcc/testsuite/gcc.dg/Wreturn-mismatch-1.c
> +++ b/gcc/testsuite/gcc.dg/Wreturn-mismatch-1.c
> @@ -1,5 +1,5 @@
> /* { dg-do compile } */
> -/* { dg-options "" } */
> +/* { dg-options "-fpermissive" } */
>
> void f1 (void);
>
> diff --git a/gcc/testsuite/gcc.dg/Wreturn-mismatch-1a.c b/gcc/testsuite/gcc.dg/Wreturn-mismatch-1a.c
> new file mode 100644
> index 00000000000..70c7c9ddb86
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/Wreturn-mismatch-1a.c
> @@ -0,0 +1,40 @@
> +/* { dg-do compile } */
> +/* { dg-options "" } */
> +
> +void f1 (void);
> +
> +int
> +f2 (void)
> +{
> + f1 ();
> +}
> +
> +static inline int
> +f3 (void)
> +{
> + f1 ();
> +}
> +
> +void
> +f4 (void)
> +{
> + return 1; /* { dg-error "'return' with a value\[^\n\r\]*-Wreturn-mismatch" } */
> +}
> +
> +void
> +f5 (void)
> +{
> + return f1 (); /* { dg-bogus "ISO C" } */
> +}
> +
> +int
> +f6 (void)
> +{
> + return; /* { dg-error "'return' with no value\[^\n\r\]*-Wreturn-mismatch" } */
> +}
> +
> +int
> +f7 (void)
> +{
> + return f1 (); /* { dg-error "void value not ignored as it ought to be" } */
> +}
> diff --git a/gcc/testsuite/gcc.dg/Wreturn-mismatch-2.c b/gcc/testsuite/gcc.dg/Wreturn-mismatch-2.c
> index 49eb5a5a95c..08811024b7e 100644
> --- a/gcc/testsuite/gcc.dg/Wreturn-mismatch-2.c
> +++ b/gcc/testsuite/gcc.dg/Wreturn-mismatch-2.c
> @@ -1,5 +1,5 @@
> /* { dg-do compile } */
> -/* { dg-options "-Wall" } */
> +/* { dg-options "-fpermissive -Wall" } */
>
> void f1 (void);
>
> diff --git a/gcc/testsuite/gcc.dg/Wreturn-mismatch-2a.c b/gcc/testsuite/gcc.dg/Wreturn-mismatch-2a.c
> new file mode 100644
> index 00000000000..836651ed925
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/Wreturn-mismatch-2a.c
> @@ -0,0 +1,41 @@
> +/* { dg-do compile } */
> +/* { dg-options "-Wall" } */
> +
> +void f1 (void);
> +
> +int
> +f2 (void)
> +{
> + f1 ();
> +} /* { dg-warning "control reaches end of non-void\[^\n\r\]*-Wreturn-type" } */
> +
> +static inline int
> +f3 (void)
> +{
> + f1 ();
> +} /* { dg-warning "no return statement in function\[^\n\r\]*-Wreturn-type" } */
> +
> +void
> +f4 (void)
> +{
> + return 1; /* { dg-error "with a value,\[^\n\r\]*-Wreturn-mismatch" } */
> +}
> +
> +void
> +f5 (void)
> +{
> + return f1 ();
> +}
> +
> +int
> +f6 (void)
> +{
> + return; /* { dg-error "with no value,\[^\n\r\]*Wreturn-mismatch" } */
> +}
> +
> +int
> +f7 (void)
> +{
> + return f1 (); /* { dg-error "void value not ignored as it ought to be" } */
> +} /* { dg-warning "control reaches end of non-void\[^\n\r\]*-Wreturn-type" } */
> +
> diff --git a/gcc/testsuite/gcc.dg/diagnostic-range-bad-return-2.c b/gcc/testsuite/gcc.dg/diagnostic-range-bad-return-2.c
> new file mode 100644
> index 00000000000..2fe8d341dba
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/diagnostic-range-bad-return-2.c
> @@ -0,0 +1,52 @@
> +/* { dg-options "-fdiagnostics-show-caret -Wreturn-local-addr" } */
> +
> +int *address_of_local (void)
> +{
> + int some_local;
> + return &some_local; /* { dg-warning "function returns address of local variable" } */
> +/* { dg-begin-multiline-output "" }
