From a9ce03858d657f4bab5cae242cfba7cfc1c144de Mon Sep 17 00:00:00 2001
From: Peter Collingbourne <peter@pcc.me.uk>
Date: Thu, 27 Nov 2014 00:15:21 +0000
Subject: [PATCH] Teach LLVM about llgo subproject.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222860 91177308-0d34-0410-b5e6-96231b3b80d8
---
 cmake/modules/AddLLVM.cmake | 25 +++++++++++++++++++++++++
 tools/CMakeLists.txt        |  1 +
 tools/llvm-go/llvm-go.go    | 35 ++++++++++++++++++++++++++++++++---
 3 files changed, 58 insertions(+), 3 deletions(-)

diff --git a/cmake/modules/AddLLVM.cmake b/cmake/modules/AddLLVM.cmake
index bc26f067166..2ef73fb8e5d 100644
--- a/cmake/modules/AddLLVM.cmake
+++ b/cmake/modules/AddLLVM.cmake
@@ -603,6 +603,31 @@ function(add_unittest test_suite test_name)
   endif ()
 endfunction()
 
+function(llvm_add_go_executable binary pkgpath)
+  cmake_parse_arguments(ARG "ALL" "" "DEPENDS;GOFLAGS" ${ARGN})
+
+  if(LLVM_BINDINGS MATCHES "go")
+    # FIXME: This should depend only on the libraries Go needs.
+    get_property(llvmlibs GLOBAL PROPERTY LLVM_LIBS)
+    set(binpath ${CMAKE_BINARY_DIR}/bin/${binary}${CMAKE_EXECUTABLE_SUFFIX})
+    set(cc "${CMAKE_C_COMPILER} ${CMAKE_C_COMPILER_ARG1}")
+    set(cxx "${CMAKE_CXX_COMPILER} ${CMAKE_CXX_COMPILER_ARG1}")
+    set(ldflags "${CMAKE_EXE_LINKER_FLAGS}")
+    add_custom_command(OUTPUT ${binpath}
+      COMMAND ${CMAKE_BINARY_DIR}/bin/llvm-go "cc=${cc}" "cxx=${cxx}" "ldflags=${ldflags}"
+              ${ARG_GOFLAGS} build -o ${binpath} ${pkgpath}
+      DEPENDS llvm-config ${CMAKE_BINARY_DIR}/bin/llvm-go${CMAKE_EXECUTABLE_SUFFIX}
+              ${llvmlibs} ${ARG_DEPENDS}
+      COMMENT "Building Go executable ${binary}"
+      VERBATIM)
+    if (ARG_ALL)
+      add_custom_target(${binary} ALL DEPENDS ${binpath})
+    else()
+      add_custom_target(${binary} DEPENDS ${binpath})
+    endif()
+  endif()
+endfunction()
+
 # This function provides an automatic way to 'configure'-like generate a file
 # based on a set of common and custom variables, specifically targeting the
 # variables needed for the 'lit.site.cfg' files. This function bundles the
diff --git a/tools/CMakeLists.txt b/tools/CMakeLists.txt
index fd761ecfe43..5905baf9813 100644
--- a/tools/CMakeLists.txt
+++ b/tools/CMakeLists.txt
@@ -81,6 +81,7 @@ else()
 endif()
 
 add_llvm_external_project(clang)
+add_llvm_external_project(llgo)
 
 if( NOT LLVM_INCLUDE_TOOLS STREQUAL "bootstrap-only" )
   add_llvm_external_project(lld)
diff --git a/tools/llvm-go/llvm-go.go b/tools/llvm-go/llvm-go.go
index 47f948150f0..cf520bd90e9 100644
--- a/tools/llvm-go/llvm-go.go
+++ b/tools/llvm-go/llvm-go.go
@@ -30,6 +30,7 @@ type pkg struct {
 
 var packages = []pkg{
 	{"bindings/go/llvm", "llvm.org/llvm/bindings/go/llvm"},
+	{"tools/llgo", "llvm.org/llgo"},
 }
 
 type compilerFlags struct {
@@ -136,7 +137,7 @@ type (run_build_sh int)
 `, flags.cpp, flags.cxx, flags.ld)
 }
 
