fix: use global handle checking

Previously, the algorithm for checking that two constraints do not have
the same handle (in the same module) only worked when the constraints
were defined within the same module block.  However, if they were
defined in different blocks (e.g. in different files) the duplicate
handle was not reported as an error.

To resolve this, a global map of all handles is now maintained which is
shared across all source files and module blocks.

Author: DavePearce

pkg/corset/compiler/parser.go

@@ -42,18 +42,22 @@ import (
 // Thus, you should never expect to see duplicate module names in the returned
 // array.
 func ParseSourceFiles(files []source.File, enforceTypes bool) (ast.Circuit, *source.Maps[ast.Node], []SyntaxError) {
-	var circuit ast.Circuit
-	// (for now) at most one error per source file is supported.
-	var errors []SyntaxError
-	// Construct an initially empty source map
-	srcmaps := source.NewSourceMaps[ast.Node]()
-	// Contents map holds the combined fragments of each module.
-	contents := make(map[string]ast.Module, 0)
-	// Names identifies the names of each unique module.
-	names := make([]string, 0)
+	var (
+		circuit ast.Circuit
+		// (for now) at most one error per source file is supported.
+		errors []SyntaxError
+		// Construct an initially empty source map
+		srcmaps = source.NewSourceMaps[ast.Node]()
+		// Contents map holds the combined fragments of each module.
+		contents = make(map[string]ast.Module, 0)
+		// Names identifies the names of each unique module.
+		names = make([]string, 0)
+		// Handles used for detecting duplicate constraint handles
+		handles = make(map[string]bool)
+	)
 	//
 	for _, file := range files {
-		c, srcmap, errs := ParseSourceFile(file, enforceTypes)
+		c, srcmap, errs := parseSourceFile(file, enforceTypes, handles)
 		// Handle errors
 		if len(errs) > 0 {
 			// Report any errors encountered
@@ -94,10 +98,9 @@ func ParseSourceFiles(files []source.File, enforceTypes bool) (ast.Circuit, *sou
 	return circuit, srcmaps, nil
 }
 
-// ParseSourceFile parses the contents of a single lisp file into one or more
-// modules.  Observe that every lisp file starts in the "prelude" or "root"
-// module, and may declare items for additional modules as necessary.
-func ParseSourceFile(srcfile source.File, enforceTypes bool) (ast.Circuit, *source.Map[ast.Node], []SyntaxError) {
+func parseSourceFile(srcfile source.File, enforceTypes bool,
+	handles map[string]bool) (ast.Circuit, *source.Map[ast.Node], []SyntaxError) {
+	//
 	//
 	var (
 		circuit ast.Circuit
@@ -111,7 +114,7 @@ func ParseSourceFile(srcfile source.File, enforceTypes bool) (ast.Circuit, *sour
 		return circuit, nil, []SyntaxError{*err}
 	}
 	// Construct parser for corset syntax
-	p := NewParser(srcfile, srcmap, enforceTypes)
+	p := NewParser(srcfile, srcmap, enforceTypes, handles)
 	// Parse whatever is declared at the beginning of the file before the first
 	// module declaration.  These declarations form part of the "prelude".
 	if circuit.Declarations, terms, errors = p.parseModuleContents(path, terms); len(errors) > 0 {
@@ -150,6 +153,8 @@ func ParseSourceFile(srcfile source.File, enforceTypes bool) (ast.Circuit, *sour
 // ensuring that expressions are well-typed, etc) --- that is left up to the
 // compiler.
 type Parser struct {
+	// Handles map used to detect duplicate handles
+	handles map[string]bool
 	// Translator used for recursive expressions.
 	translator *sexp.Translator[ast.Expr]
 	// Mapping from constructed S-Expressions to their spans in the original text.
@@ -160,12 +165,14 @@ type Parser struct {
 
