Preprocessor: better handling of '#if A==1'

lib/preprocessor.cpp

@@ -1003,6 +1003,42 @@ std::list<std::string> Preprocessor::getcfgs(const std::string &filedata, const
 
             if (! deflist.empty() && line.compare(0, 6, "#elif ") == 0)
                 deflist.pop_back();
+
+            // translate A==1 condition to A=1 configuration
+            if (def.find("==") != std::string::npos) {
+                // Check if condition match pattern "%var% == %num%"
+                // %var%
+                std::string::size_type pos = 0;
+                if (std::isalpha(def[pos]) || def[pos] == '_') {
+                    ++pos;
+                    while (std::isalnum(def[pos]) || def[pos] == '_')
+                        ++pos;
+                }
+
+                // ==
+                if (def.compare(pos,2,"==",0,2)==0)
+                    pos += 2;
+
+                // %num%
+                if (pos<def.size() && std::isdigit(def[pos])) {
+                    if (def.compare(pos,2,"0x",0,2)==0) {
+                        pos += 2;
+                        if (pos >= def.size())
+                            pos = 0;
+                        while (pos < def.size() && std::isxdigit(def[pos]))
+                            ++pos;
+                    } else {
+                        while (pos < def.size() && std::isdigit(def[pos]))
+                            ++pos;
+                    }
+
+                    // Does the condition match the pattern "%var% == %num%"?
+                    if (pos == def.size()) {
+                        def.erase(def.find("=="),1);
+                    }
+                }
+            }
+
             deflist.push_back(def);
             def = "";
 

test/testpreprocessor.cpp

@@ -76,6 +76,7 @@ private:
         TEST_CASE(test7c);
         TEST_CASE(test7d);
         TEST_CASE(test7e);
+        TEST_CASE(test8);  // #if A==1  => cfg: A=1
 
         // #error => don't extract any code
         TEST_CASE(error1);
@@ -617,6 +618,27 @@ private:
         ASSERT_EQUALS(2, static_cast<unsigned int>(actual.size()));
     }
 
+    void test8() {
+        const char filedata[] = "#ifdef A == 1\n"
+                                "1\n"
+                                "#endif\n";
+
+        // Preprocess => actual result..
+        std::istringstream istr(filedata);
+        std::map<std::string, std::string> actual;
+        Settings settings;
+        Preprocessor preprocessor(&settings, this);
+        errout.str("");
+        preprocessor.preprocess(istr, actual, "file.c");
+
+        // No error..
+        ASSERT_EQUALS("", errout.str());
+
+        // Compare results..
+        ASSERT_EQUALS(2U, actual.size());
+        ASSERT_EQUALS("\n\n\n", actual[""]);
+        ASSERT_EQUALS("\n1\n\n", actual["A=1"]);
+    }
 
     void error1() {
         const char filedata[] = "#ifdef A\n"