Shaders: report all shader file paths

When reporting a shader log error, include all the shader file
paths and the effect path in the detailed error information.

simgear/scene/material/Effect.cxx

@@ -227,8 +227,9 @@ Effect::Effect()
 }
 
 Effect::Effect(const Effect& rhs, const CopyOp& copyop)
-    : osg::Object(rhs,copyop), root(rhs.root), parametersProp(rhs.parametersProp), _cache(0),
-      _isRealized(rhs._isRealized)
+    : osg::Object(rhs, copyop), root(rhs.root), parametersProp(rhs.parametersProp), _cache(0),
+      _isRealized(rhs._isRealized),
+      _effectFilePath(rhs._effectFilePath)
 {
     typedef vector<ref_ptr<Technique> > TechniqueList;
     for (TechniqueList::const_iterator itr = rhs.techniques.begin(),
@@ -961,7 +962,11 @@ void ShaderProgramBuilder::buildAttribute(Effect* effect, Pass* pass,
         pass->setAttributeAndModes(program);
         return;
     }
-    program = new SGProgram;
+
+    auto sgprogram = new SGProgram;
+    program = sgprogram;
+    sgprogram->setEffectFilePath(effect->filePath());
+
     for (const auto& skey : resolvedKey.shaders) {
         const string& fileName = skey.first;
         Shader::Type stype = (Shader::Type)skey.second;
@@ -1654,3 +1659,15 @@ expression::ExpParserRegistrar propvalueRegistrar("float-property",
                                                  propertyExpressionParser<float>);
 
 }
+
+using namespace simgear;
+
+void Effect::setFilePath(const SGPath& path)
+{
+    _effectFilePath = path;
+}
+
+SGPath Effect::filePath() const
+{
+    return _effectFilePath;
+}

simgear/scene/material/Effect.hxx

@@ -29,10 +29,11 @@
 #include <osg/observer_ptr>
 #include <osgDB/ReaderWriter>
 
+#include <simgear/misc/sg_path.hxx>
 #include <simgear/props/props.hxx>
 #include <simgear/scene/util/UpdateOnceCallback.hxx>
-#include <simgear/threads/SGThread.hxx>
 #include <simgear/structure/Singleton.hxx>
+#include <simgear/threads/SGThread.hxx>
 
 namespace osg
 {
@@ -106,6 +107,10 @@ public:
 
     std::string getName(){return _name;}
     void setName(std::string name){_name = name;}
+
+    void setFilePath(const SGPath& path);
+    SGPath filePath() const;
+
 protected:
     ~Effect();
     // Support for a cache of effects that inherit from this one, so
@@ -142,10 +147,13 @@ protected:
     Cache* _cache;
     friend size_t hash_value(const Key& key);
     friend Effect* makeEffect(SGPropertyNode* prop, bool realizeTechniques,
-                              const SGReaderWriterOptions* options);
+                              const SGReaderWriterOptions* options,
+                              const SGPath& path);
     bool _isRealized;
     std::string _name;
+    SGPath _effectFilePath;
 };
+
 // Automatic support for boost hash function
 size_t hash_value(const Effect::Key&);
 
@@ -156,7 +164,8 @@ Effect* makeEffect(const std::string& name,
 
 Effect* makeEffect(SGPropertyNode* prop,
                    bool realizeTechniques,
-                   const SGReaderWriterOptions* options);
+                   const SGReaderWriterOptions* options,
+                   const SGPath& path = SGPath{});
 
 bool makeParametersFromStateSet(SGPropertyNode* paramRoot,
                                 const osg::StateSet* ss);

simgear/scene/material/makeEffect.cxx

@@ -26,8 +26,9 @@
 #include <osgDB/Registry>
 
 #include <simgear/debug/logstream.hxx>
-#include <simgear/scene/util/SGReaderWriterOptions.hxx>
+#include <simgear/misc/sg_path.hxx>
 #include <simgear/props/props_io.hxx>
+#include <simgear/scene/util/SGReaderWriterOptions.hxx>
 #include <simgear/scene/util/SGSceneFeatures.hxx>
 #include <simgear/scene/util/SplicingVisitor.hxx>
 #include <simgear/structure/SGExpression.hxx>
@@ -139,7 +140,7 @@ Effect* makeEffect(const string& name,
         return 0;
     }
     ref_ptr<Effect> result = makeEffect(effectProps.ptr(), realizeTechniques,
-                                        options);
+                                        options, SGPath::fromUtf8(absFileName));
     if (result.valid()) {
         OpenThreads::ScopedLock<OpenThreads::ReentrantMutex> lock(effectMutex);
         pair<EffectMap::iterator, bool> irslt
@@ -156,7 +157,8 @@ Effect* makeEffect(const string& name,
 
