Author: efriedma Date: Mon Feb 11 14:54:27 2019 New Revision: 353762 URL: http://llvm.org/viewvc/llvm-project?rev=353762&view=rev Log: [Sema] Mark GNU compound literal array init as an rvalue.
Basically the same issue as string init, except it didn't really have any visible consequences before I removed the implicit lvalue-to-rvalue conversion from CodeGen. While I'm here, a couple minor drive-by cleanups: IgnoreParens never returns a ConstantExpr, and there was a potential crash with string init involving a ChooseExpr. The analyzer test change maybe indicates we could simplify the analyzer code a little with this fix? Apparently a hack was added to support lvalues in initializers in r315750, but I'm not really familiar with the relevant code. Fixes regression reported in the kernel build at https://bugs.llvm.org/show_bug.cgi?id=40430#c6 . Differential Revision: https://reviews.llvm.org/D58069 Modified: cfe/trunk/lib/Sema/SemaInit.cpp cfe/trunk/test/Analysis/compound-literals.c cfe/trunk/test/CodeGen/compound-literal.c Modified: cfe/trunk/lib/Sema/SemaInit.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaInit.cpp?rev=353762&r1=353761&r2=353762&view=diff ============================================================================== --- cfe/trunk/lib/Sema/SemaInit.cpp (original) +++ cfe/trunk/lib/Sema/SemaInit.cpp Mon Feb 11 14:54:27 2019 @@ -145,16 +145,42 @@ static void updateStringLiteralType(Expr while (true) { E->setType(Ty); E->setValueKind(VK_RValue); - if (isa<StringLiteral>(E) || isa<ObjCEncodeExpr>(E)) + if (isa<StringLiteral>(E) || isa<ObjCEncodeExpr>(E)) { break; - else if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) + } else if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { E = PE->getSubExpr(); - else if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) + } else if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) { + assert(UO->getOpcode() == UO_Extension); E = UO->getSubExpr(); - else if (GenericSelectionExpr *GSE = dyn_cast<GenericSelectionExpr>(E)) + } else if (GenericSelectionExpr *GSE = dyn_cast<GenericSelectionExpr>(E)) { E = GSE->getResultExpr(); - else + } else if (ChooseExpr *CE = dyn_cast<ChooseExpr>(E)) { + E = CE->getChosenSubExpr(); + } else { llvm_unreachable("unexpected expr in string literal init"); + } + } +} + +/// Fix a compound literal initializing an array so it's correctly marked +/// as an rvalue. +static void updateGNUCompoundLiteralRValue(Expr *E) { + while (true) { + E->setValueKind(VK_RValue); + if (isa<CompoundLiteralExpr>(E)) { + break; + } else if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { + E = PE->getSubExpr(); + } else if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) { + assert(UO->getOpcode() == UO_Extension); + E = UO->getSubExpr(); + } else if (GenericSelectionExpr *GSE = dyn_cast<GenericSelectionExpr>(E)) { + E = GSE->getResultExpr(); + } else if (ChooseExpr *CE = dyn_cast<ChooseExpr>(E)) { + E = CE->getChosenSubExpr(); + } else { + llvm_unreachable("unexpected expr in array compound literal init"); + } } } @@ -5542,8 +5568,7 @@ void InitializationSequence::InitializeF // array from a compound literal that creates an array of the same // type, so long as the initializer has no side effects. if (!S.getLangOpts().CPlusPlus && Initializer && - (isa<ConstantExpr>(Initializer->IgnoreParens()) || - isa<CompoundLiteralExpr>(Initializer->IgnoreParens())) && + isa<CompoundLiteralExpr>(Initializer->IgnoreParens()) && Initializer->getType()->isArrayType()) { const ArrayType *SourceAT = Context.getAsArrayType(Initializer->getType()); @@ -7956,6 +7981,7 @@ ExprResult InitializationSequence::Perfo S.Diag(Kind.getLocation(), diag::ext_array_init_copy) << Step->Type << CurInit.get()->getType() << CurInit.get()->getSourceRange(); + updateGNUCompoundLiteralRValue(CurInit.get()); LLVM_FALLTHROUGH; case SK_ArrayInit: // If the destination type is an incomplete array type, update the Modified: cfe/trunk/test/Analysis/compound-literals.c URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/compound-literals.c?rev=353762&r1=353761&r2=353762&view=diff ============================================================================== --- cfe/trunk/test/Analysis/compound-literals.c (original) +++ cfe/trunk/test/Analysis/compound-literals.c Mon Feb 11 14:54:27 2019 @@ -4,6 +4,5 @@ void clang_analyzer_eval(int); // pr28449: Used to crash. void foo(void) { static const unsigned short array[] = (const unsigned short[]){0x0F00}; - // FIXME: Should be true. - clang_analyzer_eval(array[0] == 0x0F00); // expected-warning{{UNKNOWN}} + clang_analyzer_eval(array[0] == 0x0F00); // expected-warning{{TRUE}} } Modified: cfe/trunk/test/CodeGen/compound-literal.c URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/compound-literal.c?rev=353762&r1=353761&r2=353762&view=diff ============================================================================== --- cfe/trunk/test/CodeGen/compound-literal.c (original) +++ cfe/trunk/test/CodeGen/compound-literal.c Mon Feb 11 14:54:27 2019 @@ -11,6 +11,11 @@ _Complex double * x = &(_Complex double) typedef int v4i32 __attribute((vector_size(16))); v4i32 *y = &(v4i32){1,2,3,4}; +// Check generated code for GNU constant array init from compound literal, +// for a global variable. +// CHECK: @compound_array = global [8 x i32] [i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 8] +int compound_array[] = __extension__(__builtin_choose_expr(0, 0, _Generic(1, int: (int[]){1, 2, 3, 4, 5, 6, 7, 8}))); + void xxx() { int* a = &(int){1}; struct s {int a, b, c;} * b = &(struct s) {1, 2, 3}; @@ -82,3 +87,13 @@ int compareMyCLH() { const void *b = MyCLH; return a == b; } + +// Check generated code for GNU constant array init from compound literal, +// for a local variable. +// CHECK-LABEL: define i32 @compound_array_fn() +// CHECK: [[COMPOUND_ARRAY:%.*]] = alloca [8 x i32] +// CHECK: call void @llvm.memcpy.p0i8.p0i8.i64({{.*}}, i64 32, i1 false) +int compound_array_fn() { + int compound_array[] = (int[]){1,2,3,4,5,6,7,8}; + return compound_array[0]; +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
