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[209.132.180.131]) by mx.google.com with ESMTPS id o62si16703340pfi.119.2016.01.15.05.52.35 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 15 Jan 2016 05:52:35 -0800 (PST) Received-SPF: pass (google.com: domain of gcc-patches-return-419135-patch=linaro.org@gcc.gnu.org designates 209.132.180.131 as permitted sender) client-ip=209.132.180.131; Authentication-Results: mx.google.com; spf=pass (google.com: domain of gcc-patches-return-419135-patch=linaro.org@gcc.gnu.org designates 209.132.180.131 as permitted sender) smtp.mailfrom=gcc-patches-return-419135-patch=linaro.org@gcc.gnu.org; dkim=pass header.i=@gcc.gnu.org DomainKey-Signature: a=rsa-sha1; c=nofws; d=gcc.gnu.org; h=list-id :list-unsubscribe:list-archive:list-post:list-help:sender :mime-version:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; q=dns; s=default; b=nYCoE0ZVj6BM8Z4kUT /iUu65V/7zr0Gq4UIDR4EQdNgj+5TSCuQudXhxoGj7ueAHXwHtKvLHLneMHD+3CD xfMOLovgev7jja5rE6wUC++YZRWwqerIsMRBk1xtY+cE4uN7M5hNwgSIpLWOkcP6 FCZLOmFFlIcKHa2t2Qw8GTz+4= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=gcc.gnu.org; h=list-id :list-unsubscribe:list-archive:list-post:list-help:sender :mime-version:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; s=default; bh=hToCsWSn0zsqyxSwRFV/7ajJ Z6A=; b=ax4BLCJrKYjNq3CF2Rx8TVldecHxm4S9vs1q+aQ7CsHLGC6U4OJNm7D8 qkiICp2bTrHm0/wS6zSeCqcltCUfr9126pYygvPQTh4LYoRA4HSihVw1txmT92sk yNdq0x30cqU2ezp8KaSXoNqszbjUXWDJEkjfaZHSELs/KYGVS98= Received: (qmail 94864 invoked by alias); 15 Jan 2016 13:52:24 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Delivered-To: mailing list gcc-patches@gcc.gnu.org Received: (qmail 94848 invoked by uid 89); 15 Jan 2016 13:52:22 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_LOW, SPF_PASS autolearn=ham version=3.3.2 spammy=598, 596, 59, 6 X-HELO: mail-io0-f181.google.com Received: from mail-io0-f181.google.com (HELO mail-io0-f181.google.com) (209.85.223.181) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-GCM-SHA256 encrypted) ESMTPS; Fri, 15 Jan 2016 13:52:21 +0000 Received: by mail-io0-f181.google.com with SMTP id 77so455361169ioc.2 for ; Fri, 15 Jan 2016 05:52:20 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type; bh=X7rtQkb9Lsp1yir9c5F+MIFTv9bQG+//bzpoLXd1bpM=; b=LGFlo36OAk8Mte8hMkK0Uv+Z2T+YtuGDVKOWP1uuGQIOOtmHHDFQl0iBm1w35qedAL IavE0F3ohdBynB9Lgxow2GGDF4ZsCQJaPQSrF1MQOzdSBMgGTufy7ArxTjTRaNJ5PKvw zFNPIKNADTh6M+v3Wt738KflnTYA53WBt1h/Q0GmuSGr/R57XSy43iUuHo8h5LFsJkwQ SmlZE0wz1+7K3RGhbOUMnz0oSfULZoEn7bvmxZzwTEr+aispFBA+xvDVuC9ftLroedmg oA+1U2iy/5zOnUmrO184z8LSmEWVAv3udvwzoOotmb+Zeksv9jFUsB1CQLavqpRpxCCE 97UQ== X-Gm-Message-State: ALoCoQnmHm7ccjLTksjXeGs3pmYyXRQE4Yv6wmbOSYWis+B55pfY4k9aqKkAMqMqfNr8+92BYzypx0u9wK4UvLQV2wqJLrutfq87pfLfvp6rilNQpJDMw8s= MIME-Version: 1.0 X-Received: by 10.107.159.7 with SMTP id i7mr9657050ioe.29.1452865938892; Fri, 15 Jan 2016 05:52:18 -0800 (PST) Received: by 10.36.214.70 with HTTP; Fri, 15 Jan 2016 05:52:18 -0800 (PST) In-Reply-To: References: Date: Fri, 15 Jan 2016 19:22:18 +0530 Message-ID: Subject: Re: reject decl with incomplete struct/union type in check_global_declaration() From: Prathamesh Kulkarni To: Joseph Myers Cc: gcc Patches X-IsSubscribed: yes On 15 January 2016 at 03:27, Joseph Myers wrote: > On Thu, 14 Jan 2016, Prathamesh Kulkarni wrote: > >> Hi, >> For test-case containing only the following declaration: >> static struct undefined_struct object; >> gcc rejects it at -O0 in assemble_variable() with error "storage size >> of is unknown", >> however no error is reported when compiled with -O2. > > Cf bug 24293 (for the -fsyntax-only case) - does this patch fix that? Ah this doesn't fix PR24293, it seems analyze_function() doesn't get called for -fsyntax-only. I don't have a good solution for this. I assume varpool won't be populated for -fsyntax-only ? And we need to walk over decls with incomplete struct/union types after parsing the whole translation unit. In the attached patch, I kept a global vec incomplete_record_decls; In finish_decl(), if the decl is static, has type struct/union and size 0 then it is appened to incomplete_record_decls. In c_parser_translation_unit(), iterate over incomplete_record_decls