clang-tidy: Fix 'cppcoreguidelines-pro-type-member-init' warnings

Also, fix undefined behavior when setting and reading different field of
a union (Lexer, Token) - according to the C++ Standard, it is not
allowed to use a union to zero members of a struct.

Treat these warnings as errors now.

Change-Id: I0f6d071217ef55e2c75c51138fcff47048eca62f
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

12 files changed, 19 insertions, 42 deletions

diff --git a/src/lib/corelib/api/projectfileupdater.h b/src/lib/corelib/api/projectfileupdater.h
index 3459d788e..ded4e08a9 100644
--- a/src/lib/corelib/api/projectfileupdater.h
+++ b/src/lib/corelib/api/projectfileupdater.h
@@ -85,7 +85,7 @@ private:
 
     const QString m_projectFile;
     CodeLocation m_itemPosition;
-    int m_lineOffset;
+    int m_lineOffset = 0;
 };
 
 
diff --git a/src/lib/corelib/buildgraph/artifact.cpp b/src/lib/corelib/buildgraph/artifact.cpp
index e82919560..8d3a8bd3f 100644
--- a/src/lib/corelib/buildgraph/artifact.cpp
+++ b/src/lib/corelib/buildgraph/artifact.cpp
@@ -51,9 +51,13 @@
 namespace qbs {
 namespace Internal {
 
-Artifact::Artifact()
+Artifact::Artifact() :
+    artifactType(ArtifactType::Unknown),
+    inputsScanned(false),
+    timestampRetrieved(false),
+    alwaysUpdated(false),
+    oldDataPossiblyPresent(true)
 {
-    initialize();
 }
 
 Artifact::~Artifact()
@@ -120,15 +124,6 @@ RuleNode *Artifact::producer() const
     return *ruleNodes.begin();
 }
 
-void Artifact::initialize()
-{
-    artifactType = Unknown;
-    inputsScanned = false;
-    timestampRetrieved = false;
-    alwaysUpdated = true;
-    oldDataPossiblyPresent = true;
-}
-
 const TypeFilter<Artifact> Artifact::parentArtifacts() const
 {
     return TypeFilter<Artifact>(parents);
diff --git a/src/lib/corelib/buildgraph/artifact.h b/src/lib/corelib/buildgraph/artifact.h
index ee3acea59..2572a3b52 100644
--- a/src/lib/corelib/buildgraph/artifact.h
+++ b/src/lib/corelib/buildgraph/artifact.h
@@ -114,7 +114,6 @@ public:
     bool alwaysUpdated : 1;
     bool oldDataPossiblyPresent : 1;
 
-    void initialize();
     const TypeFilter<Artifact> parentArtifacts() const;
     const TypeFilter<Artifact> childArtifacts() const;
     void onChildDisconnected(BuildGraphNode *child) override;
diff --git a/src/lib/corelib/tools/fileinfo.cpp b/src/lib/corelib/tools/fileinfo.cpp
index 3bba06ada..8f6b285d4 100644
--- a/src/lib/corelib/tools/fileinfo.cpp
+++ b/src/lib/corelib/tools/fileinfo.cpp
@@ -450,7 +450,7 @@ static QByteArray storedLinkTarget(const QString &filePath)
     const QByteArray nativeFilePath = QFile::encodeName(filePath);
     ssize_t len;
     while (true) {
-        struct stat sb;
+        struct stat sb{};
         if (lstat(nativeFilePath.constData(), &sb)) {
             qWarning("storedLinkTarget: lstat for %s failed with error code %d",
                      nativeFilePath.constData(), errno);
diff --git a/src/lib/corelib/tools/launcherpackets.h b/src/lib/corelib/tools/launcherpackets.h
index 4306718fd..b3eac4320 100644
--- a/src/lib/corelib/tools/launcherpackets.h
+++ b/src/lib/corelib/tools/launcherpackets.h
@@ -145,7 +145,7 @@ class ProcessErrorPacket : public LauncherPacket
 public:
     ProcessErrorPacket(quintptr token);
 
