qhash-namespace: Very qhash() is inside QT_*_NAMESPACE macros

This will only be done if -qt-developer is passed, as it's not
useful for user code

4 files changed, 77 insertions, 5 deletions

diff --git a/src/PreProcessorVisitor.cpp b/src/PreProcessorVisitor.cpp
index cc4bf6c3..2ddf9ffd 100644
--- a/src/PreProcessorVisitor.cpp
+++ b/src/PreProcessorVisitor.cpp
@@ -31,11 +31,37 @@ using namespace std;
 PreProcessorVisitor::PreProcessorVisitor(const clang::CompilerInstance &ci)
     : clang::PPCallbacks()
     , m_ci(ci)
+    , m_sm(ci.getSourceManager())
 {
     Preprocessor &pi = m_ci.getPreprocessor();
     pi.addPPCallbacks(std::unique_ptr<PPCallbacks>(this));
 }
 
+bool PreProcessorVisitor::isBetweenQtNamespaceMacros(SourceLocation loc)
+{
+    if (loc.isInvalid())
+        return false;
+
+    if (loc.isMacroID())
+        loc = m_sm.getExpansionLoc(loc);
+
+    uint fileId = m_sm.getFileID(loc).getHashValue();
+
+    vector<SourceRange> &pairs = m_q_namespace_macro_locations[fileId];
+    for (SourceRange &pair : pairs) {
+        if (pair.getBegin().isInvalid() || pair.getEnd().isInvalid()) {
+            //llvm::errs() << "PreProcessorVisitor::isBetweenQtNamespaceMacros Found invalid location\n";
+            continue; // shouldn't happen
+        }
+
+        if (m_sm.isBeforeInSLocAddrSpace(pair.getBegin(), loc) &&
+            m_sm.isBeforeInSLocAddrSpace(loc, pair.getEnd()))
+            return true;
+    }
+
+    return false;
+}
+
 std::string PreProcessorVisitor::getTokenSpelling(const MacroDefinition &def) const
 {
     if (!def)
@@ -62,6 +88,28 @@ void PreProcessorVisitor::updateQtVersion()
     }
 }
 
+void PreProcessorVisitor::handleQtNamespaceMacro(SourceLocation loc, StringRef name)
+{
+    const bool isBegin = name == "QT_BEGIN_NAMESPACE";
+    uint fileId = m_sm.getFileID(loc).getHashValue();
+    vector<SourceRange> &pairs = m_q_namespace_macro_locations[fileId];
+
+    if (isBegin) {
+        pairs.push_back(SourceRange(loc, {}));
+    } else {
+        if (pairs.empty()) {
+            // llvm::errs() << "FOO Received end!!";
+        } else {
+            SourceRange &range = pairs[pairs.size() - 1];
+            if (range.getBegin().isInvalid()) {
+                // llvm::errs() << "FOO Error received end before a begin\n";
+            } else {
+                range.setEnd(loc);
+            }
+        }
+    }
+}
+
 static int stringToNumber(const string &str)
 {
     if (str.empty())
@@ -71,15 +119,20 @@ static int stringToNumber(const string &str)
 }
 
 void PreProcessorVisitor::MacroExpands(const Token &MacroNameTok, const MacroDefinition &def,
-                                       SourceRange, const MacroArgs *)
+                                       SourceRange range, const MacroArgs *)
 {
-    if (m_qtVersion != -1)
-        return;
-
     IdentifierInfo *ii = MacroNameTok.getIdentifierInfo();
     if (!ii)
         return;
 
+    if (ii->getName() == "QT_BEGIN_NAMESPACE" || ii->getName() == "QT_END_NAMESPACE") {
+        handleQtNamespaceMacro(range.getBegin(), ii->getName());
+        return;
+    }
+
+    if (m_qtVersion != -1)
+        return;
+
     auto name = ii->getName();
     if (name == "QT_VERSION_MAJOR") {
         m_qtMajorVersion = stringToNumber(getTokenSpelling(def));
diff --git a/src/PreProcessorVisitor.h b/src/PreProcessorVisitor.h
index ef2e8da1..7d4c85ce 100644
--- a/src/PreProcessorVisitor.h
+++ b/src/PreProcessorVisitor.h
@@ -31,9 +31,11 @@
 