> + return &some_local;
> + ^~~~~~~~~~~
> + { dg-end-multiline-output "" } */
> +}
> +
> +void surplus_return_when_void_1 (void)
> +{
> + return 500; /* { dg-error "'return' with a value, in function returning void" } */
> +/* { dg-begin-multiline-output "" }
> + return 500;
> + ^~~
> + { dg-end-multiline-output "" } */
> +/* { dg-begin-multiline-output "" }
> + void surplus_return_when_void_1 (void)
> + ^~~~~~~~~~~~~~~~~~~~~~~~~~
> + { dg-end-multiline-output "" } */
> +}
> +
> +void surplus_return_when_void_2 (int i, int j)
> +{
> + return i * j; /* { dg-error "'return' with a value, in function returning void" } */
> +/* { dg-begin-multiline-output "" }
> + return i * j;
> + ~~^~~
> + { dg-end-multiline-output "" } */
> +/* { dg-begin-multiline-output "" }
> + void surplus_return_when_void_2 (int i, int j)
> + ^~~~~~~~~~~~~~~~~~~~~~~~~~
> + { dg-end-multiline-output "" } */
> +}
> +
> +int missing_return_value (void)
> +{
> + return; /* { dg-error "'return' with no value, in function returning non-void" } */
> +/* { dg-begin-multiline-output "" }
> + return;
> + ^~~~~~
> + { dg-end-multiline-output "" } */
> +/* { dg-begin-multiline-output "" }
> + int missing_return_value (void)
> + ^~~~~~~~~~~~~~~~~~~~
> + { dg-end-multiline-output "" } */
> +/* TODO: ideally we'd underline the return type i.e. "int", but that
> + location isn't captured. */
> +}
> diff --git a/gcc/testsuite/gcc.dg/diagnostic-range-bad-return.c b/gcc/testsuite/gcc.dg/diagnostic-range-bad-return.c
> index 063fdf1f636..b74481b870c 100644
> --- a/gcc/testsuite/gcc.dg/diagnostic-range-bad-return.c
> +++ b/gcc/testsuite/gcc.dg/diagnostic-range-bad-return.c
> @@ -1,4 +1,4 @@
> -/* { dg-options "-fdiagnostics-show-caret -Wreturn-local-addr" } */
> +/* { dg-options "-fpermissive -fdiagnostics-show-caret -Wreturn-local-addr" } */
>
> int *address_of_local (void)
> {
> diff --git a/gcc/testsuite/gcc.dg/permerror-default.c b/gcc/testsuite/gcc.dg/permerror-default.c
> index 90f2220037c..9ed9814d69e 100644
> --- a/gcc/testsuite/gcc.dg/permerror-default.c
> +++ b/gcc/testsuite/gcc.dg/permerror-default.c
> @@ -75,11 +75,11 @@ incompatible_pointer_types (int flag)
> void
> return_mismatch_1 (void)
> {
> - return 0; /* { dg-warning "'return' with a value, in function returning void \\\[-Wreturn-mismatch\\\]" } */
> + return 0; /* { dg-error "'return' with a value, in function returning void \\\[-Wreturn-mismatch\\\]" } */
> }
>
> int
> return_mismatch_2 (void)
> {
> - return; /* { dg-warning "return' with no value, in function returning non-void \\\[-Wreturn-mismatch\\\]" } */
> + return; /* { dg-error "return' with no value, in function returning non-void \\\[-Wreturn-mismatch\\\]" } */
> }
> diff --git a/gcc/testsuite/gcc.dg/permerror-gnu89-nopermissive.c b/gcc/testsuite/gcc.dg/permerror-gnu89-nopermissive.c
> index 0780e42b5cc..dc282a44489 100644
> --- a/gcc/testsuite/gcc.dg/permerror-gnu89-nopermissive.c
> +++ b/gcc/testsuite/gcc.dg/permerror-gnu89-nopermissive.c
> @@ -75,7 +75,7 @@ incompatible_pointer_types (int flag)
> void
> return_mismatch_1 (void)
> {
