diff options
author | Hans Wennborg <hans@hanshq.net> | 2019-07-26 20:47:20 +0000 |
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committer | Hans Wennborg <hans@hanshq.net> | 2019-07-26 20:47:20 +0000 |
commit | baff46673eb5d8d61bb1eb340e62ad4b25685286 (patch) | |
tree | 82b486a9928d8957bcd8762e5d2ab8d99911a2a9 | |
parent | 5e63c7348448dbe0195c8af64788638fa816292d (diff) |
Merging r367134:
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r367134 | nathan-huckleberry | 2019-07-26 19:29:35 +0200 (Fri, 26 Jul 2019) | 16 lines
[Sema] Fix -Wuninitialized for struct assignment from GNU C statement expression
Summary:
Do not automatically report self references of structs in statement expression
as warnings. Instead wait for uninitialized cfg analysis.
https://bugs.llvm.org/show_bug.cgi?id=42604
Reviewers: aaron.ballman, rsmith, nickdesaulniers
Reviewed By: aaron.ballman, nickdesaulniers
Subscribers: nathanchance, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D64678
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git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/release_90@367150 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r-- | lib/Sema/SemaDecl.cpp | 9 | ||||
-rw-r--r-- | test/Sema/warn-uninitialized-statement-expression.c | 56 |
2 files changed, 62 insertions, 3 deletions
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp index a6c52b7d4b..cf8ad9c905 100644 --- a/lib/Sema/SemaDecl.cpp +++ b/lib/Sema/SemaDecl.cpp @@ -11527,9 +11527,12 @@ void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init, bool DirectInit) { // Check for self-references within variable initializers. // Variables declared within a function/method body (except for references) // are handled by a dataflow analysis. - if (!VDecl->hasLocalStorage() || VDecl->getType()->isRecordType() || - VDecl->getType()->isReferenceType()) { - CheckSelfReference(*this, RealDecl, Init, DirectInit); + // This is undefined behavior in C++, but valid in C. + if (getLangOpts().CPlusPlus) { + if (!VDecl->hasLocalStorage() || VDecl->getType()->isRecordType() || + VDecl->getType()->isReferenceType()) { + CheckSelfReference(*this, RealDecl, Init, DirectInit); + } } // If the type changed, it means we had an incomplete type that was diff --git a/test/Sema/warn-uninitialized-statement-expression.c b/test/Sema/warn-uninitialized-statement-expression.c new file mode 100644 index 0000000000..4e29ee01ea --- /dev/null +++ b/test/Sema/warn-uninitialized-statement-expression.c @@ -0,0 +1,56 @@ +// RUN: %clang_cc1 -fsyntax-only -Wuninitialized -verify %s + +void init(int *); + +void foo(void) { + int i = ({ + init(&i); + i; + }); +} + +void foo_bad(void) { + int i = ({ + int z = i; // expected-warning{{variable 'i' is uninitialized when used within its own initialization}} + init(&i); + i; + }); +} + +struct widget { + int x, y; +}; +void init2(struct widget *); + +void bar(void) { + struct widget my_widget = ({ + init2(&my_widget); + my_widget; + }); + struct widget a = (init2(&a), a); +} + +void bar_bad(void) { + struct widget my_widget = ({ + struct widget z = my_widget; // expected-warning{{variable 'my_widget' is uninitialized when used within its own initialization}} + int x = my_widget.x; //FIXME: There should be an uninitialized warning here + init2(&my_widget); + my_widget; + }); +} + +void baz(void) { + struct widget a = ({ + struct widget b = ({ + b = a; // expected-warning{{variable 'a' is uninitialized when used within its own initialization}} + }); + a; + }); +} + +void f(void) { + struct widget *a = ({ + init2(a); // expected-warning{{variable 'a' is uninitialized when used within its own initialization}} + a; + }); +} |