[AArch64] Add soft-float ABI (#84146)

This is re-working of #74460, which adds a soft-float ABI for AArch64.
That was reverted because it causes errors when building the linux and
fuchsia kernels.

The problem is that GCC's implementation of the ABI compatibility checks
when using the hard-float ABI on a target without FP registers does it's
checks after optimisation. The previous version of this patch reported
errors for all uses of floating-point types, which is stricter than what
GCC does in practice.

This changes two things compared to the first version:
* Only check the types of function arguments and returns, not the types
of other values. This is more relaxed than GCC, while still guaranteeing
ABI compatibility.
* Move the check from Sema to CodeGen, so that inline functions are only
checked if they are actually used. There are some cases in the linux
kernel which depend on this behaviour of GCC.

1 files changed, 8 insertions, 8 deletions

diff --git a/clang/lib/CodeGen/ModuleBuilder.cpp b/clang/lib/CodeGen/ModuleBuilder.cpp
index 3594f4c..df85295 100644
--- a/clang/lib/CodeGen/ModuleBuilder.cpp
+++ b/clang/lib/CodeGen/ModuleBuilder.cpp
@@ -180,7 +180,7 @@ namespace {
 
     bool HandleTopLevelDecl(DeclGroupRef DG) override {
       // FIXME: Why not return false and abort parsing?
-      if (Diags.hasErrorOccurred())
+      if (Diags.hasUnrecoverableErrorOccurred())
         return true;
 
       HandlingTopLevelDeclRAII HandlingDecl(*this);
@@ -206,7 +206,7 @@ namespace {
     }
 
     void HandleInlineFunctionDefinition(FunctionDecl *D) override {
-      if (Diags.hasErrorOccurred())
+      if (Diags.hasUnrecoverableErrorOccurred())
         return;
 
       assert(D->doesThisDeclarationHaveABody());
@@ -233,7 +233,7 @@ namespace {
     /// client hack on the type, which can occur at any point in the file
     /// (because these can be defined in declspecs).
     void HandleTagDeclDefinition(TagDecl *D) override {
-      if (Diags.hasErrorOccurred())
+      if (Diags.hasUnrecoverableErrorOccurred())
         return;
 
       // Don't allow re-entrant calls to CodeGen triggered by PCH
@@ -269,7 +269,7 @@ namespace {
     }
 
     void HandleTagDeclRequiredDefinition(const TagDecl *D) override {
-      if (Diags.hasErrorOccurred())
+      if (Diags.hasUnrecoverableErrorOccurred())
         return;
 
       // Don't allow re-entrant calls to CodeGen triggered by PCH
@@ -283,7 +283,7 @@ namespace {
 
     void HandleTranslationUnit(ASTContext &Ctx) override {
       // Release the Builder when there is no error.
-      if (!Diags.hasErrorOccurred() && Builder)
+      if (!Diags.hasUnrecoverableErrorOccurred() && Builder)
         Builder->Release();
 
       // If there are errors before or when releasing the Builder, reset
@@ -297,14 +297,14 @@ namespace {
     }
 
     void AssignInheritanceModel(CXXRecordDecl *RD) override {
-      if (Diags.hasErrorOccurred())
+      if (Diags.hasUnrecoverableErrorOccurred())
         return;
 
       Builder->RefreshTypeCacheForClass(RD);
     }
 
     void CompleteTentativeDefinition(VarDecl *D) override {
-      if (Diags.hasErrorOccurred())
+      if (Diags.hasUnrecoverableErrorOccurred())
         return;
 
       Builder->EmitTentativeDefinition(D);
@@ -315,7 +315,7 @@ namespace {
     }
 
     void HandleVTable(CXXRecordDecl *RD) override {
-      if (Diags.hasErrorOccurred())
+      if (Diags.hasUnrecoverableErrorOccurred())
         return;
 
       Builder->EmitVTable(RD);