Better PCH/GCH detection

KNOWN_BUGS.md

@@ -0,0 +1,41 @@
+### OSXCROSS BUGS ###
+
+-------------
+
+*** ISSUE: ***
+
+GCH generation does not work with `gcc` or `clang++-gstdc++`/`-foc-use-gcc-libstdc++`
+if `-c` or `-x<lang>-header` is **not** passed to the compiler.
+
+Example:
+
+    $ o64-gcc test.h
+    Undefined symbols for architecture x86_64:
+    "_main", referenced from:
+    start in crt1.10.6.o
+
+This is due to `-Wl,-no_compact_unwind` being passed to the compiler under the hood.
+
+Example:
+
+    $ x86_64-apple-darwin14-base-gcc
+    x86_64-apple-darwin14-base-gcc: fatal error: no input files
+
+    $ x86_64-apple-darwin14-base-gcc -Wl,-no_compact_unwind
+    Undefined symbols for architecture x86_64:
+    "_main", referenced from:
+    start in crt1.10.6.o
+    ld: symbol(s) not found for architecture x86_64
+
+*** WORKAROUND: ***
+
+Add `-c` or `-x<lang>-header` to the compiler flags.
+
+Example:
+
+    o64-clang++-gstdc++ test.hpp              # BAD
+    o64-clang++-gstdc++ -xc++-header test.hpp # OK
+    o64-clang++-gstdc++ test.hpp -c           # OK
+    o64-g++ test.hpp -c                       # OK
+
+-------------

wrapper/main.cpp

@@ -158,8 +158,8 @@ bool stdlib(Target &target, const char *, const char *val, char **) {
   return true;
 }
 
-bool outputname(Target &target, const char *, const char *val, char **) {
-  target.outputname = val;
+bool language(Target &target, const char *, const char *val, char **) {
+  target.language = val;
   return true;
 }
 
@@ -250,7 +250,7 @@ constexpr struct Opt {
   {"-m32", arch},
   {"-mx32", arch},
   {"-m64", arch},
-  {"-o", outputname, true, true},
+  {"-x", language, true, true},
   {"-foc-use-gcc-libstdc++", usegcclibstdcxx},
   {"-foc-run-prog", runprog, true, false, "="}, // for internal use only
   {"-isystem", checkincludepath, true, true},

wrapper/target.cpp

@@ -173,6 +173,27 @@ bool Target::isCXX() {
   return endsWith(compilername, "++");
 }
 
+bool Target::isGCH() {
+  if (!language)
+    return false;
+
+  return !strcmp(language, "c-header") ||
+         !strcmp(language, "c++-header") ||
+         !strcmp(language, "objective-c-header") ||
+         !strcmp(language, "objective-c++-header");
+}
+
+
+bool Target::isClang() const {
+  return !strncmp(getFileName(compilername.c_str()), "clang", 5);
+}
+
+bool Target::isGCC() const {
+  const char *c = getFileName(compilername.c_str());
+  return (!strncmp(c, "gcc", 3) || !strncmp(c, "g++", 3));
+}
+
+
 const std::string &Target::getDefaultTriple(std::string &triple) const {
   triple = getArchName(Arch::x86_64);
   triple += "-";
@@ -585,13 +606,13 @@ bool Target::setup() {
         fargs.push_back("-Qunused-arguments");
       }
 
-      if (stdlib == StdLib::libstdcxx && usegcclibs && targetarch.size() < 2) {
+      if (stdlib == StdLib::libstdcxx && usegcclibs && targetarch.size() < 2 &&
+          !isGCH()) {
         // Use libs from './build_gcc' installation
         setupGCCLibs(targetarch[0]);
       }
     }
   } else if (isGCC()) {
-
     if (isCXX() && isLibCXX()) {
       fargs.push_back("-nostdinc++");
       fargs.push_back("-nodefaultlibs");
@@ -607,7 +628,8 @@ bool Target::setup() {
       fargs.push_back("-static-libstdc++");
     }
 
