[libclang] Expose some target information via the C API.

This allows users to query the target triple and target pointer width, which
would make me able to fix https://github.com/servo/rust-bindgen/issues/593 and
other related bugs in an elegant way (without having to manually parse the
target triple in the command line arguments).

Differential Revision: https://reviews.llvm.org/D32389

llvm-svn: 301648

4 files changed, 103 insertions, 2 deletions

diff --git a/clang/tools/c-index-test/c-index-test.c b/clang/tools/c-index-test/c-index-test.c
index 0978ccb28d7..1179fbf3911 100644
--- a/clang/tools/c-index-test/c-index-test.c
+++ b/clang/tools/c-index-test/c-index-test.c
@@ -1560,6 +1560,51 @@ static enum CXChildVisitResult PrintTypeDeclaration(CXCursor cursor, CXCursor p,
 }
 
 /******************************************************************************/
+/* Target information testing.                                                */
+/******************************************************************************/
+
+static int print_target_info(int argc, const char **argv) {
+  CXIndex Idx;
+  CXTranslationUnit TU;
+  CXTargetInfo TargetInfo;
+  CXString Triple;
+  const char *FileName;
+  enum CXErrorCode Err;
+  int PointerWidth;
+
+  if (argc == 0) {
+    fprintf(stderr, "No filename specified\n");
+    return 1;
+  }
+
+  FileName = argv[1];
+
+  Idx = clang_createIndex(0, 1);
+  Err = clang_parseTranslationUnit2(Idx, FileName, argv, argc, NULL, 0,
+                                    getDefaultParsingOptions(), &TU);
+  if (Err != CXError_Success) {
+    fprintf(stderr, "Couldn't parse translation unit!\n");
+    describeLibclangFailure(Err);
+    clang_disposeIndex(Idx);
+    return 1;
+  }
+
+  TargetInfo = clang_getTranslationUnitTargetInfo(TU);
+
+  Triple = clang_TargetInfo_getTriple(TargetInfo);
+  printf("TargetTriple: %s\n", clang_getCString(Triple));
+  clang_disposeString(Triple);
+
+  PointerWidth = clang_TargetInfo_getPointerWidth(TargetInfo);
+  printf("PointerWidth: %d\n", PointerWidth);
+
+  clang_TargetInfo_dispose(TargetInfo);
+  clang_disposeTranslationUnit(TU);
+  clang_disposeIndex(Idx);
+  return 0;
+}
+
+/******************************************************************************/
 /* Loading ASTs/source.                                                       */
 /******************************************************************************/
 
@@ -4301,11 +4346,12 @@ static void print_usage(void) {
     "       c-index-test -test-print-type {<args>}*\n"
     "       c-index-test -test-print-type-size {<args>}*\n"
     "       c-index-test -test-print-bitwidth {<args>}*\n"
+    "       c-index-test -test-print-target-info {<args>}*\n"
     "       c-index-test -test-print-type-declaration {<args>}*\n"
     "       c-index-test -print-usr [<CursorKind> {<args>}]*\n"
-    "       c-index-test -print-usr-file <file>\n"
-    "       c-index-test -write-pch <file> <compiler arguments>\n");
+    "       c-index-test -print-usr-file <file>\n");
   fprintf(stderr,
+    "       c-index-test -write-pch <file> <compiler arguments>\n"
     "       c-index-test -compilation-db [lookup <filename>] database\n");
   fprintf(stderr,
     "       c-index-test -print-build-session-timestamp\n");
@@ -4411,6 +4457,8 @@ int cindextest_main(int argc, const char **argv) {
     return perform_test_load_tu(argv[2], "all", NULL, PrintMangledName, NULL);
   else if (argc > 2 && strcmp(argv[1], "-test-print-manglings") == 0)
     return perform_test_load_tu(argv[2], "all", NULL, PrintManglings, NULL);
+  else if (argc > 2 && strcmp(argv[1], "-test-print-target-info") == 0)
+    return print_target_info(argc - 2, argv + 2);
   else if (argc > 1 && strcmp(argv[1], "-print-usr") == 0) {
     if (argc > 2)
       return print_usrs(argv + 2, argv + argc);
diff --git a/clang/tools/libclang/CIndex.cpp b/clang/tools/libclang/CIndex.cpp
index c7fdb5ad1aa..86f1047dee9 100644
--- a/clang/tools/libclang/CIndex.cpp
+++ b/clang/tools/libclang/CIndex.cpp
@@ -26,6 +26,7 @@
 #include "clang/Basic/Diagnostic.h"
 #include "clang/Basic/DiagnosticCategories.h"
 #include "clang/Basic/DiagnosticIDs.h"
+#include "clang/Basic/TargetInfo.h"
 #include "clang/Basic/Version.h"
 #include "clang/Frontend/ASTUnit.h"
 #include "clang/Frontend/CompilerInstance.h"
@@ -4018,6 +4019,50 @@ CXCursor clang_getTranslationUnitCursor(CXTranslationUnit TU) {
   return MakeCXCursor(CXXUnit->getASTContext().getTranslationUnitDecl(), TU);
 }
 
