Add some support for diagnosing possibly mismatched constraint, type size and
modifiers. (From an idea by Eric...)
<rdar://problem/12284092>
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@166647 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 56cb206..cd7fb00 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -5146,6 +5146,9 @@
"invalid use of a cast in a inline asm context requiring an l-value: "
"accepted due to -fheinous-gnu-extensions, but clang may remove support "
"for this in the future">;
+ def warn_mismatched_size_modifier : Warning<
+ "the size being stored may not be the size intended, use a modifier to "
+ "specify the size">;
def err_inline_ms_asm_parsing : Error<"%0">;
}
diff --git a/include/clang/Basic/TargetInfo.h b/include/clang/Basic/TargetInfo.h
index ea520e8..b0e5805 100644
--- a/include/clang/Basic/TargetInfo.h
+++ b/include/clang/Basic/TargetInfo.h
@@ -517,6 +517,11 @@
bool validateInputConstraint(ConstraintInfo *OutputConstraints,
unsigned NumOutputs,
ConstraintInfo &info) const;
+ virtual bool validateConstraintModifier(StringRef /*Constraint*/,
+ const char /*Modifier*/,
+ unsigned /*Size*/) const {
+ return true;
+ }
bool resolveSymbolicName(const char *&Name,
ConstraintInfo *OutputConstraints,
unsigned NumOutputs, unsigned &Index) const;
diff --git a/lib/Basic/Targets.cpp b/lib/Basic/Targets.cpp
index ba96185..960a285 100644
--- a/lib/Basic/Targets.cpp
+++ b/lib/Basic/Targets.cpp
@@ -3315,6 +3315,29 @@
}
return R;
}
+ virtual bool validateConstraintModifier(StringRef Constraint,
+ const char Modifier,
+ unsigned Size) const {
+ // Strip off constraint modifiers.
+ while (Constraint[0] == '=' ||
+ Constraint[0] == '+' ||
+ Constraint[0] == '&')
+ Constraint = Constraint.substr(1);
+
+ switch (Constraint[0]) {
+ default: break;
+ case 'r': {
+ switch (Modifier) {
+ default: return Size == 32;
+ case 'q':
+ // A register of size 32 cannot fit a vector type.
+ return false;
+ }
+ }
+ }
+
+ return true;
+ }
virtual const char *getClobbers() const {
// FIXME: Is this really right?
return "";
diff --git a/lib/Sema/SemaStmtAsm.cpp b/lib/Sema/SemaStmtAsm.cpp
index 3a5f40c7..138d671 100644
--- a/lib/Sema/SemaStmtAsm.cpp
+++ b/lib/Sema/SemaStmtAsm.cpp
@@ -208,6 +208,54 @@
return StmtError();
}
+ // Validate constraints and modifiers.
+ for (unsigned i = 0, e = Pieces.size(); i != e; ++i) {
+ GCCAsmStmt::AsmStringPiece &Piece = Pieces[i];
+ if (!Piece.isOperand()) continue;
+
+ // Look for the correct constraint index.
+ unsigned Idx = 0;
+ unsigned ConstraintIdx = 0;
+ for (unsigned i = 0, e = NS->getNumOutputs(); i != e; ++i, ++ConstraintIdx) {
+ TargetInfo::ConstraintInfo &Info = OutputConstraintInfos[i];
+ if (Idx == Piece.getOperandNo())
+ break;
+ ++Idx;
+
+ if (Info.isReadWrite()) {
+ if (Idx == Piece.getOperandNo())
+ break;
+ ++Idx;
+ }
+ }
+
+ for (unsigned i = 0, e = NS->getNumInputs(); i != e; ++i, ++ConstraintIdx) {
+ TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i];
+ if (Idx == Piece.getOperandNo())
+ break;
+ ++Idx;
+
+ if (Info.isReadWrite()) {
+ if (Idx == Piece.getOperandNo())
+ break;
+ ++Idx;
+ }
+ }
+
+ // Now that we have the right indexes go ahead and check.
+ StringLiteral *Literal = Constraints[ConstraintIdx];
+ const Type *Ty = Exprs[ConstraintIdx]->getType().getTypePtr();
+ if (Ty->isDependentType() || Ty->isIncompleteType())
+ continue;
+
+ unsigned Size = Context.getTypeSize(Ty);
+ if (!Context.getTargetInfo()
+ .validateConstraintModifier(Literal->getString(),
+ Piece.getModifier(), Size))
+ Diag(Exprs[ConstraintIdx]->getLocStart(),
+ diag::warn_mismatched_size_modifier);
+ }
+
// Validate tied input operands for type mismatches.
for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) {
TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i];
diff --git a/test/Misc/warning-flags.c b/test/Misc/warning-flags.c
index 302abcc..fa73db1 100644
--- a/test/Misc/warning-flags.c
+++ b/test/Misc/warning-flags.c
@@ -18,7 +18,7 @@
The list of warnings below should NEVER grow. It should gradually shrink to 0.
-CHECK: Warnings without flags (154):
+CHECK: Warnings without flags (155):
CHECK-NEXT: ext_delete_void_ptr_operand
CHECK-NEXT: ext_enum_friend
CHECK-NEXT: ext_expected_semi_decl_list
@@ -100,6 +100,7 @@
CHECK-NEXT: warn_maynot_respond
CHECK-NEXT: warn_method_param_redefinition
CHECK-NEXT: warn_mismatched_exception_spec
+CHECK-NEXT: warn_mismatched_size_modifier
CHECK-NEXT: warn_missing_case_for_condition
CHECK-NEXT: warn_missing_dependent_template_keyword
CHECK-NEXT: warn_missing_exception_specification
