clang-cl: Store the linker options for the ASAN runtime libraries in the obj files as opposed to pass it to the linker on the command line

[• ehsan]

Summary

This enables using to compile the code and then
link it using link.exe directly without invoking the linker through clang-cl.
It should hopefully make it easier for projects that don't use the compiler
to invoke the linker to use ASAN.

[rnk]

Generally we want to be careful about embedding full paths into the binary. While nobody is doing distributed builds today, in the future we want to support that.

What do you think of embedding just the basename into .drectve, and adding clang's resource dir to the LIB environment variable in the build system? That's a far less invasive change than making clang do the link step instead of link.exe, and should solve the problem.

[• ehsan]

Addressed the review comment.

lib/Driver/Tools.cpp

for (size_t I = 0, E = EHVal.size(); I != E; ++I) {
       }
       D.Diag(clang::diag::err_drv_invalid_value) << "/EH" << EHVal;
       break;
     }
   }
   return EH;
 }
 
+static void addSanitizerRTDependentLib(const ToolChain &TC, const ArgList &Args,
+                                       ArgStringList &CmdArgs,
+                                       const StringRef RTName) {
+  SmallString<128> ArgStr("--dependent-lib=");
+  ArgStr.append("clang_rt.");
+  ArgStr.append(RTName);
+  ArgStr.append(".lib");
+  CmdArgs.push_back(Args.MakeArgString(ArgStr));
+}
+
 void Clang::AddClangCLArgs(const ArgList &Args, ArgStringList &CmdArgs) const {
   unsigned RTOptionID = options::OPT__SLASH_MT;
 
   if (Args.hasArg(options::OPT__SLASH_LDd))
     // The /LDd option implies /MTd. The dependent lib part can be overridden,
     // but defining _DEBUG is sticky.
     RTOptionID = options::OPT__SLASH_MTd;
 
   if (Arg *A = Args.getLastArg(options::OPT__SLASH_M_Group))
     RTOptionID = A->getOption().getID();
 
+  if (getToolChain().getSanitizerArgs().needsAsanRt()) {
+    // FIXME: Handle 64-bit.
+    bool DLL = Args.hasArg(options::OPT__SLASH_LD, options::OPT__SLASH_LDd);
+    if (DLL) {
+      addSanitizerRTDependentLib(getToolChain(), Args, CmdArgs, "asan_dll_thunk-i386");
+    } else {
+      addSanitizerRTDependentLib(getToolChain(), Args, CmdArgs, "asan-i386");
+      addSanitizerRTDependentLib(getToolChain(), Args, CmdArgs, "asan_cxx-i386");
+    }
+  }
+
   switch(RTOptionID) {
     case options::OPT__SLASH_MD:
       if (Args.hasArg(options::OPT__SLASH_LDd))
         CmdArgs.push_back("-D_DEBUG");
       CmdArgs.push_back("-D_MT");
       CmdArgs.push_back("-D_DLL");
       CmdArgs.push_back("--dependent-lib=msvcrt");
       break;
void dragonfly::Link::ConstructJob(Compilation &C, const JobAction &JA,
   }
 
   addProfileRT(getToolChain(), Args, CmdArgs);
 
   const char *Exec = Args.MakeArgString(getToolChain().GetLinkerPath());
   C.addCommand(new Command(JA, *this, Exec, CmdArgs));
 }
 
