[WebAssembly] Check function signatures by default

But only produce a warning (for now) unless --fatal-warnings
is passed.

Differential Revision: https://reviews.llvm.org/D46484

llvm-svn: 331574

45 files changed, 82 insertions, 77 deletions

diff --git a/lld/test/wasm/alias.ll b/lld/test/wasm/alias.ll
index c12ef2dd129..af2f87b7d3a 100644
--- a/lld/test/wasm/alias.ll
+++ b/lld/test/wasm/alias.ll
@@ -1,5 +1,5 @@
 ; RUN: llc -filetype=obj -o %t.o %s
-; RUN: wasm-ld --check-signatures %t.o -o %t.wasm
+; RUN: wasm-ld %t.o -o %t.wasm
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 target triple = "wasm32-unknown-unknown-wasm"
diff --git a/lld/test/wasm/archive.ll b/lld/test/wasm/archive.ll
index 78daff0e93c..8a7ddf42491 100644
--- a/lld/test/wasm/archive.ll
+++ b/lld/test/wasm/archive.ll
@@ -4,12 +4,12 @@
 ; RUN: llc -filetype=obj %S/Inputs/hello.ll -o %t.a3.o
 ; RUN: llvm-ar rcs %t.a %t.a1.o %t.a2.o %t.a3.o
 ; RUN: rm -f %t.imports
-; RUN: not wasm-ld --check-signatures %t.a %t.o -o %t.wasm 2>&1 | FileCheck -check-prefix=CHECK-UNDEFINED %s
+; RUN: not wasm-ld %t.a %t.o -o %t.wasm 2>&1 | FileCheck -check-prefix=CHECK-UNDEFINED %s
 
 ; CHECK-UNDEFINED: undefined symbol: missing_func
 
 ; RUN: echo 'missing_func' > %t.imports
-; RUN: wasm-ld --check-signatures -r %t.a %t.o -o %t.wasm
+; RUN: wasm-ld -r %t.a %t.o -o %t.wasm
 
 ; RUN: llvm-nm -a %t.wasm | FileCheck %s
 
@@ -40,4 +40,4 @@ entry:
 ; CHECK-NOT: hello
 
 ; Specifying the same archive twice is allowed.
-; RUN: wasm-ld --check-signatures %t.a %t.a %t.o -o %t.wasm
+; RUN: wasm-ld %t.a %t.a %t.o -o %t.wasm
diff --git a/lld/test/wasm/call-indirect.ll b/lld/test/wasm/call-indirect.ll
index 9a6d64f98d1..39f056089ea 100644
--- a/lld/test/wasm/call-indirect.ll
+++ b/lld/test/wasm/call-indirect.ll
@@ -1,6 +1,6 @@
 ; RUN: llc -filetype=obj %p/Inputs/call-indirect.ll -o %t2.o
 ; RUN: llc -filetype=obj %s -o %t.o
-; RUN: wasm-ld --check-signatures -o %t.wasm %t2.o %t.o
+; RUN: wasm-ld -o %t.wasm %t2.o %t.o
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 ; bitcode generated from the following C code:
diff --git a/lld/test/wasm/comdats.ll b/lld/test/wasm/comdats.ll
index d737132d705..64ad0f2a9ea 100644
--- a/lld/test/wasm/comdats.ll
+++ b/lld/test/wasm/comdats.ll
@@ -1,7 +1,7 @@
 ; RUN: llc -filetype=obj -mtriple=wasm32-unknown-uknown-wasm %p/Inputs/comdat1.ll -o %t1.o
 ; RUN: llc -filetype=obj -mtriple=wasm32-unknown-uknown-wasm %p/Inputs/comdat2.ll -o %t2.o
 ; RUN: llc -filetype=obj -mtriple=wasm32-unknown-uknown-wasm %s -o %t.o
-; RUN: wasm-ld --check-signatures -o %t.wasm %t.o %t1.o %t2.o
+; RUN: wasm-ld -o %t.wasm %t.o %t1.o %t2.o
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 target triple = "wasm32-unknown-unknown-wasm"
diff --git a/lld/test/wasm/conflict.test b/lld/test/wasm/conflict.test
index c8698027f1d..9adc92ed1ed 100644
--- a/lld/test/wasm/conflict.test
+++ b/lld/test/wasm/conflict.test
@@ -1,5 +1,5 @@
 # RUN: llc -filetype=obj %p/Inputs/ret32.ll -o %t.ret32.o
-# RUN: not wasm-ld --check-signatures -o %t.wasm %t.ret32.o %t.ret32.o 2>&1 | FileCheck %s
+# RUN: not wasm-ld -o %t.wasm %t.ret32.o %t.ret32.o 2>&1 | FileCheck %s
 
