Do not rebuild files unless cleaned first.

Signed-off-by: Slendi <slendi@socopon.com>

1 files changed, 42 insertions, 7 deletions

diff --git a/cbuild_impl.c b/cbuild_impl.c
index 71bed29..67e92f4 100644
--- a/cbuild_impl.c
+++ b/cbuild_impl.c
@@ -8,6 +8,7 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/wait.h>
+#include <time.h>
 #ifdef __TINYC__
 #define __STDC_NO_VLA__ 1
 #endif
@@ -19,10 +20,12 @@
 #include <unistd.h>
 #endif
 
-bool file_exists(char *filename) {
+bool file_exists(char *filename, time_t *mtime) {
   struct stat path_stat;
   if (stat(filename, &path_stat) == -1)
     return false;
+  if (mtime)
+    *mtime = path_stat.st_mtime;
   return S_ISREG(path_stat.st_mode);
 }
 
@@ -51,7 +54,7 @@ executable_t create_executable(char *name, char *sources) {
   for (size_t off = 0; exe.header.sources[off];
        off += strlen(exe.header.sources) + 1) {
     char *path = exe.header.sources + off;
-    if (!file_exists(path)) {
+    if (!file_exists(path, NULL)) {
       fprintf(stderr, "File %s does not exist\n", path);
       exit(1);
     }
@@ -103,6 +106,7 @@ void build(project_t build) {
   if (build.language & LANG_CXX)
     fprintf(stderr, " - C++\n");
   size_t sources_count = 0;
+  size_t sources_count_real = 0;
   size_t count_operations = 0;
   for (size_t i = 0; i < build.target_count; i++) {
     target_header_t *target = build.targets[i];
@@ -111,13 +115,30 @@ void build(project_t build) {
       count_operations++; // Linking
       for (size_t off = 0; exe->header.sources[off];
            off += strlen(exe->header.sources) + 1) {
-        sources_count++;
-        count_operations++;
+        sources_count_real++;
+        time_t mtime_source;
+        if (!file_exists(exe->header.sources + off, &mtime_source)) {
+          fprintf(stderr, "File %s does not exist\n",
+                  exe->header.sources + off);
+          exit(1);
+        }
+        char *dot_o = change_ext_to_dot_o(exe->header.sources + off);
+        time_t mtime_dot_o = 0;
+        if (!file_exists(dot_o, &mtime_dot_o)) {
+        }
+        free(dot_o);
+        if (mtime_source > mtime_dot_o) {
+          sources_count++;
+          count_operations++;
+        }
       }
     }
   }
   if (sources_count == 0) {
-    fprintf(stderr, "No sources specified\n");
+    if (sources_count_real == 0)
+      fprintf(stderr, "No sources specified\n");
+    else
+      fprintf(stderr, "Nothing to do\n");
     exit(1);
   }
 
@@ -145,8 +166,22 @@ void build(project_t build) {
            off += strlen(exe->header.sources) + 1) {
         char *source = exe->header.sources + off;
         char *dot_o = change_ext_to_dot_o(source);
-        fprintf(stderr, "\33[2K\r(%ld/%ld) Building \33[1m%s\33[0m", count,
+        fprintf(stderr, "\33[2K\r(%ld/%ld) Building \33[1m%s\33[0m", count++,
                 count_operations, source);
+
+        time_t mtime_source;
+        if (!file_exists(source, &mtime_source)) {
+          fprintf(stderr, "File %s does not exist\n", source);
+          exit(1);
+        }
+        time_t mtime_dot_o = 0;
+        if (!file_exists(dot_o, &mtime_dot_o)) {
+        }
+        if (mtime_source <= mtime_dot_o) {
+          free(dot_o);
+          continue;
+        }
+
         if (processes_alive == processing_units) {
           int status;
           waitpid(-1, &status, 0);
@@ -208,7 +243,7 @@ void build(project_t build) {
       for (int j = 0; j < processing_units; j++)
         waitpid(-1, NULL, 0);
 
-      fprintf(stderr, "\33[2K\r(%ld/%ld) Linking \33[1m%s\33[0m", count,
+      fprintf(stderr, "\33[2K\r(%ld/%ld) Linking \33[1m%s\33[0m", count++,
               count_operations, exe->header.name);
       char *argv[4 + sources_count];
       argv[0] = "gcc";