> - return 0; /* { dg-warning "'return' with a value, in function returning void \\\[-Wreturn-mismatch\\\]" } */
> + return 0; /* { dg-error "'return' with a value, in function returning void \\\[-Wreturn-mismatch\\\]" } */
> }
>
> int
> diff --git a/gcc/testsuite/gcc.dg/permerror-system.c b/gcc/testsuite/gcc.dg/permerror-system.c
> index cad48c93f90..f00420358d9 100644
> --- a/gcc/testsuite/gcc.dg/permerror-system.c
> +++ b/gcc/testsuite/gcc.dg/permerror-system.c
> @@ -27,3 +27,6 @@
> /* { dg-error "initialization of 'int \\\*' from 'int' makes pointer from integer without a cast \\\[-Wint-conversion\\\]" "" { target *-*-* } 45 } */
> /* { dg-error "assignment to 'int \\\*' from 'int' makes pointer from integer without a cast \\\[-Wint-conversion\\\]" "" { target *-*-* } 46 } */
> /* { dg-error "returning 'int \\\*' from a function with return type 'int' makes integer from pointer without a cast \\\[-Wint-conversion\\\]" "" { target *-*-* } 48 } */
> +
> +/* { dg-error "'return' with a value, in function returning void \\\[-Wreturn-mismatch\\\]" "" { target *-*-* } 78 } */
> +/* { dg-error "return' with no value, in function returning non-void \\\[-Wreturn-mismatch\\\]" "" { target *-*-* } 84 } */
You may want to use 'return' here too (as in, add the leading ').
> diff --git a/gcc/testsuite/gcc.dg/pr105635-2.c b/gcc/testsuite/gcc.dg/pr105635-2.c
> index 807eef0b7cd..019dbc7e557 100644
> --- a/gcc/testsuite/gcc.dg/pr105635-2.c
> +++ b/gcc/testsuite/gcc.dg/pr105635-2.c
> @@ -7,5 +7,5 @@ void foo (int, int[*]); /* { dg-message "previous declaration of 'foo' with type
> foo (int x, int y) /* { dg-error "return type defaults to 'int'" } */
> { /* { dg-warning "conflicting types for 'foo'" "" { target *-*-* } .-1 } */
> /* { dg-message "declared here" "" { target *-*-* } .-2 } */
> - return (x >= 0) != (y < 0); /* { dg-warning "'return' with a value, in function returning void" } */
> + return (x >= 0) != (y < 0); /* { dg-error "'return' with a value, in function returning void" } */
> }
> diff --git a/gcc/testsuite/gcc.dg/pr23075-2.c b/gcc/testsuite/gcc.dg/pr23075-2.c
> new file mode 100644
> index 00000000000..0702ddf1a66
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr23075-2.c
> @@ -0,0 +1,14 @@
> +/* PR c/23075 */
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -Wreturn-type" } */
> +
> +int
> +foo (void)
> +{
> + return; /* { dg-error "with no value" } */
> +} /* { dg-bogus "control reaches end" } */
> +
> +int
> +bar (void)
> +{
> +} /* { dg-warning "control reaches end" } */
> diff --git a/gcc/testsuite/gcc.dg/pr23075.c b/gcc/testsuite/gcc.dg/pr23075.c
> index 2d85fb0650f..28baf41006a 100644
> --- a/gcc/testsuite/gcc.dg/pr23075.c
> +++ b/gcc/testsuite/gcc.dg/pr23075.c
> @@ -1,6 +1,6 @@
> /* PR c/23075 */
> /* { dg-do compile } */
> -/* { dg-options "-O2 -Wreturn-type" } */
> +/* { dg-options "-O2 -fpermissive -Wreturn-type" } */
>
> int
> foo (void)
> diff --git a/gcc/testsuite/gcc.dg/pr29521-a.c b/gcc/testsuite/gcc.dg/pr29521-a.c
> new file mode 100644
> index 00000000000..2c6a48b7e30
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr29521-a.c
