[clang] d68aa30 - [clang][Interp] Do r-to-l conversion immediately when returning (#80662)
via cfe-commits
cfe-commits at lists.llvm.org
Thu Feb 15 06:13:16 PST 2024
Author: Timm Baeder
Date: 2024-02-15T15:13:12+01:00
New Revision: d68aa303fe779a29a981d1d4166c45a128aa65d6
URL: https://github.com/llvm/llvm-project/commit/d68aa303fe779a29a981d1d4166c45a128aa65d6
DIFF: https://github.com/llvm/llvm-project/commit/d68aa303fe779a29a981d1d4166c45a128aa65d6.diff
LOG: [clang][Interp] Do r-to-l conversion immediately when returning (#80662)
First, we need to register local constant variables in C, so we get the
same diagnostic behavior as the current interpeter.
Second, when returning an LValue (as a Pointer), which we eventually
convert to an RValue, we need to do the conversion immediately when
saving the Pointer in the EvaluationResult. Otherwise, we will possibly
deallocate the data before doing the conversion (which will look at the
Block*).
Added:
Modified:
clang/lib/AST/Interp/ByteCodeExprGen.cpp
clang/lib/AST/Interp/Context.cpp
clang/lib/AST/Interp/EvalEmitter.cpp
clang/lib/AST/Interp/EvalEmitter.h
clang/lib/AST/Interp/EvaluationResult.h
clang/test/AST/Interp/c.c
clang/test/Sema/warn-char-subscripts.c
Removed:
################################################################################
diff --git a/clang/lib/AST/Interp/ByteCodeExprGen.cpp b/clang/lib/AST/Interp/ByteCodeExprGen.cpp
index 988765972a36e6..31e7f02dd4305c 100644
--- a/clang/lib/AST/Interp/ByteCodeExprGen.cpp
+++ b/clang/lib/AST/Interp/ByteCodeExprGen.cpp
@@ -3243,8 +3243,7 @@ bool ByteCodeExprGen<Emitter>::VisitDeclRefExpr(const DeclRefExpr *E) {
// This happens in C.
if (!Ctx.getLangOpts().CPlusPlus) {
if (const auto *VD = dyn_cast<VarDecl>(D);
- VD && VD->hasGlobalStorage() && VD->getAnyInitializer() &&
- VD->getType().isConstQualified()) {
+ VD && VD->getAnyInitializer() && VD->getType().isConstQualified()) {
if (!this->visitVarDecl(VD))
return false;
// Retry.
diff --git a/clang/lib/AST/Interp/Context.cpp b/clang/lib/AST/Interp/Context.cpp
index 7396db22943663..6068b1a5680c83 100644
--- a/clang/lib/AST/Interp/Context.cpp
+++ b/clang/lib/AST/Interp/Context.cpp
@@ -44,7 +44,7 @@ bool Context::evaluateAsRValue(State &Parent, const Expr *E, APValue &Result) {
assert(Stk.empty());
ByteCodeExprGen<EvalEmitter> C(*this, *P, Parent, Stk, Result);
- auto Res = C.interpretExpr(E);
+ auto Res = C.interpretExpr(E, /*ConvertResultToRValue=*/E->isGLValue());
if (Res.isInvalid()) {
Stk.clear();
@@ -58,16 +58,7 @@ bool Context::evaluateAsRValue(State &Parent, const Expr *E, APValue &Result) {
Stk.clear();
#endif
- // Implicit lvalue-to-rvalue conversion.
- if (E->isGLValue()) {
- std::optional<APValue> RValueResult = Res.toRValue();
- if (!RValueResult) {
- return false;
- }
- Result = *RValueResult;
- } else {
- Result = Res.toAPValue();
- }
+ Result = Res.toAPValue();
return true;
}
@@ -120,7 +111,8 @@ bool Context::evaluateAsInitializer(State &Parent, const VarDecl *VD,
!Res.checkFullyInitialized(C.getState()))
return false;
- // lvalue-to-rvalue conversion.
+ // lvalue-to-rvalue conversion. We do this manually here so we can
+ // examine the result above before converting and returning it.
std::optional<APValue> RValueResult = Res.toRValue();
if (!RValueResult)
return false;
diff --git a/clang/lib/AST/Interp/EvalEmitter.cpp b/clang/lib/AST/Interp/EvalEmitter.cpp
index c1e4ce3ebb0729..f14023a23af9b3 100644
--- a/clang/lib/AST/Interp/EvalEmitter.cpp
+++ b/clang/lib/AST/Interp/EvalEmitter.cpp
@@ -33,7 +33,9 @@ EvalEmitter::~EvalEmitter() {
}
}
-EvaluationResult EvalEmitter::interpretExpr(const Expr *E) {
+EvaluationResult EvalEmitter::interpretExpr(const Expr *E,
+ bool ConvertResultToRValue) {
+ this->ConvertResultToRValue = ConvertResultToRValue;
EvalResult.setSource(E);
if (!this->visitExpr(E) && EvalResult.empty())
@@ -119,12 +121,26 @@ template <PrimType OpType> bool EvalEmitter::emitRet(const SourceInfo &Info) {
template <> bool EvalEmitter::emitRet<PT_Ptr>(const SourceInfo &Info) {
if (!isActive())
return true;
- EvalResult.setPointer(S.Stk.pop<Pointer>());
+
+ const Pointer &Ptr = S.Stk.pop<Pointer>();
+ // Implicitly convert lvalue to rvalue, if requested.
