parsing call functions to derive import/export

Signed-off-by: vsoch <vsoch@users.noreply.github.com>
vsoch · Oct 20, 2021 · 6cc5a2d · 6cc5a2d
1 parent ea3bfd2
commit 6cc5a2d
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Showing 4 changed files with 136 additions and 84 deletions.
diff --git a/corpus/corpus.go b/corpus/corpus.go
@@ -104,11 +104,18 @@ func (c *Corpus) Parse(f *file.File) {
 
 			switch symbol.GetType() {
 			case "STT_FUNC":
-				entry, ok := lookup["functions"][symbol.GetName()]
-				if !ok {
-					continue
+
+				// First look if it's a call site
+				entry, ok := lookup["calls"][symbol.GetName()]
+				if ok {
+					c.parseFunction(f, symbol, &entry, true)
+				} else {
+					entry, ok := lookup["functions"][symbol.GetName()]
+					if !ok {
+						continue
+					}
+					c.parseFunction(f, symbol, &entry, false)
 				}
-				c.parseFunction(f, symbol, &entry)
 
 			case "STT_OBJECT":
 
@@ -123,11 +130,11 @@ func (c *Corpus) Parse(f *file.File) {
 }
 
 // parse a dynamic function symbol
-func (c *Corpus) parseFunction(f *file.File, symbol file.Symbol, entry *file.DwarfEntry) {
+func (c *Corpus) parseFunction(f *file.File, symbol file.Symbol, entry *file.DwarfEntry, isCallSite bool) {
 
 	switch f.GoArch() {
 	case "amd64":
-		newFunction := x86_64.ParseFunction(f, symbol, entry, c.Disasm)
+		newFunction := x86_64.ParseFunction(f, symbol, entry, c.Disasm, isCallSite)
 		loc := map[string]descriptor.LocationDescription{}
 		loc["function"] = newFunction
 		c.Locations = append(c.Locations, loc)
@@ -141,8 +148,8 @@ func (c *Corpus) parseVariable(f *file.File, symbol file.Symbol, entry *file.Dwa
 
 	switch f.GoArch() {
 	case "amd64":
-		// Don't allow variables without name or type
-		variable := x86_64.ParseVariable(f, symbol, entry)
+		// Don't allow variables without name or type (variables cannot be call sites)
+		variable := x86_64.ParseVariable(f, symbol, entry, false)
 		if !reflect.DeepEqual(variable, descriptor.VariableDescription{}) {
 			loc := map[string]descriptor.LocationDescription{}
 			loc["variable"] = variable

diff --git a/descriptor/types.go b/descriptor/types.go
@@ -9,6 +9,7 @@ type Parameter interface {
 	GetName() string
 	GetLocation() string
 	GetType() string
+	GetDirection() string
 }
 
 // A General Location description holds a variable or function
@@ -18,6 +19,7 @@ type LocationDescription interface{}
 type FunctionDescription struct {
 	Parameters []Parameter `json:"parameters,omitempty"`
 	Name       string      `json:"name"`
+	Direction  string      `json:"direction,omitempty"`
 	Type       string      `json:"type"`
 }
 
@@ -71,13 +73,22 @@ func (f QualifiedParameter) GetType() string { return f.Type }
 func (f BasicParameter) GetType() string     { return f.Type }
 func (f EnumParameter) GetType() string      { return f.Type }
 
