From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 123570 invoked by alias); 30 Nov 2018 23:01:19 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 121002 invoked by uid 89); 30 Nov 2018 23:01:01 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-26.9 required=5.0 tests=BAYES_00,GIT_PATCH_0,GIT_PATCH_1,GIT_PATCH_2,GIT_PATCH_3,SPF_HELO_PASS,TIME_LIMIT_EXCEEDED autolearn=unavailable version=3.3.2 spammy=selftest, sk:maybe_a, lvalue_p, cpp_ttype X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 30 Nov 2018 23:00:40 +0000 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C6F1058E4A; Fri, 30 Nov 2018 23:00:38 +0000 (UTC) Received: from c64.redhat.com (ovpn-112-38.phx2.redhat.com [10.3.112.38]) by smtp.corp.redhat.com (Postfix) with ESMTP id 113EA5D9CD; Fri, 30 Nov 2018 23:00:34 +0000 (UTC) From: David Malcolm To: Joseph Myers , Jason Merrill , law@redhat.com Cc: Martin Sebor , Eric Gallager , gcc-patches List , David Malcolm Subject: [PATCH] v4: C/C++: add fix-it hints for missing '&' and '*' (PR c++/87850) Date: Fri, 30 Nov 2018 23:01:00 -0000 Message-Id: <1543621685-20785-1-git-send-email-dmalcolm@redhat.com> In-Reply-To: References: X-IsSubscribed: yes X-SW-Source: 2018-11/txt/msg02617.txt.bz2 On Tue, 2018-11-20 at 22:23 +0000, Joseph Myers wrote: > On Tue, 20 Nov 2018, David Malcolm wrote: > > > Should I do: > > You should do whatever is appropriate for the warning in > question. But if > what's appropriate for the warning in question includes types that > are > compatible but not the same, the comments need to avoid saying it's > about > the types being the same. Thanks. Here's an updated version of the patch. I added a new compatible_types_for_indirection_note_p specifically for use by maybe_emit_indirection_note, and provided implementations for C and C++. Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu. OK for trunk? Changed in v4: introduce a compatible_types_for_indirection_note_p function, and use it in place of same_type_p. Changed in v3: use same_type_p rather than pointer equality. Provide implementation of same_type_p for C. Changed in v2: add a note, and put the fix-it hint on that instead Blurb follows: This patch adds a note with a fix-it hint to various pointer-vs-non-pointer diagnostics, suggesting the addition of a leading '&' or '*'. For example, note the ampersand fix-it hint in the following: demo.c: In function 'int main()': demo.c:5:22: error: invalid conversion from 'pthread_key_t' {aka 'unsigned int'} to 'pthread_key_t*' {aka 'unsigned int*'} [-fpermissive] 5 | pthread_key_create(key, NULL); | ^~~ | | | pthread_key_t {aka unsigned int} demo.c:5:22: note: possible fix: take the address with '&' 5 | pthread_key_create(key, NULL); | ^~~ | & In file included from demo.c:1: /usr/include/pthread.h:1122:47: note: initializing argument 1 of 'int pthread_key_create(pthread_key_t*, void (*)(void*))' 1122 | extern int pthread_key_create (pthread_key_t *__key, | ~~~~~~~~~~~~~~~^~~~~ gcc/c-family/ChangeLog: PR c++/87850 * c-common.c: Include "gcc-rich-location.h". (maybe_emit_indirection_note): New function. * c-common.h (maybe_emit_indirection_note): New decl. (compatible_types_for_indirection_note_p): New decl. gcc/c/ChangeLog: PR c++/87850 * c-typeck.c (compatible_types_for_indirection_note_p): New function. (convert_for_assignment): Call maybe_emit_indirection_note for pointer vs non-pointer diagnostics. gcc/cp/ChangeLog: PR c++/87850 * call.c (convert_like_real): Call maybe_emit_indirection_note for "invalid conversion" diagnostic. * typeck.c (compatible_types_for_indirection_note_p): New function. gcc/testsuite/ChangeLog: PR c++/87850 * c-c++-common/indirection-fixits.c: New test. --- gcc/c-family/c-common.c | 35 +++ gcc/c-family/c-common.h | 4 + gcc/c/c-typeck.c | 18 +- gcc/cp/call.c | 2 + gcc/cp/typeck.c | 8 + gcc/testsuite/c-c++-common/indirection-fixits.c | 299 ++++++++++++++++++++++++ 6 files changed, 364 insertions(+), 2 deletions(-) create mode 100644 