Add support for multiple paths for searching compiler files.

This also adds support for the `FASTBASIC_HOME` environment variable,
fixes #67.

compiler/USAGE.md

@@ -89,7 +89,12 @@ The compilation is a three step process:
 
 - The compiler calls the `CA65` assembler to produce an object file.
 
-- The compiler calls the `LD65` linker to join the object file with the runtime library, generating the `XEX`, `ROM` or `BIN` depending on the target.
+- The compiler calls the `LD65` linker to join the object file with the runtime
+  library, generating the `XEX`, `ROM` or `BIN` depending on the target.
+
+- To search the target, syntax, libraries and other tools, the compiler
+  searches in the installation path and in the path in the `FASTBASIC_HOME`
+  environment variable.
 
 
 Advanced Usage
@@ -187,11 +192,18 @@ an `:` or an `=` to separate the option from the argument.
   target will produce a 16kB cartridge binary instead of the 32kB default.
 
 - **-target-path**:*path*  
-  Sets the path where the target definition files are searched. The default is
-  to search in the same folder as the compiler executable.
+  Sets the list of paths where the target definition files are searched, as a
+  list of folder names separated by `:`.
+
+  The default is to search in the same folder as the compiler executable, and
+  in the path in the `FASTBASIC_HOME` environment variable.
 
 - **-syntax-path**:*path*  
-  Sets the path where the syntax grammar files are searched.
+  Sets the list of paths where the syntax grammar files are searched, as a list
+  of folder names separated by `:`.
+
+  The default path is the same as the target path with `syntax` folder at the
+  end.
 
 - **-keep**  
   Do not remove the intermediate files on compilation.

src/compiler/main.cc

@@ -75,14 +75,32 @@ static std::string to_lower(std::string in)
     return ret;
 }
 
+// Parse path list into a vector of strings
+static std::vector<std::string> parse_path_list(const std::string &str)
+{
+    std::vector<std::string> ret;
+    size_t pos = 0;
+    while(1)
+    {
+        auto nxt = str.find(':', pos);
+        if(nxt == str.npos)
+        {
+            ret.emplace_back(str.substr(pos));
+            return ret;
+        }
+        ret.emplace_back(str.substr(pos, nxt - pos));
+        pos = nxt + 1;
+    }
+}
+
 int main(int argc, char **argv)
 {
     // OS specific initializations
     os::init(argv[0]);
 
     // Default folders for target and syntax files
-    auto syntax_folder = os::compiler_path("syntax");
-    auto target_folder = os::compiler_path("");
+    auto syntax_folder = os::get_search_path("syntax");
+    auto target_folder = os::get_search_path("");
     std::vector<std::string> args(argv + 1, argv + argc);
     std::string out_name;
     std::string exe_name;
@@ -217,11 +235,11 @@ int main(int argc, char **argv)
         }
         else if(arg.rfind("-syntax-path:", 0) == 0 || arg.rfind("-syntax-path=", 0) == 0)
         {
-            syntax_folder = arg.substr(13);
+            syntax_folder = parse_path_list(arg.substr(13));
         }
         else if(arg.rfind("-target-path:", 0) == 0 || arg.rfind("-target-path=", 0) == 0)
         {
-            target_folder = arg.substr(13);
+            target_folder = parse_path_list(arg.substr(13));
         }
         else if(arg[0] == '-')
             return show_error("invalid option '" + arg + "', try -h for help");

src/compiler/os.cc

@@ -19,6 +19,7 @@
 // os.cc: Host OS functions
 #include "os.h"
 #include <memory>
+#include <sys/stat.h>
 
 #ifdef _WIN32
 #include <windows.h>
@@ -33,7 +34,7 @@ static const char *path_sep = "\\/";
 static const char *path_sep = "/";
 #endif
 
