From e5578013b199e142864cbf374b4a143e5d0c184a Mon Sep 17 00:00:00 2001
From: Melanie Blower <melanie.blower@intel.com>
Date: Wed, 6 May 2020 11:45:55 -0700
Subject: [PATCH] When pragma FENV_ACCESS is ignored do not modify
 Sema.CurFPFeatures Bug reported by @uabelho against reviews.llvm.org/D72841

Reviewers: rjmccall

Differential Revision: https://reviews.llvm.org/D79510
---
 clang/lib/Parse/ParsePragma.cpp               |  1 +
 clang/test/CodeGen/fp-floatcontrol-pragma.cpp | 14 ++++++++++++++
 clang/test/Parser/fp-floatcontrol-syntax.cpp  |  5 +++--
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/clang/lib/Parse/ParsePragma.cpp b/clang/lib/Parse/ParsePragma.cpp
index 8adf978..828d429 100644
--- a/clang/lib/Parse/ParsePragma.cpp
+++ b/clang/lib/Parse/ParsePragma.cpp
@@ -108,6 +108,7 @@ struct PragmaSTDC_FENV_ACCESSHandler : public PragmaHandler {
      return;
     if (OOS == tok::OOS_ON) {
       PP.Diag(Tok, diag::warn_stdc_fenv_access_not_supported);
+      return;
     }
 
     MutableArrayRef<Token> Toks(PP.getPreprocessorAllocator().Allocate<Token>(1),
diff --git a/clang/test/CodeGen/fp-floatcontrol-pragma.cpp b/clang/test/CodeGen/fp-floatcontrol-pragma.cpp
index caaab3c..773cfcd 100644
--- a/clang/test/CodeGen/fp-floatcontrol-pragma.cpp
+++ b/clang/test/CodeGen/fp-floatcontrol-pragma.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -triple x86_64-linux-gnu -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -verify -DFENV_ON=1 -triple x86_64-linux-gnu -emit-llvm -o - %s | FileCheck %s
 
 float fff(float x, float y) {
 // CHECK-LABEL: define float @_Z3fffff{{.*}}
@@ -38,6 +39,7 @@ float check_precise(float x, float y) {
   }
   return z;
 }
+
 float fma_test1(float a, float b, float c) {
 // CHECK-LABEL define float @_Z9fma_test1fff{{.*}}
 #pragma float_control(precise, on)
@@ -45,3 +47,15 @@ float fma_test1(float a, float b, float c) {
   //CHECK: fmuladd
   return x;
 }
+
+#if FENV_ON
+// expected-warning@+1{{pragma STDC FENV_ACCESS ON is not supported, ignoring pragma}}
+#pragma STDC FENV_ACCESS ON
+#endif
+// CHECK-LABEL: define {{.*}}callt{{.*}}
+
+void callt() {
+  volatile float z;
+  z = z * z;
+//CHECK: = fmul float
+}
diff --git a/clang/test/Parser/fp-floatcontrol-syntax.cpp b/clang/test/Parser/fp-floatcontrol-syntax.cpp
index a730372..4bdc34d 100644
--- a/clang/test/Parser/fp-floatcontrol-syntax.cpp
+++ b/clang/test/Parser/fp-floatcontrol-syntax.cpp
@@ -30,14 +30,15 @@ double b = 1.0;
 //      document the warning
 #ifdef FAST
 // expected-warning@+1{{pragma STDC FENV_ACCESS ON is not supported, ignoring pragma}}
-#pragma STDC FENV_ACCESS ON // expected-error{{'#pragma STDC FENV_ACCESS ON' is illegal when precise is disabled}}
+#pragma STDC FENV_ACCESS ON
 #else
 #pragma STDC FENV_ACCESS ON // expected-warning{{pragma STDC FENV_ACCESS ON is not supported, ignoring pragma}}
 #endif
 #ifdef STRICT
 #pragma float_control(precise, off) // expected-error {{'#pragma float_control(precise, off)' is illegal when except is enabled}}
 #else
-#pragma float_control(precise, off) // expected-error {{'#pragma float_control(precise, off)' is illegal when fenv_access is enabled}}
+// Currently FENV_ACCESS cannot be enabled by pragma, skip error check
+#pragma float_control(precise, off) // not-expected-error {{'#pragma float_control(precise, off)' is illegal when fenv_access is enabled}}
 #endif
 
 #pragma float_control(precise, on)
-- 
2.7.4