-    QProcess::ProcessError error;
+    QProcess::ProcessError error = QProcess::UnknownError;
     QString errorString;
 
 private:
diff --git a/src/lib/corelib/tools/msvcinfo.cpp b/src/lib/corelib/tools/msvcinfo.cpp
index 462f921a4..5097ca2e1 100644
--- a/src/lib/corelib/tools/msvcinfo.cpp
+++ b/src/lib/corelib/tools/msvcinfo.cpp
@@ -344,7 +344,7 @@ static std::vector<MSVCInstallInfo> retrieveInstancesFromVSWhere(
                      .append(formatVswhereOutput(stdOut, stdErr));
         return result;
     }
-    QJsonParseError parseError;
+    QJsonParseError parseError{};
     QJsonDocument jsonOutput = QJsonDocument::fromJson(vsWhere.readAllStandardOutput(),
                                                        &parseError);
     if (parseError.error != QJsonParseError::NoError) {
diff --git a/src/plugins/scanner/cpp/Lexer.cpp b/src/plugins/scanner/cpp/Lexer.cpp
index 5bf5b2367..16556ac73 100644
--- a/src/plugins/scanner/cpp/Lexer.cpp
+++ b/src/plugins/scanner/cpp/Lexer.cpp
@@ -64,7 +64,6 @@ namespace CPlusPlus {
 
 Lexer::Lexer(const char *firstChar, const char *lastChar)
     : _state(State_Default),
-      _flags(0),
       _currentLine(1)
 {
     setSource(firstChar, lastChar);
diff --git a/src/plugins/scanner/cpp/Lexer.h b/src/plugins/scanner/cpp/Lexer.h
index 1cf829ebb..8f55f84e9 100644
--- a/src/plugins/scanner/cpp/Lexer.h
+++ b/src/plugins/scanner/cpp/Lexer.h
@@ -151,10 +151,7 @@ private:
     const char *_tokenStart = nullptr;
     unsigned char _yychar = 0;
     int _state = 0;
-    union {
-        unsigned _flags;
-        Flags f;
-    };
+    Flags f{};
     unsigned _currentLine = 0;
 };
 
diff --git a/src/plugins/scanner/cpp/Token.cpp b/src/plugins/scanner/cpp/Token.cpp
index 603918f63..b488bf0d4 100644
--- a/src/plugins/scanner/cpp/Token.cpp
+++ b/src/plugins/scanner/cpp/Token.cpp
@@ -113,16 +113,9 @@ static const char *token_names[] = {
 
 };
 
-Token::Token() :
-    flags(0), offset(0), ptr(nullptr)
-{
-}
-
-Token::~Token() = default;
-
 void Token::reset()
 {
-    flags = 0;
+    f = {};
     offset = 0;
     ptr = nullptr;
 }
diff --git a/src/plugins/scanner/cpp/Token.h b/src/plugins/scanner/cpp/Token.h
index 846aa5a12..a042c1087 100644
--- a/src/plugins/scanner/cpp/Token.h
+++ b/src/plugins/scanner/cpp/Token.h
@@ -295,9 +295,6 @@ enum Kind {
 class CPLUSPLUS_EXPORT Token
 {
 public:
-    Token();
-    ~Token();
-
     inline bool is(unsigned k) const    { return f.kind == k; }
     inline bool isNot(unsigned k) const { return f.kind != k; }
 #ifndef CPLUSPLUS_NO_PARSER
@@ -348,15 +345,12 @@ public:
         unsigned pad        : 3;
         unsigned length     : 16;
     };
-    union {
-        unsigned flags;
-        Flags f;
-    };
+    Flags f{};
 
     unsigned offset = 0;
 
     union {
-        void *ptr;
+        void *ptr = nullptr;
 #ifndef CPLUSPLUS_NO_PARSER
         const Literal *literal;
         const NumericLiteral *number;
diff --git a/src/plugins/scanner/cpp/cppscanner.cpp b/src/plugins/scanner/cpp/cppscanner.cpp
index 191a0f8d2..0acb25172 100644
--- a/src/plugins/scanner/cpp/cppscanner.cpp
+++ b/src/plugins/scanner/cpp/cppscanner.cpp
@@ -65,9 +65,9 @@ using namespace CPlusPlus;
 
 struct ScanResult
 {
-    char *fileName;
-    int size;
-    int flags;
+    char *fileName = nullptr;
+    int size = 0;
+    int flags = 0;
 };
 
 struct Opaq
@@ -226,7 +226,7 @@ static void *openScanner(const unsigned short *filePath, const char *fileTags, i
         return nullptr;
     }
 
-    struct stat s;
+    struct stat s{};
     int r = fstat(opaque->fd, &s);
     if (r != 0)
         return nullptr;
diff --git a/src/plugins/scanner/qt/qtscanner.cpp b/src/plugins/scanner/qt/qtscanner.cpp
index 22fdcb79d..22ef294d0 100644
--- a/src/plugins/scanner/qt/qtscanner.cpp
+++ b/src/plugins/scanner/qt/qtscanner.cpp
@@ -107,7 +107,7 @@ static void *openScannerQrc(const unsigned short *filePath, const char *fileTags
         return nullptr;
     }
 
-    struct stat s;
+    struct stat s{};
     int r = fstat(opaque->fd, &s);
     if (r != 0)
         return nullptr;