 // NewParser constructs a new parser using a given mapping from S-Expressions to
 // spans in the underlying source file.
-func NewParser(srcfile source.File, srcmap *source.Map[sexp.SExp], enforceTypes bool) *Parser {
+func NewParser(srcfile source.File, srcmap *source.Map[sexp.SExp], enforceTypes bool, handles map[string]bool,
+) *Parser {
+	//
 	p := sexp.NewTranslator[ast.Expr](&srcfile, srcmap)
 	// Construct (initially empty) node map
 	nodemap := source.NewSourceMap[ast.Node](srcmap.Source())
 	// Construct parser
-	parser := &Parser{p, nodemap, enforceTypes}
+	parser := &Parser{handles, p, nodemap, enforceTypes}
 	// Configure expression translator
 	p.AddSymbolRule(constantParserRule)
 	p.AddSymbolRule(varAccessParserRule)
@@ -215,9 +222,8 @@ func (p *Parser) parseModuleContents(path file.Path, terms []sexp.SExp) ([]ast.D
 	[]SyntaxError) {
 	//
 	var (
-		errors  []SyntaxError
-		handles = make(map[string]bool)
-		decls   = make([]ast.Declaration, 0)
+		errors []SyntaxError
+		decls  = make([]ast.Declaration, 0)
 	)
 	//
 	for i, s := range terms {
@@ -228,7 +234,7 @@ func (p *Parser) parseModuleContents(path file.Path, terms []sexp.SExp) ([]ast.D
 			errors = append(errors, *err)
 		} else if e.MatchSymbols(2, "module") {
 			return decls, terms[i:], errors
-		} else if decl, errs := p.parseDeclaration(path, e, handles); len(errs) > 0 {
+		} else if decl, errs := p.parseDeclaration(path, e); len(errs) > 0 {
 			errors = append(errors, errs...)
 		} else {
 			// Continue accumulating declarations for this module.
@@ -268,8 +274,7 @@ func (p *Parser) parseModuleStart(s sexp.SExp) (string, []SyntaxError) {
 	return name, errors
 }
 
-func (p *Parser) parseDeclaration(module file.Path, s *sexp.List,
-	handles map[string]bool) (ast.Declaration, []SyntaxError) {
+func (p *Parser) parseDeclaration(module file.Path, s *sexp.List) (ast.Declaration, []SyntaxError) {
 	//
 	var (
 		decl   ast.Declaration
@@ -285,7 +290,7 @@ func (p *Parser) parseDeclaration(module file.Path, s *sexp.List,
 	} else if s.Len() > 1 && s.MatchSymbols(1, "defconst") {
 		decl, errors = p.parseDefConst(module, s.Elements)
 	} else if s.Len() == 4 && s.MatchSymbols(2, "defconstraint") {
-		decl, errors = p.parseDefConstraint(module, s.Elements, handles)
+		decl, errors = p.parseDefConstraint(module, s.Elements)
 	} else if s.Len() == 3 && s.MatchSymbols(1, "defpurefun") {
 		decl, errors = p.parseDefFun(module, true, s.Elements)
 	} else if s.Len() == 3 && s.MatchSymbols(1, "defun") {
@@ -295,21 +300,21 @@ func (p *Parser) parseDeclaration(module file.Path, s *sexp.List,
 	} else if s.Len() == 3 && s.MatchSymbols(1, "definterleaved") {
 		decl, errors = p.parseDefInterleaved(module, s.Elements)
 	} else if s.Len() == 4 && s.MatchSymbols(1, "deflookup") {
-		decl, errors = p.parseDefLookup(s.Elements, handles)
+		decl, errors = p.parseDefLookup(module, s.Elements)
 	} else if (s.Len() == 5 || s.Len() == 6) && s.MatchSymbols(1, "defclookup") {
-		decl, errors = p.parseDefConditionalLookup(s.Elements, handles)
+		decl, errors = p.parseDefConditionalLookup(module, s.Elements)
 	} else if s.Len() == 4 && s.MatchSymbols(1, "defmlookup") {
-		decl, errors = p.parseDefMultiLookup(s.Elements, handles)
+		decl, errors = p.parseDefMultiLookup(module, s.Elements)
 	} else if s.Len() == 3 && s.MatchSymbols(2, "defpermutation") {
 		decl, errors = p.parseDefPermutation(module, s.Elements)
 	} else if s.Len() == 4 && s.MatchSymbols(2, "defperspective") {
 		decl, errors = p.parseDefPerspective(module, s.Elements)
 	} else if 3 <= s.Len() && s.Len() <= 4 && s.MatchSymbols(2, "defproperty") {
-		decl, errors = p.parseDefProperty(s.Elements, handles)
+		decl, errors = p.parseDefProperty(module, s.Elements)
 	} else if s.Len() == 3 && s.MatchSymbols(2, "defsorted") {
-		decl, errors = p.parseDefSorted(false, s.Elements, handles)
+		decl, errors = p.parseDefSorted(module, false, s.Elements)
 	} else if 3 <= s.Len() && s.Len() <= 4 && s.MatchSymbols(2, "defstrictsorted") {
-		decl, errors = p.parseDefSorted(true, s.Elements, handles)
+		decl, errors = p.parseDefSorted(module, true, s.Elements)
 	} else if s.Len() == 3 && s.MatchSymbols(1, "defcomputedcolumn") {
 		decl, errors = p.parseDefComputedColumn(module, s.Elements)
 	} else {
@@ -761,23 +766,20 @@ func (p *Parser) parseDefConstHead(head sexp.SExp) (*sexp.Symbol, ast.Type, bool
 }
 