 Effect* makeEffect(SGPropertyNode* prop,
                    bool realizeTechniques,
-                   const SGReaderWriterOptions* options)
+                   const SGReaderWriterOptions* options,
+                   const SGPath& filePath)
 {
     // Give default names to techniques and passes
     vector<SGPropertyNode_ptr> techniques = prop->getChildren("technique");
@@ -217,6 +219,7 @@ Effect* makeEffect(SGPropertyNode* prop,
             if (!effect.valid()) {
                 effect = new Effect;
                 effect->setName(nameProp->getStringValue());
+                effect->setFilePath(filePath.isNull() ? parent->filePath() : filePath);
                 effect->root = new SGPropertyNode;
                 mergePropertyTrees(effect->root, prop, parent->root);
                 effect->parametersProp = effect->root->getChild("parameters");
@@ -240,6 +243,7 @@ Effect* makeEffect(SGPropertyNode* prop,
         }
     } else {
         effect = new Effect;
+        effect->setFilePath(filePath);
         effect->setName(nameProp->getStringValue());
         effect->root = prop;
         effect->parametersProp = effect->root->getChild("parameters");

simgear/scene/util/SGProgram.cxx

@@ -20,13 +20,25 @@
 #include "SGProgram.hxx"
 
 #include <osg/State>
+#include <sstream>
 
 #include <simgear/debug/ErrorReportingCallback.hxx>
+#include <simgear/debug/logstream.hxx>
 
-SGProgram::SGProgram(const SGProgram& rhs, const osg::CopyOp& copyop) : osg::Program(rhs, copyop)
+SGProgram::SGProgram()
 {
 }
 
+SGProgram::SGProgram(const SGProgram& rhs, const osg::CopyOp& copyop) : osg::Program(rhs, copyop),
+                                                                        _effectFilePath(rhs._effectFilePath)
+{
+}
+
+void SGProgram::setEffectFilePath(const SGPath& p)
+{
+    _effectFilePath = p;
+}
+
 void SGProgram::apply(osg::State& state) const
 {
     osg::Program::apply(state);
@@ -41,8 +53,17 @@ void SGProgram::apply(osg::State& state) const
         _checkState = FailedToApply;
         getPCP(state)->getInfoLog(infoLog);
 
+        // log all the shader source file names, to help in debugging link errors
+        std::ostringstream os;
+        for (int i = 0; i < getNumShaders(); ++i) {
+            const auto shader = getShader(i);
+            os << "\t" << shader->getFileName() << "\n";
+        }
+
         simgear::reportFailure(simgear::LoadFailure::BadData, simgear::ErrorCode::LoadEffectsShaders,
-                               "Shader program errors: " + infoLog, sg_location());
+                               "Shader program errors: " + infoLog +
+                                   "\n\nShader sources:\n" + os.str(),
+                               _effectFilePath);
 
         for (int i = 0; i < getNumShaders(); ++i) {
             const auto shader = getShader(i);

simgear/scene/util/SGProgram.hxx

@@ -18,6 +18,8 @@
 
 #include <osg/Program>
 
+#include <simgear/misc/sg_path.hxx>
+
 /**
  * @brief wrapper around osg::Program to allow detecting shader/link
  * errors in the GLSL code at runtime, and reporting of them
@@ -26,7 +28,7 @@
 class SGProgram : public osg::Program
 {
 public:
-    SGProgram() = default;
+    SGProgram();
 
     SGProgram(const SGProgram& rhs, const osg::CopyOp& copyop = osg::CopyOp::SHALLOW_COPY);
 
@@ -40,6 +42,9 @@ public:
         FailedToApply
     };
 
+    void setEffectFilePath(const SGPath& p);
+
 private:
+    SGPath _effectFilePath;
     mutable ErrorCheckState _checkState = NotApplied;
 };