[lld] r358995 - [WebAssembly] Fix typo in relocation checking

Sam Clegg via llvm-commits llvm-commits at lists.llvm.org
Tue Apr 23 07:49:38 PDT 2019


Author: sbc
Date: Tue Apr 23 07:49:38 2019
New Revision: 358995

URL: http://llvm.org/viewvc/llvm-project?rev=358995&view=rev
Log:
[WebAssembly] Fix typo in relocation checking

Runtime relocation are generated for relocations of type
R_WASM_MEMORY_ADDR_I32 when in PIC mode (either -shared or -pie).

Followup on https://reviews.llvm.org/D60882.

Differential Revision: https://reviews.llvm.org/D60992

Added:
    lld/trunk/test/wasm/pie.ll
Modified:
    lld/trunk/wasm/InputFiles.cpp

Added: lld/trunk/test/wasm/pie.ll
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/wasm/pie.ll?rev=358995&view=auto
==============================================================================
--- lld/trunk/test/wasm/pie.ll (added)
+++ lld/trunk/test/wasm/pie.ll Tue Apr 23 07:49:38 2019
@@ -0,0 +1,53 @@
+; RUN: llc -relocation-model=pic -filetype=obj %s -o %t.o
+; RUN: wasm-ld --no-gc-sections --allow-undefined -pie -o %t.wasm %t.o
+; RUN: obj2yaml %t.wasm | FileCheck %s
+
+target triple = "wasm32-unknown-unknown"
+
+ at data = global i32 2, align 4
+ at data_external = external global i32
+ at indirect_func = local_unnamed_addr global i32 ()* @foo, align 4
+
+ at data_addr = local_unnamed_addr global i32* @data, align 4
+ at data_addr_external = local_unnamed_addr global i32* @data_external, align 4
+
+define i32 @foo() {
+entry:
+  ; To ensure we use __stack_pointer
+  %ptr = alloca i32
+  %0 = load i32, i32* @data, align 4
+  %1 = load i32 ()*, i32 ()** @indirect_func, align 4
+  call i32 %1()
+  ret i32 %0
+}
+
+define default i32** @get_data_address() {
+entry:
+  ret i32** @data_addr_external
+}
+
+define void @_start() {
+  ret void
+}
+
+; CHECK:        - Type:            IMPORT
+; CHECK-NEXT:     Imports:
+; CHECK-NEXT:       - Module:          env
+; CHECK-NEXT:         Field:           __indirect_function_table
+; CHECK-NEXT:         Kind:            TABLE
+; CHECK-NEXT:         Table:
+; CHECK-NEXT:           ElemType:        FUNCREF
+; CHECK-NEXT:           Limits:
+; CHECK-NEXT:             Initial:         0x00000001
+; CHECK-NEXT:       - Module:          env
+; CHECK-NEXT:         Field:           __memory_base
+; CHECK-NEXT:         Kind:            GLOBAL
+; CHECK-NEXT:         GlobalType:      I32
+; CHECK-NEXT:         GlobalMutable:   false
+; CHECK-NEXT:       - Module:          env
+; CHECK-NEXT:         Field:           __table_base
+; CHECK-NEXT:         Kind:            GLOBAL
+; CHECK-NEXT:         GlobalType:      I32
+; CHECK-NEXT:         GlobalMutable:   false
+
+

Modified: lld/trunk/wasm/InputFiles.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/wasm/InputFiles.cpp?rev=358995&r1=358994&r2=358995&view=diff
==============================================================================
--- lld/trunk/wasm/InputFiles.cpp (original)
+++ lld/trunk/wasm/InputFiles.cpp Tue Apr 23 07:49:38 2019
@@ -155,7 +155,9 @@ uint32_t ObjFile::calcNewValue(const Was
     if (isa<DataSymbol>(Sym) && Sym->isUndefined()) {
       if (Sym->isWeak() || Config->Relocatable)
         return 0;
-      if (Config->Shared && Reloc.Type == R_WASM_MEMORY_ADDR_I32)
+      // R_WASM_MEMORY_ADDR_I32 relocations in PIC code are turned into runtime
+      // fixups in __wasm_apply_relocs
+      if (Config->Pic && Reloc.Type == R_WASM_MEMORY_ADDR_I32)
         return 0;
       if (Reloc.Type != R_WASM_GLOBAL_INDEX_LEB) {
         llvm_unreachable(




More information about the llvm-commits mailing list