1 //===--- State.cpp - State chain for the VM and AST Walker ------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 #include "State.h"
10 #include "Frame.h"
11 #include "Program.h"
12 #include "clang/AST/ASTContext.h"
13 #include "clang/AST/CXXInheritance.h"
14 #include "clang/AST/OptionalDiagnostic.h"
15
16 using namespace clang;
17 using namespace clang::interp;
18
~State()19 State::~State() {}
20
FFDiag(SourceLocation Loc,diag::kind DiagId,unsigned ExtraNotes)21 OptionalDiagnostic State::FFDiag(SourceLocation Loc, diag::kind DiagId,
22 unsigned ExtraNotes) {
23 return diag(Loc, DiagId, ExtraNotes, false);
24 }
25
FFDiag(const Expr * E,diag::kind DiagId,unsigned ExtraNotes)26 OptionalDiagnostic State::FFDiag(const Expr *E, diag::kind DiagId,
27 unsigned ExtraNotes) {
28 if (getEvalStatus().Diag)
29 return diag(E->getExprLoc(), DiagId, ExtraNotes, false);
30 setActiveDiagnostic(false);
31 return OptionalDiagnostic();
32 }
33
FFDiag(const SourceInfo & SI,diag::kind DiagId,unsigned ExtraNotes)34 OptionalDiagnostic State::FFDiag(const SourceInfo &SI, diag::kind DiagId,
35 unsigned ExtraNotes) {
36 if (getEvalStatus().Diag)
37 return diag(SI.getLoc(), DiagId, ExtraNotes, false);
38 setActiveDiagnostic(false);
39 return OptionalDiagnostic();
40 }
41
CCEDiag(SourceLocation Loc,diag::kind DiagId,unsigned ExtraNotes)42 OptionalDiagnostic State::CCEDiag(SourceLocation Loc, diag::kind DiagId,
43 unsigned ExtraNotes) {
44 // Don't override a previous diagnostic. Don't bother collecting
45 // diagnostics if we're evaluating for overflow.
46 if (!getEvalStatus().Diag || !getEvalStatus().Diag->empty()) {
47 setActiveDiagnostic(false);
48 return OptionalDiagnostic();
49 }
50 return diag(Loc, DiagId, ExtraNotes, true);
51 }
52
CCEDiag(const Expr * E,diag::kind DiagId,unsigned ExtraNotes)53 OptionalDiagnostic State::CCEDiag(const Expr *E, diag::kind DiagId,
54 unsigned ExtraNotes) {
55 return CCEDiag(E->getExprLoc(), DiagId, ExtraNotes);
56 }
57
CCEDiag(const SourceInfo & SI,diag::kind DiagId,unsigned ExtraNotes)58 OptionalDiagnostic State::CCEDiag(const SourceInfo &SI, diag::kind DiagId,
59 unsigned ExtraNotes) {
60 return CCEDiag(SI.getLoc(), DiagId, ExtraNotes);
61 }
62
Note(SourceLocation Loc,diag::kind DiagId)63 OptionalDiagnostic State::Note(SourceLocation Loc, diag::kind DiagId) {
64 if (!hasActiveDiagnostic())
65 return OptionalDiagnostic();
66 return OptionalDiagnostic(&addDiag(Loc, DiagId));
67 }
68
addNotes(ArrayRef<PartialDiagnosticAt> Diags)69 void State::addNotes(ArrayRef<PartialDiagnosticAt> Diags) {
70 if (hasActiveDiagnostic())
71 llvm::append_range(*getEvalStatus().Diag, Diags);
72 }
73
report(SourceLocation Loc,diag::kind DiagId)74 DiagnosticBuilder State::report(SourceLocation Loc, diag::kind DiagId) {
75 return getASTContext().getDiagnostics().Report(Loc, DiagId);
76 }
77
78 /// Add a diagnostic to the diagnostics list.