-func runGoWithLLVMEnv(args []string, cc, cxx, cppflags, cxxflags, ldflags string) {
+func runGoWithLLVMEnv(args []string, cc, cxx, llgo, cppflags, cxxflags, ldflags string) {
 	args = addTag(args, "byollvm")
 
 	srcdir := llvmConfig("--src-root")
@@ -159,6 +160,28 @@ func runGoWithLLVMEnv(args []string, cc, cxx, cppflags, cxxflags, ldflags string
 		}
 	}
 
+	newpath := os.Getenv("PATH")
+
+	if llgo != "" {
+		bindir := filepath.Join(tmpgopath, "bin")
+
+		err = os.MkdirAll(bindir, os.ModePerm)
+		if err != nil {
+			panic(err.Error())
+		}
+
+		err = os.Symlink(llgo, filepath.Join(bindir, "gccgo"))
+		if err != nil {
+			panic(err.Error())
+		}
+
+		newpathlist := []string{bindir}
+		newpathlist = append(newpathlist, filepath.SplitList(newpath)...)
+		newpath = strings.Join(newpathlist, string(filepath.ListSeparator))
+
+		args = append([]string{args[0], "-compiler", "gccgo"}, args[1:]...)
+	}
+
 	newgopathlist := []string{tmpgopath}
 	newgopathlist = append(newgopathlist, filepath.SplitList(os.Getenv("GOPATH"))...)
 	newgopath := strings.Join(newgopathlist, string(filepath.ListSeparator))
@@ -172,6 +195,7 @@ func runGoWithLLVMEnv(args []string, cc, cxx, cppflags, cxxflags, ldflags string
 		"CGO_CXXFLAGS=" + flags.cxx + " " + cxxflags,
 		"CGO_LDFLAGS=" + flags.ld + " " + ldflags,
 		"GOPATH=" + newgopath,
+		"PATH=" + newpath,
 	}
 	for _, v := range os.Environ() {
 		if !strings.HasPrefix(v, "CC=") &&
@@ -179,7 +203,8 @@ func runGoWithLLVMEnv(args []string, cc, cxx, cppflags, cxxflags, ldflags string
 			!strings.HasPrefix(v, "CGO_CPPFLAGS=") &&
 			!strings.HasPrefix(v, "CGO_CXXFLAGS=") &&
 			!strings.HasPrefix(v, "CGO_LDFLAGS=") &&
-			!strings.HasPrefix(v, "GOPATH=") {
+			!strings.HasPrefix(v, "GOPATH=") &&
+			!strings.HasPrefix(v, "PATH=") {
 			newenv = append(newenv, v)
 		}
 	}
@@ -222,6 +247,7 @@ func main() {
 	cppflags := os.Getenv("CGO_CPPFLAGS")
 	cxxflags := os.Getenv("CGO_CXXFLAGS")
 	ldflags := os.Getenv("CGO_LDFLAGS")
+	llgo := ""
 
 	args := os.Args[1:]
 	DONE: for {
@@ -234,6 +260,9 @@ func main() {
 		case strings.HasPrefix(args[0], "cxx="):
 			cxx = args[0][4:]
 			args = args[1:]
+		case strings.HasPrefix(args[0], "llgo="):
+			llgo = args[0][5:]
+			args = args[1:]
 		case strings.HasPrefix(args[0], "cppflags="):
 			cppflags = args[0][9:]
 			args = args[1:]
@@ -250,7 +279,7 @@ func main() {
 
 	switch args[0] {
 	case "build", "get", "install", "run", "test":
-		runGoWithLLVMEnv(args, cc, cxx, cppflags, cxxflags, ldflags)
+		runGoWithLLVMEnv(args, cc, cxx, llgo, cppflags, cxxflags, ldflags)
 	case "print-components":
 		printComponents()
 	case "print-config":
-- 
2.34.1