Changeset 71d6bd8 for src/ResolvExpr/CandidateFinder.cpp

Timestamp:

Nov 28, 2019, 4:31:05 PM (4 years ago)

Author:

Thierry Delisle <tdelisle@…>

Branches:

ADT, arm-eh, ast-experimental, enum, forall-pointer-decay, jacob/cs343-translation, master, new-ast, new-ast-unique-expr, pthread-emulation, qualifiedEnum

Children:

7030dab

Parents:

9802f4c

Message:

First attempt at better errors on 'No reasonable alternatives' split not found and found but didn't match

File:

• src/ResolvExpr/CandidateFinder.cpp (modified) (11 diffs)

src/ResolvExpr/CandidateFinder.cpp

@@ -601 +601 @@
                 ast::ptr< ast::Type > & targetType;
 
+                enum Errors {
+                        NotFound,
+                        NoMatch,
+                        ArgsToFew,
+                        ArgsToMany,
+                        RetsToFew,
+                        RetsToMany,
+                        NoReason
+                };
+
+                struct {
+                        Errors code = NotFound;
+                } reason;
+
                 Finder( CandidateFinder & f )
                 : symtab( f.localSyms ), selfFinder( f ), candidates( f.candidates ), tenv( f.env ),
@@ -611 +625 @@
                 void addCandidate( Args &&... args ) {
                         candidates.emplace_back( new Candidate{ std::forward<Args>( args )... } );
+                        reason.code = NoReason;
                 }
 
@@ -836 +851 @@
                         // short-circuit if no candidates
                         if ( funcFinder.candidates.empty() ) return;
+
+                        reason.code = NoMatch;
 
                         std::vector< CandidateFinder > argCandidates =
@@ -989 +1006 @@
                         CandidateFinder finder{ symtab, tenv };
                         finder.find( addressExpr->arg );
+
+                        if( finder.candidates.empty() ) return;
+
+                        reason.code = NoMatch;
+
                         for ( CandidateRef & r : finder.candidates ) {
                                 if ( ! isLvalue( r->expr ) ) continue;
@@ -1008 +1030 @@
                         CandidateFinder finder{ symtab, tenv, toType };
                         finder.find( castExpr->arg, ResolvMode::withAdjustment() );
+
+                        if( !finder.candidates.empty() ) reason.code = NoMatch;
 
                         CandidateList matches;
@@ -1093 +1117 @@
                         std::vector< ast::SymbolTable::IdData > declList = symtab.lookupId( nameExpr->name );
                         PRINT( std::cerr << "nameExpr is " << nameExpr->name << std::endl; )
+                        if( declList.empty() ) return;
+
+                        reason.code = NoMatch;
+
                         for ( auto & data : declList ) {
                                 Cost cost = Cost::zero;
@@ -1208 +1236 @@
                         if ( finder2.candidates.empty() ) return;
 
+                        reason.code = NoMatch;
+
                         for ( const CandidateRef & r1 : finder1.candidates ) {
                                 for ( const CandidateRef & r2 : finder2.candidates ) {
@@ -1241 +1271 @@
                         finder3.find( conditionalExpr->arg3, ResolvMode::withAdjustment() );
                         if ( finder3.candidates.empty() ) return;
+
+                        reason.code = NoMatch;
 
                         for ( const CandidateRef & r1 : finder1.candidates ) {
@@ -1319 +1351 @@
                         if ( finder2.candidates.empty() ) return;
 
+                        reason.code = NoMatch;
+
                         for ( const CandidateRef & r1 : finder1.candidates ) {
                                 for ( const CandidateRef & r2 : finder2.candidates ) {
@@ -1419 +1453 @@
                                 finder.find( initExpr->expr, ResolvMode::withAdjustment() );
                                 for ( CandidateRef & cand : finder.candidates ) {
+                                        if(reason.code == NotFound) reason.code = NoMatch;
+
                                         ast::TypeEnvironment env{ cand->env };
                                         ast::AssertionSet need( cand->need.begin(), cand->need.end() ), have;
@@ -1552 +1588 @@
 
         if ( mode.failFast && candidates.empty() ) {
-                SemanticError( expr, "No reasonable alternatives for expression " );
+                switch(finder.pass.reason.code) {
+                case Finder::NotFound:
+                        { SemanticError( expr, "No alternatives for expression " ); break; }
+                case Finder::NoMatch:
+                        { SemanticError( expr, "Invalid application of existing declaration(s) in expression " ); break; }
+                case Finder::ArgsToFew:
+                case Finder::ArgsToMany:
+                case Finder::RetsToFew:
+                case Finder::RetsToMany:
+                case Finder::NoReason:
+                default:
+                        { SemanticError( expr->location, "No reasonable alternatives for expression : reasons unkown" ); }
+                }
         }