From 1a83d067687e2f5eb04b9692d2a59b283d3371eb Mon Sep 17 00:00:00 2001
From: Gabor Buella <gabor.buella@intel.com>
Date: Thu, 7 Jun 2018 08:48:36 +0000
Subject: [CodeGen] Improve diagnostics related to target attributes

Summary:
When requirement imposed by __target__ attributes on functions
are not satisfied, prefer printing those requirements, which
are explicitly mentioned in the attributes.

This makes such messages more useful, e.g. printing avx512f instead of avx2
in the following scenario:

```
$ cat foo.c
static inline void __attribute__((__always_inline__, __target__("avx512f")))
x(void)
{
}

int main(void)
{
            x();
}
$ clang foo.c
foo.c:7:2: error: always_inline function 'x' requires target feature 'avx2', but would be inlined into function 'main' that is compiled without support for 'avx2'
        x();
    ^
1 error generated.
```

bugzilla: https://bugs.llvm.org/show_bug.cgi?id=37338

Reviewers: craig.topper, echristo, dblaikie

Reviewed By: craig.topper, echristo

Differential Revision: https://reviews.llvm.org/D46541

llvm-svn: 334174
---
 clang/lib/CodeGen/CodeGenModule.cpp | 26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

(limited to 'clang/lib/CodeGen/CodeGenModule.cpp')

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index b57004f7e12..19cfffd81c4 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -5033,22 +5033,28 @@ void CodeGenModule::AddVTableTypeMetadata(llvm::GlobalVariable *VTable,
   }
 }
 
+TargetAttr::ParsedTargetAttr CodeGenModule::filterFunctionTargetAttrs(const TargetAttr *TD) {
+  assert(TD != nullptr);
+  TargetAttr::ParsedTargetAttr ParsedAttr = TD->parse();
+
+  ParsedAttr.Features.erase(
+      llvm::remove_if(ParsedAttr.Features,
+                      [&](const std::string &Feat) {
+                        return !Target.isValidFeatureName(
+                            StringRef{Feat}.substr(1));
+                      }),
+      ParsedAttr.Features.end());
+  return ParsedAttr;
+}
+
+
 // Fills in the supplied string map with the set of target features for the
 // passed in function.
 void CodeGenModule::getFunctionFeatureMap(llvm::StringMap<bool> &FeatureMap,
                                           const FunctionDecl *FD) {
   StringRef TargetCPU = Target.getTargetOpts().CPU;
   if (const auto *TD = FD->getAttr<TargetAttr>()) {
-    // If we have a TargetAttr build up the feature map based on that.
-    TargetAttr::ParsedTargetAttr ParsedAttr = TD->parse();
-
-    ParsedAttr.Features.erase(
-        llvm::remove_if(ParsedAttr.Features,
-                        [&](const std::string &Feat) {
-                          return !Target.isValidFeatureName(
-                              StringRef{Feat}.substr(1));
-                        }),
-        ParsedAttr.Features.end());
+    TargetAttr::ParsedTargetAttr ParsedAttr = filterFunctionTargetAttrs(TD);
 
     // Make a copy of the features as passed on the command line into the
     // beginning of the additional features from the function to override.
-- 
cgit v1.2.3