[lld] [lld][WebAssembly] Allow `--no-stack-first` in addition to `--stack-first` (PR #166384)
Sam Clegg via llvm-commits
llvm-commits at lists.llvm.org
Tue Nov 4 07:41:50 PST 2025
https://github.com/sbc100 updated https://github.com/llvm/llvm-project/pull/166384
>From e31e761ca738cf83d5f9e01be306db3b4053c058 Mon Sep 17 00:00:00 2001
From: Sam Clegg <sbc at chromium.org>
Date: Tue, 4 Nov 2025 07:37:02 -0800
Subject: [PATCH] [lld][WebAssembly] Enable `--no-stack-first` in addition to
`--stack-first`
This paves the way to make `--stack-first` the default.
See: #151015
---
lld/test/wasm/stack-first.test | 25 +++++++++++++++++++++++++
lld/wasm/Options.td | 5 +++--
2 files changed, 28 insertions(+), 2 deletions(-)
diff --git a/lld/test/wasm/stack-first.test b/lld/test/wasm/stack-first.test
index 72e1a006d5700..33f5e6a14b564 100644
--- a/lld/test/wasm/stack-first.test
+++ b/lld/test/wasm/stack-first.test
@@ -8,6 +8,15 @@ RUN: llvm-mc -filetype=obj -triple=wasm32-unknown-unknown %p/Inputs/stack-first.
RUN: wasm-ld -z stack-size=512 --stack-first --export=__data_end --export=__heap_base --export=someByte -o %t.wasm %t.o
RUN: obj2yaml %t.wasm | FileCheck %s
+; Check `--no-stack-first`
+RUN: wasm-ld -z stack-size=512 --no-stack-first --export=__data_end --export=__heap_base --export=someByte -o %t.wasm %t.o
+RUN: obj2yaml %t.wasm | FileCheck %s --check-prefix=NOT-FIRST
+
+; Check that the default
+RUN: wasm-ld -z stack-size=512 --export=__data_end --export=__heap_base --export=someByte -o %t.wasm %t.o
+RUN: obj2yaml %t.wasm | FileCheck %s --check-prefix=NOT-FIRST
+
+
CHECK: - Type: GLOBAL
CHECK-NEXT: Globals:
CHECK-NEXT: - Index: 0
@@ -51,3 +60,19 @@ CHECK-NEXT: Index: 2
CHECK-NEXT: - Name: __heap_base
CHECK-NEXT: Kind: GLOBAL
CHECK-NEXT: Index: 3
+
+NOT-FIRST: - Type: GLOBAL
+NOT-FIRST-NEXT: Globals:
+NOT-FIRST-NEXT: - Index: 0
+NOT-FIRST-NEXT: Type: I32
+NOT-FIRST-NEXT: Mutable: true
+NOT-FIRST-NEXT: InitExpr:
+NOT-FIRST-NEXT: Opcode: I32_CONST
+NOT-FIRST-NEXT: Value: 1552
+NOT-FIRST-NEXT: - Index: 1
+NOT-FIRST-NEXT: Type: I32
+NOT-FIRST-NEXT: Mutable: false
+NOT-FIRST-NEXT: InitExpr:
+NOT-FIRST-NEXT: Opcode: I32_CONST
+NOT-FIRST-NEXT: Value: 1024
+
diff --git a/lld/wasm/Options.td b/lld/wasm/Options.td
index 2f699e2f68350..0ed69258d99aa 100644
--- a/lld/wasm/Options.td
+++ b/lld/wasm/Options.td
@@ -250,8 +250,9 @@ def no_entry: FF<"no-entry">,
def no_shlib_sigcheck: FF<"no-shlib-sigcheck">,
HelpText<"Do not check signatures of functions defined in shared libraries.">;
-def stack_first: FF<"stack-first">,
- HelpText<"Place stack at start of linear memory rather than after data">;
+defm stack_first: B<"stack-first",
+ "Place stack at start of linear memory",
+ "Place the stack after static data refion (default)">;
def table_base: JJ<"table-base=">,
HelpText<"Table offset at which to place address taken functions (Defaults to 1)">;
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