> @@ -0,0 +1,15 @@
> +/* PR 29521 : warning for return with expression in function returning void */
> +/* { dg-do compile } */
> +/* { dg-options "" } */
> +
> +void func (void) { }
> +
> +void func2 (void)
> +{
> + return func ();
> +}
> +
> +void func3 (void)
> +{
> + return 1; /* { dg-error "'return' with a value" } */
> +}
> diff --git a/gcc/testsuite/gcc.dg/pr29521.c b/gcc/testsuite/gcc.dg/pr29521.c
> index b6fb535fab7..cd431514ed2 100644
> --- a/gcc/testsuite/gcc.dg/pr29521.c
> +++ b/gcc/testsuite/gcc.dg/pr29521.c
> @@ -1,6 +1,6 @@
> /* PR 29521 : warning for return with expression in function returning void */
> /* { dg-do compile } */
> -/* { dg-options "" } */
> +/* { dg-options "-fpermissive" } */
>
> void func (void) { }
>
> diff --git a/gcc/testsuite/gcc.dg/pr67730-a.c b/gcc/testsuite/gcc.dg/pr67730-a.c
> new file mode 100644
> index 00000000000..08737cc9811
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr67730-a.c
> @@ -0,0 +1,11 @@
> +/* PR c/67730 */
> +/* { dg-do compile } */
> +/* { dg-options "" } */
> +
> +#include <stddef.h>
> +
> +void
> +fn1 (void)
> +{
> + return NULL; /* { dg-error "10:.return. with a value" } */
> +}
> diff --git a/gcc/testsuite/gcc.dg/pr67730.c b/gcc/testsuite/gcc.dg/pr67730.c
> index 54d73a62cf8..cc51858c531 100644
> --- a/gcc/testsuite/gcc.dg/pr67730.c
> +++ b/gcc/testsuite/gcc.dg/pr67730.c
> @@ -1,6 +1,6 @@
> /* PR c/67730 */
> /* { dg-do compile } */
> -/* { dg-options "" } */
> +/* { dg-options "-fpermissive" } */
>
> #include <stddef.h>
>
> diff --git a/gcc/testsuite/gcc.target/powerpc/conditional-return.c b/gcc/testsuite/gcc.target/powerpc/conditional-return.c
> index 6b3ef5f52ca..c6491216752 100644
> --- a/gcc/testsuite/gcc.target/powerpc/conditional-return.c
> +++ b/gcc/testsuite/gcc.target/powerpc/conditional-return.c
> @@ -1,7 +1,7 @@
> /* Check that a conditional return is used. */
>
> /* { dg-do compile } */
> -/* { dg-options "-O2 -w" } */
> +/* { dg-options "-O2 -fpermissive -w" } */
>
> /* { dg-final { scan-assembler {\mbeqlr\M} } } */
>
These seem fine.
Should we have a test for -Wno-error=return-mismatch and -Wno-return-mismatch?
I didn't see those.
Marek
* Marek Polacek:
> On Mon, Nov 20, 2023 at 10:56:30AM +0100, Florian Weimer wrote:
>> gcc/
>>
>> * doc/invoke.texi (Warning Options): Document changes.
>
> That's pretty vague :). How about "Document that -Wreturn-mismatch is a
> permerror in C99."?
Applied (with “in C99 and later”).
>> * gcc.target/powerpc/conditional-return.c: Compile with
>> -fpermissive due to expected -Wreturn-mismatch error.
>
> There seem to be some extra whitespaces after "expected".
Fixed.
>> @@ -7375,7 +7376,10 @@ Attempting to use the return value of a non-@code{void} function other
>> than @code{main} that flows off the end by reaching the closing curly
>> brace that terminates the function is undefined.
>>
>> -This warning is specific to C and enabled by default.
>> +This warning is specific to C and enabled by default. In C99 and later
>> +language dialects, it is treated as an error. It an be downgraded
>
> an -> can
Fixed.