addDiag(SourceLocation Loc,diag::kind DiagId)79 PartialDiagnostic &State::addDiag(SourceLocation Loc, diag::kind DiagId) {
80 PartialDiagnostic PD(DiagId, getASTContext().getDiagAllocator());
81 getEvalStatus().Diag->push_back(std::make_pair(Loc, PD));
82 return getEvalStatus().Diag->back().second;
83 }
84
diag(SourceLocation Loc,diag::kind DiagId,unsigned ExtraNotes,bool IsCCEDiag)85 OptionalDiagnostic State::diag(SourceLocation Loc, diag::kind DiagId,
86 unsigned ExtraNotes, bool IsCCEDiag) {
87 Expr::EvalStatus &EvalStatus = getEvalStatus();
88 if (EvalStatus.Diag) {
89 if (hasPriorDiagnostic()) {
90 return OptionalDiagnostic();
91 }
92
93 unsigned CallStackNotes = getCallStackDepth() - 1;
94 unsigned Limit =
95 getASTContext().getDiagnostics().getConstexprBacktraceLimit();
96 if (Limit)
97 CallStackNotes = std::min(CallStackNotes, Limit + 1);
98 if (checkingPotentialConstantExpression())
99 CallStackNotes = 0;
100
101 setActiveDiagnostic(true);
102 setFoldFailureDiagnostic(!IsCCEDiag);
103 EvalStatus.Diag->clear();
104 EvalStatus.Diag->reserve(1 + ExtraNotes + CallStackNotes);
105 addDiag(Loc, DiagId);
106 if (!checkingPotentialConstantExpression()) {
107 addCallStack(Limit);
108 }
109 return OptionalDiagnostic(&(*EvalStatus.Diag)[0].second);
110 }
111 setActiveDiagnostic(false);
112 return OptionalDiagnostic();
113 }
114
getLangOpts() const115 const LangOptions &State::getLangOpts() const {
116 return getASTContext().getLangOpts();
117 }
118
addCallStack(unsigned Limit)119 void State::addCallStack(unsigned Limit) {
120 // Determine which calls to skip, if any.
121 unsigned ActiveCalls = getCallStackDepth() - 1;
122 unsigned SkipStart = ActiveCalls, SkipEnd = SkipStart;
123 if (Limit && Limit < ActiveCalls) {
124 SkipStart = Limit / 2 + Limit % 2;
125 SkipEnd = ActiveCalls - Limit / 2;
126 }
127
128 // Walk the call stack and add the diagnostics.
129 unsigned CallIdx = 0;
130 const Frame *Top = getCurrentFrame();
131 const Frame *Bottom = getBottomFrame();
132 for (const Frame *F = Top; F != Bottom; F = F->getCaller(), ++CallIdx) {
133 SourceRange CallRange = F->getCallRange();
134
135 // Skip this call?
136 if (CallIdx >= SkipStart && CallIdx < SkipEnd) {
137 if (CallIdx == SkipStart) {
138 // Note that we're skipping calls.
139 addDiag(CallRange.getBegin(), diag::note_constexpr_calls_suppressed)
140 << unsigned(ActiveCalls - Limit);
141 }
142 continue;
143 }
144
145 // Use a different note for an inheriting constructor, because from the
146 // user's perspective it's not really a function at all.
147 if (const auto *CD =
148 dyn_cast_if_present<CXXConstructorDecl>(F->getCallee());
149 CD && CD->isInheritingConstructor()) {
150 addDiag(CallRange.getBegin(),
151 diag::note_constexpr_inherited_ctor_call_here)
152 << CD->getParent();
153 continue;
154 }
155
156 SmallString<128> Buffer;
157 llvm::raw_svector_ostream Out(Buffer);
158 F->describe(Out);
159 if (!Buffer.empty())
160 addDiag(CallRange.getBegin(), diag::note_constexpr_call_here)
161 << Out.str() << CallRange;
162 }
163 }
164