+ if (ConvertResultToRValue) {
+ if (std::optional<APValue> V = Ptr.toRValue(Ctx)) {
+ EvalResult.setValue(*V);
+ } else {
+ return false;
+ }
+ } else {
+ EvalResult.setPointer(Ptr);
+ }
+
return true;
}
template <> bool EvalEmitter::emitRet<PT_FnPtr>(const SourceInfo &Info) {
if (!isActive())
return true;
+ // Function pointers cannot be converted to rvalues.
+ assert(!ConvertResultToRValue);
EvalResult.setFunctionPointer(S.Stk.pop<FunctionPointer>());
return true;
}
diff --git a/clang/lib/AST/Interp/EvalEmitter.h b/clang/lib/AST/Interp/EvalEmitter.h
index deb2ebc4e61fa0..8159e489f168e3 100644
--- a/clang/lib/AST/Interp/EvalEmitter.h
+++ b/clang/lib/AST/Interp/EvalEmitter.h
@@ -34,7 +34,8 @@ class EvalEmitter : public SourceMapper {
using AddrTy = uintptr_t;
using Local = Scope::Local;
- EvaluationResult interpretExpr(const Expr *E);
+ EvaluationResult interpretExpr(const Expr *E,
+ bool ConvertResultToRValue = false);
EvaluationResult interpretDecl(const VarDecl *VD);
InterpState &getState() { return S; }
@@ -86,6 +87,8 @@ class EvalEmitter : public SourceMapper {
InterpState S;
/// Location to write the result to.
EvaluationResult EvalResult;
+ /// Whether the result should be converted to an RValue.
+ bool ConvertResultToRValue = false;
/// Temporaries which require storage.
llvm::DenseMap<unsigned, std::unique_ptr<char[]>> Locals;
diff --git a/clang/lib/AST/Interp/EvaluationResult.h b/clang/lib/AST/Interp/EvaluationResult.h
index 2b9fc16f1a0abc..52a6c011e39e1b 100644
--- a/clang/lib/AST/Interp/EvaluationResult.h
+++ b/clang/lib/AST/Interp/EvaluationResult.h
@@ -56,8 +56,8 @@ class EvaluationResult final {
void setSource(DeclTy D) { Source = D; }
void setValue(const APValue &V) {
+ // V could still be an LValue.
assert(empty());
- assert(!V.isLValue());
Value = std::move(V);
Kind = RValue;
}
diff --git a/clang/test/AST/Interp/c.c b/clang/test/AST/Interp/c.c
index 85c195d33a96d7..31cd2729f0bc72 100644
--- a/clang/test/AST/Interp/c.c
+++ b/clang/test/AST/Interp/c.c
@@ -125,3 +125,16 @@ struct XY { int before; struct XX xx, *xp; float* after; } xy[] = {
0, // all-warning {{initializer overrides prior initialization of this subobject}}
&xy[2].xx.a, &xy[2].xx, &global_float
};
+
+void t14(void) {
+ int array[256] = { 0 }; // expected-note {{array 'array' declared here}} \
+ // pedantic-expected-note {{array 'array' declared here}} \
+ // ref-note {{array 'array' declared here}} \
+ // pedantic-ref-note {{array 'array' declared here}}
+ const char b = -1;
+ int val = array[b]; // expected-warning {{array index -1 is before the beginning of the array}} \
+ // pedantic-expected-warning {{array index -1 is before the beginning of the array}} \
+ // ref-warning {{array index -1 is before the beginning of the array}} \
+ // pedantic-ref-warning {{array index -1 is before the beginning of the array}}
+
+}
diff --git a/clang/test/Sema/warn-char-subscripts.c b/clang/test/Sema/warn-char-subscripts.c
index 0a012f68feae07..c2f7a3731d72c8 100644
--- a/clang/test/Sema/warn-char-subscripts.c
+++ b/clang/test/Sema/warn-char-subscripts.c
@@ -1,4 +1,5 @@
// RUN: %clang_cc1 -Wchar-subscripts -fsyntax-only -verify %s
+// RUN: %clang_cc1 -Wchar-subscripts -fsyntax-only -verify %s -fexperimental-new-constant-interpreter
void t1(void) {
int array[1] = { 0 };
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