 #include <string>
 #include <clang/Lex/PPCallbacks.h>
+#include <unordered_map>
 
 namespace clang {
     class CompilerInstance;
+    class SourceManager;
     class SourceRange;
     class Token;
     class MacroDefinition;
@@ -49,18 +51,25 @@ public:
     // Returns for example 050601 (Qt 5.6.1), or -1 if we don't know the version
     int qtVersion() const { return m_qtVersion; }
 
+    bool isBetweenQtNamespaceMacros(clang::SourceLocation loc);
+
 protected:
     void MacroExpands(const clang::Token &MacroNameTok, const clang::MacroDefinition &,
                       clang::SourceRange range, const clang::MacroArgs *) override;
 private:
     std::string getTokenSpelling(const clang::MacroDefinition &) const;
     void updateQtVersion();
+    void handleQtNamespaceMacro(clang::SourceLocation loc, clang::StringRef name);
 
     const clang::CompilerInstance &m_ci;
     int m_qtMajorVersion  = -1;
     int m_qtMinorVersion  = -1;
     int m_qtPatchVersion = -1;
     int m_qtVersion = -1;
+
+    // Indexed by FileId, has a list of QT_BEGIN_NAMESPACE/QT_END_NAMESPACE location
+    std::unordered_map<uint, std::vector<clang::SourceRange>> m_q_namespace_macro_locations;
+    const clang::SourceManager &m_sm;
 };
 
 #endif
diff --git a/src/checks/level1/qhash-namespace.cpp b/src/checks/level1/qhash-namespace.cpp
index ad8562c2..c78be0c0 100644
--- a/src/checks/level1/qhash-namespace.cpp
+++ b/src/checks/level1/qhash-namespace.cpp
@@ -26,7 +26,9 @@
 #include "TypeUtils.h"
 #include "ContextUtils.h"
 #include "StringUtils.h"
+#include "ClazyContext.h"
 #include "checkmanager.h"
+#include "PreProcessorVisitor.h"
 
 #include <clang/AST/AST.h>
 
@@ -37,6 +39,8 @@ using namespace std;
 qhash_namespace::qhash_namespace(const std::string &name, ClazyContext *context)
     : CheckBase(name, context)
 {
+    if (context->isQtDeveloper())
+        context->enablePreprocessorVisitor();
 }
 
 void qhash_namespace::VisitDecl(clang::Decl *decl)
@@ -63,6 +67,13 @@ void qhash_namespace::VisitDecl(clang::Decl *decl)
 
     if (!msg.empty())
         emitWarning(decl, msg);
+
+    if (m_context->isQtDeveloper()) {
+        PreProcessorVisitor *preProcessorVisitor = m_context->preprocessorVisitor;
+        if (preProcessorVisitor && !preProcessorVisitor->isBetweenQtNamespaceMacros(func->getLocStart())) {
+            emitWarning(decl, "qHash(" + StringUtils::simpleTypeName(firstArg->getType(), lo()) + ") must be declared before QT_END_NAMESPACE");
+        }
+    }
 }
 
 REGISTER_CHECK("qhash-namespace", qhash_namespace, CheckLevel1)
diff --git a/src/checks/level1/qhash-namespace.h b/src/checks/level1/qhash-namespace.h
index 820ca541..06e51e18 100644
--- a/src/checks/level1/qhash-namespace.h
+++ b/src/checks/level1/qhash-namespace.h
@@ -33,7 +33,6 @@ class qhash_namespace : public CheckBase
 public:
     explicit qhash_namespace(const std::string &name, ClazyContext *context);
     void VisitDecl(clang::Decl *decl) override;
-private:
 };
 
 #endif