From f57637d7fc4c3e9a475d007679d1ce675c892fb2 Mon Sep 17 00:00:00 2001
From: Sasha Koshka <sashakoshka@tebibyte.media>
Date: Sun, 16 Oct 2022 02:53:37 -0400
Subject: [PATCH] Untested data section analysis

---
 analyzer/analyzer.go                |  2 +
 analyzer/data-section.go            | 81 +++++++++++++++++++++++++++++
 analyzer/data-section_test.go       |  9 ++++
 tests/analyzer/dataSection/main.arf | 10 ++++
 tests/analyzer/typeSection/main.arf |  2 +
 5 files changed, 104 insertions(+)
 create mode 100644 analyzer/data-section.go
 create mode 100644 analyzer/data-section_test.go
 create mode 100644 tests/analyzer/dataSection/main.arf

diff --git a/analyzer/analyzer.go b/analyzer/analyzer.go
index dbcb11a..4125756 100644
--- a/analyzer/analyzer.go
+++ b/analyzer/analyzer.go
@@ -127,6 +127,8 @@ func (analyzer *analysisOperation) fetchSection (
 		if err != nil { return}
 	case parser.FaceSection:
 	case parser.DataSection:
+		section, err = analyzer.analyzeDataSection()
+		if err != nil { return}
 	case parser.FuncSection:
 	}
 	
diff --git a/analyzer/data-section.go b/analyzer/data-section.go
new file mode 100644
index 0000000..23f66e6
--- /dev/null
+++ b/analyzer/data-section.go
@@ -0,0 +1,81 @@
+package analyzer
+
+import "git.tebibyte.media/arf/arf/types"
+import "git.tebibyte.media/arf/arf/parser"
+import "git.tebibyte.media/arf/arf/infoerr"
+
+// DataSection represents a global variable section.
+type DataSection struct {
+	sectionBase
+	what     Type
+	argument Argument
+}
+
+// ToString returns all data stored within the data section, in string form.
+func (section DataSection) ToString (indent int) (output string) {
+	output += doIndent(indent, "typeSection ")
+	output += section.permission.ToString() + " "
+	output += section.where.ToString()
+	output += "\n"
+	output += section.what.ToString(indent + 1)
+	if section.argument != nil {
+		output += section.argument.ToString(indent + 1)
+	}
+	return
+}
+
+// analyzeDataSection analyzes a data section.
+func (analyzer analysisOperation) analyzeDataSection () (
+	section Section,
+	err error,
+) {
+	outputSection := DataSection { }
+	outputSection.where = analyzer.currentPosition
+
+	section = &outputSection
+	analyzer.addSection(section)
+
+	inputSection := analyzer.currentSection.(parser.DataSection)
+	outputSection.location = analyzer.currentSection.Location()
+
+	if inputSection.Permission() == types.PermissionReadWrite {
+		err = inputSection.NewError (
+			"read-write (rw) permission not understood in this " +
+			"context, try read-only (ro)",
+			infoerr.ErrorKindError)
+		return
+	}
+
+	outputSection.permission = inputSection.Permission()
+
+	// get inherited type
+	outputSection.what, err = analyzer.analyzeType(inputSection.Type())
+	if err != nil { return }
+
+	// data sections are only allowed to inherit type, enum, and face sections
+	_, inheritsFromTypeSection := outputSection.what.actual.(*TypeSection)
+	_, inheritsFromEnumSection := outputSection.what.actual.(*EnumSection)
+	// _, inheritsFromFaceSection := outputSection.what.actual.(*FaceSection)
+	if !inheritsFromTypeSection && inheritsFromEnumSection {
+		err = inputSection.Type().NewError (
+			"type sections can only inherit from type, enum, and " +
+			"face sections",
+			infoerr.ErrorKindError)
+		return
+	}
+
+	if !inputSection.Argument().Nil() {
+		outputSection.argument,
+		err = analyzer.analyzeArgument(inputSection.Argument())
+		if err != nil { return }
+
+		// type check default value
+		err = analyzer.typeCheck (
+			outputSection.argument,
+			outputSection.what)
+		if err != nil { return }
+	}
+	
+	outputSection.complete = true
+	return
+}
diff --git a/analyzer/data-section_test.go b/analyzer/data-section_test.go
new file mode 100644
index 0000000..d5c4e9d
--- /dev/null
+++ b/analyzer/data-section_test.go
@@ -0,0 +1,9 @@
+package analyzer
+
+import "testing"
+
+func TestDataSection (test *testing.T) {
+	checkTree ("../tests/analyzer/dataSection", false,
+`
+`, test)
+}
diff --git a/tests/analyzer/dataSection/main.arf b/tests/analyzer/dataSection/main.arf
new file mode 100644
index 0000000..6f62c82
--- /dev/null
+++ b/tests/analyzer/dataSection/main.arf
@@ -0,0 +1,10 @@
+:arf
+---
+
+data ro aBasicInt:Int 5
+
+data ro bRune:Int 'A'
+
+data ro cString:String 'A very large bird'
+
+data ro dCharBuffer:U8:32 'A very large bird\000'
diff --git a/tests/analyzer/typeSection/main.arf b/tests/analyzer/typeSection/main.arf
index 286db2a..3416a9b 100644
--- a/tests/analyzer/typeSection/main.arf
+++ b/tests/analyzer/typeSection/main.arf
@@ -18,3 +18,5 @@ type ro eInheritObject:cBasicObject
 type ro fInheritObjectFromOther:required.bBird
 	ro wing 2
 	ro beak:Int 238
+
+# TODO: test a type that has a member pointing to itself