 # CHECK:      duplicate symbol: ret32
 # CHECK-NEXT: >>> defined in {{.*}}conflict.test.tmp.ret32.o
diff --git a/lld/test/wasm/custom-sections.ll b/lld/test/wasm/custom-sections.ll
index 201653c272b..b9a9f355d99 100644
--- a/lld/test/wasm/custom-sections.ll
+++ b/lld/test/wasm/custom-sections.ll
@@ -1,6 +1,6 @@
 ; RUN: llc -filetype=obj %s -o %t1.o
 ; RUN: llc -filetype=obj  %S/Inputs/custom.ll -o %t2.o
-; RUN: wasm-ld --check-signatures --relocatable -o %t.wasm %t1.o %t2.o
+; RUN: wasm-ld --relocatable -o %t.wasm %t1.o %t2.o
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 target triple = "wasm32-unknown-unknown-wasm"
diff --git a/lld/test/wasm/cxx-mangling.ll b/lld/test/wasm/cxx-mangling.ll
index 8b73ca9bfe2..9fa51fc40cf 100644
--- a/lld/test/wasm/cxx-mangling.ll
+++ b/lld/test/wasm/cxx-mangling.ll
@@ -1,7 +1,7 @@
 ; RUN: llc -filetype=obj %s -o %t.o
-; RUN: wasm-ld --demangle --check-signatures -o %t_demangle.wasm %t.o
+; RUN: wasm-ld --demangle -o %t_demangle.wasm %t.o
 ; RUN: obj2yaml %t_demangle.wasm | FileCheck %s
-; RUN: wasm-ld --no-demangle --check-signatures -o %t_nodemangle.wasm %t.o
+; RUN: wasm-ld --no-demangle -o %t_nodemangle.wasm %t.o
 ; RUN: obj2yaml %t_nodemangle.wasm | FileCheck %s
 
 target triple = "wasm32-unknown-unknown-wasm"
diff --git a/lld/test/wasm/data-layout.ll b/lld/test/wasm/data-layout.ll
index df7177cf019..a42b72aad39 100644
--- a/lld/test/wasm/data-layout.ll
+++ b/lld/test/wasm/data-layout.ll
@@ -13,7 +13,7 @@ target triple = "wasm32-unknown-unknown-wasm"
 @local_struct = hidden global %struct.s zeroinitializer, align 4
 @local_struct_internal_ptr = hidden local_unnamed_addr global i32* getelementptr inbounds (%struct.s, %struct.s* @local_struct, i32 0, i32 1), align 4
 
-; RUN: wasm-ld -no-gc-sections --check-signatures --allow-undefined -o %t.wasm %t.o %t.hello.o
+; RUN: wasm-ld -no-gc-sections --allow-undefined -o %t.wasm %t.o %t.hello.o
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 ; CHECK:        - Type:            MEMORY
@@ -57,7 +57,7 @@ target triple = "wasm32-unknown-unknown-wasm"
 ; CHECK-NEXT:    - Type:            CUSTOM
 
 
-; RUN: wasm-ld -no-gc-sections --check-signatures --allow-undefined \
+; RUN: wasm-ld -no-gc-sections --allow-undefined \
 ; RUN:     --initial-memory=131072 --max-memory=131072 -o %t_max.wasm %t.o \
 ; RUN:     %t.hello.o
 ; RUN: obj2yaml %t_max.wasm | FileCheck %s -check-prefix=CHECK-MAX
@@ -69,7 +69,7 @@ target triple = "wasm32-unknown-unknown-wasm"
 ; CHECK-MAX-NEXT:         Maximum:         0x00000002
 
 
-; RUN: wasm-ld --check-signatures --relocatable -o %t_reloc.wasm %t.o %t.hello.o
+; RUN: wasm-ld --relocatable -o %t_reloc.wasm %t.o %t.hello.o
 ; RUN: obj2yaml %t_reloc.wasm | FileCheck %s -check-prefix=RELOC
 
 ; RELOC:       - Type:            DATA
diff --git a/lld/test/wasm/demangle.ll b/lld/test/wasm/demangle.ll
index 07f99274556..9a9741bcaef 100644
--- a/lld/test/wasm/demangle.ll
+++ b/lld/test/wasm/demangle.ll
@@ -1,10 +1,10 @@
 ; RUN: llc -filetype=obj %s -o %t.o
-; RUN: not wasm-ld --check-signatures --undefined _Z3fooi \
+; RUN: not wasm-ld --undefined _Z3fooi \
 ; RUN:     -o %t.wasm %t.o 2>&1 | FileCheck %s
 
 ; CHECK: error: undefined symbol: foo(int)
 
-; RUN: not wasm-ld --check-signatures --no-demangle --undefined _Z3fooi \
+; RUN: not wasm-ld --no-demangle --undefined _Z3fooi \
 ; RUN:     -o %t.wasm %t.o 2>&1 |  FileCheck -check-prefix=CHECK-NODEMANGLE %s
 
 ; CHECK-NODEMANGLE: error: undefined symbol: _Z3fooi
diff --git a/lld/test/wasm/entry.ll b/lld/test/wasm/entry.ll
index 083bf97a3b5..ea45e138358 100644
--- a/lld/test/wasm/entry.ll
+++ b/lld/test/wasm/entry.ll
@@ -7,9 +7,9 @@ entry:
   ret void
 }
 
-; RUN: wasm-ld --check-signatures -e entry -o %t1.wasm %t.o
+; RUN: wasm-ld -e entry -o %t1.wasm %t.o
 ; RUN: obj2yaml %t1.wasm | FileCheck %s
-; RUN: wasm-ld --check-signatures --entry=entry -o %t2.wasm %t.o
+; RUN: wasm-ld --entry=entry -o %t2.wasm %t.o
 ; RUN: obj2yaml %t2.wasm | FileCheck %s
 
 ; CHECK:        - Type:            EXPORT
@@ -30,7 +30,7 @@ entry:
 
 ; The __wasm_call_ctors is somewhat special.  Make sure we can use it
 ; as the entry point if we choose
-; RUN: wasm-ld --check-signatures --entry=__wasm_call_ctors -o %t3.wasm %t.o
+; RUN: wasm-ld --entry=__wasm_call_ctors -o %t3.wasm %t.o
 ; RUN: obj2yaml %t3.wasm | FileCheck %s -check-prefix=CHECK-CTOR
 
