fixed #13606/#13607 - consistently print (precise) float as such in ValueFlow debug output (cppcheck-opensource#7274)

Author: firewave

Makefile

@@ -335,7 +335,8 @@ TESTOBJ =     test/fixture.o \
               test/testutils.o \
               test/testvaarg.o \
               test/testvalueflow.o \
-              test/testvarid.o
+              test/testvarid.o \
+              test/testvfvalue.o
 
 .PHONY: run-dmake tags
 
@@ -900,6 +901,9 @@ test/testvalueflow.o: test/testvalueflow.cpp externals/simplecpp/simplecpp.h lib
 test/testvarid.o: test/testvarid.cpp externals/simplecpp/simplecpp.h lib/addoninfo.h lib/check.h lib/checkers.h lib/color.h lib/config.h lib/errorlogger.h lib/errortypes.h lib/library.h lib/mathlib.h lib/platform.h lib/preprocessor.h lib/settings.h lib/standards.h lib/templatesimplifier.h lib/token.h lib/tokenize.h lib/tokenlist.h lib/utils.h lib/vfvalue.h test/fixture.h test/helpers.h
 	$(CXX) ${INCLUDE_FOR_TEST} $(CPPFLAGS) $(CXXFLAGS) -c -o $@ test/testvarid.cpp
 
+test/testvfvalue.o: test/testvfvalue.cpp lib/addoninfo.h lib/check.h lib/checkers.h lib/color.h lib/config.h lib/errorlogger.h lib/errortypes.h lib/library.h lib/mathlib.h lib/platform.h lib/settings.h lib/standards.h lib/utils.h lib/vfvalue.h test/fixture.h
+	$(CXX) ${INCLUDE_FOR_TEST} $(CPPFLAGS) $(CXXFLAGS) -c -o $@ test/testvfvalue.cpp
+
 externals/simplecpp/simplecpp.o: externals/simplecpp/simplecpp.cpp externals/simplecpp/simplecpp.h
 	$(CXX)  $(CPPFLAGS) $(CXXFLAGS) -w -c -o $@ externals/simplecpp/simplecpp.cpp
 

lib/token.cpp

@@ -21,6 +21,7 @@
 #include "astutils.h"
 #include "errortypes.h"
 #include "library.h"
+#include "mathlib.h"
 #include "settings.h"
 #include "simplecpp.h"
 #include "symboldatabase.h"
@@ -1801,7 +1802,7 @@ void Token::printValueFlow(bool xml, std::ostream &out) const
                     break;
                 case ValueFlow::Value::ValueType::FLOAT:
                     outs += "floatvalue=\"";
-                    outs += std::to_string(value.floatValue); // TODO: should this be MathLib::toString()?
+                    outs += MathLib::toString(value.floatValue);
                     outs += '\"';
                     break;
                 case ValueFlow::Value::ValueType::MOVED:
@@ -1875,7 +1876,6 @@ void Token::printValueFlow(bool xml, std::ostream &out) const
 
                 outs += "/>\n";
             }
-
             else {
                 if (&value != &values->front())
                     outs += ",";

lib/vfvalue.cpp

@@ -19,6 +19,7 @@
 #include "vfvalue.h"
 
 #include "errortypes.h"
+#include "mathlib.h"
 #include "token.h"
 
 #include <sstream>
@@ -58,7 +59,7 @@ namespace ValueFlow {
             ss << this->tokvalue->str();
             break;
         case ValueType::FLOAT:
-            ss << this->floatValue;
+            ss << MathLib::toString(this->floatValue);
             break;
         case ValueType::MOVED:
             ss << toString(this->moveKind);

