comments

Author: kabiroberai

Sources/_SwiftSyntaxCShims/wasm_support.c

@@ -18,10 +18,13 @@
 #define _STR(X) #X
 #define STR(X) _STR(X)
 
-// this must be a metadata section rather than a data section so we can't
-// use __attribute__((section)) for it
+// LLVM has special-cased handling to map .custom_section.foo to
+// Wasm Custom Section "foo". this must be a metadata section rather
+// than a data section so we can't use __attribute__((section)) for it.
+// See: https://reviews.llvm.org/D43097
 __asm__("\t.section .custom_section.swift_wasm_macro_abi,\"\",@\n\t.4byte " STR(SWIFT_WASM_ABI_VERSION_RAW) "\n");
 
+// defined in CompilerPlugin.swift
 void _swift_wasm_macro_pump(void);
 
 __attribute__((export_name("swift_wasm_macro_pump")))