stage2: Fix wasm linker for llvm backend

This fixes 2 entrypoints within the self-hosted wasm linker that would be called
for the llvm backend, whereas we should simply call into the llvm backend to perform such action.
i.e. not allocate a decl index when we have an llvm object, and when flushing a module,
we should be calling it on llvm's object, rather than have the wasm linker perform the operation.

Also, this fixes the wasm intrinsics for wasm.memory.size and wasm.memory.grow.
Lastly, this commit ensures that when an extern function is being resolved, we tell LLVM how
to import such function.

1 files changed, 10 insertions, 2 deletions

diff --git a/src/codegen/llvm.zig b/src/codegen/llvm.zig
index 368a67f4b4..446876dfe5 100644
--- a/src/codegen/llvm.zig
+++ b/src/codegen/llvm.zig
@@ -708,6 +708,14 @@ pub const DeclGen = struct {
         if (!is_extern) {
             llvm_fn.setLinkage(.Internal);
             llvm_fn.setUnnamedAddr(.True);
+        } else if (dg.module.getTarget().isWasm()) {
+            dg.addFnAttrString(llvm_fn, "wasm-import-name", std.mem.sliceTo(decl.name, 0));
+            if (decl.getExternFn().?.lib_name) |lib_name| {
+                const module_name = std.mem.sliceTo(lib_name, 0);
+                if (!std.mem.eql(u8, module_name, "c")) {
+                    dg.addFnAttrString(llvm_fn, "wasm-import-module", module_name);
+                }
+            }
         }
 
         if (sret) {
@@ -3483,7 +3491,7 @@ pub const FuncGen = struct {
         const pl_op = self.air.instructions.items(.data)[inst].pl_op;
         const index = pl_op.payload;
         const llvm_u32 = self.context.intType(32);
-        const llvm_fn = self.getIntrinsic("llvm.wasm.memory.size.i32", &.{llvm_u32});
+        const llvm_fn = self.getIntrinsic("llvm.wasm.memory.size", &.{llvm_u32});
         const args: [1]*const llvm.Value = .{llvm_u32.constInt(index, .False)};
         return self.builder.buildCall(llvm_fn, &args, args.len, .Fast, .Auto, "");
     }
@@ -3493,7 +3501,7 @@ pub const FuncGen = struct {
         const index = pl_op.payload;
         const operand = try self.resolveInst(pl_op.operand);
         const llvm_u32 = self.context.intType(32);
-        const llvm_fn = self.getIntrinsic("llvm.wasm.memory.grow.i32", &.{ llvm_u32, llvm_u32 });
+        const llvm_fn = self.getIntrinsic("llvm.wasm.memory.grow", &.{llvm_u32});
         const args: [2]*const llvm.Value = .{
             llvm_u32.constInt(index, .False),
             operand,