[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 rust-lang/rust-bindgen#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

Author: emilio

clang/include/clang-c/Index.h

@@ -32,7 +32,7 @@
  * compatible, thus CINDEX_VERSION_MAJOR is expected to remain stable.
  */
 #define CINDEX_VERSION_MAJOR 0
-#define CINDEX_VERSION_MINOR 37
+#define CINDEX_VERSION_MINOR 38
 
 #define CINDEX_VERSION_ENCODE(major, minor) ( \
       ((major) * 10000)                       \
@@ -80,6 +80,12 @@ extern "C" {
  */
 typedef void *CXIndex;
 
+/**
+ * \brief An opaque type representing target information for a given translation
+ * unit.
+ */
+typedef struct CXTargetInfoImpl *CXTargetInfo;
+
 /**
  * \brief A single translation unit, which resides in an index.
  */
@@ -1552,6 +1558,36 @@ CINDEX_LINKAGE CXTUResourceUsage clang_getCXTUResourceUsage(CXTranslationUnit TU
 
 CINDEX_LINKAGE void clang_disposeCXTUResourceUsage(CXTUResourceUsage usage);
 
+/**
+ * \brief Get target information for this translation unit.
+ *
+ * The CXTargetInfo object cannot outlive the CXTranslationUnit object.
+ */
+CINDEX_LINKAGE CXTargetInfo
+clang_getTranslationUnitTargetInfo(CXTranslationUnit CTUnit);
+
+/**
+ * \brief Destroy the CXTargetInfo object.
+ */
+CINDEX_LINKAGE void
+clang_TargetInfo_dispose(CXTargetInfo Info);
+
+/**
+ * \brief Get the normalized target triple as a string.
+ *
+ * Returns the empty string in case of any error.
+ */
+CINDEX_LINKAGE CXString
+clang_TargetInfo_getTriple(CXTargetInfo Info);
+
+/**
+ * \brief Get the pointer width of the target in bits.
+ *
+ * Returns -1 in case of error.
+ */
+CINDEX_LINKAGE int
+clang_TargetInfo_getPointerWidth(CXTargetInfo Info);
+
 /**
  * @}
  */

clang/test/Index/target-info.c

@@ -0,0 +1,6 @@
+// RUN: c-index-test -test-print-target-info %s --target=i386-unknown-linux-gnu | FileCheck %s
+// RUN: c-index-test -test-print-target-info %s --target=x86_64-unknown-linux-gnu | FileCheck --check-prefix=CHECK-1 %s
+// CHECK: TargetTriple: i386-unknown-linux-gnu
+// CHECK: PointerWidth: 32
+// CHECK-1: TargetTriple: x86_64-unknown-linux-gnu
+// CHECK-1: PointerWidth: 64

clang/tools/c-index-test/c-index-test.c

@@ -1559,6 +1559,51 @@ static enum CXChildVisitResult PrintTypeDeclaration(CXCursor cursor, CXCursor p,
   return CXChildVisit_Recurse;
 }
 
+/******************************************************************************/
+/* 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);

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.
 //===----------------------------------------------------------------------===//

clang/tools/libclang/CXTranslationUnit.h

@@ -35,6 +35,10 @@ struct CXTranslationUnitImpl {
   clang::index::CommentToXMLConverter *CommentToXML;
 };
 
+struct CXTargetInfoImpl {
+  CXTranslationUnit TranslationUnit;
+};
+
 namespace clang {
 namespace cxtu {
 

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