 ; CHECK-CTOR:        - Type:            EXPORT
diff --git a/lld/test/wasm/export-table.test b/lld/test/wasm/export-table.test
index 0923af69273..58775b928f7 100644
--- a/lld/test/wasm/export-table.test
+++ b/lld/test/wasm/export-table.test
@@ -1,5 +1,5 @@
 # RUN: llc -filetype=obj %p/Inputs/start.ll -o %t.start.o
-# RUN: wasm-ld --check-signatures --export-table -o %t.wasm %t.start.o
+# RUN: wasm-ld --export-table -o %t.wasm %t.start.o
 # RUN: obj2yaml %t.wasm | FileCheck %s
 
 # Verify the --export-table flag creates a table export
diff --git a/lld/test/wasm/export.ll b/lld/test/wasm/export.ll
index f2a4fff13cd..9e3606d4d7d 100644
--- a/lld/test/wasm/export.ll
+++ b/lld/test/wasm/export.ll
@@ -1,6 +1,6 @@
 ; RUN: llc -filetype=obj %s -o %t.o
-; RUN: not wasm-ld --check-signatures --export=missing -o %t.wasm %t.o 2>&1 | FileCheck -check-prefix=CHECK-ERROR %s
-; RUN: wasm-ld --check-signatures --export=hidden_function -o %t.wasm %t.o
+; RUN: not wasm-ld --export=missing -o %t.wasm %t.o 2>&1 | FileCheck -check-prefix=CHECK-ERROR %s
+; RUN: wasm-ld --export=hidden_function -o %t.wasm %t.o
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 target triple = "wasm32-unknown-unknown-wasm"
diff --git a/lld/test/wasm/fatal-warnings.ll b/lld/test/wasm/fatal-warnings.ll
new file mode 100644
index 00000000000..f3f1d3b64e4
--- /dev/null
+++ b/lld/test/wasm/fatal-warnings.ll
@@ -0,0 +1,14 @@
+; RUN: llc -filetype=obj %s -o %t.main.o
+; RUN: lld -flavor wasm -o %t.wasm %t.main.o 2>&1 | FileCheck %s -check-prefix=CHECK-WARN
+; RUN: not lld -flavor wasm --fatal-warnings -o %t.wasm %t.main.o 2>&1 | FileCheck %s -check-prefix=CHECK-FATAL
+
+; CHECK-WARN: warning: Function type mismatch: _start
+; CHECK-FATAL: error: Function type mismatch: _start
+
+target triple = "wasm32-unknown-unknown-wasm"
+
+define hidden i32 @_start(i32 %arg) local_unnamed_addr {
+entry:
+  ret i32 %arg
+}
+
diff --git a/lld/test/wasm/function-imports-first.ll b/lld/test/wasm/function-imports-first.ll
index be71d7c3ca1..ec8bd4ef0cf 100644
--- a/lld/test/wasm/function-imports-first.ll
+++ b/lld/test/wasm/function-imports-first.ll
@@ -1,6 +1,6 @@
 ; RUN: llc -filetype=obj %p/Inputs/ret32.ll -o %t.ret32.o
 ; RUN: llc -filetype=obj %s -o %t.o
-; RUN: wasm-ld --check-signatures -o %t.wasm %t.o %t.ret32.o
+; RUN: wasm-ld -o %t.wasm %t.o %t.ret32.o
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 target triple = "wasm32-unknown-unknown-wasm"
diff --git a/lld/test/wasm/function-imports.ll b/lld/test/wasm/function-imports.ll
index 742cec290fc..ec509e6d4d9 100644
--- a/lld/test/wasm/function-imports.ll
+++ b/lld/test/wasm/function-imports.ll
@@ -1,6 +1,6 @@
 ; RUN: llc -filetype=obj %p/Inputs/ret32.ll -o %t.ret32.o
 ; RUN: llc -filetype=obj %s -o %t.o
-; RUN: wasm-ld --check-signatures -o %t.wasm %t.ret32.o %t.o
+; RUN: wasm-ld -o %t.wasm %t.ret32.o %t.o
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 target triple = "wasm32-unknown-unknown-wasm"
diff --git a/lld/test/wasm/function-index.test b/lld/test/wasm/function-index.test
index 87842714f92..82f5d0cfb24 100644
--- a/lld/test/wasm/function-index.test
+++ b/lld/test/wasm/function-index.test
@@ -1,6 +1,6 @@
 # RUN: llc -filetype=obj %p/Inputs/ret32.ll -o %t.ret32.o
 # RUN: llc -filetype=obj %p/Inputs/ret64.ll -o %t.ret64.o
-# RUN: wasm-ld --check-signatures -r -o %t.wasm %t.ret32.o %t.ret64.o
+# RUN: wasm-ld -r -o %t.wasm %t.ret32.o %t.ret64.o
 # RUN: obj2yaml %t.wasm | FileCheck %s
 
 CHECK: Sections:
diff --git a/lld/test/wasm/import-memory.test b/lld/test/wasm/import-memory.test
index 955d2df0ea8..49bf06b7483 100644
--- a/lld/test/wasm/import-memory.test
+++ b/lld/test/wasm/import-memory.test
@@ -1,5 +1,5 @@
 # RUN: llc -filetype=obj %p/Inputs/start.ll -o %t.start.o
-# RUN: wasm-ld --check-signatures --import-memory -o %t.wasm %t.start.o
+# RUN: wasm-ld --import-memory -o %t.wasm %t.start.o
 # RUN: obj2yaml %t.wasm | FileCheck %s
 
