[llvm] [Lint] Lint mismatch in ABI attributes (PR #121929)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-analysis

Author: Nikita Popov (nikic)

<details>
<summary>Changes</summary>

Detect cases where ABI attributes between the call-site and the called function differ. For now this only handles argument attributes.

Inspired by https://discourse.llvm.org/t/difference-between-call-site-attributes-and-declaration-attributes/83902.

---
Full diff: https://github.com/llvm/llvm-project/pull/121929.diff


2 Files Affected:

- (modified) llvm/lib/Analysis/Lint.cpp (+24) 
- (added) llvm/test/Analysis/Lint/abi-attrs.ll (+106) 


``````````diff
diff --git a/llvm/lib/Analysis/Lint.cpp b/llvm/lib/Analysis/Lint.cpp
index 4689451243cd96..e9d96a0c2972ad 100644
--- a/llvm/lib/Analysis/Lint.cpp
+++ b/llvm/lib/Analysis/Lint.cpp
@@ -266,6 +266,30 @@ void Lint::visitCallBase(CallBase &I) {
           visitMemoryReference(I, Loc, DL->getABITypeAlign(Ty), Ty,
                                MemRef::Read | MemRef::Write);
         }
+
+        // Check that ABI attributes for the function and call-site match.
+        unsigned ArgNo = AI->getOperandNo();
+        Attribute::AttrKind ABIAttributes[] = {
+            Attribute::ZExt,         Attribute::SExt,     Attribute::InReg,
+            Attribute::ByVal,        Attribute::ByRef,    Attribute::InAlloca,
+            Attribute::Preallocated, Attribute::StructRet};
+        AttributeList CallAttrs = I.getAttributes();
+        for (Attribute::AttrKind Attr : ABIAttributes) {
+          Attribute CallAttr = CallAttrs.getParamAttr(ArgNo, Attr);
+          Attribute FnAttr = F->getParamAttribute(ArgNo, Attr);
+          Check(CallAttr.isValid() == FnAttr.isValid(),
+                Twine("Undefined behavior: ABI attribute ") +
+                    Attribute::getNameFromAttrKind(Attr) +
+                    " not present on both function and call-site",
+                &I);
+          if (CallAttr.isValid() && FnAttr.isValid()) {
+            Check(CallAttr == FnAttr,
+                  Twine("Undefined behavior: ABI attribute ") +
+                      Attribute::getNameFromAttrKind(Attr) +
+                      " does not have same argument for function and call-site",
+                  &I);
+          }
+        }
       }
     }
   }
diff --git a/llvm/test/Analysis/Lint/abi-attrs.ll b/llvm/test/Analysis/Lint/abi-attrs.ll
new file mode 100644
index 00000000000000..5a3ece6602f9c1
--- /dev/null
+++ b/llvm/test/Analysis/Lint/abi-attrs.ll
@@ -0,0 +1,106 @@
+; RUN: opt < %s -passes=lint -disable-output 2>&1 | FileCheck %s
+
+declare void @fn_nothing_i8(i8 %x)
+declare void @fn_zeroext(i8 zeroext %x)
+declare void @fn_signext(i8 signext %x)
+declare void @fn_inreg(i8 inreg %x)
+
+declare void @fn_nothing_ptr(ptr %x)
+declare void @fn_byval(ptr byval(i8) %x)
+declare void @fn_byref(ptr byref(i8) %x)
+declare void @fn_inalloca(ptr inalloca(i8) %x)
+declare void @fn_preallocated(ptr preallocated(i8) %x)
+declare void @fn_sret(ptr sret(i8) %x)
+
+define void @caller_zeroext(i8 %x) {
+; CHECK: Undefined behavior: ABI attribute zeroext not present on both function and call-site
+; CHECK:  call void @fn_zeroext(i8 %x)
+  call void @fn_zeroext(i8 %x)
+
+; CHECK: Undefined behavior: ABI attribute zeroext not present on both function and call-site
+; CHECK:  call void @fn_nothing_i8(i8 zeroext %x)
