Add a specific error for nested macro definitions

This case was previously being reported with the message "The macro
definition was not terminated, add a ';' character to terminate", which
was not very helpful.

2 files changed, 11 insertions, 5 deletions

diff --git a/src/stages/syntactic.rs b/src/stages/syntactic.rs
index a1ba833..227b399 100644
--- a/src/stages/syntactic.rs
+++ b/src/stages/syntactic.rs
@@ -4,10 +4,10 @@ use assembler::Tokeniser;
 
 
 pub fn parse_syntactic<P: Into<PathBuf>>(source_code: &str, path: Option<P>) -> Result<Vec<Tracked<SyntacticToken>>, Vec<Tracked<SyntacticError>>> {
-    parse_syntactic_from_tokeniser(Tokeniser::new(source_code, path))
+    parse_syntactic_from_tokeniser(Tokeniser::new(source_code, path), false)
 }
 
-fn parse_syntactic_from_tokeniser(mut t: Tokeniser) -> Result<Vec<Tracked<SyntacticToken>>, Vec<Tracked<SyntacticError>>> {
+fn parse_syntactic_from_tokeniser(mut t: Tokeniser, in_macro: bool) -> Result<Vec<Tracked<SyntacticToken>>, Vec<Tracked<SyntacticError>>> {
     t.add_delimiters(&['@','&','%',';',':','|','{','}','(',')','[',']','#','~','"','\'']);
     let mut tokens = Vec::new();
     let mut errors = Vec::new();
@@ -77,7 +77,7 @@ fn parse_syntactic_from_tokeniser(mut t: Tokeniser) -> Result<Vec<Tracked<Syntac
                 t.mark_child();
                 if let Some(_) = t.track_until(is_matching!('{','}')) {
                     let child = t.tokenise_child_span();
-                    match parse_syntactic_from_tokeniser(child) {
+                    match parse_syntactic_from_tokeniser(child, in_macro) {
                         Ok(tokens) => SyntacticToken::BlockLiteral(tokens),
                         Err(mut parse_errors) => {
                             errors.append(&mut parse_errors);
@@ -93,7 +93,7 @@ fn parse_syntactic_from_tokeniser(mut t: Tokeniser) -> Result<Vec<Tracked<Syntac
                 t.mark_child();
                 if let Some(_) = t.track_until(is_matching!('[',']')) {
                     let child = t.tokenise_child_span();
-                    match parse_syntactic_from_tokeniser(child) {
+                    match parse_syntactic_from_tokeniser(child, in_macro) {
                         Ok(tokens) => SyntacticToken::Expression(tokens),
                         Err(mut parse_errors) => {
                             errors.append(&mut parse_errors);
@@ -121,11 +121,14 @@ fn parse_syntactic_from_tokeniser(mut t: Tokeniser) -> Result<Vec<Tracked<Syntac
             }
             '%' => {
                 let name = t.eat_token();
+                if in_macro {
+                    err!(SyntacticError::MacroDefinitionInMacroDefinition);
+                }
                 let source = t.get_source();
                 t.mark_child();
                 if let Some(_) = t.track_until(is_any!(';')) {
                     let child = t.tokenise_child_span();
-                    match parse_syntactic_from_tokeniser(child) {
+                    match parse_syntactic_from_tokeniser(child, true) {
                         Ok(body) => {
                             let name = Tracked::from(name, source);
                             let definition = SyntacticMacroDefinition { name, body };
diff --git a/src/stages/syntactic_tokens.rs b/src/stages/syntactic_tokens.rs
index 5a0ac9e..1f8db7f 100644
--- a/src/stages/syntactic_tokens.rs
+++ b/src/stages/syntactic_tokens.rs
@@ -57,6 +57,7 @@ pub enum SyntacticError {
     UnterminatedCharacterLiteral,
     UnterminatedStringLiteral,
     UnterminatedMacroDefinition(String),
+    MacroDefinitionInMacroDefinition,
 
     UnmatchedBlockTerminator,
     UnmatchedExpressionTerminator,
@@ -96,6 +97,8 @@ fn report_syntactic_error(error: &Tracked<SyntacticError>, source_code: &str) {
             "String was not terminated, add a '\"' character to terminate",
         SyntacticError::UnterminatedMacroDefinition(name) =>
             &format!("The '{name}' macro definition was not terminated, add a ';' character to terminate"),
+        SyntacticError::MacroDefinitionInMacroDefinition =>
+            &format!("Attempted to define a macro inside another macro definition"),
 
         SyntacticError::UnmatchedBlockTerminator =>
             "Attempted to terminate a block, but no block was in progress",