r285544 - Add support for __builtin_alloca_with_align
David Majnemer via cfe-commits
cfe-commits at lists.llvm.org
Mon Oct 31 11:17:45 PDT 2016
Added in r285609.
On Mon, Oct 31, 2016 at 9:21 AM, Hal Finkel <hfinkel at anl.gov> wrote:
> Hi David,
>
> On Reid's patch for this (D25581), Richard said, "This takes the alignment
> in bits? That's so ridiculously dumb that I would feel bad about accepting
> this patch unless it comes with a warning for people writing the
> obvious-but-wrong __builtin_alloca_with_align(sizeof(T), alignof(T))". We
> should add the warning.
>
> Thanks again,
> Hal
>
> ----- Original Message -----
> > From: "David Majnemer via cfe-commits" <cfe-commits at lists.llvm.org>
> > To: cfe-commits at lists.llvm.org
> > Sent: Monday, October 31, 2016 12:37:49 AM
> > Subject: r285544 - Add support for __builtin_alloca_with_align
> >
> > Author: majnemer
> > Date: Mon Oct 31 00:37:48 2016
> > New Revision: 285544
> >
> > URL: http://llvm.org/viewvc/llvm-project?rev=285544&view=rev
> > Log:
> > Add support for __builtin_alloca_with_align
> >
> > __builtin_alloca always uses __BIGGEST_ALIGNMENT__ for the alignment
> > of
> > the allocation. __builtin_alloca_with_align allows the programmer to
> > specify the alignment of the allocation.
> >
> > This fixes PR30658.
> >
> > Added:
> > cfe/trunk/test/Sema/builtin-alloca-with-align.c
> > Modified:
> > cfe/trunk/include/clang/Basic/Builtins.def
> > cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
> > cfe/trunk/include/clang/Sema/Sema.h
> > cfe/trunk/lib/CodeGen/CGBuiltin.cpp
> > cfe/trunk/lib/Sema/SemaChecking.cpp
> > cfe/trunk/lib/StaticAnalyzer/Checkers/BuiltinFunctionChecker.cpp
> > cfe/trunk/lib/StaticAnalyzer/Checkers/UnixAPIChecker.cpp
> > cfe/trunk/test/CodeGen/builtins-ms.c
> >
> > Modified: cfe/trunk/include/clang/Basic/Builtins.def
> > URL:
> > http://llvm.org/viewvc/llvm-project/cfe/trunk/include/
> clang/Basic/Builtins.def?rev=285544&r1=285543&r2=285544&view=diff
> > ============================================================
> ==================
> > --- cfe/trunk/include/clang/Basic/Builtins.def (original)
> > +++ cfe/trunk/include/clang/Basic/Builtins.def Mon Oct 31 00:37:48
> > 2016
> > @@ -512,6 +512,7 @@ BUILTIN(__builtin_unreachable, "v", "nr"
> > BUILTIN(__builtin_shufflevector, "v." , "nc")
> > BUILTIN(__builtin_convertvector, "v." , "nct")
> > BUILTIN(__builtin_alloca, "v*z" , "Fn")
> > +BUILTIN(__builtin_alloca_with_align, "v*zIz", "Fn")
> > BUILTIN(__builtin_call_with_static_chain, "v.", "nt")
> >
> > // "Overloaded" Atomic operator builtins. These are overloaded to
> > support data
> >
> > Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
> > URL:
> > http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/
> DiagnosticSemaKinds.td?rev=285544&r1=285543&r2=285544&view=diff
> > ============================================================
> ==================
> > --- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
> > +++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Mon Oct 31
> > 00:37:48 2016
> > @@ -2440,6 +2440,10 @@ def err_no_accessor_for_property : Error
> > def error_cannot_find_suitable_accessor : Error<
> > "cannot find suitable %select{getter|setter}0 for property %1">;
> >
> > +def err_alignment_too_small : Error<
> > + "requested alignment must be %0 or greater">;