and if report error if any decl has size zero. The patch passes testsuite. Thanks, Prathamesh > >> g++ rejects it during parsing. I tried similarly in C FE by adding a >> check for decl with incomplete struct/union type in finish_decl(), >> however that fails to compile the following case: >> typedef struct foo foo_t; >> foo_t x; >> struct foo { int i; }; >> g++ rejects the above case as well but gcc accepts it. >> Do C and C++ standards differ in this regard ? > > I don't know about C++, but this sort of thing is valid C if the type is > complete at the end of the translation unit or is an incomplete array type > (but not in the case where the variable is static - such a case with > static, if supported, is an extension). > > -- > Joseph S. Myers > joseph@codesourcery.com diff --git a/gcc/c/c-decl.c b/gcc/c/c-decl.c index 915376d..ac542e1 100644 --- a/gcc/c/c-decl.c +++ b/gcc/c/c-decl.c @@ -4791,6 +4791,12 @@ finish_decl (tree decl, location_t init_loc, tree init, TREE_TYPE (decl) = error_mark_node; } + if (RECORD_OR_UNION_TYPE_P (TREE_TYPE (decl)) + && DECL_SIZE (decl) == 0 && TREE_STATIC (decl)) + { + incomplete_record_decls.safe_push (decl); + } + if (is_global_var (decl) && DECL_SIZE (decl) != 0) { if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST) diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c index a0e0052..8af04f7 100644 --- a/gcc/c/c-parser.c +++ b/gcc/c/c-parser.c @@ -59,6 +59,8 @@ along with GCC; see the file COPYING3. If not see #include "gimple-expr.h" #include "context.h" +vec incomplete_record_decls = vNULL; + void set_c_expr_source_range (c_expr *expr, location_t start, location_t finish) @@ -1421,6 +1423,13 @@ c_parser_translation_unit (c_parser *parser) } while (c_parser_next_token_is_not (parser, CPP_EOF)); } + + for (unsigned i = 0; i < incomplete_record_decls.length (); ++i) + { + tree decl = incomplete_record_decls[i]; + if (DECL_SIZE (decl) == 0) + error ("storage size of %q+D isn%'t known", decl); + } } /* Parse an external declaration (C90 6.7, C99 6.9). diff --git a/gcc/c/c-tree.h b/gcc/c/c-tree.h index 81a3d58..cf79ba7 100644 --- a/gcc/c/c-tree.h +++ b/gcc/c/c-tree.h @@ -731,4 +731,6 @@ set_c_expr_source_range (c_expr *expr, /* In c-fold.c */ extern tree decl_constant_value_for_optimization (tree); +extern vec incomplete_record_decls; + #endif /* ! GCC_C_TREE_H */ diff --git a/gcc/testsuite/gcc.dg/Wcxx-compat-8.c b/gcc/testsuite/gcc.dg/Wcxx-compat-8.c index f7e8c55..4e9ddc1 100644 --- a/gcc/testsuite/gcc.dg/Wcxx-compat-8.c +++ b/gcc/testsuite/gcc.dg/Wcxx-compat-8.c @@ -33,6 +33,7 @@ enum e3 __typeof__ (struct s5 { int i; }) v5; /* { dg-warning "invalid in C\[+\]\[+\]" } */ __typeof__ (struct t5) w5; /* { dg-bogus "invalid in C\[+\]\[+\]" } */ + /* { dg-error "storage size of 'w5' isn't known" "" { target *-*-* } 35 } */ int f1 (struct s1 *p) @@ -64,4 +65,4 @@ f5 () return &((struct t8) { }); /* { dg-warning "invalid in C\[+\]\[+\]" } */ } -/* { dg-error "invalid use of undefined type" "" { target *-*-* } 64 } */ +/* { dg-error "invalid use of undefined type" "" { target *-*-* } 65 } */ diff --git a/gcc/testsuite/gcc.dg/declspec-1.c b/gcc/testsuite/gcc.dg/declspec-1.c index c19f107..9113076 100644 --- a/gcc/testsuite/gcc.dg/declspec-1.c +++ b/gcc/testsuite/gcc.dg/declspec-1.c @@ -9,7 +9,8 @@ typedef int t; /* These should all be diagnosed, but only once, not for every identifier declared. */ struct s0 int x0, /* { dg-error "two or more data types" } */ -x1; +/* { dg-error "storage size of 'x0' isn't known" "" { target *-*-* } 11 } */ +x1; /* { dg-error "storage size of 'x1' isn't known" } */ char union u0 x2, /* { dg-error "two or more data types" } */ x3; diff --git a/gcc/testsuite/gcc.dg/pr24293.c b/gcc/testsuite/gcc.dg/pr24293.c new file mode 100644 index 0000000..33285e7 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr24293.c @@ -0,0 +1,10 @@ +/* { dg-do compile } */ +/* { dg-options "-fsyntax-only" } */ + +static struct foo x; /* { dg-error "storage size of 'x' isn't known" } */ +static union bar y; /* { dg-error "storage size of 'y' isn't known" } */ + +typedef struct P p; +static p p_obj; /* { dg-error "storage size of 'p_obj' isn't known" } */ + +extern struct undefined_object object;