 # Verify the --import-memory flag creates a memory import
@@ -15,7 +15,7 @@
 
 
 
-# RUN: wasm-ld --check-signatures --import-memory --initial-memory=262144 \
+# RUN: wasm-ld --import-memory --initial-memory=262144 \
 # RUN:     --max-memory=327680 -o %t.max.wasm %t.start.o
 # RUN: obj2yaml %t.max.wasm | FileCheck -check-prefix=CHECK-MAX %s
 
diff --git a/lld/test/wasm/import-table.test b/lld/test/wasm/import-table.test
index 98e07491ec4..eb767090292 100644
--- a/lld/test/wasm/import-table.test
+++ b/lld/test/wasm/import-table.test
@@ -1,5 +1,5 @@
 # RUN: llc -filetype=obj %p/Inputs/start.ll -o %t.start.o
-# RUN: wasm-ld --check-signatures --import-table -o %t.wasm %t.start.o
+# RUN: wasm-ld --import-table -o %t.wasm %t.start.o
 # RUN: obj2yaml %t.wasm | FileCheck %s
 
 # Verify the --import-table flag creates a table import
diff --git a/lld/test/wasm/init-fini.ll b/lld/test/wasm/init-fini.ll
index c93314cc368..966e679792e 100644
--- a/lld/test/wasm/init-fini.ll
+++ b/lld/test/wasm/init-fini.ll
@@ -49,7 +49,7 @@ entry:
   { i32, void ()*, i8* } { i32 4000, void ()* @externDtor, i8* null }
 ]
 
-; RUN: wasm-ld --check-signatures --allow-undefined %t.o %t.global-ctor-dtor.o -o %t.wasm
+; RUN: wasm-ld --allow-undefined %t.o %t.global-ctor-dtor.o -o %t.wasm
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 ; CHECK:        - Type:            IMPORT
@@ -128,7 +128,7 @@ entry:
 ; CHECK-NEXT: ...
 
 
-; RUN: wasm-ld --check-signatures -r %t.o %t.global-ctor-dtor.o -o %t.reloc.wasm
+; RUN: wasm-ld -r %t.o %t.global-ctor-dtor.o -o %t.reloc.wasm
 ; RUN: obj2yaml %t.reloc.wasm | FileCheck -check-prefix=RELOC %s
 
 ; RELOC:          SymbolTable:
diff --git a/lld/test/wasm/invalid-stack-size.test b/lld/test/wasm/invalid-stack-size.test
index da47c689c9c..90c9fda113e 100644
--- a/lld/test/wasm/invalid-stack-size.test
+++ b/lld/test/wasm/invalid-stack-size.test
@@ -1,4 +1,4 @@
 ; RUN: llc -filetype=obj %p/Inputs/start.ll -o %t.o
-; RUN: not wasm-ld --check-signatures -o %t.wasm -z stack-size=1 %t.o 2>&1 | FileCheck %s
+; RUN: not wasm-ld -o %t.wasm -z stack-size=1 %t.o 2>&1 | FileCheck %s
 
 ; CHECK: error: stack size must be 16-byte aligned
diff --git a/lld/test/wasm/load-undefined.test b/lld/test/wasm/load-undefined.test
index 7e78bf0c2e5..afa5b008fbc 100644
--- a/lld/test/wasm/load-undefined.test
+++ b/lld/test/wasm/load-undefined.test
@@ -5,7 +5,7 @@
 ; RUN: llc -filetype=obj %S/Inputs/ret32.ll -o %t2.o
 ; RUN: llc -filetype=obj %S/Inputs/start.ll -o %t.start.o
 ; RUN: llvm-ar rcs %t2.a %t2.o
-; RUN: wasm-ld --check-signatures %t.start.o %t2.a %t.o -o %t.wasm -u ret32 --undefined ret64
+; RUN: wasm-ld %t.start.o %t2.a %t.o -o %t.wasm -u ret32 --undefined ret64
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 ; CHECK:        - Type:            EXPORT
@@ -32,8 +32,8 @@
 
 
 ; Verify that referencing a symbol that doesn't exist won't work
-; RUN: not wasm-ld --check-signatures %t.start.o -o %t.wasm -u symboldoesnotexist 2>&1 | FileCheck -check-prefix=CHECK-UNDEFINED1 %s
+; RUN: not wasm-ld %t.start.o -o %t.wasm -u symboldoesnotexist 2>&1 | FileCheck -check-prefix=CHECK-UNDEFINED1 %s
 ; CHECK-UNDEFINED1: error: undefined symbol: symboldoesnotexist
 