> > +def err_alignment_too_big : Error<
> > + "requested alignment must be %0 or smaller">;
> > def err_alignment_not_power_of_two : Error<
> > "requested alignment is not a power of 2">;
> > def err_alignment_dependent_typedef_name : Error<
> >
> > Modified: cfe/trunk/include/clang/Sema/Sema.h
> > URL:
> > http://llvm.org/viewvc/llvm-project/cfe/trunk/include/
> clang/Sema/Sema.h?rev=285544&r1=285543&r2=285544&view=diff
> > ============================================================
> ==================
> > --- cfe/trunk/include/clang/Sema/Sema.h (original)
> > +++ cfe/trunk/include/clang/Sema/Sema.h Mon Oct 31 00:37:48 2016
> > @@ -9719,6 +9719,7 @@ public:
> >
> > private:
> > bool SemaBuiltinPrefetch(CallExpr *TheCall);
> > + bool SemaBuiltinAllocaWithAlign(CallExpr *TheCall);
> > bool SemaBuiltinAssume(CallExpr *TheCall);
> > bool SemaBuiltinAssumeAligned(CallExpr *TheCall);
> > bool SemaBuiltinLongjmp(CallExpr *TheCall);
> >
> > Modified: cfe/trunk/lib/CodeGen/CGBuiltin.cpp
> > URL:
> > http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/
> CGBuiltin.cpp?rev=285544&r1=285543&r2=285544&view=diff
> > ============================================================
> ==================
> > --- cfe/trunk/lib/CodeGen/CGBuiltin.cpp (original)
> > +++ cfe/trunk/lib/CodeGen/CGBuiltin.cpp Mon Oct 31 00:37:48 2016
> > @@ -1147,6 +1147,19 @@ RValue CodeGenFunction::EmitBuiltinExpr(
> > AI->setAlignment(SuitableAlignmentInBytes);
> > return RValue::get(AI);
> > }
> > +
> > + case Builtin::BI__builtin_alloca_with_align: {
> > + Value *Size = EmitScalarExpr(E->getArg(0));
> > + Value *AlignmentValue = EmitScalarExpr(E->getArg(1));
> > + auto *AlignmentCI = cast<ConstantInt>(AlignmentValue);
> > + unsigned Alignment = AlignmentCI->getZExtValue();
> > + const TargetInfo &TI = getContext().getTargetInfo();
> > + unsigned AlignmentInBytes = Alignment / TI.getCharWidth();
> > + AllocaInst *AI = Builder.CreateAlloca(Builder.getInt8Ty(),
> > Size);
> > + AI->setAlignment(AlignmentInBytes);
> > + return RValue::get(AI);
> > + }
> > +
> > case Builtin::BIbzero:
> > case Builtin::BI__builtin_bzero: {
> > Address Dest = EmitPointerWithAlignment(E->getArg(0));
> >
> > Modified: cfe/trunk/lib/Sema/SemaChecking.cpp
> > URL:
> > http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/
> SemaChecking.cpp?rev=285544&r1=285543&r2=285544&view=diff
> > ============================================================
> ==================
> > --- cfe/trunk/lib/Sema/SemaChecking.cpp (original)
> > +++ cfe/trunk/lib/Sema/SemaChecking.cpp Mon Oct 31 00:37:48 2016
> > @@ -791,6 +791,10 @@ Sema::CheckBuiltinFunctionCall(FunctionD
> > if (SemaBuiltinPrefetch(TheCall))
> > return ExprError();
> > break;
> > + case Builtin::BI__builtin_alloca_with_align:
> > + if (SemaBuiltinAllocaWithAlign(TheCall))
> > + return ExprError();
> > + break;
> > case Builtin::BI__assume:
> > case Builtin::BI__builtin_assume:
> > if (SemaBuiltinAssume(TheCall))
> > @@ -3902,6 +3906,36 @@ bool Sema::SemaBuiltinAssume(CallExpr *T
> >
> > return false;
> > }
> > +
> > +/// Handle __builtin_assume_aligned. This is declared
> > +/// as (size_t, size_t) where the second size_t must be a power of 2
> > greater
> > +/// than 8.
> > +bool Sema::SemaBuiltinAllocaWithAlign(CallExpr *TheCall) {
> > + // The alignment must be a constant integer.
