yonghong-song updated this revision to Diff 365893.
yonghong-song added a comment.
- fix clant-format warnings.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D107882/new/
https://reviews.llvm.org/D107882
Files:
clang/lib/Sema/SemaType.cpp
clang/test/CodeGen/bpf-vla.c
llvm/include/llvm/ADT/Triple.h
Index: llvm/include/llvm/ADT/Triple.h
===================================================================
--- llvm/include/llvm/ADT/Triple.h
+++ llvm/include/llvm/ADT/Triple.h
@@ -738,6 +738,11 @@
: PointerWidth == 64;
}
+ /// Tests whether the target is BPF (little and big endian).
+ bool isBPF() const {
+ return getArch() == Triple::bpfel || getArch() == Triple::bpfeb;
+ }
+
/// Tests whether the target is MIPS 32-bit (little and big endian).
bool isMIPS32() const {
return getArch() == Triple::mips || getArch() == Triple::mipsel;
Index: clang/test/CodeGen/bpf-vla.c
===================================================================
--- /dev/null
+++ clang/test/CodeGen/bpf-vla.c
@@ -0,0 +1,29 @@
+// REQUIRES: bpf-registered-target
+// RUN: %clang -target bpf -emit-llvm -S -g %s -o - | FileCheck %s
+
+#define AA 40
+struct t {
+ char a[20];
+};
+void foo(void *);
+int test() {
+ const int a = 8;
+ char tmp[AA + sizeof(struct t) + a];
+
+// CHECK: define dso_local i32 @test(
+// CHECK: %tmp = alloca [68 x i8], align 1
+// CHECK-NOT: llvm.stacksave
+
+ foo(tmp);
+ return 0;
+}
+
+int test2(int b) {
+ const int a = 8;
+ char tmp[a + b];
+
+// CHECK: define dso_local i32 @test2(
+// CHECK: llvm.stacksave
+ foo(tmp);
+ return 0;
+}
Index: clang/lib/Sema/SemaType.cpp
===================================================================
--- clang/lib/Sema/SemaType.cpp
+++ clang/lib/Sema/SemaType.cpp
@@ -2279,7 +2279,7 @@
/// ExprError().
static ExprResult checkArraySize(Sema &S, Expr *&ArraySize,
llvm::APSInt &SizeVal, unsigned VLADiag,
- bool VLAIsError) {
+ bool VLAIsError, Sema::AllowFoldKind CanFold) {
if (S.getLangOpts().CPlusPlus14 &&
(VLAIsError ||
!ArraySize->getType()->isIntegralOrUnscopedEnumerationType())) {
@@ -2323,8 +2323,8 @@
}
} Diagnoser(VLADiag, VLAIsError);
- ExprResult R =
- S.VerifyIntegerConstantExpression(ArraySize, &SizeVal, Diagnoser);
+ ExprResult R = S.VerifyIntegerConstantExpression(ArraySize, &SizeVal,
+ Diagnoser, CanFold);
if (Diagnoser.IsVLA)
return ExprResult();
return R;
@@ -2442,10 +2442,20 @@
// VLAs always produce at least a -Wvla diagnostic, sometimes an error.
unsigned VLADiag;
bool VLAIsError;
+ AllowFoldKind CanFold = Sema::NoFold;
if (getLangOpts().OpenCL) {
// OpenCL v1.2 s6.9.d: variable length arrays are not supported.
VLADiag = diag::err_opencl_vla;
VLAIsError = true;
+ } else if (Context.getTargetInfo().getTriple().isBPF()) {
+ // BPF target does not support variable length array, but
+ // we don't force an error here. We will try to do constant
+ // folding for array size as much as possible. LLVM backend
+ // will do some checking and warn users if variable length
+ // array still remains.
+ VLADiag = diag::warn_vla_used;
+ VLAIsError = false;
+ CanFold = Sema::AllowFold;
} else if (getLangOpts().C99) {
VLADiag = diag::warn_vla_used;
VLAIsError = false;
@@ -2471,8 +2481,8 @@
} else if (ArraySize->isTypeDependent() || ArraySize->isValueDependent()) {
T = Context.getDependentSizedArrayType(T, ArraySize, ASM, Quals, Brackets);
} else {
- ExprResult R =
- checkArraySize(*this, ArraySize, ConstVal, VLADiag, VLAIsError);
+ ExprResult R = checkArraySize(*this, ArraySize, ConstVal, VLADiag,
+ VLAIsError, CanFold);
if (R.isInvalid())
return QualType();
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