test/cli/other_test.py

@@ -3064,4 +3064,102 @@ def test_file_ignore_2(tmp_path):  # #13570
         'cppcheck: error: could not find or open any of the paths given.',
         'cppcheck: Maybe all paths were ignored?'
     ]
-    assert stderr.splitlines() == []
+    assert stderr.splitlines() == []
+
+
+def test_debug_valueflow(tmp_path):
+    test_file = tmp_path / 'test.c'
+    with open(test_file, "w") as f:
+        f.write(
+"""int f()
+{
+    double d = 1.0 / 0.5;
+    return d;
+}
+""")
+
+    args = [
+        '-q',
+        '--debug',  # TODO: limit to valueflow output
+        str(test_file)
+    ]
+
+    exitcode, stdout, stderr = cppcheck(args)
+    assert exitcode == 0, stdout
+
+    # check sections in output
+    assert stdout.find('##file ') != -1
+    assert stdout.find('##Value flow') != -1
+    assert stdout.find('### Symbol database ###') == -1
+    assert stdout.find('##AST') == -1
+    assert stdout.find('### Template Simplifier pass ') == -1
+    assert stderr.splitlines() == []
+
+    # check precision in output - #13607
+    valueflow = stdout[stdout.find('##Value flow'):]
+    assert valueflow.splitlines() == [
+        '##Value flow',
+        'File {}'.format(str(test_file).replace('\\', '/')),
+        'Line 3',
+        '  = always 2.0',
+        '  1.0 always 1.0',
+        '  / always 2.0',
+        '  0.5 always 0.5',
+        'Line 4',
+        '  d always {symbolic=(1.0/0.5),2.0}'
+    ]
+
+
+def test_debug_valueflow_xml(tmp_path):  # #13606
+    test_file = tmp_path / 'test.c'
+    with open(test_file, "w") as f:
+        f.write(
+"""double f()
+{
+    double d = 0.0000001;
+    return d;
+}
+""")
+
+    args = [
+        '-q',
+        '--debug',  # TODO: limit to valueflow output
+        '--xml',
+        str(test_file)
+    ]
+
+    exitcode, stdout, stderr = cppcheck(args)
+    assert exitcode == 0, stdout
+
+    assert stderr
+    assert ElementTree.fromstring(stderr) is not None
+
+    # check sections in output
+    assert stdout.find('##file ') != -1  # also exists in CDATA
+    assert stdout.find('##Value flow') == -1
+    assert stdout.find('### Symbol database ###') == -1
+    assert stdout.find('##AST') == -1
+    assert stdout.find('### Template Simplifier pass ') == -1
+
+    # check XML nodes in output
+    debug_xml = ElementTree.fromstring(stdout)
+    assert debug_xml is not None
+    assert debug_xml.tag == 'debug'
+    file_elem = debug_xml.findall('file')
+    assert len(file_elem) == 1
+    valueflow_elem = debug_xml.findall('valueflow')
+    assert len(valueflow_elem) == 1
+    scopes_elem = debug_xml.findall('scopes')
+    assert len(scopes_elem) == 1
+    ast_elem = debug_xml.findall('ast')
+    assert len(ast_elem) == 0
+
+    # check precision in output - #13606
+    value_elem = valueflow_elem[0].findall('values/value')
+    assert len(value_elem) == 3
+    assert 'floatvalue' in value_elem[0].attrib
+    assert value_elem[0].attrib['floatvalue'] == '1e-07'
+    assert 'floatvalue' in value_elem[1].attrib
+    assert value_elem[1].attrib['floatvalue'] == '1e-07'
+    assert 'floatvalue' in value_elem[2].attrib
+    assert value_elem[2].attrib['floatvalue'] == '1e-07'

test/testrunner.vcxproj

@@ -111,6 +111,7 @@
     <ClCompile Include="testvaarg.cpp" />
     <ClCompile Include="testvalueflow.cpp" />
     <ClCompile Include="testvarid.cpp" />
+    <ClCompile Include="testvfvalue.cpp" />
   </ItemGroup>
   <ItemGroup Label="HeaderFiles">
     <ClInclude Include="..\cli\cmdlineparser.h" />

test/testvfvalue.cpp

@@ -0,0 +1,48 @@
+/*
+ * Cppcheck - A tool for static C/C++ code analysis
+ * Copyright (C) 2007-2024 Cppcheck team.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "fixture.h"
+#include "vfvalue.h"
+
+class TestValueFlowValue : public TestFixture {
+public:
+    TestValueFlowValue() : TestFixture("TestValueFlowValue") {}
+
+private:
+    void run() override {
+        TEST_CASE(toString);
+    }
+
+    void toString() const {
+        {
+            ValueFlow::Value v;
+            ASSERT_EQUALS("0", v.toString());
+            v.intvalue = -1;
+            ASSERT_EQUALS("-1", v.toString());
+        }
+        {
+            ValueFlow::Value v;
+            v.valueType = ValueFlow::Value::ValueType::FLOAT;
+            ASSERT_EQUALS("0.0", v.toString());
+            v.floatValue = 0.0000000000001;
+            ASSERT_EQUALS("1e-13", v.toString());
+        }
+    }
+};
+
+REGISTER_TEST(TestValueFlowValue)