+func (f FunctionParameter) GetDirection() string  { return f.Direction }
+func (f StructureParameter) GetDirection() string { return f.Direction }
+func (f PointerParameter) GetDirection() string   { return f.Direction }
+func (f ArrayParameter) GetDirection() string     { return f.Direction }
+func (f QualifiedParameter) GetDirection() string { return f.Direction }
+func (f BasicParameter) GetDirection() string     { return f.Direction }
+func (f EnumParameter) GetDirection() string      { return f.Direction }
+
 type StructureParameter struct {
-	Name     string      `json:"name,omitempty"`
-	Type     string      `json:"type,omitempty"`
-	Class    string      `json:"class,omitempty"`
-	Size     int64       `json:"size,omitempty"`
-	Location string      `json:"location,omitempty"`
-	Fields   []Parameter `json:"fields,omitempty"`
+	Name      string      `json:"name,omitempty"`
+	Type      string      `json:"type,omitempty"`
+	Class     string      `json:"class,omitempty"`
+	Size      int64       `json:"size,omitempty"`
+	Direction string      `json:"direction,omitempty"`
+	Location  string      `json:"location,omitempty"`
+	Fields    []Parameter `json:"fields,omitempty"`
 }
 
 type PointerParameter struct {
@@ -92,13 +103,14 @@ type PointerParameter struct {
 }
 
 type ArrayParameter struct {
-	Name     string    `json:"name,omitempty"`
-	Type     string    `json:"type,omitempty"`
-	Class    string    `json:"class,omitempty"`
-	Size     int64     `json:"size,omitempty"`
-	Length   int64     `json:"count,omitempty"`
-	Location string    `json:"location,omitempty"`
-	ItemType Parameter `json:"items_type,omitemtpy"`
+	Name      string    `json:"name,omitempty"`
+	Type      string    `json:"type,omitempty"`
+	Class     string    `json:"class,omitempty"`
+	Size      int64     `json:"size,omitempty"`
+	Length    int64     `json:"count,omitempty"`
+	Location  string    `json:"location,omitempty"`
+	Direction string    `json:"direction,omitempty"`
+	ItemType  Parameter `json:"items_type,omitemtpy"`
 }
 
 type EnumParameter struct {
@@ -108,24 +120,27 @@ type EnumParameter struct {
 	Size      int64            `json:"size,omitempty"`
 	Location  string           `json:"location,omitempty"`
 	Length    int              `json:"count,omitempty"`
+	Direction string           `json:"direction,omitempty"`
 	Constants map[string]int64 `json:"constants,omitemtpy"`
 }
 
 // QualifiedParameter and BasicParameter are the same, but we are modeling after debug/dwarf
 type QualifiedParameter struct {
-	Name     string `json:"name,omitempty"`
-	Class    string `json:"class,omitempty"`
-	Type     string `json:"type,omitempty"`
-	Location string `json:"location,omitempty"`
-	Size     int64  `json:"size,omitempty"`
+	Name      string `json:"name,omitempty"`
+	Class     string `json:"class,omitempty"`
+	Type      string `json:"type,omitempty"`
+	Direction string `json:"direction,omitempty"`
+	Location  string `json:"location,omitempty"`
+	Size      int64  `json:"size,omitempty"`
 }
 
 type BasicParameter struct {
-	Name     string `json:"name,omitempty"`
-	Type     string `json:"type,omitempty"`
-	Class    string `json:"class,omitempty"`
-	Location string `json:"location,omitempty"`
-	Size     int64  `json:"size,omitempty"`
+	Name      string `json:"name,omitempty"`
+	Type      string `json:"type,omitempty"`
+	Class     string `json:"class,omitempty"`
+	Location  string `json:"location,omitempty"`
+	Direction string `json:"direction,omitempty"`
+	Size      int64  `json:"size,omitempty"`
 }
 
 // A Variable description is general and can also describe an underlying type

diff --git a/parsers/file/dwarf.go b/parsers/file/dwarf.go
@@ -183,8 +183,7 @@ func (f *FunctionEntry) GetComponents() []Component {
 
 	}
 
-	// Get the Return value - the "type" of
-	// TODO can we use := entry.Val(dwarf.AttrVarParam)
+	// Get the Return value - for a library this is the only export (unless a call site)
 	returnType, err := GetUnderlyingType(f.Entry, f.Data)
 	if returnType != nil && err != nil {
 		comps = append(comps, Component{Name: "return", Type: returnType.Common().Name,