> > + Expr *Arg = TheCall->getArg(1);
> > +
> > + // We can't check the value of a dependent argument.
> > + if (!Arg->isTypeDependent() && !Arg->isValueDependent()) {
> > + llvm::APSInt Result = Arg->EvaluateKnownConstInt(Context);
> > +
> > + if (!Result.isPowerOf2())
> > + return Diag(TheCall->getLocStart(),
> > + diag::err_alignment_not_power_of_two)
> > + << Arg->getSourceRange();
> > +
> > + if (Result < Context.getCharWidth())
> > + return Diag(TheCall->getLocStart(),
> > diag::err_alignment_too_small)
> > + << (unsigned)Context.getCharWidth()
> > + << Arg->getSourceRange();
> > +
> > + if (Result > INT32_MAX)
> > + return Diag(TheCall->getLocStart(),
> > diag::err_alignment_too_big)
> > + << INT32_MAX
> > + << Arg->getSourceRange();
> > + }
> > +
> > + return false;
> > +}
> >
> > /// Handle __builtin_assume_aligned. This is declared
> > /// as (const void*, size_t, ...) and can take one optional constant
> > int arg.
> >
> > Modified:
> > cfe/trunk/lib/StaticAnalyzer/Checkers/BuiltinFunctionChecker.cpp
> > URL:
> > http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/
> StaticAnalyzer/Checkers/BuiltinFunctionChecker.cpp?
> rev=285544&r1=285543&r2=285544&view=diff
> > ============================================================
> ==================
> > --- cfe/trunk/lib/StaticAnalyzer/Checkers/BuiltinFunctionChecker.cpp
> > (original)
> > +++ cfe/trunk/lib/StaticAnalyzer/Checkers/BuiltinFunctionChecker.cpp
> > Mon Oct 31 00:37:48 2016
> > @@ -55,6 +55,7 @@ bool BuiltinFunctionChecker::evalCall(co
> > return true;
> > }
> >
> > + case Builtin::BI__builtin_alloca_with_align:
> > case Builtin::BI__builtin_alloca: {
> > // FIXME: Refactor into StoreManager itself?
> > MemRegionManager& RM = C.getStoreManager().getRegionManager();
> >
> > Modified: cfe/trunk/lib/StaticAnalyzer/Checkers/UnixAPIChecker.cpp
> > URL:
> > http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/
> StaticAnalyzer/Checkers/UnixAPIChecker.cpp?rev=285544&
> r1=285543&r2=285544&view=diff
> > ============================================================
> ==================
> > --- cfe/trunk/lib/StaticAnalyzer/Checkers/UnixAPIChecker.cpp
> > (original)
> > +++ cfe/trunk/lib/StaticAnalyzer/Checkers/UnixAPIChecker.cpp Mon Oct
> > 31 00:37:48 2016
> > @@ -43,6 +43,7 @@ public:
> > void CheckReallocZero(CheckerContext &C, const CallExpr *CE)
> > const;
> > void CheckReallocfZero(CheckerContext &C, const CallExpr *CE)
> > const;
> > void CheckAllocaZero(CheckerContext &C, const CallExpr *CE) const;
> > + void CheckAllocaWithAlignZero(CheckerContext &C, const CallExpr
> > *CE) const;
> > void CheckVallocZero(CheckerContext &C, const CallExpr *CE) const;
> >
> > typedef void (UnixAPIChecker::*SubChecker)(CheckerContext &,
> > @@ -337,6 +338,11 @@ void UnixAPIChecker::CheckAllocaZero(Che
> > BasicAllocationCheck(C, CE, 1, 0, "alloca");
> > }
> >
> > +void UnixAPIChecker::CheckAllocaWithAlignZero(CheckerContext &C,
> > + const CallExpr *CE)
> > const {
> > + BasicAllocationCheck(C, CE, 2, 0, "__builtin_alloca_with_align");
> > +}
> > +
> > void UnixAPIChecker::CheckVallocZero(CheckerContext &C,
> > const CallExpr *CE) const {
> > BasicAllocationCheck(C, CE, 1, 0, "valloc");
> > @@ -366,6 +372,8 @@ void UnixAPIChecker::checkPreStmt(const
> > .Case("realloc", &UnixAPIChecker::CheckReallocZero)