gcc/testsuite/c-c++-common/indirection-fixits.c diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c index 9d51815..f235c9d 100644 --- a/gcc/c-family/c-common.c +++ b/gcc/c-family/c-common.c @@ -48,6 +48,7 @@ along with GCC; see the file COPYING3. If not see #include "gimplify.h" #include "substring-locations.h" #include "spellcheck.h" +#include "gcc-rich-location.h" #include "selftest.h" cpp_reader *parse_in; /* Declared in c-pragma.h. */ @@ -8420,6 +8421,40 @@ maybe_suggest_missing_token_insertion (rich_location *richloc, } } +/* Potentially emit a note about likely missing '&' or '*', + depending on EXPR and EXPECTED_TYPE. */ + +void +maybe_emit_indirection_note (location_t loc, + tree expr, tree expected_type) +{ + gcc_assert (expr); + gcc_assert (expected_type); + + tree actual_type = TREE_TYPE (expr); + + /* Missing '&'. */ + if (TREE_CODE (expected_type) == POINTER_TYPE + && compatible_types_for_indirection_note_p (actual_type, + TREE_TYPE (expected_type)) + && lvalue_p (expr)) + { + gcc_rich_location richloc (loc); + richloc.add_fixit_insert_before ("&"); + inform (&richloc, "possible fix: take the address with %qs", "&"); + } + + /* Missing '*'. */ + if (TREE_CODE (actual_type) == POINTER_TYPE + && compatible_types_for_indirection_note_p (TREE_TYPE (actual_type), + expected_type)) + { + gcc_rich_location richloc (loc); + richloc.add_fixit_insert_before ("*"); + inform (&richloc, "possible fix: dereference with %qs", "*"); + } +} + #if CHECKING_P namespace selftest { diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h index 4187343..0b1fdd7 100644 --- a/gcc/c-family/c-common.h +++ b/gcc/c-family/c-common.h @@ -1355,6 +1355,10 @@ extern void maybe_add_include_fixit (rich_location *, const char *, bool); extern void maybe_suggest_missing_token_insertion (rich_location *richloc, enum cpp_ttype token_type, location_t prev_token_loc); +extern void maybe_emit_indirection_note (location_t loc, + tree expr, tree expected_type); +extern bool compatible_types_for_indirection_note_p (tree type1, tree type2); + extern tree braced_list_to_string (tree, tree); extern bool has_attribute (location_t, tree, tree, tree (*)(tree)); diff --git a/gcc/c/c-typeck.c b/gcc/c/c-typeck.c index 81c520a..cb7184b 100644 --- a/gcc/c/c-typeck.c +++ b/gcc/c/c-typeck.c @@ -1004,6 +1004,14 @@ common_type (tree t1, tree t2) return c_common_type (t1, t2); } +/* C implementation of compatible_types_for_indirection_note_p. */ + +bool +compatible_types_for_indirection_note_p (tree type1, tree type2) +{ + return comptypes (type1, type2) == 1; +} + /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment or various other operations. Return 2 if they are compatible but a warning may be needed if you use them together. */ @@ -7293,7 +7301,10 @@ convert_for_assignment (location_t location, location_t expr_loc, tree type, if (pedwarn (&richloc, OPT_Wint_conversion, "passing argument %d of %qE makes pointer from " "integer without a cast", parmnum, rname)) - inform_for_arg (fundecl, expr_loc, parmnum, type, rhstype); + { + maybe_emit_indirection_note (expr_loc, rhs, type); + inform_for_arg (fundecl, expr_loc, parmnum, type, rhstype); + } } break; case ic_assign: @@ -7329,7 +7340,10 @@ convert_for_assignment (location_t location, location_t expr_loc, tree type, if (pedwarn (&richloc, OPT_Wint_conversion, "passing argument %d of %qE makes integer from " "pointer without a cast", parmnum, rname)) - inform_for_arg (fundecl, expr_loc, parmnum, type, rhstype); + { + maybe_emit_indirection_note (expr_loc, rhs, type); + inform_for_arg (fundecl, expr_loc, parmnum, type, rhstype); + } } break; case ic_assign: diff --git a/gcc/cp/call.c b/gcc/cp/call.c index ee099cc..a25d109 100644 --- a/gcc/cp/call.c +++ b/gcc/cp/call.c @@ -6862,6 +6862,8 @@ convert_like_real (conversion *convs, tree expr, tree fn, int argnum, complained = permerror (&richloc, "invalid conversion from %qH to %qI", TREE_TYPE (expr), totype); + if (complained) + maybe_emit_indirection_note (loc, expr, totype); } if (complained && fn) inform (get_fndecl_argument_location (fn, argnum), diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c index 81cb405..2730f77 100644 --- a/gcc/cp/typeck.c +++ b/gcc/cp/typeck.c @@ -1448,6 +1448,14 @@ structural_comptypes (tree t1, tree t2, int strict) return comp_type_attributes (t1, t2); } +/* C++ implementation of compatible_types_for_indirection_note_p. */ + +bool +compatible_types_for_indirection_note_p (tree type1, tree type2) +{ + return same_type_p (type1, type2); +} + /* Return true if T1 and T2 are related as allowed by STRICT. STRICT is a bitwise-or of the COMPARE_* flags. */ diff --git a/gcc/testsuite/c-c++-common/indirection-fixits.c b/gcc/testsuite/c-c++-common/indirection-fixits.c new file mode 100644 index 0000000..8987ee9 --- /dev/null +++ b/gcc/testsuite/c-c++-common/indirection-fixits.c @@ -0,0 +1,299 @@ +/* { dg-options "-fdiagnostics-show-caret" } */ + +void takes_int_ptr(int*); +void takes_char_ptr(char*); +void takes_int(int); +int returns_int(void); + +int ivar; +char cvar; +int *int_ptr; +char *char_ptr; + +void test_1 (void) +{ + takes_int_ptr(&ivar); + takes_int_ptr(int_ptr); + takes_char_ptr(&cvar); + takes_char_ptr(char_ptr); + + ivar = 42; + cvar = 'b'; + int_ptr = &ivar; + char_ptr = &cvar; +} + +void test_2 (void) +{ + takes_int_ptr(ivar); /* { dg-warning "" "" { target c } } */ + /* { dg-error "" "" { target c++ } .-1 } */ + /* { dg-message "possible fix: take the address with '&'" "" { target *-*-* } .-2 } */ + + /* Expect an '&' fix-it hint. */ + /* { dg-begin-multiline-output "" } + takes_int_ptr(ivar); + ^~~~ + | + int + { dg-end-multiline-output "" } */ + /* { dg-begin-multiline-output "" } + takes_int_ptr(ivar); + ^~~~ + & + { dg-end-multiline-output "" } */ + /* { dg-begin-multiline-output "" } + void takes_int_ptr(int*); + ^~~~ + { dg-end-multiline-output "" } */ +} + +void test_3 (void) +{ + takes_int_ptr(cvar); /* { dg-warning "" "" { target c } } */ + /* { dg-error "" "" { target c++ } .-1 } */ + + /* Don't expect an '&' fix-it hint. */ + /* { dg-begin-multiline-output "" } + takes_int_ptr(cvar); + ^~~~ + | + char + { dg-end-multiline-output "" } */ + /* { dg-begin-multiline-output "" } + void takes_int_ptr(int*); + ^~~~ + { dg-end-multiline-output "" } */ +} + +void test_4 (void) +{ + takes_char_ptr(ivar); /* { dg-warning "" "" { target c } } */ + /* { dg-error "" "" { target c++ } .-1 } */ + + /* Don't expect an '&' fix-it hint. */ + /* { dg-begin-multiline-output "" } + takes_char_ptr(ivar); + ^~~~ + | + int + { dg-end-multiline-output "" } */ + /* { dg-begin-multiline-output "" } + void takes_char_ptr(char*); + ^~~~~ + { dg-end-multiline-output "" } */ +} + +void test_5 (void) +{ + takes_char_ptr(cvar); /* { dg-warning "" "" { target c } } */ + /* { dg-error "" "" { target c++ } .-1 } */ + + /* Expect an '&' fix-it hint. */ + /* { dg-begin-multiline-output "" } + takes_char_ptr(cvar); + ^~~~ + | + char + { dg-end-multiline-output "" } */ + /* { dg-begin-multiline-output "" } + takes_char_ptr(cvar); + ^~~~ + & + { dg-end-multiline-output "" } */ + /* { dg-begin-multiline-output "" } + void takes_char_ptr(char*); + ^~~~~ + { dg-end-multiline-output "" } */ +} + +void test_6 (void) +{ + takes_int(int_ptr); /* { dg-warning "" "" { target c } } */ + /* { dg-error "" "" { target c++ } .-1 } */ + /* { dg-message "possible fix: dereference with '*'" "" { target *-*-* } .-2 } */ + + /* Expect a '*' fix-it hint. */ + /* { dg-begin-multiline-output "" } + takes_int(int_ptr); + ^~~~~~~ + | + int * + { dg-end-multiline-output "" { target c } } */ + /* { dg-begin-multiline-output "" } + takes_int(int_ptr); + ^~~~~~~ + | + int* + { dg-end-multiline-output "" { target c++ } } */ + /* { dg-begin-multiline-output "" } + takes_int(int_ptr); + ^~~~~~~ + * + { dg-end-multiline-output "" } */ + /* { dg-begin-multiline-output "" } + void takes_int(int); + ^~~ + { dg-end-multiline-output "" } */ +} + +void test_7 (void) +{ + takes_int(char_ptr); /* { dg-warning "" "" { target c } } */ + /* { dg-error "" "" { target c++ } .