For Linux/gnu compatibility, preinclude <stdc-predef.h> if the file is available
As reported in llvm bugzilla 32377.
Here’s a patch to add preinclude of stdc-predef.h.
The gcc documentation says “On GNU/Linux, <stdc-predef.h> is pre-included.” See https://gcc.gnu.org/gcc-4.8/porting_to.html;
The preinclude is inhibited with –ffreestanding.
Basically I fixed the failing test cases by adding –ffreestanding which inhibits this behavior.
I fixed all the failing tests, including some in extra/test, there's a separate patch for that which is linked here
Note: this is a recommit after a test failure took down the original (r318669)
Patch By: mibintc
Differential Revision: https://reviews.llvm.org/D34158
llvm-svn: 320391
diff --git a/clang/lib/Driver/Job.cpp b/clang/lib/Driver/Job.cpp
index 765c057..b494bc7 100644
--- a/clang/lib/Driver/Job.cpp
+++ b/clang/lib/Driver/Job.cpp
@@ -64,7 +64,7 @@
.Cases("-internal-externc-isystem", "-iprefix", true)
.Cases("-iwithprefixbefore", "-isystem", "-iquote", true)
.Cases("-isysroot", "-I", "-F", "-resource-dir", true)
- .Cases("-iframework", "-include-pch", true)
+ .Cases("-iframework", "-include-pch", "-fsystem-include-if-exists", true)
.Default(false);
if (IsInclude)
return HaveCrashVFS ? false : true;
diff --git a/clang/lib/Driver/ToolChains/Linux.cpp b/clang/lib/Driver/ToolChains/Linux.cpp
index 1301cdf..5c36973 100644
--- a/clang/lib/Driver/ToolChains/Linux.cpp
+++ b/clang/lib/Driver/ToolChains/Linux.cpp
@@ -710,6 +710,8 @@
addExternCSystemInclude(DriverArgs, CC1Args, SysRoot + "/include");
addExternCSystemInclude(DriverArgs, CC1Args, SysRoot + "/usr/include");
+
+ AddGnuIncludeArgs(DriverArgs, CC1Args);
}
static std::string DetectLibcxxIncludePath(StringRef base) {
@@ -748,6 +750,16 @@
return "";
}
+void Linux::AddGnuIncludeArgs(const llvm::opt::ArgList &DriverArgs,
+ llvm::opt::ArgStringList &CC1Args) const {
+ if (!DriverArgs.hasArg(options::OPT_ffreestanding)) {
+ // For gcc compatibility, clang will preinclude <stdc-predef.h>
+ // -ffreestanding suppresses this behavior.
+ CC1Args.push_back("-fsystem-include-if-exists");
+ CC1Args.push_back("stdc-predef.h");
+ }
+}
+
void Linux::addLibStdCxxIncludePaths(const llvm::opt::ArgList &DriverArgs,
llvm::opt::ArgStringList &CC1Args) const {
// We need a detected GCC installation on Linux to provide libstdc++'s
diff --git a/clang/lib/Driver/ToolChains/Linux.h b/clang/lib/Driver/ToolChains/Linux.h
index 9778c18..8b7e2e2 100644
--- a/clang/lib/Driver/ToolChains/Linux.h
+++ b/clang/lib/Driver/ToolChains/Linux.h
@@ -31,6 +31,8 @@
void addLibStdCxxIncludePaths(
const llvm::opt::ArgList &DriverArgs,
llvm::opt::ArgStringList &CC1Args) const override;
+ void AddGnuIncludeArgs(const llvm::opt::ArgList &DriverArgs,
+ llvm::opt::ArgStringList &CC1Args) const;
void AddCudaIncludeArgs(const llvm::opt::ArgList &DriverArgs,
llvm::opt::ArgStringList &CC1Args) const override;
void AddIAMCUIncludeArgs(const llvm::opt::ArgList &DriverArgs,
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 2ebdc2a..60802da 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -2611,6 +2611,10 @@
for (const Arg *A : Args.filtered(OPT_chain_include))
Opts.ChainedIncludes.emplace_back(A->getValue());
+ // Add the ordered list of -fsystem-include-if-exists.
+ for (const Arg *A : Args.filtered(OPT_fsystem_include_if_exists))
+ Opts.FSystemIncludeIfExists.emplace_back(A->getValue());
+
for (const Arg *A : Args.filtered(OPT_remap_file)) {
std::pair<StringRef, StringRef> Split = StringRef(A->getValue()).split(';');
diff --git a/clang/lib/Frontend/InitPreprocessor.cpp b/clang/lib/Frontend/InitPreprocessor.cpp
index d398904..45760ae 100644
--- a/clang/lib/Frontend/InitPreprocessor.cpp
+++ b/clang/lib/Frontend/InitPreprocessor.cpp
@@ -70,6 +70,15 @@
Builder.append(Twine("#include \"") + File + "\"");
}
+/// AddImplicitSystemIncludeIfExists - Add an implicit system \#include of the
+/// specified file to the predefines buffer: precheck with __has_include.
+static void AddImplicitSystemIncludeIfExists(MacroBuilder &Builder,
+ StringRef File) {
+ Builder.append(Twine("#if __has_include( <") + File + ">)");
+ Builder.append(Twine("#include <") + File + ">");
+ Builder.append(Twine("#endif"));
+}
+
static void AddImplicitIncludeMacros(MacroBuilder &Builder, StringRef File) {
Builder.append(Twine("#__include_macros \"") + File + "\"");
// Marker token to stop the __include_macros fetch loop.
@@ -1133,6 +1142,13 @@
if (!PP.getLangOpts().AsmPreprocessor)
Builder.append("# 1 \"<built-in>\" 2");
+ // Process -fsystem-include-if-exists directives.
+ for (unsigned i = 0,
+ e = InitOpts.FSystemIncludeIfExists.size(); i != e; ++i) {
+ const std::string &Path = InitOpts.FSystemIncludeIfExists[i];
+ AddImplicitSystemIncludeIfExists(Builder, Path);
+ }
+
// If -imacros are specified, include them now. These are processed before
// any -include directives.
for (unsigned i = 0, e = InitOpts.MacroIncludes.size(); i != e; ++i)