-static void addSanitizerRTWindows(const ToolChain &TC, const ArgList &Args,
-                                  ArgStringList &CmdArgs,
-                                  const StringRef RTName) {
-  SmallString<128> LibSanitizer(getCompilerRTLibDir(TC));
-  llvm::sys::path::append(LibSanitizer,
-                          Twine("clang_rt.") + RTName + ".lib");
-  CmdArgs.push_back(Args.MakeArgString(LibSanitizer));
-}
-
 void visualstudio::Link::ConstructJob(Compilation &C, const JobAction &JA,
                                       const InputInfo &Output,
                                       const InputInfoList &Inputs,
                                       const ArgList &Args,
                                       const char *LinkingOutput) const {
   ArgStringList CmdArgs;
 
   if (Output.isFilename()) {
if (DLL) {
     llvm::sys::path::replace_extension(ImplibName, "lib");
     CmdArgs.push_back(Args.MakeArgString(std::string("-implib:") +
                                          ImplibName.str()));
   }
 
   if (getToolChain().getSanitizerArgs().needsAsanRt()) {
     CmdArgs.push_back(Args.MakeArgString("-debug"));
     CmdArgs.push_back(Args.MakeArgString("-incremental:no"));
-    // FIXME: Handle 64-bit.
-    if (DLL) {
-      addSanitizerRTWindows(getToolChain(), Args, CmdArgs,
-                            "asan_dll_thunk-i386");
-    } else {
-      addSanitizerRTWindows(getToolChain(), Args, CmdArgs, "asan-i386");
-      addSanitizerRTWindows(getToolChain(), Args, CmdArgs, "asan_cxx-i386");
-    }
   }
 
   Args.AddAllArgValues(CmdArgs, options::OPT_l);
   Args.AddAllArgValues(CmdArgs, options::OPT__SLASH_link);
 
   // Add filenames immediately.
   for (const auto &Input : Inputs)
     if (Input.isFilename())

test/Driver/cl-link.c

 // Don't attempt slash switches on msys bash.
 // REQUIRES: shell-preserves-root
 
 // Note: %s must be preceded by -- or bound to another option, otherwise it may
 // be interpreted as a command-line option, e.g. on Mac where %s is commonly
 // under /Users.
 
 // RUN: %clang_cl /Tc%s -### /link foo bar baz 2>&1 | FileCheck --check-prefix=LINK %s
 // LINK: link.exe
 // LINK: "foo"
 // LINK: "bar"
 // LINK: "baz"
 
 // RUN: %clang_cl /Tc%s -### -fsanitize=address 2>&1 | FileCheck --check-prefix=ASAN %s
+// ASAN: "--dependent-lib=clang_rt.asan-i386.lib"
+// ASAN: "--dependent-lib=clang_rt.asan_cxx-i386.lib"
 // ASAN: link.exe
 // ASAN: "-debug"
 // ASAN: "-incremental:no"
-// ASAN: "{{.*}}clang_rt.asan-i386.lib"
-// ASAN: "{{.*}}clang_rt.asan_cxx-i386.lib"
+// ASAN-NOT: .lib
 // ASAN: "{{.*}}cl-link{{.*}}.obj"
 
 // RUN: %clang_cl /LD -### /Tc%s 2>&1 | FileCheck --check-prefix=DLL %s
 // RUN: %clang_cl /LDd -### /Tc%s 2>&1 | FileCheck --check-prefix=DLL %s
 // DLL: link.exe
 // "-dll"
 
 // RUN: %clang_cl /LD /Tc%s -### -fsanitize=address 2>&1 | FileCheck --check-prefix=ASAN-DLL %s
 // RUN: %clang_cl /LDd /Tc%s -### -fsanitize=address 2>&1 | FileCheck --check-prefix=ASAN-DLL %s
+// ASAN-DLL: "--dependent-lib=clang_rt.asan_dll_thunk-i386.lib"
 // ASAN-DLL: link.exe
 // ASAN-DLL: "-dll"
 // ASAN-DLL: "-debug"
 // ASAN-DLL: "-incremental:no"
-// ASAN-DLL: "{{.*}}clang_rt.asan_dll_thunk-i386.lib"
+// ASAN-DLL-NOT: .lib
 // ASAN-DLL: "{{.*}}cl-link{{.*}}.obj"
 
 // RUN: %clang_cl /Zi /Tc%s -### 2>&1 | FileCheck --check-prefix=DEBUG %s
 // DEBUG: link.exe
 // DEBUG: "-debug"