-1 } */ + + /* Don't expect a '*' fix-it hint. */ + /* { dg-begin-multiline-output "" } + takes_int(char_ptr); + ^~~~~~~~ + | + char * + { dg-end-multiline-output "" { target c } } */ + /* { dg-begin-multiline-output "" } + takes_int(char_ptr); + ^~~~~~~~ + | + char* + { dg-end-multiline-output "" { target c++ } } */ + /* { dg-begin-multiline-output "" } + void takes_int(int); + ^~~ + { dg-end-multiline-output "" } */ +} + +void test_8 (void) +{ + ivar = int_ptr; /* { dg-warning "" "" { target c } } */ + /* { dg-error "" "" { target c++ } .-1 } */ + + /* Expect a fix-it hint from the C++ FE, but not from C (due to missing + location). */ + /* { dg-begin-multiline-output "" } + ivar = int_ptr; + ^~~~~~~ + | + int* + { dg-end-multiline-output "" { target c++ } } */ + /* { dg-begin-multiline-output "" } + ivar = int_ptr; + ^~~~~~~ + * + { dg-end-multiline-output "" { target c++ } } */ + /* { dg-begin-multiline-output "" } + ivar = int_ptr; + ^ + { dg-end-multiline-output "" { target c } } */ +} + +void test_9 (void) +{ + cvar = int_ptr; /* { dg-warning "" "" { target c } } */ + /* { dg-error "" "" { target c++ } .-1 } */ + + /* Don't expect a '*' fix-it hint. */ + /* { dg-begin-multiline-output "" } + cvar = int_ptr; + ^~~~~~~ + | + int* + { dg-end-multiline-output "" { target c++ } } */ + /* { dg-begin-multiline-output "" } + cvar = int_ptr; + ^ + { dg-end-multiline-output "" { target c } } */ +} + +void test_10 (void) +{ + int_ptr = ivar; /* { dg-warning "" "" { target c } } */ + /* { dg-error "" "" { target c++ } .-1 } */ + + /* Expect a fix-it hint from the C++ FE, but not from C (due to missing + location). */ + /* { dg-begin-multiline-output "" } + int_ptr = ivar; + ^~~~ + | + int + { dg-end-multiline-output "" { target c++ } } */ + /* { dg-begin-multiline-output "" } + int_ptr = ivar; + ^~~~ + & + { dg-end-multiline-output "" { target c++ } } */ + /* { dg-begin-multiline-output "" } + int_ptr = ivar; + ^ + { dg-end-multiline-output "" { target c } } */ +} + +void test_11 (void) +{ + char_ptr = ivar; /* { dg-warning "" "" { target c } } */ + /* { dg-error "" "" { target c++ } .-1 } */ + + /* Don't expect a fix-it hint, due to mismatching types. */ + /* { dg-begin-multiline-output "" } + char_ptr = ivar; + ^~~~ + | + int + { dg-end-multiline-output "" { target c++ } } */ + /* { dg-begin-multiline-output "" } + char_ptr = ivar; + ^ + { dg-end-multiline-output "" { target c } } */ +} + +/* We shouldn't offer '&' fix-it hints for non-lvalues. */ + +void test_12 (void) +{ + takes_int_ptr (returns_int ()); /* { dg-warning "" "" { target c } } */ + /* { dg-error "" "" { target c++ } .-1 } */ + + /* { dg-begin-multiline-output "" } + takes_int_ptr (returns_int ()); + ^~~~~~~~~~~~~~ + | + int + { dg-end-multiline-output "" { target c } } */ + /* { dg-begin-multiline-output "" } + takes_int_ptr (returns_int ()); + ~~~~~~~~~~~~^~ + | + int + { dg-end-multiline-output "" { target c++ } } */ + /* { dg-begin-multiline-output "" } + void takes_int_ptr(int*); + ^~~~ + { dg-end-multiline-output "" } */ +} + +/* Ignore typedefs when offering fix-it hints. */ + +typedef int typedef_int_t; +typedef_int_t typedef_int_t_var; + +void test_13 (void) +{ + takes_int_ptr (typedef_int_t_var); /* { dg-warning "" "" { target c } } */ + /* { dg-error "" "" { target c++ } .-1 } */ + /* { dg-message "possible fix: take the address with '&'" "" { target *-*-* } .-2 } */ + + /* Expect an '&' fix-it hint. */ + /* { dg-begin-multiline-output "" } + takes_int_ptr (typedef_int_t_var); + ^~~~~~~~~~~~~~~~~ + | + typedef_int_t {aka int} + { dg-end-multiline-output "" } */ + /* { dg-begin-multiline-output "" } + takes_int_ptr (typedef_int_t_var); + ^~~~~~~~~~~~~~~~~ + & + { dg-end-multiline-output "" } */ + /* { dg-begin-multiline-output "" } + void takes_int_ptr(int*); + ^~~~ + { dg-end-multiline-output "" } */ +} -- 1.8.5.3