Bug Summary

File:tools/clang/lib/Format/AffectedRangeManager.cpp
Warning:line 134, column 20
Access to field 'NewlinesBefore' results in a dereference of a null pointer (loaded from field 'First')

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name AffectedRangeManager.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-eagerly-assume -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -mrelocation-model pic -pic-level 2 -mthread-model posix -relaxed-aliasing -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-7/lib/clang/7.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-7~svn329677/build-llvm/tools/clang/lib/Format -I /build/llvm-toolchain-snapshot-7~svn329677/tools/clang/lib/Format -I /build/llvm-toolchain-snapshot-7~svn329677/tools/clang/include -I /build/llvm-toolchain-snapshot-7~svn329677/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-7~svn329677/build-llvm/include -I /build/llvm-toolchain-snapshot-7~svn329677/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/c++/7.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/x86_64-linux-gnu/c++/7.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/x86_64-linux-gnu/c++/7.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/c++/7.3.0/backward -internal-isystem /usr/include/clang/7.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-7/lib/clang/7.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-7~svn329677/build-llvm/tools/clang/lib/Format -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -fobjc-runtime=gcc -fno-common -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-checker optin.performance.Padding -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2018-04-11-031539-24776-1 -x c++ /build/llvm-toolchain-snapshot-7~svn329677/tools/clang/lib/Format/AffectedRangeManager.cpp
1//===--- AffectedRangeManager.cpp - Format C++ code -----------------------===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9///
10/// \file
11/// \brief This file implements AffectRangeManager class.
12///
13//===----------------------------------------------------------------------===//
14
15#include "AffectedRangeManager.h"
16
17#include "FormatToken.h"
18#include "TokenAnnotator.h"
19
20namespace clang {
21namespace format {
22
23bool AffectedRangeManager::computeAffectedLines(
24 SmallVectorImpl<AnnotatedLine *>::iterator I,
25 SmallVectorImpl<AnnotatedLine *>::iterator E) {
26 bool SomeLineAffected = false;
27 const AnnotatedLine *PreviousLine = nullptr;
28 while (I != E) {
1
Assuming 'I' is not equal to 'E'
2
Loop condition is true. Entering loop body
6
Loop condition is true. Entering loop body
29 AnnotatedLine *Line = *I;
30 Line->LeadingEmptyLinesAffected = affectsLeadingEmptyLines(*Line->First);
31
32 // If a line is part of a preprocessor directive, it needs to be formatted
33 // if any token within the directive is affected.
34 if (Line->InPPDirective) {
3
Assuming the condition is false
4
Taking false branch
7
Assuming the condition is false
8
Taking false branch
35 FormatToken *Last = Line->Last;
36 SmallVectorImpl<AnnotatedLine *>::iterator PPEnd = I + 1;
37 while (PPEnd != E && !(*PPEnd)->First->HasUnescapedNewline) {
38 Last = (*PPEnd)->Last;
39 ++PPEnd;
40 }
41
42 if (affectsTokenRange(*Line->First, *Last,
43 /*IncludeLeadingNewlines=*/false)) {
44 SomeLineAffected = true;
45 markAllAsAffected(I, PPEnd);
46 }
47 I = PPEnd;
48 continue;
49 }
50
51 if (nonPPLineAffected(Line, PreviousLine))
5
Taking false branch
9
Calling 'AffectedRangeManager::nonPPLineAffected'
52 SomeLineAffected = true;
53
54 PreviousLine = Line;
55 ++I;
56 }
57 return SomeLineAffected;
58}
59
60bool AffectedRangeManager::affectsCharSourceRange(