>> diff --git a/gcc/testsuite/gcc.target/powerpc/conditional-return.c b/gcc/testsuite/gcc.target/powerpc/conditional-return.c
>> index 6b3ef5f52ca..c6491216752 100644
>> --- a/gcc/testsuite/gcc.target/powerpc/conditional-return.c
>> +++ b/gcc/testsuite/gcc.target/powerpc/conditional-return.c
>> @@ -1,7 +1,7 @@
>> /* Check that a conditional return is used. */
>>
>> /* { dg-do compile } */
>> -/* { dg-options "-O2 -w" } */
>> +/* { dg-options "-O2 -fpermissive -w" } */
>>
>> /* { dg-final { scan-assembler {\mbeqlr\M} } } */
>>
>
> These seem fine.
>
> Should we have a test for -Wno-error=return-mismatch and -Wno-return-mismatch?
> I didn't see those.
See gcc/testsuite/gcc.dg/permerror-noerror.c and
gcc/testsuite/gcc.dg/permerror-nowarning.c. They don't show up in the
patch because the diagnostics don't change.
Thanks,
Florian
On Thu, Nov 23, 2023 at 07:22:58PM +0100, Florian Weimer wrote:
> * Marek Polacek:
>
> > On Mon, Nov 20, 2023 at 10:56:30AM +0100, Florian Weimer wrote:
> >> gcc/
> >>
> >> * doc/invoke.texi (Warning Options): Document changes.
> >
> > That's pretty vague :). How about "Document that -Wreturn-mismatch is a
> > permerror in C99."?
>
> Applied (with “in C99 and later”).
>
> >> * gcc.target/powerpc/conditional-return.c: Compile with
> >> -fpermissive due to expected -Wreturn-mismatch error.
> >
> > There seem to be some extra whitespaces after "expected".
>
> Fixed.
>
> >> @@ -7375,7 +7376,10 @@ Attempting to use the return value of a non-@code{void} function other
> >> than @code{main} that flows off the end by reaching the closing curly
> >> brace that terminates the function is undefined.
> >>
> >> -This warning is specific to C and enabled by default.
> >> +This warning is specific to C and enabled by default. In C99 and later
> >> +language dialects, it is treated as an error. It an be downgraded
> >
> > an -> can
>
> Fixed.
>
> >> diff --git a/gcc/testsuite/gcc.target/powerpc/conditional-return.c b/gcc/testsuite/gcc.target/powerpc/conditional-return.c
> >> index 6b3ef5f52ca..c6491216752 100644
> >> --- a/gcc/testsuite/gcc.target/powerpc/conditional-return.c
> >> +++ b/gcc/testsuite/gcc.target/powerpc/conditional-return.c
> >> @@ -1,7 +1,7 @@
> >> /* Check that a conditional return is used. */
> >>
> >> /* { dg-do compile } */
> >> -/* { dg-options "-O2 -w" } */
> >> +/* { dg-options "-O2 -fpermissive -w" } */
> >>
> >> /* { dg-final { scan-assembler {\mbeqlr\M} } } */
> >>
> >
> > These seem fine.
> >
> > Should we have a test for -Wno-error=return-mismatch and -Wno-return-mismatch?
> > I didn't see those.
>
> See gcc/testsuite/gcc.dg/permerror-noerror.c and
> gcc/testsuite/gcc.dg/permerror-nowarning.c. They don't show up in the
> patch because the diagnostics don't change.
Ah, I see that now. This patch is OK then. Thanks.
