Suppressions: Add special case for backwards compatibility. suppression comment after a {.

lib/preprocessor.cpp

@@ -166,10 +166,20 @@ static void inlineSuppressions(const simplecpp::TokenList &tokens, Settings &mSe
         }
         relativeFilename = Path::simplifyPath(relativeFilename);
 
+        // special handling when suppressing { warnings for backwards compatibility
+        const bool thisAndNextLine = tok->previous &&
+                                     tok->previous->previous &&
+                                     tok->next &&
+                                     !sameline(tok->previous->previous, tok->previous) &&
+                                     tok->location.line + 1 == tok->next->location.line &&
+                                     tok->location.fileIndex == tok->next->location.fileIndex &&
+                                     tok->previous->str() == "{";
+
         // Add the suppressions.
         for (Suppressions::Suppression &suppr : inlineSuppressions) {
             suppr.fileName = relativeFilename;
             suppr.lineNumber = tok->location.line;
+            suppr.thisAndNextLine = thisAndNextLine;
             mSettings.nomsg.addSuppression(suppr);
         }
     }

lib/suppressions.cpp

@@ -291,8 +291,10 @@ bool Suppressions::Suppression::isSuppressed(const Suppressions::ErrorMessage &e
         return false;
     if (!fileName.empty() && !matchglob(fileName, errmsg.getFileName()))
         return false;
-    if (lineNumber != NO_LINE && lineNumber != errmsg.lineNumber)
-        return false;
+    if (lineNumber != NO_LINE && lineNumber != errmsg.lineNumber) {
+        if (!thisAndNextLine || lineNumber + 1 != errmsg.lineNumber)
+            return false;
+    }
     if (!symbolName.empty()) {
         for (std::string::size_type pos = 0; pos < errmsg.symbolNames.size();) {
             const std::string::size_type pos2 = errmsg.symbolNames.find('\n',pos);

lib/suppressions.h

@@ -53,7 +53,7 @@ public:
         Suppression(const Suppression &other) {
             *this = other;
         }
-        Suppression(const std::string &id, const std::string &file, int line=NO_LINE) : errorId(id), fileName(file), lineNumber(line), hash(0), matched(false) {}
+        Suppression(const std::string &id, const std::string &file, int line=NO_LINE) : errorId(id), fileName(file), lineNumber(line), hash(0), thisAndNextLine(false), matched(false) {}
 
         Suppression & operator=(const Suppression &other) {
             errorId = other.errorId;
@@ -61,6 +61,7 @@ public:
             lineNumber = other.lineNumber;
             symbolName = other.symbolName;
             hash = other.hash;
+            thisAndNextLine = other.thisAndNextLine;
             matched = other.matched;
             return *this;
         }
@@ -76,6 +77,8 @@ public:
                 return symbolName < other.symbolName;
             if (hash != other.hash)
                 return hash < other.hash;
+            if (thisAndNextLine != other.thisAndNextLine)
+                return thisAndNextLine;
             return false;
         }
 
@@ -101,6 +104,7 @@ public:
         int lineNumber;
         std::string symbolName;
         std::size_t hash;
+        bool thisAndNextLine; // Special case for backwards compatibility: { // cppcheck-suppress something
         bool matched;
 
         enum { NO_LINE = -1 };

test/cli/test-inline-suppress.py

@@ -24,3 +24,11 @@ def test_unmatched_suppression_path_with_extra_stuf():
     ret, stdout, stderr = cppcheck(['--inline-suppr', '--enable=information', '--error-exitcode=1', './proj-inline-suppress/2.c'])
     assert ret == 1
     assert 'Unmatched suppression: some_warning_id' in stderr
+
+def test_backwards_compatibility():
+    ret, stdout, stderr = cppcheck(['--enable=unusedFunction', 'proj-inline-suppress/3.cpp'])
+    assert len(stderr) > 0
+
+    ret, stdout, stderr = cppcheck(['--inline-suppr', '--enable=unusedFunction', 'proj-inline-suppress/3.cpp'])
+    assert ret == 0
+    assert stderr == ''