61 const CharSourceRange &Range) {
62 for (SmallVectorImpl<CharSourceRange>::const_iterator I = Ranges.begin(),
63 E = Ranges.end();
64 I != E; ++I) {
65 if (!SourceMgr.isBeforeInTranslationUnit(Range.getEnd(), I->getBegin()) &&
66 !SourceMgr.isBeforeInTranslationUnit(I->getEnd(), Range.getBegin()))
67 return true;
68 }
69 return false;
70}
71
72bool AffectedRangeManager::affectsTokenRange(const FormatToken &First,
73 const FormatToken &Last,
74 bool IncludeLeadingNewlines) {
75 SourceLocation Start = First.WhitespaceRange.getBegin();
76 if (!IncludeLeadingNewlines)
77 Start = Start.getLocWithOffset(First.LastNewlineOffset);
78 SourceLocation End = Last.getStartOfNonWhitespace();
79 End = End.getLocWithOffset(Last.TokenText.size());
80 CharSourceRange Range = CharSourceRange::getCharRange(Start, End);
81 return affectsCharSourceRange(Range);
82}
83
84bool AffectedRangeManager::affectsLeadingEmptyLines(const FormatToken &Tok) {
85 CharSourceRange EmptyLineRange = CharSourceRange::getCharRange(
86 Tok.WhitespaceRange.getBegin(),
87 Tok.WhitespaceRange.getBegin().getLocWithOffset(Tok.LastNewlineOffset));
88 return affectsCharSourceRange(EmptyLineRange);
89}
90
91void AffectedRangeManager::markAllAsAffected(
92 SmallVectorImpl<AnnotatedLine *>::iterator I,
93 SmallVectorImpl<AnnotatedLine *>::iterator E) {
94 while (I != E) {
95 (*I)->Affected = true;
96 markAllAsAffected((*I)->Children.begin(), (*I)->Children.end());
97 ++I;
98 }
99}
100
101bool AffectedRangeManager::nonPPLineAffected(
102 AnnotatedLine *Line, const AnnotatedLine *PreviousLine) {
103 bool SomeLineAffected = false;
104 Line->ChildrenAffected =
105 computeAffectedLines(Line->Children.begin(), Line->Children.end());
10
Value assigned to field 'First'
106 if (Line->ChildrenAffected)
11
Assuming the condition is false
12
Taking false branch
107 SomeLineAffected = true;
108
109 // Stores whether one of the line's tokens is directly affected.
110 bool SomeTokenAffected = false;
111 // Stores whether we need to look at the leading newlines of the next token
112 // in order to determine whether it was affected.
113 bool IncludeLeadingNewlines = false;
114
115 // Stores whether the first child line of any of this line's tokens is
116 // affected.
117 bool SomeFirstChildAffected = false;
118
119 for (FormatToken *Tok = Line->First; Tok; Tok = Tok->Next) {
13
Assuming pointer value is null
14
Loop condition is false. Execution continues on line 133
120 // Determine whether 'Tok' was affected.
121 if (affectsTokenRange(*Tok, *Tok, IncludeLeadingNewlines))
122 SomeTokenAffected = true;
123
124 // Determine whether the first child of 'Tok' was affected.
125 if (!Tok->Children.empty() && Tok->Children.front()->Affected)
126 SomeFirstChildAffected = true;
127
128 IncludeLeadingNewlines = Tok->Children.empty();
129 }
130
131 // Was this line moved, i.e. has it previously been on the same line as an
132 // affected line?
133 bool LineMoved = PreviousLine && PreviousLine->Affected &&
15
Assuming the condition is true
134 Line->First->NewlinesBefore == 0;
16
Access to field 'NewlinesBefore' results in a dereference of a null pointer (loaded from field 'First')
135
136 bool IsContinuedComment =
137 Line->First->is(tok::comment) && Line->First->Next == nullptr &&
138 Line->First->NewlinesBefore < 2 && PreviousLine &&
139 PreviousLine->Affected && PreviousLine->Last->is(tok::comment);
140
141 if (SomeTokenAffected || SomeFirstChildAffected || LineMoved ||
142 IsContinuedComment) {
143 Line->Affected = true;
144 SomeLineAffected = true;
145 }
146 return SomeLineAffected;
147}
148
149} // namespace format
150} // namespace clang