Marek
@@ -11205,7 +11205,7 @@ c_finish_return (location_t loc, tree retval, tree origtype)
&& valtype != NULL_TREE && TREE_CODE (valtype) != VOID_TYPE)
{
no_warning = true;
- if (emit_diagnostic (flag_isoc99 ? DK_PEDWARN : DK_WARNING,
+ if (emit_diagnostic (flag_isoc99 ? DK_PERMERROR : DK_WARNING,
loc, OPT_Wreturn_mismatch,
"%<return%> with no value,"
" in function returning non-void"))
@@ -11218,7 +11218,7 @@ c_finish_return (location_t loc, tree retval, tree origtype)
current_function_returns_null = 1;
bool warned_here;
if (TREE_CODE (TREE_TYPE (retval)) != VOID_TYPE)
- warned_here = pedwarn
+ warned_here = permerror_opt
(xloc, OPT_Wreturn_mismatch,
"%<return%> with a value, in function returning void");
else
@@ -6185,6 +6185,7 @@ that have their own flag:
-Wimplicit-int @r{(C)}
-Wint-conversion @r{(C)}
-Wnarrowing @r{(C++)}
+-Wreturn-mismatch @r{(C)}
}
The @option{-fpermissive} option is the default for historic C language
@@ -7375,7 +7376,10 @@ Attempting to use the return value of a non-@code{void} function other
than @code{main} that flows off the end by reaching the closing curly
brace that terminates the function is undefined.
-This warning is specific to C and enabled by default.
+This warning is specific to C and enabled by default. In C99 and later
+language dialects, it is treated as an error. It an be downgraded
+to a warning using @option{-fpermissive} (along with other warnings),
+or for just this warning, with @option{-Wno-error=return-mismatch}.
@opindex Wreturn-type
@opindex Wno-return-type
@@ -2,7 +2,7 @@
Copyright (C) 2003 Free Software Foundation Inc. */
/* { dg-do compile } */
-/* { dg-options "-O -finline-functions -Wreturn-type" } */
+/* { dg-options "-fpermissive -O -finline-functions -Wreturn-type" } */
extern int i;
extern int foo (void);
new file mode 100644
@@ -0,0 +1,21 @@
+/* Bug 9862 -- Spurious warnings with -finline-functions.
+ Copyright (C) 2003 Free Software Foundation Inc. */
+
+/* { dg-do compile } */
+/* { dg-options "-O -finline-functions -Wreturn-type" } */
+
+extern int i;
+extern int foo (void);
+extern int bar (void);
+
+int foo (void)
+{
+ if( i ) return 0;
+ else return 1;
+}
+
+int bar (void)
+{
+ if( i ) return; /* { dg-error "'return' with no value, in function returning non-void" } */
+ else return 1;
+}
@@ -2,7 +2,7 @@
Copyright (C) 2003 Free Software Foundation Inc. */
/* { dg-do compile } */
-/* { dg-options "-O -finline-functions -Wreturn-type" } */
+/* { dg-options "-fpermissive -O -finline-functions -Wreturn-type" } */
extern int i;
extern int foo (void);
new file mode 100644
@@ -0,0 +1,21 @@
+/* Bug 9862 -- Spurious warnings with -finline-functions.
+ Copyright (C) 2003 Free Software Foundation Inc. */
+
+/* { dg-do compile } */
+/* { dg-options "-O -finline-functions -Wreturn-type" } */
+
+extern int i;
+extern int foo (void);
+extern int bar (void);
+
+int foo (void)
+{
+ if( i ) return; /* { dg-error "'return' with no value, in function returning non-void" } */
+ else return 1;
+}
+
+int bar (void)
+{
+ if( i ) return 0;
+ else return 1;
+}
@@ -1,5 +1,5 @@
/* { dg-do compile } */
-/* { dg-options "" } */
+/* { dg-options "-fpermissive" } */
void f1 (void);
new file mode 100644
@@ -0,0 +1,40 @@
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+void f1 (void);
+
+int
+f2 (void)
+{
+ f1 ();
+}
+
+static inline int
+f3 (void)
+{
+ f1 ();
+}
+
