Fix false positives for SQL string concatenation with constants from another file (#247)

* Allow for SQL concatenation of nodes that resolve to literals

If node.Y resolves to a literal, it will not be considered as an issue.

* Fix typo in comment.

* Go through all files in package to resolve that identifier

* Refactor code and added comments.

* Changed checking to not var or func.

* Allow for supporting code for test cases.

* Resolve merge conflict changes.

analyzer.go

@@ -39,6 +39,7 @@ type Context struct {
 	Comments ast.CommentMap
 	Info     *types.Info
 	Pkg      *types.Package
+	PkgFiles []*ast.File
 	Root     *ast.File
 	Config   map[string]interface{}
 	Imports  *ImportTracker
@@ -139,6 +140,7 @@ func (gosec *Analyzer) Process(buildTags []string, packagePaths ...string) error
 			gosec.context.Root = file
 			gosec.context.Info = &pkg.Info
 			gosec.context.Pkg = pkg.Pkg
+			gosec.context.PkgFiles = pkg.Files
 			gosec.context.Imports = NewImportTracker()
 			gosec.context.Imports.TrackPackages(gosec.context.Pkg.Imports()...)
 			ast.Walk(gosec, file)