 // Parse a vanishing declaration
-func (p *Parser) parseDefConstraint(module file.Path, elements []sexp.SExp,
-	handles map[string]bool) (ast.Declaration, []SyntaxError) {
-	var (
-		errors []SyntaxError
-		handle string
-	)
+func (p *Parser) parseDefConstraint(module file.Path, elements []sexp.SExp) (ast.Declaration, []SyntaxError) {
+	var errors []SyntaxError
 	// Initial sanity checks
 	if !isIdentifier(elements[1]) {
 		return nil, p.translator.SyntaxErrors(elements[1], "invalid constraint handle")
-	} else {
-		handle = elements[1].AsSymbol().Value
 	}
+	//
+	handle := elements[1].AsSymbol().Value
+	qualifiedHandle := fmt.Sprintf("%s:%s", module.String(), handle)
 	// Check for duplicate
-	if _, ok := handles[handle]; ok {
+	if _, ok := p.handles[qualifiedHandle]; ok {
 		return nil, p.translator.SyntaxErrors(elements[1], "duplicate handle")
 	} else {
-		handles[handle] = true
+		p.handles[qualifiedHandle] = true
 	}
 	// Vanishing constraints do not have global scope, hence qualified column
 	// accesses are not permitted.
@@ -869,9 +871,9 @@ func (p *Parser) parseDefInterleavedSourceArray(source *sexp.Array) (ast.TypedSy
 }
 
 // Parse a lookup declaration
-func (p *Parser) parseDefLookup(elements []sexp.SExp, handles map[string]bool) (ast.Declaration, []SyntaxError) {
+func (p *Parser) parseDefLookup(module file.Path, elements []sexp.SExp) (ast.Declaration, []SyntaxError) {
 	// Extract items
-	handle, checked, errors := p.parseLookupHandle(elements[1], handles)
+	handle, checked, errors := p.parseLookupHandle(module, elements[1])
 	targets, tgtErrors := p.parseDefLookupSources("target", elements[2])
 	sources, srcErrors := p.parseDefLookupSources("source", elements[3])
 	// Combine any and all errors
@@ -897,16 +899,15 @@ func (p *Parser) parseDefLookup(elements []sexp.SExp, handles map[string]bool) (
 }
 
 // Parse a conditional lookup declaration
-func (p *Parser) parseDefConditionalLookup(elements []sexp.SExp,
-	handles map[string]bool) (ast.Declaration, []SyntaxError) {
+func (p *Parser) parseDefConditionalLookup(module file.Path, elements []sexp.SExp) (ast.Declaration, []SyntaxError) {
 	// Extract items
 	var (
 		targets, sources               []ast.Expr
 		targetSelector, sourceSelector ast.Expr
 		errs1, errs2, errs3, errs4     []SyntaxError
 	)
 	//
-	handle, checked, errors := p.parseLookupHandle(elements[1], handles)
+	handle, checked, errors := p.parseLookupHandle(module, elements[1])
 	//
 	if len(elements) == 6 {
 		targetSelector, errs1 = p.translator.Translate(elements[2])
@@ -942,9 +943,9 @@ func (p *Parser) parseDefConditionalLookup(elements []sexp.SExp,
 		[][]ast.Expr{targets}), nil
 }
 
-func (p *Parser) parseDefMultiLookup(elements []sexp.SExp, handles map[string]bool) (ast.Declaration, []SyntaxError) {
+func (p *Parser) parseDefMultiLookup(module file.Path, elements []sexp.SExp) (ast.Declaration, []SyntaxError) {
 	// Extract items
-	handle, checked, errors := p.parseLookupHandle(elements[1], handles)
+	handle, checked, errors := p.parseLookupHandle(module, elements[1])
 	m, targets, tgtErrors := p.parseDefLookupMultiSources("target", elements[2])
 	n, sources, srcErrors := p.parseDefLookupMultiSources("source", elements[3])
 	// Combine any and all errors
@@ -966,7 +967,7 @@ func (p *Parser) parseDefMultiLookup(elements []sexp.SExp, handles map[string]bo
 	return ast.NewDefLookup(handle, checked, sourceSelectors, sources, targetSelectors, targets), nil
 }
 
