Feature: Add C compiler discovery and file discovery feature

src/discovery.c

@@ -7,6 +7,9 @@
 
 #include <assert.h>
 #include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <unistd.h>
 
 Discovery discovery_create(Arena* a, StringPool* sp)
 {
@@ -31,23 +34,18 @@ Discovery discovery_create(Arena* a, StringPool* sp)
   return d;
 }
 
-void discovery_cleanup(Discovery* d)
-{
-  
-}
-
 void discovery_discover(Discovery* d)
 {
   assert(d != NULL);
   DirOpContext doc;
   doc.a_f = d->a;
   doc.sp = d->sp;
-  StringView path = SV(d->sp, ".");
+  StringView path = STR_LIT(d->sp, ".");
   size_t count = dir_get_recursive(&doc, &path);
   d->file_count = count;
   LOG_DEBUG("Discovered %d files.", count);
 
-  StringView c_ext = SV(d->sp, ".c");
+  StringView c_ext = STR_LIT(d->sp, ".c");
   ExtDiscoveryResult c_res = discovery_discover_ext(d, d->a, &c_ext);
 
   if(c_res.mem != NULL) 
@@ -57,7 +55,7 @@ void discovery_discover(Discovery* d)
     d->c_files = c_res.mem;
   }
   
-  StringView h_ext = SV(d->sp, ".h");
+  StringView h_ext = STR_LIT(d->sp, ".h");
   ExtDiscoveryResult h_res = discovery_discover_ext(d, d->a, &h_ext);
 
   if(h_res.mem != NULL) 
@@ -66,6 +64,35 @@ void discovery_discover(Discovery* d)
     d->h_count = h_res.len;
     d->h_files = h_res.mem;
   }
+
+  if(d->c_count > 0)
+  {
+    discovery_discover_ccompiler(d);
+  }
+}
+
+void discovery_discover_ccompiler(Discovery* d)
+{
+  assert(d != NULL);
+
+  StringView gcc = STR_LIT(d->sp, "gcc");
+  StringView cc_gcc = discovery_discover_path(d, &gcc);
+
+  if(cc_gcc.buf != NULL)
+  {
+    d->cc = cc_gcc;
+    return;
+  }
+
+  StringView clang = STR_LIT(d->sp, "clang");
+  StringView cc_clang = discovery_discover_path(d, &clang);
+
+  if(cc_clang.buf != NULL)
+  {
+    d->cc = cc_clang;
+    return;
+  }
+  LOG_DEBUG("No C compilers were found, however, %d C files were found. Not installed?", d->c_count); 
 }
 
 // TODO: Make the search logic faster, or at least search all of the wanted extension at once, uniformly.
@@ -91,9 +118,40 @@ ExtDiscoveryResult discovery_discover_ext(Discovery* d, Arena* a, StringView* ex
       DirEntry** entry = (DirEntry**)arena_alloc(a, sizeof(DirEntry*));
       *entry = &d->files[i];
       count++;
+      continue;
     }
   }
 
   if(count > 0) return (ExtDiscoveryResult){.mem = res, .len = count};
   return (ExtDiscoveryResult){.mem = NULL, .len = 0};
 }
+
+StringView discovery_discover_path(Discovery* d, StringView* s)
+{
+  assert(d != NULL);
+  assert(s != NULL);
+ 
+  char* path_env = getenv("PATH");
+
+  if(path_env == NULL) return (StringView){.buf = NULL, .len = 0};
+
+  char* path = strdup(path_env);
+  
+  errno = 0;
+  if(path == NULL && errno != 0) DIE("String copy failure.");
+
+  char* current = strtok(path, ":");
+  do
+  {
+    LOG_DEBUG("Checking: %s for %s in PATH.", current, s->buf);
+    StringView p = string_create(d->sp, current, strlen(current));
+    StringView fp = path_concat_ss(d->sp, &p, s);
+    if(access(fp.buf, X_OK) == 0)
+    {
+      LOG_DEBUG("Found %s in PATH:%s", s->buf, p.buf);
+      return fp;
+    }
+  }while((current = strtok(NULL, ":")) != NULL);
+    
+  return (StringView){.buf = NULL, .len = 0};
+}

src/discovery.h

@@ -3,11 +3,12 @@
 
 typedef struct Arena Arena;
 typedef struct StringPool StringPool;
-typedef struct StringView StringView;
 typedef struct DirEntry DirEntry;
 
 #include <stddef.h>
 
+#include "string.h"
+
 struct Discovery
 {
   // Memory
@@ -25,6 +26,9 @@ struct Discovery
   size_t c_count;
   size_t h_count;
   size_t cpp_count;
+
+  StringView cc;
+  StringView cxx;
 };
 
 struct ExtDiscoveryResult
@@ -40,6 +44,9 @@ Discovery discovery_create(Arena* a, StringPool* sp);
 void discovery_cleanup(Discovery* d);
 void discovery_discover(Discovery* d);
 
+void discovery_discover_ccompiler(Discovery* d);
+
 ExtDiscoveryResult discovery_discover_ext(Discovery* d, Arena* a, StringView* ext);
+StringView discovery_discover_path(Discovery* d, StringView* s);
 
 #endif