Added an option to TableGen that allows users to specify a directory in which

to find include files.  TableGen will load include files from this directory if
it cannot find them in the current directory.
This feature was needed for building code inside the object tree (a la autoconf
style).
TODO: Allow for multiple -I options to specify a list of directories to search.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@8159 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 42 insertions, 5 deletions

diff --git a/support/tools/TableGen/FileLexer.l b/support/tools/TableGen/FileLexer.l
index 98370a7fef..f3cd32522a 100644
--- a/support/tools/TableGen/FileLexer.l
+++ b/support/tools/TableGen/FileLexer.l
@@ -21,9 +21,13 @@
 
 %{
 #include "Record.h"
+#include "Support/CommandLine.h"
 typedef std::pair<Record*, std::vector<Init*>*> SubClassRefTy;
 #include "FileParser.h"
 
+// Global variable recording the location of the include directory
+std::string IncludeDirectory;
+
 // ParseInt - This has to handle the special case of binary numbers 0b0101
 static int ParseInt(const char *Str) {
   if (Str[0] == '0' && Str[1] == 'b')
@@ -61,7 +65,18 @@ std::ostream &err() {
 
 int Fileparse();
 
-void ParseFile(const std::string &Filename) {
+//
+// Function: ParseFile()
+//
+// Description:
+//	This function begins the parsing of the specified tablegen file.
+//
+// Inputs:
+//	Filename - A string containing the name of the file to parse.
+//	IncludeDir - A string containing the directory from which include
+//	             files can be found.
+//
+void ParseFile(const std::string &Filename, const std::string & IncludeDir) {
   FILE *F = stdin;
   if (Filename != "-") {
     F = fopen(Filename.c_str(), "r");
@@ -75,6 +90,12 @@ void ParseFile(const std::string &Filename) {
     IncludeStack.push_back(IncludeRec("<stdin>", stdin));
   }
 
+  //
+  // Record the location of the include directory so that the lexer can find
+  // it later.
+  //
+  IncludeDirectory = IncludeDir;
+ 
   Filein = F;
   Filelineno = 1;
   Fileparse();
@@ -103,8 +124,20 @@ static void HandleInclude(const char *Buffer) {
   // Open the new input file...
   yyin = fopen(Filename.c_str(), "r");
   if (yyin == 0) {
-    err() << "Could not find include file '" << Filename << "'!\n";
-    abort();
+    //
+    // If we couldn't find the file in the current directory, look for it in
+    // the include directories.
+    //
+    // NOTE:
+    //  Right now, there is only one directory.  We need to eventually add
+    //  support for more.
+    //
+    Filename = IncludeDirectory + "/" + Filename;
+    yyin = fopen(Filename.c_str(), "r");
+    if (yyin == 0) {
+      err() << "Could not find include file '" << Filename << "'!\n";
+      abort();
+    }
   }
 
   // Add the file to our include stack...
diff --git a/support/tools/TableGen/TableGen.cpp b/support/tools/TableGen/TableGen.cpp
index 85a63ceaf6..67efdb46c8 100644
--- a/support/tools/TableGen/TableGen.cpp
+++ b/support/tools/TableGen/TableGen.cpp
@@ -64,10 +64,14 @@ namespace {
 
   cl::opt<std::string>
   InputFilename(cl::Positional, cl::desc("<input file>"), cl::init("-"));
+
+  cl::opt<std::string>
+  IncludeDir("I", cl::desc("Directory of include files"),
+                  cl::value_desc("directory"), cl::init(""));
 }
 
 
-void ParseFile(const std::string &Filename);
+void ParseFile(const std::string &Filename, const std::string & IncludeDir);
 
 RecordKeeper Records;
 
@@ -398,7 +402,7 @@ static void ParseMachineCode() {
 
 int main(int argc, char **argv) {
   cl::ParseCommandLineOptions(argc, argv);
-  ParseFile(InputFilename);
+  ParseFile(InputFilename, IncludeDir);
 
   std::ostream *Out = &std::cout;
   if (OutputFilename != "-") {