From 5cfebb0f904131d1df8e36fcb9c290f12c06e9ba Mon Sep 17 00:00:00 2001
From: Brad King <brad.king@kitware.com>
Date: Tue, 9 Feb 2016 11:24:47 -0500
Subject: [PATCH] RunClang: Avoid GNU extensions in glibc math headers on i386

On i386 with optimizations enabled, the `bits/mathinline.h` header may
use a GNU extension not implemented by Clang.  Avoid parsing this code
by defining `__NO_MATH_INLINES` so it will be preprocessed out.

GitHub-Issue: #47
---
 src/RunClang.cxx                                   | 14 ++++++++++++++
 test/CMakeLists.txt                                |  2 ++
 test/expect/cmd.cc-gnu-c-tgt-i386-opt-E.stdout.txt | 11 +++++++++++
 test/expect/cmd.cc-gnu-tgt-i386-opt-E.stdout.txt   | 12 ++++++++++++
 4 files changed, 39 insertions(+)
 create mode 100644 test/expect/cmd.cc-gnu-c-tgt-i386-opt-E.stdout.txt
 create mode 100644 test/expect/cmd.cc-gnu-tgt-i386-opt-E.stdout.txt

diff --git a/src/RunClang.cxx b/src/RunClang.cxx
index 9768a25..0a68698 100644
--- a/src/RunClang.cxx
+++ b/src/RunClang.cxx
@@ -204,6 +204,13 @@ class CastXMLPredefines: public T
         }
       }
 
+      // Prevent glibc use of a GNU extension not implemented by Clang.
+      if (this->NeedNoMathInlines(this->Opts.Predefines)) {
+        builtins += "\n"
+          "#define __NO_MATH_INLINES 1\n"
+          ;
+      }
+
     } else {
       builtins += predefines.substr(start, end-start);
     }
@@ -229,6 +236,13 @@ class CastXMLPredefines: public T
              pd.find("#define __ia64__ ") != pd.npos));
   }
 
+  bool NeedNoMathInlines(std::string const& pd) const {
+    return (this->IsActualGNU(pd) &&
+            (pd.find("#define __i386__ ") != pd.npos &&
+             pd.find("#define __OPTIMIZE__ ") != pd.npos &&
+             pd.find("#define __NO_MATH_INLINES ") == pd.npos));
+  }
+
   bool BeginSourceFileAction(clang::CompilerInstance& CI,
                              llvm::StringRef /*Filename*/) {
     CI.getPreprocessor().setPredefines(this->UpdatePredefines(CI));
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index e13d308..9ed4a50 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -205,6 +205,7 @@ castxml_test_cmd(cc-gnu-src-cxx-cmd --castxml-cc-gnu $<TARGET_FILE:cc-gnu> ${emp
 castxml_test_cmd(cc-gnu-tgt-amd64 --castxml-cc-gnu "(" $<TARGET_FILE:cc-gnu> --cc-define=__amd64__ ")" ${empty_cxx} "-###")
 castxml_test_cmd(cc-gnu-tgt-explicit --castxml-cc-gnu "(" $<TARGET_FILE:cc-gnu> ")" -target explicit-target-triple ${empty_cxx} "-###")
 castxml_test_cmd(cc-gnu-tgt-i386 --castxml-cc-gnu "(" $<TARGET_FILE:cc-gnu> --cc-define=__i386__ ")" ${empty_cxx} "-###")
+castxml_test_cmd(cc-gnu-tgt-i386-opt-E --castxml-cc-gnu "(" $<TARGET_FILE:cc-gnu> --cc-define=__i386__ --cc-define=__OPTIMIZE__ ")" ${empty_cxx} -E -dM)
 castxml_test_cmd(cc-gnu-tgt-mingw --castxml-cc-gnu "(" $<TARGET_FILE:cc-gnu> --cc-define=_WIN32 --cc-define=__MINGW32__ ")" ${empty_cxx} "-###")
 castxml_test_cmd(cc-gnu-tgt-win --castxml-cc-gnu "(" $<TARGET_FILE:cc-gnu> --cc-define=_WIN32 ")" ${empty_cxx} "-###")
 castxml_test_cmd(cc-gnu-tgt-x86_64 --castxml-cc-gnu "(" $<TARGET_FILE:cc-gnu> --cc-define=__x86_64__ ")" ${empty_cxx} "-###")
@@ -224,6 +225,7 @@ castxml_test_cmd(cc-gnu-c-std-c11 --castxml-cc-gnu-c "(" $<TARGET_FILE:cc-gnu> -
 castxml_test_cmd(cc-gnu-c-std-gnu89 --castxml-cc-gnu-c "(" $<TARGET_FILE:cc-gnu>              ")" ${empty_c} "-###")
 castxml_test_cmd(cc-gnu-c-std-gnu99 --castxml-cc-gnu-c "(" $<TARGET_FILE:cc-gnu> -std=199901L ")" ${empty_c} "-###")
 castxml_test_cmd(cc-gnu-c-std-gnu11 --castxml-cc-gnu-c "(" $<TARGET_FILE:cc-gnu> -std=201112L ")" ${empty_c} "-###")
+castxml_test_cmd(cc-gnu-c-tgt-i386-opt-E --castxml-cc-gnu-c "(" $<TARGET_FILE:cc-gnu> --cc-define=__i386__ --cc-define=__OPTIMIZE__ ")" ${empty_c} -E -dM)
 
 # Test --castxml-cc-msvc detection.
 add_executable(cc-msvc cc-msvc.c)
diff --git a/test/expect/cmd.cc-gnu-c-tgt-i386-opt-E.stdout.txt b/test/expect/cmd.cc-gnu-c-tgt-i386-opt-E.stdout.txt
new file mode 100644
index 0000000..865095d
--- /dev/null
+++ b/test/expect/cmd.cc-gnu-c-tgt-i386-opt-E.stdout.txt
@@ -0,0 +1,11 @@
+^#define __GNUC_MINOR__ 1
+#define __GNUC__ 1
+#define __NO_MATH_INLINES 1
+#define __OPTIMIZE__ 1
+#define __builtin_va_arg_pack\(\) 0
+#define __builtin_va_arg_pack_len\(\) 1
+#define __castxml__ [0-9]+
+#define __castxml_clang_major__ [0-9]+
+#define __castxml_clang_minor__ [0-9]+
+#define __castxml_clang_patchlevel__ [0-9]+
+#define __i386__ 1$
diff --git a/test/expect/cmd.cc-gnu-tgt-i386-opt-E.stdout.txt b/test/expect/cmd.cc-gnu-tgt-i386-opt-E.stdout.txt
new file mode 100644
index 0000000..fa9c1e5
--- /dev/null
+++ b/test/expect/cmd.cc-gnu-tgt-i386-opt-E.stdout.txt
@@ -0,0 +1,12 @@
+^#define __GNUC_MINOR__ 1
+#define __GNUC__ 1
+#define __NO_MATH_INLINES 1
+#define __OPTIMIZE__ 1
+#define __builtin_va_arg_pack\(\) 0
+#define __builtin_va_arg_pack_len\(\) 1
+#define __castxml__ [0-9]+
+#define __castxml_clang_major__ [0-9]+
+#define __castxml_clang_minor__ [0-9]+
+#define __castxml_clang_patchlevel__ [0-9]+
+#define __cplusplus 199711L
+#define __i386__ 1$