+  call void @fn_nothing_i8(i8 zeroext %x)
+  ret void
+}
+
+define void @caller_signext(i8 %x) {
+; CHECK: Undefined behavior: ABI attribute signext not present on both function and call-site
+; CHECK:  call void @fn_signext(i8 %x)
+  call void @fn_signext(i8 %x)
+
+; CHECK: Undefined behavior: ABI attribute signext not present on both function and call-site
+; CHECK:  call void @fn_nothing_i8(i8 signext %x)
+  call void @fn_nothing_i8(i8 signext %x)
+  ret void
+}
+
+define void @caller_inreg(i8 %x) {
+; CHECK: Undefined behavior: ABI attribute inreg not present on both function and call-site
+; CHECK:  call void @fn_inreg(i8 %x)
+  call void @fn_inreg(i8 %x)
+
+; CHECK: Undefined behavior: ABI attribute inreg not present on both function and call-site
+; CHECK:  call void @fn_nothing_i8(i8 inreg %x)
+  call void @fn_nothing_i8(i8 inreg %x)
+  ret void
+}
+
+define void @caller_byval(ptr %x) {
+; CHECK: Undefined behavior: ABI attribute byval not present on both function and call-site
+; CHECK:  call void @fn_byval(ptr %x)
+  call void @fn_byval(ptr %x)
+
+; CHECK: Undefined behavior: ABI attribute byval not present on both function and call-site
+; CHECK:  call void @fn_nothing_ptr(ptr byval(i8) %x)
+  call void @fn_nothing_ptr(ptr byval(i8) %x)
+
+; CHECK: Undefined behavior: ABI attribute byval does not have same argument for function and call-site
+; CHECK:  call void @fn_byval(ptr byval(i16) %x)
+  call void @fn_byval(ptr byval(i16) %x)
+  ret void
+}
+
+define void @caller_byref(ptr %x) {
+; CHECK: Undefined behavior: ABI attribute byref not present on both function and call-site
+; CHECK:  call void @fn_byref(ptr %x)
+  call void @fn_byref(ptr %x)
+
+; CHECK: Undefined behavior: ABI attribute byref not present on both function and call-site
+; CHECK:  call void @fn_nothing_ptr(ptr byref(i8) %x)
+  call void @fn_nothing_ptr(ptr byref(i8) %x)
+
+; CHECK: Undefined behavior: ABI attribute byref does not have same argument for function and call-site
+; CHECK:  call void @fn_byref(ptr byref(i16) %x)
+  call void @fn_byref(ptr byref(i16) %x)
+  ret void
+}
+
+define void @caller_inalloca(ptr %x) {
+; CHECK: Undefined behavior: ABI attribute inalloca not present on both function and call-site
+; CHECK:  call void @fn_inalloca(ptr %x)
+  call void @fn_inalloca(ptr %x)
+
+; CHECK: Undefined behavior: ABI attribute inalloca not present on both function and call-site
+; CHECK:  call void @fn_nothing_ptr(ptr inalloca(i8) %x)
+  call void @fn_nothing_ptr(ptr inalloca(i8) %x)
+
+; CHECK: Undefined behavior: ABI attribute inalloca does not have same argument for function and call-site
+; CHECK:  call void @fn_inalloca(ptr inalloca(i16) %x)
+  call void @fn_inalloca(ptr inalloca(i16) %x)
+  ret void
+}
+
+define void @caller_sret(ptr %x) {
+; CHECK: Undefined behavior: ABI attribute sret not present on both function and call-site
+; CHECK:  call void @fn_sret(ptr %x)
+  call void @fn_sret(ptr %x)
+
+; CHECK: Undefined behavior: ABI attribute sret not present on both function and call-site
+; CHECK:  call void @fn_nothing_ptr(ptr sret(i8) %x)
+  call void @fn_nothing_ptr(ptr sret(i8) %x)
+
+; CHECK: Undefined behavior: ABI attribute sret does not have same argument for function and call-site
+; CHECK:  call void @fn_sret(ptr sret(i16) %x)
+  call void @fn_sret(ptr sret(i16) %x)
+  ret void
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/121929