-; RUN: not wasm-ld --check-signatures %t.start.o -o %t.wasm --undefined symboldoesnotexist --allow-undefined 2>&1 | FileCheck -check-prefix=CHECK-UNDEFINED2 %s
+; RUN: not wasm-ld %t.start.o -o %t.wasm --undefined symboldoesnotexist --allow-undefined 2>&1 | FileCheck -check-prefix=CHECK-UNDEFINED2 %s
 ; CHECK-UNDEFINED2: function forced with --undefined not found: symboldoesnotexist
diff --git a/lld/test/wasm/local-symbols.ll b/lld/test/wasm/local-symbols.ll
index fcb3c42783c..d7778cf83a0 100644
--- a/lld/test/wasm/local-symbols.ll
+++ b/lld/test/wasm/local-symbols.ll
@@ -1,5 +1,5 @@
 ; RUN: llc -filetype=obj %s -o %t.o
-; RUN: wasm-ld --check-signatures -o %t.wasm %t.o
+; RUN: wasm-ld -o %t.wasm %t.o
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 target triple = "wasm32-unknown-unknown-wasm"
diff --git a/lld/test/wasm/locals-duplicate.test b/lld/test/wasm/locals-duplicate.test
index 00a8dc1ed03..3c67cdd8cfa 100644
--- a/lld/test/wasm/locals-duplicate.test
+++ b/lld/test/wasm/locals-duplicate.test
@@ -1,6 +1,6 @@
 ; RUN: llc -filetype=obj %p/Inputs/locals-duplicate1.ll -o %t1.o
 ; RUN: llc -filetype=obj %p/Inputs/locals-duplicate2.ll -o %t2.o
-; RUN: wasm-ld --check-signatures --no-entry -o %t.wasm %t1.o %t2.o
+; RUN: wasm-ld --no-entry -o %t.wasm %t1.o %t2.o
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 ; CHECK:      --- !WASM
@@ -236,7 +236,7 @@
 ; CHECK-NEXT: ...
 
 
-; RUN: wasm-ld --check-signatures -r --no-entry -o %t.reloc.wasm %t1.o %t2.o
+; RUN: wasm-ld -r --no-entry -o %t.reloc.wasm %t1.o %t2.o
 ; RUN: obj2yaml %t.reloc.wasm | FileCheck -check-prefix=RELOC %s
 
 ; RELOC:      --- !WASM
diff --git a/lld/test/wasm/many-functions.ll b/lld/test/wasm/many-functions.ll
index 4116c47bfbb..43e7cfab8ae 100644
--- a/lld/test/wasm/many-functions.ll
+++ b/lld/test/wasm/many-functions.ll
@@ -1,6 +1,6 @@
 ; RUN: llc -filetype=obj %p/Inputs/many-funcs.ll -o %t.many.o
 ; RUN: llc -filetype=obj %s -o %t.o
-; RUN: wasm-ld --check-signatures -r -o %t.wasm %t.many.o %t.o
+; RUN: wasm-ld -r -o %t.wasm %t.many.o %t.o
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 ; Test that relocations within the CODE section correctly handle
diff --git a/lld/test/wasm/reloc-addend.ll b/lld/test/wasm/reloc-addend.ll
index 630bd868916..ceca9a65d57 100644
--- a/lld/test/wasm/reloc-addend.ll
+++ b/lld/test/wasm/reloc-addend.ll
@@ -1,5 +1,5 @@
 ; RUN: llc -filetype=obj %s -o %t.o
-; RUN: wasm-ld --check-signatures -r -o %t.wasm %t.o
+; RUN: wasm-ld -r -o %t.wasm %t.o
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 target triple = "wasm32-unknown-unknown-wasm"
diff --git a/lld/test/wasm/relocatable.ll b/lld/test/wasm/relocatable.ll
index bcbeca2dedb..b7323065c34 100644
--- a/lld/test/wasm/relocatable.ll
+++ b/lld/test/wasm/relocatable.ll
@@ -1,6 +1,6 @@
 ; RUN: llc -filetype=obj %p/Inputs/hello.ll -o %t.hello.o
 ; RUN: llc -filetype=obj %s -o %t.o
-; RUN: wasm-ld --check-signatures -r -o %t.wasm %t.hello.o %t.o
+; RUN: wasm-ld -r -o %t.wasm %t.hello.o %t.o
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 target triple = "wasm32-unknown-unknown-wasm"
diff --git a/lld/test/wasm/signature-mismatch-weak.ll b/lld/test/wasm/signature-mismatch-weak.ll
index fcf96469b27..a4148a2b4a7 100644
--- a/lld/test/wasm/signature-mismatch-weak.ll
+++ b/lld/test/wasm/signature-mismatch-weak.ll
@@ -1,8 +1,7 @@
 ; RUN: llc -filetype=obj %p/Inputs/weak-symbol1.ll -o %t.weak.o
 ; RUN: llc -filetype=obj %p/Inputs/strong-symbol.ll -o %t.strong.o
 ; RUN: llc -filetype=obj %s -o %t.o
-; RUN: not wasm-ld --check-signatures -o %t.wasm %t.o %t.strong.o %t.weak.o 2>&1 | FileCheck %s
-; RUN: wasm-ld -o %t.wasm %t.o %t.strong.o %t.weak.o
+; RUN: wasm-ld -o %t.wasm %t.o %t.strong.o %t.weak.o 2>&1 | FileCheck %s
 
 target triple = "wasm32-unknown-unknown-wasm"
 
