From: Daniel Dunbar
Arg instances themselves do not generally store the - values of parameters. In almost all cases, this would + values of parameters. In many cases, this would simply result in creating unnecessary string copies. Instead, Arg instances are always embedded inside an ArgList structure, which contains the original vector - of argument strings. Each Arg itself can then only contain + of argument strings. Each Arg itself only needs to contain an index into this vector instead of storing its values directly.
-The current clang driver can dump the results of this +
The clang driver can dump the results of this stage using the -ccc-print-options flag (which must preceed any actual command line arguments). For example:
@@ -255,7 +255,7 @@ is BindArchAction, which conceptually alters the architecture to be used for all of its input Actions. -The current clang driver can dump the results of this +
The clang driver can dump the results of this stage using the -ccc-print-phases flag. For example:
@@ -307,21 +307,28 @@
This stage (in conjunction with the Translate stage) turns - the tree of Actions into a list of actual subprocess to - run. Conceptually, the driver performs a simple tree match - to assign Action(s) to Tools. Once an Action has been - bound to a Tool, the driver interacts with the tool to - determine how the Tools should be connected (via pipes, - temporary files, or user provided filenames) and whether - the tool supports things like an integrated - preprocessor.
+This stage (in conjunction with the Translate stage) + turns the tree of Actions into a list of actual subprocess + to run. Conceptually, the driver performs a top down + matching to assign Action(s) to Tools. The ToolChain is + responsible for selecting the tool to perform a particular + action; once seleected the driver interacts with the tool + to see if it can match additional actions (for example, by + having an integrated preprocessor). + +
Once Tools have been selected for all actions, the driver + determines how the tools should be connected (for example, + using an inprocess module, pipes, temporary files, or user + provided filenames). If an output file is required, the + driver also computes the appropriate file name (the suffix + and file location depend on the input types and options + such as -save-temps).
The driver interacts with a ToolChain to perform the Tool bindings. Each ToolChain contains information about all the tools needed for compilation for a particular architecture, platform, and operating system. A single - driver may query multiple ToolChains during a single + driver invocation may query multiple ToolChains during one compilation in order to interact with tools for separate architectures.
@@ -330,13 +337,13 @@ the -ccc-print-bindings option. For example:$ clang -ccc-print-bindings -arch i386 -arch ppc t0.c - # "i386-apple-darwin10.0.0d6" - "clang", inputs: ["t0.c"], output: "/tmp/cc-Sn4RKF.s" - # "i386-apple-darwin10.0.0d6" - "darwin::Assemble", inputs: ["/tmp/cc-Sn4RKF.s"], output: "/tmp/cc-gvSnbS.o" - # "i386-apple-darwin10.0.0d6" - "darwin::Link", inputs: ["/tmp/cc-gvSnbS.o"], output: "/tmp/cc-jgHQxi.out" - # "ppc-apple-darwin10.0.0d6" - "gcc::Compile", inputs: ["t0.c"], output: "/tmp/cc-Q0bTox.s" - # "ppc-apple-darwin10.0.0d6" - "gcc::Assemble", inputs: ["/tmp/cc-Q0bTox.s"], output: "/tmp/cc-WCdicw.o" - # "ppc-apple-darwin10.0.0d6" - "gcc::Link", inputs: ["/tmp/cc-WCdicw.o"], output: "/tmp/cc-HHBEBh.out" - # "i386-apple-darwin10.0.0d6" - "darwin::Lipo", inputs: ["/tmp/cc-jgHQxi.out", "/tmp/cc-HHBEBh.out"], output: "a.out" + # "i386-apple-darwin9" - "clang", inputs: ["t0.c"], output: "/tmp/cc-Sn4RKF.s" + # "i386-apple-darwin9" - "darwin::Assemble", inputs: ["/tmp/cc-Sn4RKF.s"], output: "/tmp/cc-gvSnbS.o" + # "i386-apple-darwin9" - "darwin::Link", inputs: ["/tmp/cc-gvSnbS.o"], output: "/tmp/cc-jgHQxi.out" + # "ppc-apple-darwin9" - "gcc::Compile", inputs: ["t0.c"], output: "/tmp/cc-Q0bTox.s" + # "ppc-apple-darwin9" - "gcc::Assemble", inputs: ["/tmp/cc-Q0bTox.s"], output: "/tmp/cc-WCdicw.o" + # "ppc-apple-darwin9" - "gcc::Link", inputs: ["/tmp/cc-WCdicw.o"], output: "/tmp/cc-HHBEBh.out" + # "i386-apple-darwin9" - "darwin::Lipo", inputs: ["/tmp/cc-jgHQxi.out", "/tmp/cc-HHBEBh.out"], output: "a.out"
This shows the tool chain, tool, inputs and outputs which