> > .Case("reallocf", &UnixAPIChecker::CheckReallocfZero)
> > .Cases("alloca", "__builtin_alloca",
> > &UnixAPIChecker::CheckAllocaZero)
> > + .Case("__builtin_alloca_with_align",
> > + &UnixAPIChecker::CheckAllocaWithAlignZero)
> > .Case("valloc", &UnixAPIChecker::CheckVallocZero)
> > .Default(nullptr);
> >
> >
> > Modified: cfe/trunk/test/CodeGen/builtins-ms.c
> > URL:
> > http://llvm.org/viewvc/llvm-project/cfe/trunk/test/
> CodeGen/builtins-ms.c?rev=285544&r1=285543&r2=285544&view=diff
> > ============================================================
> ==================
> > --- cfe/trunk/test/CodeGen/builtins-ms.c (original)
> > +++ cfe/trunk/test/CodeGen/builtins-ms.c Mon Oct 31 00:37:48 2016
> > @@ -1,9 +1,16 @@
> > // RUN: %clang_cc1 %s -emit-llvm -o - -fms-extensions -triple
> > i686-pc-win32 | FileCheck %s
> >
> > -// CHECK-LABEL: define void @test_alloca
> > +// CHECK-LABEL: define void @test_alloca(
> > void capture(void *);
> > void test_alloca(int n) {
> > capture(_alloca(n));
> > // CHECK: %[[arg:.*]] = alloca i8, i32 %{{.*}}, align 16
> > // CHECK: call void @capture(i8* %[[arg]])
> > }
> > +
> > +// CHECK-LABEL: define void @test_alloca_with_align(
> > +void test_alloca_with_align(int n) {
> > + capture(__builtin_alloca_with_align(n, 64));
> > + // CHECK: %[[arg:.*]] = alloca i8, i32 %{{.*}}, align 8
> > + // CHECK: call void @capture(i8* %[[arg]])
> > +}
> >
> > Added: cfe/trunk/test/Sema/builtin-alloca-with-align.c
> > URL:
> > http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/
> builtin-alloca-with-align.c?rev=285544&view=auto
> > ============================================================
> ==================
> > --- cfe/trunk/test/Sema/builtin-alloca-with-align.c (added)
> > +++ cfe/trunk/test/Sema/builtin-alloca-with-align.c Mon Oct 31
> > 00:37:48 2016
> > @@ -0,0 +1,29 @@
> > +// RUN: %clang_cc1 -fsyntax-only -verify %s
> > +
> > +void test1(int a) {
> > + __builtin_alloca_with_align(a, 32);
> > +}
> > +
> > +void test2(int a) {
> > + __builtin_alloca_with_align(a, -32); // expected-error {{requested
> > alignment is not a power of 2}}
> > +}
> > +
> > +void test3(unsigned *b) {
> > + __builtin_alloca_with_align(b, 32); // expected-warning
> > {{incompatible pointer to integer conversion passing 'unsigned int
> > *' to parameter of type}}
> > +}
> > +
> > +void test4(int a) {
> > + __builtin_alloca_with_align(a, 32, 0); // expected-error {{too
> > many arguments to function call, expected 2, have 3}}
> > +}
> > +
> > +void test5(int a) {
> > + __builtin_alloca_with_align(a, 31); // expected-error {{requested
> > alignment is not a power of 2}}
> > +}
> > +
> > +void test6(int a, int j) {
> > + __builtin_alloca_with_align(a, j); // expected-error {{must be a
> > constant integer}}
> > +}
> > +
> > +void test7(int a) {
> > + __builtin_alloca_with_align(a, 2); // expected-error {{requested
> > alignment must be 8 or greater}}
> > +}
> >
> >
> > _______________________________________________
> > cfe-commits mailing list
> > cfe-commits at lists.llvm.org
> > http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
> >
>
> --
> Hal Finkel
> Lead, Compiler Technology and Programming Languages
> Leadership Computing Facility
> Argonne National Laboratory
>
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