@@ -14,6 +13,6 @@ entry:
   ret void
 }
 
-; CHECK: error: Function type mismatch: weakFn
+; CHECK: warning: Function type mismatch: weakFn
 ; CHECK-NEXT: >>> defined as () -> I32 in {{.*}}signature-mismatch-weak.ll.tmp.o
 ; CHECK-NEXT: >>> defined as () -> I64 in {{.*}}signature-mismatch-weak.ll.tmp.strong.o
diff --git a/lld/test/wasm/signature-mismatch.ll b/lld/test/wasm/signature-mismatch.ll
index 602239ddd19..e7874c39a6d 100644
--- a/lld/test/wasm/signature-mismatch.ll
+++ b/lld/test/wasm/signature-mismatch.ll
@@ -1,10 +1,10 @@
 ; RUN: llc -filetype=obj %p/Inputs/ret32.ll -o %t.ret32.o
 ; RUN: llc -filetype=obj %s -o %t.main.o
-; RUN: not wasm-ld --check-signatures -o %t.wasm %t.main.o %t.ret32.o 2>&1 | FileCheck %s
+; RUN: not wasm-ld --fatal-warnings -o %t.wasm %t.main.o %t.ret32.o 2>&1 | FileCheck %s
 ; Run the test again by with the object files in the other order to verify
 ; the check works when the undefined symbol is resolved by an existing defined
 ; one.
-; RUN: not wasm-ld --check-signatures -o %t.wasm %t.ret32.o %t.main.o 2>&1 | FileCheck %s -check-prefix=REVERSE
+; RUN: not wasm-ld --fatal-warnings -o %t.wasm %t.ret32.o %t.main.o 2>&1 | FileCheck %s -check-prefix=REVERSE
 
 target triple = "wasm32-unknown-unknown-wasm"
 
diff --git a/lld/test/wasm/stack-first.test b/lld/test/wasm/stack-first.test
index c0e186cff54..71d1e9dde85 100644
--- a/lld/test/wasm/stack-first.test
+++ b/lld/test/wasm/stack-first.test
@@ -5,7 +5,7 @@
 
 RUN: llc -filetype=obj %p/Inputs/start.ll -o %t.o
 
-RUN: wasm-ld --check-signatures -z stack-size=512 --stack-first --allow-undefined -o %t.wasm %t.o
+RUN: wasm-ld -z stack-size=512 --stack-first --allow-undefined -o %t.wasm %t.o
 RUN: obj2yaml %t.wasm | FileCheck %s
 
 CHECK:        - Type:            GLOBAL
diff --git a/lld/test/wasm/stack-pointer.ll b/lld/test/wasm/stack-pointer.ll
index 808f6261f72..ed366d6aecb 100644
--- a/lld/test/wasm/stack-pointer.ll
+++ b/lld/test/wasm/stack-pointer.ll
@@ -1,5 +1,5 @@
 ; RUN: llc -filetype=obj %s -o %t.o
-; RUN: wasm-ld --check-signatures --relocatable -o %t.wasm %t.o
+; RUN: wasm-ld --relocatable -o %t.wasm %t.o
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 target triple = "wasm32-unknown-unknown-wasm"
diff --git a/lld/test/wasm/strip-debug.test b/lld/test/wasm/strip-debug.test
index 5a74ac8920c..be5ba700e25 100644
--- a/lld/test/wasm/strip-debug.test
+++ b/lld/test/wasm/strip-debug.test
@@ -1,5 +1,5 @@
 RUN: llc -filetype=obj %p/Inputs/start.ll -o %t.start.o
-RUN: wasm-ld --check-signatures --strip-debug -o %t.wasm %t.start.o
+RUN: wasm-ld --strip-debug -o %t.wasm %t.start.o
 RUN: obj2yaml %t.wasm | FileCheck %s
 
 # Check that there is no name section
diff --git a/lld/test/wasm/symbol-type-mismatch.ll b/lld/test/wasm/symbol-type-mismatch.ll
index 16e0f4dc8d5..641782d808f 100644
--- a/lld/test/wasm/symbol-type-mismatch.ll
+++ b/lld/test/wasm/symbol-type-mismatch.ll
@@ -1,6 +1,6 @@
 ; RUN: llc -filetype=obj %s -o %t.o
 ; RUN: llc -filetype=obj %p/Inputs/ret32.ll -o %t.ret32.o
-; RUN: not wasm-ld --check-signatures -o %t.wasm %t.o %t.ret32.o 2>&1 | FileCheck %s
+; RUN: not wasm-ld -o %t.wasm %t.o %t.ret32.o 2>&1 | FileCheck %s
 
 target triple = "wasm32-unknown-unknown-wasm"
 
diff --git a/lld/test/wasm/undefined-entry.test b/lld/test/wasm/undefined-entry.test
index 7906ec9bb17..3adb785a587 100644
--- a/lld/test/wasm/undefined-entry.test
+++ b/lld/test/wasm/undefined-entry.test
@@ -1,10 +1,10 @@
 RUN: llc -filetype=obj %p/Inputs/ret32.ll -o %t.ret32.o
-RUN: not wasm-ld --check-signatures -o %t.wasm %t.ret32.o 2>&1 | FileCheck %s
+RUN: not wasm-ld -o %t.wasm %t.ret32.o 2>&1 | FileCheck %s
 
 CHECK: error: undefined symbol: _start
 
-RUN: not wasm-ld --check-signatures -entry=foo -o %t.wasm %t.ret32.o 2>&1 | FileCheck %s -check-prefix=CHECK-CUSTOM
+RUN: not wasm-ld -entry=foo -o %t.wasm %t.ret32.o 2>&1 | FileCheck %s -check-prefix=CHECK-CUSTOM
 