+void
+f4 (void)
+{
+ return 1; /* { dg-error "'return' with a value\[^\n\r\]*-Wreturn-mismatch" } */
+}
+
+void
+f5 (void)
+{
+ return f1 (); /* { dg-bogus "ISO C" } */
+}
+
+int
+f6 (void)
+{
+ return; /* { dg-error "'return' with no value\[^\n\r\]*-Wreturn-mismatch" } */
+}
+
+int
+f7 (void)
+{
+ return f1 (); /* { dg-error "void value not ignored as it ought to be" } */
+}
@@ -1,5 +1,5 @@
/* { dg-do compile } */
-/* { dg-options "-Wall" } */
+/* { dg-options "-fpermissive -Wall" } */
void f1 (void);
new file mode 100644
@@ -0,0 +1,41 @@
+/* { dg-do compile } */
+/* { dg-options "-Wall" } */
+
+void f1 (void);
+
+int
+f2 (void)
+{
+ f1 ();
+} /* { dg-warning "control reaches end of non-void\[^\n\r\]*-Wreturn-type" } */
+
+static inline int
+f3 (void)
+{
+ f1 ();
+} /* { dg-warning "no return statement in function\[^\n\r\]*-Wreturn-type" } */
+
+void
+f4 (void)
+{
+ return 1; /* { dg-error "with a value,\[^\n\r\]*-Wreturn-mismatch" } */
+}
+
+void
+f5 (void)
+{
+ return f1 ();
+}
+
+int
+f6 (void)
+{
+ return; /* { dg-error "with no value,\[^\n\r\]*Wreturn-mismatch" } */
+}
+
+int
+f7 (void)
+{
+ return f1 (); /* { dg-error "void value not ignored as it ought to be" } */
+} /* { dg-warning "control reaches end of non-void\[^\n\r\]*-Wreturn-type" } */
+
new file mode 100644
@@ -0,0 +1,52 @@
+/* { dg-options "-fdiagnostics-show-caret -Wreturn-local-addr" } */
+
+int *address_of_local (void)
+{
+ int some_local;
+ return &some_local; /* { dg-warning "function returns address of local variable" } */
+/* { dg-begin-multiline-output "" }
+ return &some_local;
+ ^~~~~~~~~~~
+ { dg-end-multiline-output "" } */
+}
+
+void surplus_return_when_void_1 (void)
+{
+ return 500; /* { dg-error "'return' with a value, in function returning void" } */
+/* { dg-begin-multiline-output "" }
+ return 500;
+ ^~~
+ { dg-end-multiline-output "" } */
+/* { dg-begin-multiline-output "" }
+ void surplus_return_when_void_1 (void)
+ ^~~~~~~~~~~~~~~~~~~~~~~~~~
+ { dg-end-multiline-output "" } */
+}
+
+void surplus_return_when_void_2 (int i, int j)
+{
+ return i * j; /* { dg-error "'return' with a value, in function returning void" } */
+/* { dg-begin-multiline-output "" }
+ return i * j;
+ ~~^~~
+ { dg-end-multiline-output "" } */
+/* { dg-begin-multiline-output "" }
+ void surplus_return_when_void_2 (int i, int j)
+ ^~~~~~~~~~~~~~~~~~~~~~~~~~
+ { dg-end-multiline-output "" } */
+}
+
+int missing_return_value (void)
+{
+ return; /* { dg-error "'return' with no value, in function returning non-void" } */
+/* { dg-begin-multiline-output "" }
+ return;
+ ^~~~~~
+ { dg-end-multiline-output "" } */
+/* { dg-begin-multiline-output "" }
+ int missing_return_value (void)
+ ^~~~~~~~~~~~~~~~~~~~
+ { dg-end-multiline-output "" } */
+/* TODO: ideally we'd underline the return type i.e. "int", but that
+ location isn't captured. */
+}
@@ -1,4 +1,4 @@
-/* { dg-options "-fdiagnostics-show-caret -Wreturn-local-addr" } */
+/* { dg-options "-fpermissive -fdiagnostics-show-caret -Wreturn-local-addr" } */
int *address_of_local (void)
{
@@ -75,11 +75,11 @@ incompatible_pointer_types (int flag)
void
return_mismatch_1 (void)
{
- return 0; /* { dg-warning "'return' with a value, in function returning void \\\[-Wreturn-mismatch\\\]" } */
+ return 0; /* { dg-error "'return' with a value, in function returning void \\\[-Wreturn-mismatch\\\]" } */
}
int
