- Hard limit of 127 characters for identifiers.

releasenotes.md

@@ -19,6 +19,7 @@
 - Typedefs and structs with inline types supporting lengthof would not work with lengthof #2641.
 - `$defined(foo())` now correctly errors if `foo()` would require a path.
 - `@if($defined((char*){}.foo()))` does not error if `foo` is missing.
+- Hard limit of 127 characters for identifiers.
 
 ### Stdlib changes
 - Add `ThreadPool` join function to wait for all threads to finish in the pool without destroying the threads.

src/compiler/compiler_internal.h

@@ -52,6 +52,7 @@ typedef uint16_t FileId;
 #define MAX_GLOBAL_DECL_STACK (65536)
 #define MAX_MODULE_NAME 31
 #define MAX_MODULE_PATH 63
+#define MAX_IDENTIFIER_LENGTH 127
 #define MAX_MACRO_RECURSION_DEPTH 128
 #define MEMCMP_INLINE_REGS 8
 #define UINT128_MAX ((Int128) { UINT64_MAX, UINT64_MAX })

src/compiler/lexer.c

@@ -349,6 +349,10 @@ EXIT:;
 		}
 		return add_error_token(lexer, "An identifier may not consist of only '_' characters.");
 	}
+	if (len > MAX_IDENTIFIER_LENGTH)
+	{
+		return add_error_token(lexer, "An identifier cannot be longer than %d characters, but this one was %u characters long.", MAX_IDENTIFIER_LENGTH, len);
+	}
 	const char* interned_string = symtab_add(lexer->lexing_start, len, hash, &type);
 	switch (type)
 	{

test/test_suite/lexing/too_long_ident.c3

@@ -0,0 +1,8 @@
+module test;
+import std;
+fn int main()
+{
+	int iodeofjoiewjfojfoiejfewjfijewfijewifjoiewjfioewjfioewjfioewjfiojewfiojewfiojeofjeiowfjioewjfioewjfioewjfijweifefefeffefefeeefef = 0;
+	int iodeofjoiewjfojfoiejfewjfijewfijewifjoiewjfioewjfioewjfioewjfiojewfiojewfiojeofjeiowfjioewjfioewjfioewjfijweifefefeffefefeeefef1 = 0; // #error: okfeokfe
+	return 0;
+}