 CHECK-CUSTOM: error: undefined symbol: foo
 
-RUN: wasm-ld --check-signatures -entry=foo --allow-undefined -o %t.wasm %t.ret32.o
+RUN: wasm-ld -entry=foo --allow-undefined -o %t.wasm %t.ret32.o
diff --git a/lld/test/wasm/undefined-weak-call.ll b/lld/test/wasm/undefined-weak-call.ll
index fed3ecc20f7..96073e67cd4 100644
--- a/lld/test/wasm/undefined-weak-call.ll
+++ b/lld/test/wasm/undefined-weak-call.ll
@@ -1,5 +1,5 @@
 ; RUN: llc -filetype=obj %s -o %t.o
-; RUN: wasm-ld --check-signatures --no-entry --print-gc-sections %t.o \
+; RUN: wasm-ld --no-entry --print-gc-sections %t.o \
 ; RUN:     -o %t.wasm 2>&1 | FileCheck -check-prefix=CHECK-GC %s
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
diff --git a/lld/test/wasm/undefined.ll b/lld/test/wasm/undefined.ll
index a74dd6d66de..bdbb11c3034 100644
--- a/lld/test/wasm/undefined.ll
+++ b/lld/test/wasm/undefined.ll
@@ -1,17 +1,17 @@
 ; RUN: llc -filetype=obj %s -o %t.o
-; RUN: wasm-ld --check-signatures --allow-undefined -o %t.wasm %t.o
+; RUN: wasm-ld --allow-undefined -o %t.wasm %t.o
 
 ; Fails due to undefined 'foo' and also 'baz'
-; RUN: not wasm-ld --check-signatures --undefined=baz -o %t.wasm %t.o 2>&1 | FileCheck %s
+; RUN: not wasm-ld --undefined=baz -o %t.wasm %t.o 2>&1 | FileCheck %s
 ; CHECK: error: {{.*}}.o: undefined symbol: foo
 ; CHECK: error: undefined symbol: baz
 
 ; Succeeds if we pass a file containing 'foo' as --allow-undefined-file.
 ; RUN: echo 'foo' > %t.txt
-; RUN: wasm-ld --check-signatures --allow-undefined-file=%t.txt -o %t.wasm %t.o
+; RUN: wasm-ld --allow-undefined-file=%t.txt -o %t.wasm %t.o
 
 ; Succeeds even if a missing symbol is added via --export
-; RUN: wasm-ld --check-signatures --allow-undefined --export=xxx -o %t.wasm %t.o
+; RUN: wasm-ld --allow-undefined --export=xxx -o %t.wasm %t.o
 
 target triple = "wasm32-unknown-unknown-wasm"
 
diff --git a/lld/test/wasm/version.ll b/lld/test/wasm/version.ll
index 3b20b395c37..ffa2654c115 100644
--- a/lld/test/wasm/version.ll
+++ b/lld/test/wasm/version.ll
@@ -1,5 +1,5 @@
 ; RUN: llc -filetype=obj %s -o %t.o
-; RUN: wasm-ld --check-signatures -o %t.wasm %t.o
+; RUN: wasm-ld -o %t.wasm %t.o
 ; RUN: llvm-readobj -file-headers %t.wasm | FileCheck %s
 
 target triple = "wasm32-unknown-unknown-wasm"
diff --git a/lld/test/wasm/visibility-hidden.ll b/lld/test/wasm/visibility-hidden.ll
index 530649be42a..30f87b311e7 100644
--- a/lld/test/wasm/visibility-hidden.ll
+++ b/lld/test/wasm/visibility-hidden.ll
@@ -1,7 +1,7 @@
 ; RUN: llc -filetype=obj -o %t.o %s
 ; RUN: llc -filetype=obj %S/Inputs/hidden.ll -o %t2.o
 ; RUN: llvm-ar rcs %t2.a %t2.o
-; RUN: wasm-ld --check-signatures %t.o %t2.a -o %t.wasm
+; RUN: wasm-ld %t.o %t2.a -o %t.wasm
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 ; Test that hidden symbols are not exported, whether pulled in from an archive
diff --git a/lld/test/wasm/weak-alias-overide.ll b/lld/test/wasm/weak-alias-overide.ll
index 22522989297..a4021fbbac1 100644
--- a/lld/test/wasm/weak-alias-overide.ll
+++ b/lld/test/wasm/weak-alias-overide.ll
@@ -1,6 +1,6 @@
 ; RUN: llc -filetype=obj -o %t.o %s
 ; RUN: llc -filetype=obj %S/Inputs/weak-alias.ll -o %t2.o
-; RUN: wasm-ld --check-signatures %t.o %t2.o -o %t.wasm
+; RUN: wasm-ld %t.o %t2.o -o %t.wasm
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 ; Test that the strongly defined alias_fn from this file is used both here
diff --git a/lld/test/wasm/weak-alias.ll b/lld/test/wasm/weak-alias.ll
index d59f0e15766..0cc5a07a586 100644
--- a/lld/test/wasm/weak-alias.ll
+++ b/lld/test/wasm/weak-alias.ll
@@ -1,6 +1,6 @@
 ; RUN: llc -filetype=obj -o %t.o %s
 ; RUN: llc -filetype=obj %S/Inputs/weak-alias.ll -o %t2.o
-; RUN: wasm-ld --check-signatures %t.o %t2.o -o %t.wasm
+; RUN: wasm-ld %t.o %t2.o -o %t.wasm
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 ; Test that weak aliases (alias_fn is a weak alias of direct_fn) are linked correctly
@@ -144,7 +144,7 @@ entry:
 ; CHECK-NEXT:         Name:            call_direct_ptr
 ; CHECK-NEXT: ...
 
