From ed026b5dffd116d36aa51508e3eefa8c36838c07 Mon Sep 17 00:00:00 2001
From: Jacob Young <jacobly0@users.noreply.github.com>
Date: Sun, 25 Feb 2024 16:04:59 +0100
Subject: [PATCH] llvm: free llvm data before running llvm optimizations

This reduces the max memory usage.
---
 src/codegen/llvm.zig         | 10 ++++----
 src/codegen/llvm/Builder.zig | 44 ++++++++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+), 4 deletions(-)

diff --git a/src/codegen/llvm.zig b/src/codegen/llvm.zig
index 140b7eeba0..1e7687b96c 100644
--- a/src/codegen/llvm.zig
+++ b/src/codegen/llvm.zig
@@ -1183,6 +1183,10 @@ pub const Object = struct {
             }
         }
 
+        const target_triple_sentinel =
+            try self.gpa.dupeZ(u8, self.builder.target_triple.slice(&self.builder).?);
+        defer self.gpa.free(target_triple_sentinel);
+
         const emit_asm_msg = options.asm_path orelse "(none)";
         const emit_bin_msg = options.bin_path orelse "(none)";
         const post_llvm_ir_msg = options.post_ir_path orelse "(none)";
@@ -1202,6 +1206,7 @@ pub const Object = struct {
 
             const bitcode = try self.builder.toBitcode(self.gpa);
             defer self.gpa.free(bitcode);
+            self.builder.clearAndFree();
 
             if (options.pre_bc_path) |path| {
                 var file = try std.fs.cwd().createFile(path, .{});
@@ -1249,16 +1254,13 @@ pub const Object = struct {
         };
         defer context.dispose();
 
-        const target_triple_sentinel =
-            try self.gpa.dupeZ(u8, self.builder.target_triple.slice(&self.builder).?);
-        defer self.gpa.free(target_triple_sentinel);
         var target: *llvm.Target = undefined;
         var error_message: [*:0]const u8 = undefined;
         if (llvm.Target.getFromTriple(target_triple_sentinel, &target, &error_message).toBool()) {
             defer llvm.disposeMessage(error_message);
 
             log.err("LLVM failed to parse '{s}': {s}", .{
-                self.builder.target_triple.slice(&self.builder).?,
+                target_triple_sentinel,
                 error_message,
             });
             @panic("Invalid LLVM triple");
diff --git a/src/codegen/llvm/Builder.zig b/src/codegen/llvm/Builder.zig
index aaddddf0c1..70a85093e8 100644
--- a/src/codegen/llvm/Builder.zig
+++ b/src/codegen/llvm/Builder.zig
@@ -8396,6 +8396,50 @@ pub fn init(options: Options) Allocator.Error!Builder {
     return self;
 }
 
+pub fn clearAndFree(self: *Builder) void {
+    self.module_asm.clearAndFree(self.gpa);
+
+    self.string_map.clearAndFree(self.gpa);
+    self.string_indices.clearAndFree(self.gpa);
+    self.string_bytes.clearAndFree(self.gpa);
+
+    self.types.clearAndFree(self.gpa);
+    self.next_unique_type_id.clearAndFree(self.gpa);
+    self.type_map.clearAndFree(self.gpa);
+    self.type_items.clearAndFree(self.gpa);
+    self.type_extra.clearAndFree(self.gpa);
+
+    self.attributes.clearAndFree(self.gpa);
+    self.attributes_map.clearAndFree(self.gpa);
+    self.attributes_indices.clearAndFree(self.gpa);
+    self.attributes_extra.clearAndFree(self.gpa);
+
+    self.function_attributes_set.clearAndFree(self.gpa);
+
+    self.globals.clearAndFree(self.gpa);
+    self.next_unique_global_id.clearAndFree(self.gpa);
+    self.aliases.clearAndFree(self.gpa);
+    self.variables.clearAndFree(self.gpa);
+    for (self.functions.items) |*function| function.deinit(self.gpa);
+    self.functions.clearAndFree(self.gpa);
+
+    self.constant_map.clearAndFree(self.gpa);
+    self.constant_items.shrinkAndFree(self.gpa, 0);
+    self.constant_extra.clearAndFree(self.gpa);
+    self.constant_limbs.clearAndFree(self.gpa);
+
+    self.metadata_map.clearAndFree(self.gpa);
+    self.metadata_items.shrinkAndFree(self.gpa, 0);
+    self.metadata_extra.clearAndFree(self.gpa);
+    self.metadata_limbs.clearAndFree(self.gpa);
+    self.metadata_forward_references.clearAndFree(self.gpa);
+    self.metadata_named.clearAndFree(self.gpa);
+
+    self.metadata_string_map.clearAndFree(self.gpa);
+    self.metadata_string_indices.clearAndFree(self.gpa);
+    self.metadata_string_bytes.clearAndFree(self.gpa);
+}
+
 pub fn deinit(self: *Builder) void {
     self.module_asm.deinit(self.gpa);