return_mismatch_2 (void)
{
- return; /* { dg-warning "return' with no value, in function returning non-void \\\[-Wreturn-mismatch\\\]" } */
+ return; /* { dg-error "return' with no value, in function returning non-void \\\[-Wreturn-mismatch\\\]" } */
}
@@ -75,7 +75,7 @@ incompatible_pointer_types (int flag)
void
return_mismatch_1 (void)
{
- return 0; /* { dg-warning "'return' with a value, in function returning void \\\[-Wreturn-mismatch\\\]" } */
+ return 0; /* { dg-error "'return' with a value, in function returning void \\\[-Wreturn-mismatch\\\]" } */
}
int
@@ -27,3 +27,6 @@
/* { dg-error "initialization of 'int \\\*' from 'int' makes pointer from integer without a cast \\\[-Wint-conversion\\\]" "" { target *-*-* } 45 } */
/* { dg-error "assignment to 'int \\\*' from 'int' makes pointer from integer without a cast \\\[-Wint-conversion\\\]" "" { target *-*-* } 46 } */
/* { dg-error "returning 'int \\\*' from a function with return type 'int' makes integer from pointer without a cast \\\[-Wint-conversion\\\]" "" { target *-*-* } 48 } */
+
+/* { dg-error "'return' with a value, in function returning void \\\[-Wreturn-mismatch\\\]" "" { target *-*-* } 78 } */
+/* { dg-error "return' with no value, in function returning non-void \\\[-Wreturn-mismatch\\\]" "" { target *-*-* } 84 } */
@@ -7,5 +7,5 @@ void foo (int, int[*]); /* { dg-message "previous declaration of 'foo' with type
foo (int x, int y) /* { dg-error "return type defaults to 'int'" } */
{ /* { dg-warning "conflicting types for 'foo'" "" { target *-*-* } .-1 } */
/* { dg-message "declared here" "" { target *-*-* } .-2 } */
- return (x >= 0) != (y < 0); /* { dg-warning "'return' with a value, in function returning void" } */
+ return (x >= 0) != (y < 0); /* { dg-error "'return' with a value, in function returning void" } */
}
new file mode 100644
@@ -0,0 +1,14 @@
+/* PR c/23075 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -Wreturn-type" } */
+
+int
+foo (void)
+{
+ return; /* { dg-error "with no value" } */
+} /* { dg-bogus "control reaches end" } */
+
+int
+bar (void)
+{
+} /* { dg-warning "control reaches end" } */
@@ -1,6 +1,6 @@
/* PR c/23075 */
/* { dg-do compile } */
-/* { dg-options "-O2 -Wreturn-type" } */
+/* { dg-options "-O2 -fpermissive -Wreturn-type" } */
int
foo (void)
new file mode 100644
@@ -0,0 +1,15 @@
+/* PR 29521 : warning for return with expression in function returning void */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+void func (void) { }
+
+void func2 (void)
+{
+ return func ();
+}
+
+void func3 (void)
+{
+ return 1; /* { dg-error "'return' with a value" } */
+}
@@ -1,6 +1,6 @@
/* PR 29521 : warning for return with expression in function returning void */
/* { dg-do compile } */
-/* { dg-options "" } */
+/* { dg-options "-fpermissive" } */
void func (void) { }
new file mode 100644
@@ -0,0 +1,11 @@
+/* PR c/67730 */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+#include <stddef.h>
+
+void
+fn1 (void)
+{
+ return NULL; /* { dg-error "10:.return. with a value" } */
+}
@@ -1,6 +1,6 @@
/* PR c/67730 */
/* { dg-do compile } */
-/* { dg-options "" } */
+/* { dg-options "-fpermissive" } */
#include <stddef.h>
@@ -1,7 +1,7 @@
/* Check that a conditional return is used. */
/* { dg-do compile } */
-/* { dg-options "-O2 -w" } */
+/* { dg-options "-O2 -fpermissive -w" } */
/* { dg-final { scan-assembler {\mbeqlr\M} } } */