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di: add safe wrapper around LLVMGlobalCopyAllMetadata #170

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di: add safe wrapper around LLVMGlobalCopyAllMetadata #170

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57 changes: 38 additions & 19 deletions src/llvm/di.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -254,8 +254,8 @@ impl DISanitizer {
);
}

if can_get_all_metadata(value) {
for (index, (kind, metadata)) in iter_metadata_copy(value).enumerate() {
if let Some(entries) = MetadataEntries::new(value) {
for (index, (metadata, kind)) in entries.iter().enumerate() {
let metadata_value = LLVMMetadataAsValue(self.context, metadata);
trace!("{one:depth$}all_metadata entry: index:{}", index);
self.discover(metadata_value, depth + 1);
Expand Down Expand Up @@ -348,15 +348,42 @@ unsafe fn iter_operands(v: LLVMValueRef) -> impl Iterator<Item = LLVMValueRef> {
(0..LLVMGetNumOperands(v)).map(move |i| LLVMGetOperand(v, i as u32))
}

unsafe fn iter_metadata_copy(v: LLVMValueRef) -> impl Iterator<Item = (u32, LLVMMetadataRef)> {
let mut count = 0;
let entries = LLVMGlobalCopyAllMetadata(v, &mut count);
(0..count).map(move |index| {
(
LLVMValueMetadataEntriesGetKind(entries, index as u32),
LLVMValueMetadataEntriesGetMetadata(entries, index as u32),
)
})
struct MetadataEntries {
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Can we move it to src/llvm/types/di.rs?

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Not all metadata is DI?

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True. I see that the LLVMGlobalCopyAllMetadata belongs to llvm/lib/IR/Core.cpp. I would then keep it in src/llvm/types/ir.rs (or, eventually, but probably too muc effort - split ir.rs into a subdir with mod.rs and core.rs, where eventual wrappers for other IR/* files could have their own files).

My main point is that I would prefer to not mix wrappers (which are currently in the types subdir) and DI sanitization logic in the same module.

entries: *mut LLVMValueMetadataEntry,
count: usize,
}

impl MetadataEntries {
fn new(v: LLVMValueRef) -> Option<Self> {
if unsafe { LLVMIsAGlobalObject(v).is_null() && LLVMIsAInstruction(v).is_null() } {
return None;
}

let mut count = 0;
let entries = unsafe { LLVMGlobalCopyAllMetadata(v, &mut count) };
if entries.is_null() {
return None;
}

Some(MetadataEntries { entries, count })
}

fn iter(&self) -> impl Iterator<Item = (LLVMMetadataRef, u32)> + '_ {
(0..self.count).map(move |index| unsafe {
(
LLVMValueMetadataEntriesGetMetadata(self.entries, index as u32),
LLVMValueMetadataEntriesGetKind(self.entries, index as u32),
)
})
}
}

impl Drop for MetadataEntries {
fn drop(&mut self) {
unsafe {
LLVMDisposeValueMetadataEntries(self.entries);
}
}
}

unsafe fn is_instruction(v: LLVMValueRef) -> bool {
Expand All @@ -371,14 +398,6 @@ unsafe fn is_user(v: LLVMValueRef) -> bool {
!LLVMIsAUser(v).is_null()
}

unsafe fn is_globalobject(v: LLVMValueRef) -> bool {
!LLVMIsAGlobalObject(v).is_null()
}

unsafe fn can_get_all_metadata(v: LLVMValueRef) -> bool {
is_globalobject(v) || is_instruction(v)
}

unsafe fn can_get_operands(v: LLVMValueRef) -> bool {
is_mdnode(v) || is_user(v)
}
Expand Down