-    fargs.push_back("-Wl,-no_compact_unwind");
+    if (!isGCH())
+      fargs.push_back("-Wl,-no_compact_unwind");
   }
 
   auto addCXXHeaderPath = [&](const std::string &path) {

wrapper/target.h

@@ -70,7 +70,7 @@ struct Target {
       : vendor(getDefaultVendor()), SDK(getenv("OSXCROSS_SDKROOT")),
         arch(Arch::x86_64), target(getDefaultTarget()), stdlib(StdLib::unset),
         usegcclibs(), nocodegen(), compilername(getDefaultCompiler()),
-        outputname() {
+        language() {
     if (!getExecutablePath(execpath, sizeof(execpath)))
       abort();
   }
@@ -93,26 +93,11 @@ struct Target {
   bool isLibCXX() const;
   bool isLibSTDCXX() const;
 
-  bool haveOutputName() { return outputname != nullptr; }
-
   bool isCXX();
+  bool isGCH();
 
-  bool isGCH() {
-    if (haveOutputName()) {
-      const char *ext = getFileExtension(outputname);
-      return !strcmp(ext, ".gch");
-    }
-    return false;
-  }
-
-  bool isClang() const {
-    return !strncmp(getFileName(compilername.c_str()), "clang", 5);
-  }
-
-  bool isGCC() const {
-    const char *c = getFileName(compilername.c_str());
-    return (!strncmp(c, "gcc", 3) || !strncmp(c, "g++", 3));
-  }
+  bool isClang() const;
+  bool isGCC() const;
 
   bool isKnownCompiler() const { return isClang() || isGCC(); }
 
@@ -143,7 +128,7 @@ struct Target {
   std::string otriple;
   string_vector fargs;
   string_vector args;
-  const char *outputname;
+  const char *language;
   char execpath[PATH_MAX + 1];
 };
 

wrapper/unittests/run.bats

@@ -172,7 +172,9 @@ eval $(osxcross-conf)
 }
 
 @test "command line parsing" {
-  run o64-clang++ -mmacosx-version-min=10.4 -g -I test1 -march=native -Itest2 -O2 -stdlib=libstdc++ -stdlib=default -stdlib=libstdc++ -otest1 -o test2 foo.cpp -c
+  run o64-clang++ -mmacosx-version-min=10.4 -g -I test1 -march=native -Itest2 -O2 \
+                  -xc-header -x c++-header -stdlib=libstdc++ -stdlib=default -stdlib=libstdc++ \
+                  -otest1 -o test2 foo.cpp -c
   [ "$status" -eq 0 ]
   [[ "${lines[0]}" == *\ -mmacosx-version-min=10.4*\ * ]]
   [[ "${lines[0]}" == *\ -g\ *\ * ]]
@@ -180,6 +182,8 @@ eval $(osxcross-conf)
   [[ "${lines[0]}" == *\ -march=native\ * ]]
   [[ "${lines[0]}" == *\ -Itest2\ * ]]
   [[ "${lines[0]}" == *\ -O2\ * ]]
+  [[ "${lines[0]}" == *\ -xc-header\ * ]]
+  [[ "${lines[0]}" == *\ -x\ c++-header\ * ]]
   [[ "${lines[0]}" != *\ -stdlib=default\ * ]]
   [[ "${lines[0]}" == *\ -otest1\ * ]]
   [[ "${lines[0]}" == *\ -o\ test2\ * ]]
@@ -337,6 +341,24 @@ eval $(osxcross-conf)
   [[ "${lines[0]}" == *error:\ value\ of\ \'-stdlib=\'\ must\ be\ \'default\',\ \'libc++\'\ or\ \'libstdc++\' ]]
 }
 
+@test "precompiled headers" {
+  function gch()
+  {
+    run $@
+    [ "$status" -eq 0 ]
+    [[ "${lines[0]}" != *\ -l* ]]
+    [[ "${lines[0]}" != *\ -Wl,* ]]
+    [[ "${lines[0]}" != *\ *.a ]]
+  }
+
+  gch o64-clang -x c-header
+  gch o64-clang++-gstdc++ -xc++-header
+
+  if [ $GCC_INSTALLED -eq 1 ]; then
+    gch o64-g++ -xc++-header
+  fi
+}
+
 @test "-arch/-m32/-m64/-m16/-mx32" {
   run o64-clang++ -arch x86_64 -arch i386 -arch x86_64 -arch i386
   [ "$status" -eq 0 ]