[ld_logger] Fix suffix match on non-absolute paths (#4577)

When using GNU make-4.2.1, then compiler binary names are not extended
to absolute path. By setting "/cc" to CC_LOGGER_GCC_LIKE we assume that
the compiler binary is provided by absolute path, since we are
performing a suffix check. However, "/cc" is not suffix of "cc".
This patch fixes the issue by virtually extending the compiler binary to
absolute path.

Author: bruntib

analyzer/tools/build-logger/src/ldlogger-tool.c

@@ -57,9 +57,29 @@ static int matchToProgramList(
 
     if (strchr(token, '/'))
     {
-      const char* posOfToken = strstr(progPath_, token);
-      if (posOfToken)
-        found = strcmp(posOfToken, token) == 0;
+      // When the token contains '/', then the program name is considered as a
+      // suffix:
+      //
+      //    token ->     /cc
+      // -------------------
+      // no match ->       c
+      //    match ->      cc
+      // no match ->     gcc
+      // no match ->  ccache
+      //    match -> bin2/cc
+      if (token[0] == '/')
+        ++token;
+
+      int len_token = strlen(token);
+      int len_prog = strlen(progPath_);
+
+      if (len_token >= len_prog)
+        found = strcmp(token, progPath_) == 0;
+      else
+      {
+        const char* suffix = progPath_ + len_prog - len_token;
+        found = suffix[-1] == '/' && strcmp(token, suffix) == 0;
+      }
     }
     else
     {

analyzer/tools/build-logger/tests/unit/test_paths.py

@@ -444,3 +444,60 @@ def test_source_abs(self):
             file=file,
             directory=binary_dirname,
         )
+
+    def test_suffix_match_on_non_absolute_path(self):
+        """
+        Test that CC_LOGGER_GCC_LIKE with a '/cc' value matches
+        both 'cc' and '/usr/bin/cc', but not 'gcc' or 'ccache'.
+        This covers the fix for suffix matching on non-absolute paths
+        (see PR #4577).
+        """
+        logger_env = self.get_envvars()
+        logger_env["CC_LOGGER_GCC_LIKE"] = "/cc"
+        file = self.source_file
+        binary = self.binary_file
+
+        # Should match 'cc' (non-absolute)
+        cc = shutil.which("cc")
+        if cc:
+            self.assume_successful_command(
+                [cc, file, "-o", binary], logger_env
+            )
+            self.assume_successful_command(
+                [binary], env=empty_env, outs="--VARIABLE--"
+            )
+            self.assert_json(
+                command=f"{cc} {file} -o {binary}",
+                file=file
+            )
+            os.remove(self.logger_file)
+
+        # Should not match 'gcc'
+        # This can be an interesting edge case test because
+        # gcc has 'cc' in the end of the path
+        gcc = shutil.which("gcc")
+        if gcc:
+            self.assume_successful_command(
+                [gcc, file, "-o", binary], logger_env
+            )
+            self.assume_successful_command(
+                [binary], env=empty_env, outs="--VARIABLE--"
+            )
+            actual_json = self.read_actual_json()
+            self.assertEqual(actual_json, "[\n]")
+            os.remove(self.logger_file)
+
+        # Should not match 'ccache'
+        # This can be an interesting edge case test because
+        # ccache has 'cc' at the beginning of the path
+        ccache = shutil.which("ccache")
+        if ccache:
+            self.assume_successful_command(
+                [ccache, file, "-o", binary], logger_env
+            )
+            self.assume_successful_command(
+                [binary], env=empty_env, outs="--VARIABLE--"
+            )
+            actual_json = self.read_actual_json()
+            self.assertEqual(actual_json, "[\n]")
+            os.remove(self.logger_file)