+CXTargetInfo clang_getTranslationUnitTargetInfo(CXTranslationUnit CTUnit) {
+  if (isNotUsableTU(CTUnit)) {
+    LOG_BAD_TU(CTUnit);
+    return nullptr;
+  }
+
+  CXTargetInfoImpl* impl = new CXTargetInfoImpl();
+  impl->TranslationUnit = CTUnit;
+  return impl;
+}
+
+CXString clang_TargetInfo_getTriple(CXTargetInfo TargetInfo) {
+  if (!TargetInfo)
+    return cxstring::createEmpty();
+
+  CXTranslationUnit CTUnit = TargetInfo->TranslationUnit;
+  assert(!isNotUsableTU(CTUnit) &&
+         "Unexpected unusable translation unit in TargetInfo");
+
+  ASTUnit *CXXUnit = cxtu::getASTUnit(CTUnit);
+  std::string Triple =
+    CXXUnit->getASTContext().getTargetInfo().getTriple().normalize();
+  return cxstring::createDup(Triple);
+}
+
+int clang_TargetInfo_getPointerWidth(CXTargetInfo TargetInfo) {
+  if (!TargetInfo)
+    return -1;
+
+  CXTranslationUnit CTUnit = TargetInfo->TranslationUnit;
+  assert(!isNotUsableTU(CTUnit) &&
+         "Unexpected unusable translation unit in TargetInfo");
+
+  ASTUnit *CXXUnit = cxtu::getASTUnit(CTUnit);
+  return CXXUnit->getASTContext().getTargetInfo().getMaxPointerWidth();
+}
+
+void clang_TargetInfo_dispose(CXTargetInfo TargetInfo) {
+  if (!TargetInfo)
+    return;
+
+  delete TargetInfo;
+}
+
 //===----------------------------------------------------------------------===//
 // CXFile Operations.
 //===----------------------------------------------------------------------===//
diff --git a/clang/tools/libclang/CXTranslationUnit.h b/clang/tools/libclang/CXTranslationUnit.h
index 67c31d2dba4..ce8469b501a 100644
--- a/clang/tools/libclang/CXTranslationUnit.h
+++ b/clang/tools/libclang/CXTranslationUnit.h
@@ -35,6 +35,10 @@ struct CXTranslationUnitImpl {
   clang::index::CommentToXMLConverter *CommentToXML;
 };
 
+struct CXTargetInfoImpl {
+  CXTranslationUnit TranslationUnit;
+};
+
 namespace clang {
 namespace cxtu {
 
diff --git a/clang/tools/libclang/libclang.exports b/clang/tools/libclang/libclang.exports
index 38ecedae3cd..895dd804b00 100644
--- a/clang/tools/libclang/libclang.exports
+++ b/clang/tools/libclang/libclang.exports
@@ -79,6 +79,9 @@ clang_TParamCommandComment_getParamName
 clang_TParamCommandComment_isParamPositionValid
 clang_TParamCommandComment_getDepth
 clang_TParamCommandComment_getIndex
+clang_TargetInfo_dispose
+clang_TargetInfo_getPointerWidth
+clang_TargetInfo_getTriple
 clang_Type_getAlignOf
 clang_Type_getClassType
 clang_Type_getSizeOf
@@ -250,6 +253,7 @@ clang_getTokenLocation
 clang_getTokenSpelling
 clang_getTranslationUnitCursor
 clang_getTranslationUnitSpelling
+clang_getTranslationUnitTargetInfo
 clang_getTypeDeclaration
 clang_getTypeKindSpelling
 clang_getTypeSpelling