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| author | Petr Hosek <phosek@chromium.org> | 2019-07-22 18:52:42 +0000 |
|---|---|---|
| committer | Petr Hosek <phosek@chromium.org> | 2019-07-22 18:52:42 +0000 |
| commit | f6cd6ffbc9f8bfa0bbe25dba6a9737607a684bab (patch) | |
| tree | 1dba4a914b3bbcb71e7b91a1c000cd5cb84b1d97 /llvm/test/Transforms/SafeStack/X86/debug-loc2.ll | |
| parent | ef5cfc2dae0725226254561b42134308720e57ab (diff) | |
| download | bcm5719-llvm-f6cd6ffbc9f8bfa0bbe25dba6a9737607a684bab.tar.gz bcm5719-llvm-f6cd6ffbc9f8bfa0bbe25dba6a9737607a684bab.zip | |
[SafeStack] Insert the deref after the offset
While debugging code that uses SafeStack, we've noticed that LLVM
produces an invalid DWARF. Concretely, in the following example:
int main(int argc, char* argv[]) {
std::string value = "";
printf("%s\n", value.c_str());
return 0;
}
DWARF would describe the value variable as being located at:
DW_OP_breg14 R14+0, DW_OP_deref, DW_OP_constu 0x20, DW_OP_minus
The assembly to get this variable is:
leaq -32(%r14), %rbx
The order of operations in the DWARF symbols is incorrect in this case.
Specifically, the deref is incorrect; this appears to be incorrectly
re-inserted in repalceOneDbgValueForAlloca.
With this change which inserts the deref after the offset instead of
before it, LLVM produces correct DWARF:
DW_OP_breg14 R14-32
Differential Revision: https://reviews.llvm.org/D64971
llvm-svn: 366726
Diffstat (limited to 'llvm/test/Transforms/SafeStack/X86/debug-loc2.ll')
| -rw-r--r-- | llvm/test/Transforms/SafeStack/X86/debug-loc2.ll | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/llvm/test/Transforms/SafeStack/X86/debug-loc2.ll b/llvm/test/Transforms/SafeStack/X86/debug-loc2.ll index afa143f9c08..30623962691 100644 --- a/llvm/test/Transforms/SafeStack/X86/debug-loc2.ll +++ b/llvm/test/Transforms/SafeStack/X86/debug-loc2.ll @@ -25,7 +25,7 @@ entry: tail call void @llvm.dbg.value(metadata i32* %x1, metadata !10, metadata !24), !dbg !16 ; Supported dbg.value: rewritted based on the [[USP]] value. -; CHECK: call void @llvm.dbg.value(metadata i8* %[[USP]], metadata ![[X1:.*]], metadata !DIExpression(DW_OP_deref, DW_OP_constu, 4, DW_OP_minus)) +; CHECK: call void @llvm.dbg.value(metadata i8* %[[USP]], metadata ![[X1:.*]], metadata !DIExpression(DW_OP_constu, 4, DW_OP_minus, DW_OP_deref)) tail call void @llvm.dbg.value(metadata i32* %x1, metadata !10, metadata !15), !dbg !16 call void @capture(i32* nonnull %x1), !dbg !17 @@ -33,7 +33,7 @@ entry: ; CHECK: call void @llvm.random.metadata.use(metadata ![[EMPTY]]) call void @llvm.random.metadata.use(metadata i32* %x2) -; CHECK: call void @llvm.dbg.value(metadata i8* %[[USP]], metadata ![[X2:.*]], metadata !DIExpression(DW_OP_deref, DW_OP_constu, 8, DW_OP_minus)) +; CHECK: call void @llvm.dbg.value(metadata i8* %[[USP]], metadata ![[X2:.*]], metadata !DIExpression(DW_OP_constu, 8, DW_OP_minus, DW_OP_deref)) call void @llvm.dbg.value(metadata i32* %x2, metadata !12, metadata !15), !dbg !18 call void @capture(i32* nonnull %x2), !dbg !19 ret void, !dbg !20 |