-; RUN: wasm-ld --check-signatures --relocatable %t.o %t2.o -o %t.reloc.o
+; RUN: wasm-ld --relocatable %t.o %t2.o -o %t.reloc.o
 ; RUN: obj2yaml %t.reloc.o | FileCheck %s -check-prefix=RELOC
 
 ; RELOC:      --- !WASM
diff --git a/lld/test/wasm/weak-symbols.ll b/lld/test/wasm/weak-symbols.ll
index 7ecb900b2e2..c1a5a0c64f1 100644
--- a/lld/test/wasm/weak-symbols.ll
+++ b/lld/test/wasm/weak-symbols.ll
@@ -1,7 +1,7 @@
 ; RUN: llc -filetype=obj %p/Inputs/weak-symbol1.ll -o %t1.o
 ; RUN: llc -filetype=obj %p/Inputs/weak-symbol2.ll -o %t2.o
 ; RUN: llc -filetype=obj %s -o %t.o
-; RUN: wasm-ld -no-gc-sections --check-signatures -o %t.wasm %t.o %t1.o %t2.o
+; RUN: wasm-ld -no-gc-sections -o %t.wasm %t.o %t1.o %t2.o
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 target triple = "wasm32-unknown-unknown-wasm"
diff --git a/lld/test/wasm/weak-undefined.ll b/lld/test/wasm/weak-undefined.ll
index ce68e54f29e..98c6d2655ad 100644
--- a/lld/test/wasm/weak-undefined.ll
+++ b/lld/test/wasm/weak-undefined.ll
@@ -1,5 +1,5 @@
 ; RUN: llc -filetype=obj -o %t.o %s
-; RUN: wasm-ld --check-signatures -strip-debug %t.o -o %t.wasm
+; RUN: wasm-ld -strip-debug %t.o -o %t.wasm
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 ; Test that undefined weak externals (global_var) and (foo) don't cause
diff --git a/lld/wasm/Config.h b/lld/wasm/Config.h
index 115acea816e..3ade61c08dd 100644
--- a/lld/wasm/Config.h
+++ b/lld/wasm/Config.h
@@ -19,7 +19,6 @@ namespace wasm {
 
 struct Configuration {
   bool AllowUndefined;
-  bool CheckSignatures;
   bool Demangle;
   bool ExportTable;
   bool GcSections;
diff --git a/lld/wasm/Driver.cpp b/lld/wasm/Driver.cpp
index 60bd71ce4c8..deaa95cbc31 100644
--- a/lld/wasm/Driver.cpp
+++ b/lld/wasm/Driver.cpp
@@ -282,11 +282,11 @@ void LinkerDriver::link(ArrayRef<const char *> ArgsArr) {
   errorHandler().ErrorLimit = args::getInteger(Args, OPT_error_limit, 20);
 
   Config->AllowUndefined = Args.hasArg(OPT_allow_undefined);
-  Config->CheckSignatures =
-      Args.hasFlag(OPT_check_signatures, OPT_no_check_signatures, false);
   Config->Demangle = Args.hasFlag(OPT_demangle, OPT_no_demangle, true);
   Config->Entry = getEntry(Args, Args.hasArg(OPT_relocatable) ? "" : "_start");
   Config->ExportTable = Args.hasArg(OPT_export_table);
+  errorHandler().FatalWarnings =
+      Args.hasFlag(OPT_fatal_warnings, OPT_no_fatal_warnings, false);
   Config->ImportMemory = Args.hasArg(OPT_import_memory);
   Config->ImportTable = Args.hasArg(OPT_import_table);
   Config->OutputFile = Args.getLastArgValue(OPT_o);
diff --git a/lld/wasm/Options.td b/lld/wasm/Options.td
index d1810bf1b8e..1a396480b8b 100644
--- a/lld/wasm/Options.td
+++ b/lld/wasm/Options.td
@@ -96,10 +96,6 @@ def allow_undefined_file: J<"allow-undefined-file=">,
 def allow_undefined_file_s: Separate<["-"], "allow-undefined-file">,
   Alias<allow_undefined_file>;
 
-defm check_signatures: B<"check-signatures",
-    "Check function signatures",
-    "Don't check function signatures">;
-
 defm export: Eq<"export">,
   HelpText<"Force a symbol to be exported">;
 
diff --git a/lld/wasm/SymbolTable.cpp b/lld/wasm/SymbolTable.cpp
index 153b507f89d..54e04ab4cd8 100644
--- a/lld/wasm/SymbolTable.cpp
+++ b/lld/wasm/SymbolTable.cpp
@@ -83,16 +83,13 @@ static void checkFunctionType(const Symbol *Existing, const InputFile *File,
     return;
   }
 
-  if (!Config->CheckSignatures)
-    return;
-
   const WasmSignature *OldSig =
       cast<FunctionSymbol>(Existing)->getFunctionType();
   if (OldSig && *NewSig != *OldSig) {
-    error("Function type mismatch: " + Existing->getName() +
-          "\n>>> defined as " + toString(*OldSig) + " in " +
-          toString(Existing->getFile()) + "\n>>> defined as " +
-          toString(*NewSig) + " in " + toString(File));
+    warn("Function type mismatch: " + Existing->getName() +
+         "\n>>> defined as " + toString(*OldSig) + " in " +
+         toString(Existing->getFile()) + "\n>>> defined as " +
+         toString(*NewSig) + " in " + toString(File));
   }
 }