From 1af27136faac16ff9f9d48519c6d3ccde7f4e5df Mon Sep 17 00:00:00 2001
From: Christoffer Lerno <christoffer@aegik.com>
Date: Sat, 17 Jul 2021 15:20:13 +0200
Subject: [PATCH] Improved error messages on incorrect module name. Issue #209

---
 src/compiler/parse_global.c                   | 22 ++++++++++++++++++-
 src/compiler/parser_internal.h                | 21 +++++++++++++++++-
 .../module/module_bad_path_ident.c3           |  1 +
 .../module/module_bad_path_invalid.c3         |  1 +
 .../module/module_bad_path_keyword.c3         |  1 +
 .../module/module_start_bad_ident.c3          |  1 +
 .../test_suite/module/module_start_invalid.c3 |  1 +
 .../test_suite/module/module_start_keyword.c3 |  1 +
 8 files changed, 47 insertions(+), 2 deletions(-)
 create mode 100644 test/test_suite/module/module_bad_path_ident.c3
 create mode 100644 test/test_suite/module/module_bad_path_invalid.c3
 create mode 100644 test/test_suite/module/module_bad_path_keyword.c3
 create mode 100644 test/test_suite/module/module_start_bad_ident.c3
 create mode 100644 test/test_suite/module/module_start_invalid.c3
 create mode 100644 test/test_suite/module/module_start_keyword.c3

diff --git a/src/compiler/parse_global.c b/src/compiler/parse_global.c
index 4ffaf7651..b09fc14a2 100644
--- a/src/compiler/parse_global.c
+++ b/src/compiler/parse_global.c
@@ -241,6 +241,16 @@ static inline Path *parse_module_path(Context *context)
 		const char *string = TOKSTR(context->tok);
 		if (!try_consume(context, TOKEN_IDENT))
 		{
+			if (token_is_keyword(context->tok.type))
+			{
+				SEMA_TOKEN_ERROR(context->tok, "The module path cannot contain a reserved keyword, try another name.");
+				return false;
+			}
+			if (token_is_some_ident(context->tok.type))
+			{
+				SEMA_TOKEN_ERROR(context->tok, "The elements of a module path must consist of only lower case letters, 0-9 and '_'.");
+				return false;
+			}
 			SEMA_TOKEN_ERROR(context->tok, "Each '::' must be followed by a regular lower case sub module name.");
 			return NULL;
 		}
@@ -338,7 +348,17 @@ bool parse_module(Context *context)
 
 	if (!TOKEN_IS(TOKEN_IDENT))
 	{
-		SEMA_TOKEN_ERROR(context->tok, "Module statement should be followed by the name of the module.");
+		if (token_is_keyword(context->tok.type))
+		{
+			SEMA_TOKEN_ERROR(context->tok, "The module name cannot contain a reserved keyword, try another name.");
+			return false;
+		}
+		if (token_is_some_ident(context->tok.type))
+		{
+			SEMA_TOKEN_ERROR(context->tok, "The module name must consist of only lower case letters, 0-9 and '_'.");
+			return false;
+		}
+		SEMA_TOKEN_ERROR(context->tok, "'module' should be followed by a module name.");
 		return false;
 	}
 
diff --git a/src/compiler/parser_internal.h b/src/compiler/parser_internal.h
index fa14583e6..2ac32b4f9 100644
--- a/src/compiler/parser_internal.h
+++ b/src/compiler/parser_internal.h
@@ -19,7 +19,6 @@
 
 #define CHECK_EXPR(_expr) do { if (!expr_ok(_expr)) return _expr; } while(0)
 
-
 #define COMMA_RPAREN_OR(_res) \
 do { if (!try_consume(context, TOKEN_COMMA) && !TOKEN_IS(TOKEN_RPAREN)) { \
 SEMA_TOKEN_ERROR(context->tok, "Expected ',' or ')'"); return _res; } } while(0)
@@ -80,6 +79,26 @@ static inline bool expect(Context *context, TokenType token_type)
 	return false;
 }
 
+static inline bool token_is_some_ident(TokenType token_type)
+{
+	switch (token_type)
+	{
+		case TOKEN_TYPE_IDENT:
+		case TOKEN_IDENT:
+		case TOKEN_CONST_IDENT:
+			return true;
+		default:
+			return false;
+	}
+}
+
+static inline bool token_is_keyword(TokenType token_type)
+{
+	if (token_type >= TOKEN_VOID && token_type <= TOKEN_TYPEID) return true;
+	if (token_type >= TOKEN_ALIAS && token_type <= TOKEN_WHILE) return true;
+	return false;
+}
+
 static inline bool expect_ident(Context *context, const char* name)
 {
 	switch (context->tok.type)
diff --git a/test/test_suite/module/module_bad_path_ident.c3 b/test/test_suite/module/module_bad_path_ident.c3
new file mode 100644
index 000000000..3897c998c
--- /dev/null
+++ b/test/test_suite/module/module_bad_path_ident.c3
@@ -0,0 +1 @@
+module big::MONEY; // #error: The elements of a module path must consist of only lower
\ No newline at end of file
diff --git a/test/test_suite/module/module_bad_path_invalid.c3 b/test/test_suite/module/module_bad_path_invalid.c3
new file mode 100644
index 000000000..1554c001d
--- /dev/null
+++ b/test/test_suite/module/module_bad_path_invalid.c3
@@ -0,0 +1 @@
+module abc::&&; // #error: Each '::' must be followed by a regular lower case sub module name
\ No newline at end of file
diff --git a/test/test_suite/module/module_bad_path_keyword.c3 b/test/test_suite/module/module_bad_path_keyword.c3
new file mode 100644
index 000000000..918aa7389
--- /dev/null
+++ b/test/test_suite/module/module_bad_path_keyword.c3
@@ -0,0 +1 @@
+module abc::if::while; // #error: The module path cannot contain a reserved keyword, try another name
\ No newline at end of file
diff --git a/test/test_suite/module/module_start_bad_ident.c3 b/test/test_suite/module/module_start_bad_ident.c3
new file mode 100644
index 000000000..3502724ba
--- /dev/null
+++ b/test/test_suite/module/module_start_bad_ident.c3
@@ -0,0 +1 @@
+module BIG::MONEY; // #error: The module name must consist of only lower case letters
\ No newline at end of file
diff --git a/test/test_suite/module/module_start_invalid.c3 b/test/test_suite/module/module_start_invalid.c3
new file mode 100644
index 000000000..1c8e68bb9
--- /dev/null
+++ b/test/test_suite/module/module_start_invalid.c3
@@ -0,0 +1 @@
+module &&; // #error: 'module' should be followed by a module name
\ No newline at end of file
diff --git a/test/test_suite/module/module_start_keyword.c3 b/test/test_suite/module/module_start_keyword.c3
new file mode 100644
index 000000000..84ff3d77c
--- /dev/null
+++ b/test/test_suite/module/module_start_keyword.c3
@@ -0,0 +1 @@
+module if::hello; // #error: The module name cannot contain a reserved keyword
\ No newline at end of file