-static std::string compiler_search_path;
+static std::vector<std::string> compiler_search_path;
 
 bool os::path_absolute(const std::string &path)
 {
@@ -110,13 +111,49 @@ void os::init(const std::string &prog)
 #else
     // No init needed.
 #endif
-    // Store out program name
-    compiler_search_path = dir_name(prog);
+    // Initialize the compiler search path:
+    // The FASTBASIC_HOME environment variable:
+    const char *env = getenv("FASTBASIC_HOME");
+    if(env)
+        compiler_search_path.emplace_back(env);
+    // The directory of the invoked program
+    compiler_search_path.emplace_back(dir_name(prog));
+    // And on Linux systems, the instalation path
+#ifndef _WIN32
+    compiler_search_path.emplace_back("/usr/local/share/fastbasic");
+    compiler_search_path.emplace_back("/usr/share/fastbasic");
+#endif
+}
+
+std::string os::search_path(const std::vector<std::string> &paths,
+                            const std::string &filename)
+{
+    // Check each possible path:
+    for(auto &path : paths)
+    {
+        struct stat st;
+        auto f = full_path(path, filename);
+        auto e = stat(f.c_str(), &st);
+        if(0 == e)
+            return f;
+    }
+    // Not found, return only file name
+    return filename;
 }
 
 std::string os::compiler_path(const std::string &filename)
 {
-    return full_path(compiler_search_path, filename);
+    return search_path(compiler_search_path, filename);
+}
+
+std::vector<std::string> os::get_search_path(const std::string &filename)
+{
+    if(filename.empty())
+        return compiler_search_path;
+    std::vector<std::string> ret;
+    for(auto &path : compiler_search_path)
+        ret.emplace_back(full_path(path, filename));
+    return ret;
 }
 
 int os::prog_exec(std::string exe, std::vector<std::string> &args)

src/compiler/os.h

@@ -24,11 +24,16 @@
 
 namespace os
 {
+// Returns the current compiler search path for the given base
+std::vector<std::string> get_search_path(const std::string &filename);
 // Locates a file or folder in the compiler data and
 // returns the path
 std::string compiler_path(const std::string &filename);
 // Appends a file name to a path
 std::string full_path(const std::string &path, const std::string &filename);
+// Search a file in a list of paths
+std::string search_path(const std::vector<std::string> &paths,
+                        const std::string &filename);
 // Returns the file name from a full path
 std::string file_name(const std::string &path);
 // Returns the directory name from a full path

src/compiler/target.cc

@@ -31,13 +31,13 @@
 class target_file
 {
   public:
-    std::string target_folder;
+    std::vector<std::string> target_path;
     std::vector<std::string> slist;
     std::vector<std::string> ca65_args;
     std::string lib_name;
     std::string cfg_name;
     std::string bin_ext;
-    target_file(std::string target_folder) : target_folder(target_folder) {}
+    target_file(std::vector<std::string> target_path) : target_path(target_path) {}
     void read_file(std::string fname);
 };
 
@@ -61,7 +61,7 @@ void target_file::read_file(std::string fname)
         fname = os::add_extension(fname, ".tgt");
 
     if(!os::path_absolute(fname))
-        fname = os::full_path(target_folder, fname);
+        fname = os::search_path(target_path, fname);
 
     std::ifstream f;
     f.open(fname);
@@ -127,10 +127,11 @@ void target_file::read_file(std::string fname)
 
 target::target() {}
 
-void target::load(std::string target_folder, std::string syntax_folder, std::string fname)
+void target::load(std::vector<std::string> target_path,
+                  std::vector<std::string> syntax_path, std::string fname)
 {
     // Read target file
-    target_file f(target_folder);
+    target_file f(target_path);
     f.read_file(fname);
     lib_name = f.lib_name;
     cfg_name = f.cfg_name;
@@ -143,7 +144,7 @@ void target::load(std::string target_folder, std::string syntax_folder, std::str
     for(auto &name : f.slist)
     {
         std::ifstream ifile;
-        ifile.open(os::full_path(syntax_folder, name));
+        ifile.open(os::search_path(syntax_path, name));
         if(!ifile.is_open())
             throw std::runtime_error("can't open syntax file: '" + name + "'");
         auto data = pre.read_input(ifile);

src/compiler/target.h

@@ -39,7 +39,8 @@ class target
 
   public:
     target();
-    void load(std::string target_folder, std::string syntax_folder, std::string fname);
+    void load(std::vector<std::string> target_folder,
+              std::vector<std::string> syntax_folder, std::string fname);
     const syntax::sm_list &sl() const { return s; }
     std::string lib() const { return lib_name; }
     std::string cfg() const { return cfg_name; }