-func (p *Parser) parseLookupHandle(element sexp.SExp, handles map[string]bool) (string, bool, []SyntaxError) {
+func (p *Parser) parseLookupHandle(module file.Path, element sexp.SExp) (string, bool, []SyntaxError) {
 	var (
 		checked = true
 		errors  []SyntaxError
@@ -981,12 +982,14 @@ func (p *Parser) parseLookupHandle(element sexp.SExp, handles map[string]bool) (
 	} else {
 		handle = element.AsSymbol().Value
 	}
+	//
+	qualifiedHandle := fmt.Sprintf("%s:%s", module.String(), handle)
 	// Check for duplicate handle
-	if _, ok := handles[handle]; ok {
+	if _, ok := p.handles[qualifiedHandle]; ok {
 		return "", checked, p.translator.SyntaxErrors(element, "duplicate handle")
 	} else if len(errors) == 0 {
 		// Done
-		handles[handle] = true
+		p.handles[qualifiedHandle] = true
 	}
 	//
 	return handle, checked, errors
@@ -1149,8 +1152,7 @@ func (p *Parser) parseDefPermutation(module file.Path, elements []sexp.SExp) (as
 }
 
 // Parse a permutation declaration
-func (p *Parser) parseDefSorted(strict bool, elements []sexp.SExp,
-	handles map[string]bool) (ast.Declaration, []SyntaxError) {
+func (p *Parser) parseDefSorted(module file.Path, strict bool, elements []sexp.SExp) (ast.Declaration, []SyntaxError) {
 	//
 	var (
 		selector           util.Option[ast.Expr]
@@ -1159,7 +1161,6 @@ func (p *Parser) parseDefSorted(strict bool, elements []sexp.SExp,
 		sexpSourcesElement sexp.SExp
 		sexpSources        *sexp.List
 		signs              []bool
-		handle             string
 	)
 	//
 	if len(elements) == 3 {
@@ -1179,15 +1180,16 @@ func (p *Parser) parseDefSorted(strict bool, elements []sexp.SExp,
 	// Check Handle
 	if !isIdentifier(elements[1]) {
 		errors = append(errors, *p.translator.SyntaxError(elements[1], "malformed handle"))
-	} else {
-		handle = elements[1].AsSymbol().Value
 	}
+	//
+	handle := elements[1].AsSymbol().Value
+	qualifiedHandle := fmt.Sprintf("%s:%s", module.String(), handle)
 	// Check for duplicate handle
-	if _, ok := handles[handle]; ok {
+	if _, ok := p.handles[qualifiedHandle]; ok {
 		return nil, p.translator.SyntaxErrors(elements[1], "duplicate handle")
 	} else if len(errors) == 0 {
 		// Record handle
-		handles[handle] = true
+		p.handles[qualifiedHandle] = true
 	}
 	// Check source Expressions
 	if sexpSources == nil {
@@ -1327,7 +1329,7 @@ func (p *Parser) parseDefPerspective(module file.Path, elements []sexp.SExp) (as
 }
 
 // Parse a property assertion
-func (p *Parser) parseDefProperty(elements []sexp.SExp, handles map[string]bool) (ast.Declaration, []SyntaxError) {
+func (p *Parser) parseDefProperty(module file.Path, elements []sexp.SExp) (ast.Declaration, []SyntaxError) {
 	var (
 		errors    []SyntaxError
 		assertion int = len(elements) - 1
@@ -1341,12 +1343,14 @@ func (p *Parser) parseDefProperty(elements []sexp.SExp, handles map[string]bool)
 		// Extract handle
 		handle = elements[1].AsSymbol().Value
 	}
+	// Generate qualified name
+	qualifiedHandle := fmt.Sprintf("%s:%s", module.String(), handle)
 	// Check for duplicate handle
-	if _, ok := handles[handle]; ok {
+	if _, ok := p.handles[qualifiedHandle]; ok {
 		return nil, p.translator.SyntaxErrors(elements[1], "duplicate handle")
 	} else if len(errors) == 0 {
 		// Record handle
-		handles[handle] = true
+		p.handles[qualifiedHandle] = true
 	}
 	// Check for any attributes
 	if len(elements) > 3 {

testdata/corset/invalid/basic_invalid_20.lisp

@@ -1,4 +1,4 @@
-;;
+;;error:8:16-20:duplicate handle
 (module m1)
 
 (defcolumns (X :i16) (Y :i16))

testdata/corset/invalid/lookup_invalid_19.lisp

@@ -1,3 +1,4 @@
+;;error:7:13-17:duplicate handle
 (module m1)
 (defcolumns (X :i16) (Y :i16))
 (defclookup test (Y) 1 (X))